Time to bet on March UAH TLT!
Note: I know some avid bettors may be blocked. Let people know that I get alerts from twitter now. So, if they are blocked they can tweet me so at least I’ll know. I’m thinking of setting up an address outside cloudflare you can visit to leave me notes! The betting form is below. The cut-off date is entered at 3/17, which means … whenever. (I think it closes 11:59:50 pm on 3/16 in California where the server is located.)
Lucia –
Do you mean that Greenwich Mean Time is no longer used to define the cut-off point? Ah – how sad! The slow demise of the British empire continues!
P.S. AFPhys – if you’d like your quatloo invested on an anomaly of your choice, let me know. You can get Lucia to pass your WAG on to me if you think it would be giving away your trade secrets to make it public…
Anteros–I’ve never quite figured out what “time()” uses….. It may just depend on how I coded. I think I used local time, but local is relative to the server. That’s in California.
I haven’t decide on my WAG. I need to contemplate.
Can I just skip the middle process and send the quatloos?
Within about 24 hours there will be a new paper Radiated Energy and the Second Law of Thermodynamics at http://principia-scientific.org/
In over 6,000 words it covers a wide range of reasons why carbon dioxide can have no warming effect and only a slight cooling effect.
This is only the sixth paper to be accepted by this organisation which is dedicated to the truth in science.
Anteros, I am going to allow you to hold that quatloo in your own bank at this time. I am looking forward to collecting the beer when we meet. 🙂 Since quatloos are even better than gold and don’t suffer inflationary effects, there is no need for computation of interest, either. We may find a “double or nothing” side bet one day, though, or another good way to spend it.
I tried to simulate being a cut and paste bot on one of Lucia’s netaccess threads … but failed completely to raise even a single red flag, I guess. Lucia just let it post without comment. I will have to really study how such bots behave if I’m going to succeed.
I was glad to see this thread up when I checked in today after a bit of a hiatus over the weekend. Time to download all the ENSO, AMO/PDO, HadCRUT, MSU, solar, CO2, Arctic Ice, land use changes, rotational, and my secret sources of temperature variations so my tiny supercomputer can start crunching and munching in search of the winning anomaly to submit before St.Patrick’s day. Unfortunately, even if I have them all dead right, the chaotic nature these coupled non-linear equations can really wreak havoc on the computations. Better get started …
Dave Cotton:
Thank you for shooting that link even though it really is not specific to this thread. I have lived naively believing I understood the Second Law for over 3/4 of my life, and I have never really questioned the re-radiation aspect of misnamed “greenhouse effects”. Over the last couple months, I have read some of the scientists and others who are questioning that, based on Second Law. I’ve been inspired to revisit my knowledge base, and in more detail. So far, that has accomplished making me realize my understanding was incredibly superficial. There are some very heavy theory papers I will have to spend a lot of study time when I am prepared, if I am going to change that. Thus far, my worry is that I am going to have as much difficulty as I had with quantum mechanics. I only started to crack that subject when I had to teach it.
I haven’t been converted to the viewpoint of those who now argue CO2 can have no effect since I don’t trust that I have sufficient depth of understanding to judge the arguments. Thus far, I am not convinced that anyone understands it in sufficient depth to make categorical statements. I hope some physicist I trust, like Shaviv though there are many others, someday weighs in on the issue so I can get more direction. I’ll read items like those you linked in hopes to discover that direction without heavy study on my part. Until I do, I am going to have to give more weight to the elementary argument that CO2 does in fact have the effect of positive re-radiation.
As it happens, the “organisation which is dedicated to the truth in science” is run by one John O’Sullivan, dragon-slayer extraordinaire (yes, it’s the same guy).
Small world!
I’m sure it’s Claes Johnson’s confused discussion of the 2nd law of thermodynamics. We’ve seen this before…..
This thing http://principia-scientific.org/ is just a re packaged version of “Slaying the Sky Dragon” with the same players.
That endeavor didn’t catch on with skeptics in general, (I threw my own free copy of it away, it was that bad) so this repackaging to make it look like some sort of scientific journal is the next phase.
I’m not impressed.
Lucia: that is the problem. The discussions are confusing, but when I have tried to sort things out, it does get down into some real questions and I find it arguable that the simple traditional “greenhouse experiment” with CO2 may not be applicable to the Earth’s atmosphere. My theory base in this area is definitely too spotty, and I’m not convinced so far that anyone has a strong enough handle on it to counter these speculations. That leaves me depending on the analogy: “Hot plate in proximity to a warm plate cools more slowly than the hot plate near a cold plate” which is the simple re-radiating CO2 situation we have depended on. I am not totally convinced that is accurate though because in the confusing arguments, it seems there are at least seeds of worthwhile questions that are hard to answer.
Dadburned coupled non-linear equations and chaos…
I love doug.
In his introduction on his web page he tries to explain how a thermos works.
“Consider “backradiation” created by the silver reflective lining on the inside of a vacuum flask filled with coffee at, say, 97 deg.C. The reflected radiation will not raise that 97 degree temperature at all. Radiation which is received from a source which is cooler is rejected by being re-emitted with exactly the same frequency and energy that it had before it arrived. ”
Now we all know that a thermos will keep coffee warmer than it would be OTHERWISE. That is, the reflection of radiation back to the coffee SLOWS the rate of cooling. Effectively, the only way the coffee cools is by conduction which is retarded by the vacuum.
In short, back radiation doesnt “warm” the coffee. It slows the rate of cooling and the end result is coffee that is warmer than it would have been otherwise –absent the re radiation. No violation of the 2nd law, because there is no NET increase.
Same thing happens dougie with the atmosphere. A silvered shield is opaque at all wavelengths. The atmosphere is not. But the atmosphere is not transparent either. There are transmission windows. What’s that? depending on the molecule and depending on the wavelength the atmosphere will be relatively transparent or relatively opaque. Understanding this is critical to the science of signal transmission. Your cell phone transmits at a certain frequency because there is a window there. Radars select a frequence based on transmission windows.
water vapor and C02 are relatively opaque to IR. They reflect it. Not all of it of course. And the amount they reflect depends upon concentration.
The earth cools to space, transmits to space from a altitude called the ‘effective radiating level”. Above this altitude the concentration of GHGs is low enough that the IR finally gets out.
This is the only way the planet cools: by returning EM back to space via radiation.
When we add GHGs to the atmopshere and increase the concentration, the ERL –effective radiating level– moves UP. as before ,the concentration of GHGs ABOVE the ERL is constant.
but now the altitude that happens at is higher.. and higher means colder.
The net result is the earth reradiates from a colder higher
altitude. And since colder objects radiate at a slower
rate the earth loses energy less rapidily than it would
otherwise. As with a thermos this doesnt mean the
surface is warmed by the atmosphere. It means the surface
cools less rapidly.. stays warmer longer.
AFPhys–
There are some real questions worth pondering. But Claes Johnson’s confused mess contains nothing worth pondering. I discussed it before. Unless he’s written something totally new and different from his previous ponderings about thermo and the greenhouse effect, the PSI “paper” will be utter bunk.
Anthony: perhaps it didn’t catch on with any skeptic is due to the major reason it can not “catch on” with me: I find myself thinking I’m out of my league in the theory I need, and therefore not being able or willing to even weigh in on the truth or falseness. Certainly, those who are dedicated to the CAGW (or even AGW) situation will counterargue based on the “simple physics” that they, like I, believed they understood all their lives. I doubt that many of them even went back to re-familiarize themselves with Second Law and ramifications, as I did. However, their dismissing it so cavalierly and without serious study does not make it wrong or worthless. I venture to say that in excess of 90% of theoretical physicists don’t actually have sufficient theoretical base to accurately judge this situation without heavy study and thought. I believe anybody who claims they are a “climate scientist” of any type is certainly suspect if they simply are falling back on common bromides and common “knowledge” without serious argument.
Right now, I don’t see the hypothesis to be well enough formed to argue either for or against, but I surely will not dismiss it out of hand. I welcome any links to solid arguments against it, or for it, if they are not confusing.
AFPhys:
Mosher’s thermos example is about as “not confusing” as you are gonna get.
I generally don’t like to argue by mere appeals to authority but when somebody claims that all the guys at RealClimate, the IPCC AND Spencer, Christie, Lindzen and Singer ALL don’t understand fundamental climate physics, then I regard that somebody as a whack job who I can safely and profitably ignore.
Steven Mosher (Comment #93204)
In short, back radiation doesnt “warm†the coffee.
Yes it does.
Consider two incandescent light bulbs. One 40 watts and the other 100 watts. Both emit heat and light in all directions equally. The 40 watt bulb is cooler.
The side of the 100 watt light bulb facing the 40 watt light bulb will be warmer then the side facing the darkened room.
The 2nd law of thermodynamics just says ‘net flow’ with always be from hotter to colder.
Judith Curry hosted discussions of the Sky Dragon thesis. Open minded of her to do that.
http://judithcurry.com/2011/02/04/slaying-a-greenhouse-dragon-part-ii/
@ AFPhys (Comment #93206)
There’s no “cavalier dismissal” here, I have quite a large backstory that I can’t share. Suffice it to say that had I not intervened after being asked to look at early drafts of the Slayer book, it would be far worse than it is.
As a result, I really want nothing to do with the whole Slayers group for the same reason I don’t allowing discussions of HAARP and Chemtrails on WUWT.
Anthony:
Now that I know who you are, assuming my reading of clues in your post are accurate, I am pleased to make your acquaintance. There is no way I would have used “cavalier” in any implication with you had I known that post was yours. I believe that your post today on WUWT may be part of the backstory you mention.
I was very gratified to see Roy Spencer write “Lay people quickly become overwhelmed, and even some of us technical types end up feeling ill-equipped to argue outside our areas of expertise…” in this area. That is precisely the point I was making. I DO very much respect Dr.Spencer and consider him a giant, not due to his unchallenged contributions, but due to his willingness to stand with one foot on each steed and attempting bravely to steer this two horse chariot. The photons he cites are childs play compared to phonons, and I am comfortable with those! His ability to write that this subject is outside the area of expertise of nearly all of us is perfect. It reinforces the statements I made earlier this thread. Be assured I will carefully consider all he writes, though knowing me I suspect I won’t see it as “the last word” until and unless I can grasp the theory much better than I do now.
Many, many thanks for directing so many to his thread.
I agree with you about considering the subject as poison as Chem Trails” even though that is much more screwy by the way, and your desire to disallow such discussions at your blog.
On a different subject: I would appreciate if you would send me a private EMail using the EAddy I use on your blog. I just tried to put a post on the “Diggler Scooter” thread to confirm who I am and make it easy to locate me, but for some reason I’m being required to “sign in to use that email address” today. It is a message I don’t recall seeing before, and I can’t see how to accomplish sign in. Fortunately, I think I am the only wyvern around there (or anywhere) with handle AFPhys so it should be easy to locate me on your site (or you can ask lucia for my EAddy). I have a question about whether I can help some mop-up with the station siting data, as well questions about this dragon issue.
AFPhys (Comment #93203),
When you say… “Hot plate in proximity to a warm plate cools more slowly than the hot plate near a cold plate  is right. BUT, that only works when the hot plate is in proximity to the warm plate.
Do the same experiment with the plates spaced half a mile apart, and you’ll find no measureable difference in the cooling rates of the hot plate when subjected to warm or cold plates at that distance.
That’s the problem I have with the greenhouse gas theory. Some of this CO2 gas is half a mile high and in tiny quantities, yet it is said to have this amazing ability to significantly warm the entire planet.
I do believe that humans are warming the planet, but I also believe that it’s a direct warming. I don’t have the latest figures, but in 2008 the total world energy supply was 143,000 terrawatts. That’s a lot of watts! Most of that energy ends up going into the atmosphere as heat. You only have to look at where the greatest warming effects are occuring… the northern hemisphere… the same place as most (approx 90%) of the world’s population lives and consumes energy.
Re: Skeptikal (Comment #93329)
Skeptikal,
If the plates are “big” relative to the half mile distance, then you just might notice the difference.
But some of the CO2 gas is right next to the surface, and as a whole, the (diffuse) CO2 “plate” is big enough to surround the entire planet!
Skeptikal:
Urgh. This is why there’s a mathematical theory. Otherwise people can make up any claim they want, like you are doing here.
That plate you were talking is made up of tiny molecules too. And it’s been a while since I’ve heard a mass of the order three quadillion kg considered to be in “tiny quantities”.
There’s a physical theory behind this. It works in plenty of other places including commercial devices. That work.
The issue isn’t whether there is an (inappropriately named) greenhouse gas effect, it’s what the consequences of that are, when we double the amount of CO2 in the atmosphere.
Carrick (Comment #93335),
If you were teaching a physics course, you could just flunk those who will not listen to reason, and you would not have to deal with their idiotic arguments after they had flunked out. Alas, some will neither learn nor stop arguing.
Oliver,
The “CO2 plate” is not a solid plate, its full of holes. Your winter clothes keep you warm in winter, but what if I punched your clothes so full of holes that there was only 400 parts per million left of those clothes.. how warm would those clothes keep you next winter?
Carrick,
Three quadillion is a very large quantity. 0.04% is a tiny quantity. The problem with your three quadrillion is that it is a stand alone quantity, whereas 0.04% is an amount relative to the entire quantity. When three quadrillion equals 0.04%, it suddenly becomes a relatively tiny quantity. 😉
Skeptikal,
Take a closer look at the insulation in your winter parka next time. It is full of holes.
If I wore a parka that were a holey 400 parts per million and 10 miles thick, that’d probably work, too.
Carrick (Comment #93335),
If you were teaching a physics course, you could just flunk those who will not listen to reason, and you would not have to deal with their id*otic arguments after they had flunked out. Alas, some will neither learn nor stop arguing.
Skeptikal:
On the scale of Earth, the holes are very small, until you reach the (radiometric) top of the atmosphere, at which point the thermal photons become “free.” You really don’t think this stuff is basic physics that hasn’t been calculated about a million times by now and that nobody would have noticed if there were a quantitative problem, do you?
Anyway, 0.04% isn’t a small number other than in relation to a really big number.
Trying to conceptualize physics in the absence of quantitative analysis is a mistake, it almost always leads to bullox.
SteveF:
The advantage we have in physics, is people who are coming into class have the expectation that they will learn something. The disadvantage here is people like Skeptikal already think they know everything, and therefore are incapable of learning anything.
The cup is full here. Time to move on.
Carrick (Comment #93343),
This stuff might be basic physics to you and calculated a million times, but the climate model predictions based on these calculations don’t seem to match what’s happening in the real world. There’s a lack of warming at the moment which can’t be explained…. I believe someone called a that ‘a travesty’.
I’m more than willing to learn… but I’ll wait to learn from someone who can match their calculations with real world observations. Until then, I’ll keep my current beliefs.
Skeptikal (Comment #93345),
OK. The models have LOTS of problems/issues, including inaccuracy in ocean heat uptake, uncertainty in aerosol and cloud effects, and inability to duplicate well known pseudo-cyclical patterns (ENSO, AMO, PDO, etc.). These alone are more than enough to explain why (for example) the current rate of warming and current rate of ocean heat accumulation do not match up with observations. There are plenty of known unknowns in climate science, and probably quite a few unknown unknowns.
.
But for goodness sakes, radiative physics is most certainly not at issue! You can keep your current beliefs, of course (and based on everything you write, I am quite certain you will), but that only means you will continue to embarrass yourself by demonstrating how little basic science you actually understand. Party with the dragon slayers all you want… but I suggest instead that you consider actually learning some of the basics, and you can start with black body radiation and infrared absorption.
Skeptikal:
As SteveF has pointed out, radiative physics is not at issue. The underlying concepts has been confirmed, millions of time. The same physics that governs the inaptly named GHG effect is used as the of patents (that work) and devices (that work), and there’s nothing particularly mysterious about it including the underlying math, which can be understood without even needing calculus, it’s that basic.
The real issue is with the effect of doubling CO2 on Earth’s climate. And that is much more involved to calculate, and there is a huge uncertainty associated with it.
You might as well argue against F = ma while you’re at it as rail so mindlessly against what is such a real and demonstrable effect.
But anyway, stay ignorant. Not my monkey.
SteveF (Comment #93348),
I already understand black body radiation and infrared absorption. Yes, CO2 absorbs radiation and radiates it back out… but calculated predictions don’t match what’s happening in the real world. Radiative physics is not the issue, the issue is whether or not calculated values represent the real world values… and they don’t. My conclusion is that the warming effect of CO2 is tiny, if at all measureable.
You want me to learn yet you can’t show me anything substantive. It seems your best argument is to call me a dragon slayer. I’d never embarrass myself like that.
Carrick (Comment #93350),
CO2 levels are still increasing yet the world has stopped warming… explain that!
Skeptickal,
Have you ever put on more clothes in the winter and still felt colder than in the summertime? Seems like a violation of physics, no?
Oliver (Comment #93353),
I don’t see any violation of physics.
Is this going somewhere constructive?
I’m just responding in kind to your previous comments.
Skeptikal:
You’ve made a plethora of elementary logical errors here. The only way you could have made it any worse is by arguing that since your hair is a bird, my argument is invalid.
1) The reality is that CO2 acts as a GHG. Adding more CO2 adds more radiative forcing to the atmosphere. The radiative physics of CO2 are well understood, replicable multiple times in a multitude of (often profitable) applications and you come across as a complete id*ot by arguing that this effect doesn’t exist. However, the reality of CO2 radiative physics tells you nothing by itself about whether during a period where you’ve added CO2 to the atmosphere, you would expect a contemporaneous warming.
2) The atmosphere responds to the sum of all forcings, not just CO2. Ignoring everything else, what you’d need to know is whether the sum of CO2 plus all other forcings have increased from 2002 till now in order to predict whether to expect a net warming. However, some of these forcings (aerosols in particular) have a large degree of uncertainty: Not only can’t we say with certainty that the models would predict a net warming for the last 10 year, some models don’t even predict a warming over that period due to the increase in coal power plant usage in China and India. (These models in fact predict a cessation of warming until circa 2040). Got it? Not all models that include CO2 as a forcing even agree it should be warming at the moment, once you include other (putatively larger, negative) forcings.
3) Then there are coupled atmospheric ocean-atmospheric oscillations that cause short-period variability to global mean temperature, and temperature variations from any long-term forcings must ride on top of this short-period climate variability…. it turns out if you want to distinguish a rate of 2°C/century from a 0°C/century, the difference in these trends doesn’t even reach the 95% CL as being different until you’ve had 15 years of “no warming”.
Simply because there is more CO2 doesn’t mean the net radiative forcings are greater now, and contrawise, simply saying that there has been no warming for 10 years says nothing about whether radiative physics of CO2 is correct or not. And we haven’t even observed the non-warming for long enough a period to even be able to say whether this warming is associated with a long term trend, or just natural variability.
Is your hair a bird? Inquiring minds want to know.
Carrick, “Hair a bird?” Wherever did you get that one?
btw, my gps project has worked out well. But then it was pretty simple.
Skeptikal (Comment #93351)
“You want me to learn yet you can’t show me anything substantive.”
.
Yes, I can. I will show you obvious substantive problems with what you said up thread in comment #93329. Let me make a prediction before I start: you will probably reject what I tell you, because you do not understand enough to see that what I tell you is technically correct.
.
“Do the same experiment with the plates spaced half a mile apart, and you’ll find no measurable difference in the cooling rates of the hot plate when subjected to warm or cold plates at that distance.”
Of course, if you increase the separation between two surfaces of finite size, the rate of radiative transfer between them (through a vacuum at least) decreases in proportion to the total area subtended by one plate as viewed from the other. Think about the angle of view of one plate from the other as the distance increases. The “portion of the sky” filled by the sun would drop by a factor of 4 if the sun were twice as far away, and the intensity of solar flux would likewise fall by a factor of 4. Same inverse square relationship applies to black body radiation for objects of finite size. If two parallel plates at different temperatures are of infinite size, or are very large compared to their separation, then changes in the separation make no (or almost no) difference in the rate of radiative transfer.
.
“That’s the problem I have with the greenhouse gas theory. Some of this CO2 gas is half a mile high and in tiny quantities, yet it is said to have this amazing ability to significantly warm the entire planet.”
There is nothing amazing about it. A cloud is a pretty wispy thing, yet it can reflect most of the visible sunlight that falls on on it, and usually absorbs ~100% of the infrared radiation that falls on it. The absorption by CO2 (and other kinds of gases) in the infrared is easily measured using a gas cell and an infrared spectrometer (I’ve done it myself many times); the rate of infrared absorption at a specified wavelength is routinely used to precisely quantify the concentration of a trace (like 0.04%) of absorbing gas mixed with a non-absorbing gas. This is a common measurement that (as Carrick notes) “works” perfectly. Read about how atmospheric CO2 concentration is monitored at Mauna Loa and other places around the world.
.
“I do believe that humans are warming the planet, but I also believe that it’s a direct warming. I don’t have the latest figures, but in 2008 the total world energy supply was 143,000 terrawatts. That’s a lot of watts! Most of that energy ends up going into the atmosphere as heat. You only have to look at where the greatest warming effects are occuring… the northern hemisphere… the same place as most (approx 90%) of the world’s population lives and consumes energy.”
The two are orders of magnitude different. Humans just don’t generate much heat (fossil, nuclear, geothermal) compared to the energy flow from the sun. The Earth’s diameter is ~12,750 kilometers, or a cross-sectional area of Pi * (12750^2)/4 = 1.28 * 10^8 km^2, or 1.28 * 10^14 M^2. Solar intensity reaching the Earth is ~1,366 watts/M^2, of which ~30% is reflected, meaning about 956 watts/M^2 is absorbed. So the total (continuous) heat flux is about 956 * 1.28 * 10^14 = 1.22 * 10^17 watts. According to Wikipedia (http://en.wikipedia.org/wiki/World_energy_consumption
the current total of human energy consumption is about 1.5 * 10^13 watts.
So the total solar flux is (1.22 * 10^17)/(1.5 * 10^13) = 8,133 times larger than the total of human energy use. This ignores the fact that about 10% the energy used (biomass, hydroelectric, etc) is in fact indirect solar energy, so the ratio is even larger than 8,133…. about 9,037. In other words, the total of direct human contribution to surface warming is on the order of 0.011% of the contribution from the sun. The solar flux averaged over the whole of Earth’s surface is about 956/4 = 239 watts/M^2; humans add ~0.026 watt/M^2, which is about 0.8% of the radiative forcing (~3 watts/M^2) from the man-made GHG’s (CO2, N2O, methane, halocarbons, etc.) that cause “global warming”. The direct contribution from human energy use is insignificant, even when compared to man-made GHG forcing. There can be a very local influence (I am sure a blast furnace warms the immediate surroundings), but in the grand scheme of things, the direct contribution from human energy use does not matter.
.
So there you have it. You made three statements in one comment, and all three are factually wrong. That is why you need to learn the basics.
j ferguson, “my hair is a bird” is a meme intended to describe especially poorly crafted arguments.
There are variations. See this.
Fun news on the gps project working!
SteveF, he does manage to brush elbows with reality in that erroneous statement you fisked, however.
While he’s wrong that other human activity (besides CO2 emission) are responsible for the majority of anthropogenic warming, it is correct to say that the vast majority of damage to the environment (and by extension endangerment to indigenous populations of humans) comes from other human activity than CO2.
The CAGW types make a big deal about threat to species from warming, ignoring the elephant rampaging through the kitchen in the process… namely the destruction of natural habitat, excess use of pesticides, clear cutting of forests and numerous other activities.
If these things they say they cared about were actually on the list of things they cared about, they’d be setting out to push for sustainable industrial, agricultural, mining and forestry practices first and foremost, and only then worry about a threat that may or may not result in net harm that might show up in about 100 years give or take.
Carrick – I think you nailed it with your last post.
however does radiative physics totally capture what happens under the tropopause?
Carrick,
“If these things they say they cared about were actually on the list of things they cared about, they’d be setting out to push for sustainable industrial, agricultural, mining and forestry practices first and foremost, and only then worry about a threat that may or may not result in net harm that might show up in about 100 years give or take.”
Well sure, but then they couldn’t force fundamental changes in the way people live their lives, which is the real point after all. 😉
I agree that we must be good stewards of the environment, but IMO, the things you list are not so terrible when compared to problems like rapid population growth, malnutrition, malaria, and a host of others… all associated with poverty. If people want wild species to not be driven to extinction, the answers are easy. First, stop eating them. Second, stop destroying where they live. Everything else is secondary.
diogenes (Comment #93372)
“however does radiative physics totally capture what happens under the tropopause?”
Of course not, it is only one of many processes. That doesn’t mean radiative physics is in any way deficient.
SteveF
once you have moved beyond the hyperbole of Mann and Gleick and the activists non both sides of the debate, then you have to get into details. Which nis where it is very difficult to get to any facts at all
diogenes (Comment #93376),
Well, there is for sure a lot of hyperbole. As to whether or not it’s difficult to get facts, I guess that depends on how much you want to read the literature, and how much basic science you understand to begin with. For many, their level of understanding of the basics is so poor that they are in no position to read the literature and critically evaluate the arguments that are made.
.
Many on both sides of the debate clearly know so little science that they are in no position to make any independent evaluation of the quality of what is published, and so are not worth listening to; they believe or disbelieve based only on their political views and who they trust.
Stevef
As a result of Cgate 1 and 2, I wonder just how much factual detail is out there….I don’t want to start monitoring meteorological shit, but if the official agencies cannot guarantee what they are up to without some moron like Jones or Mann or Hansen getting in between the data and the transmission….
Skeptical –
I just wanted to add one note to SteveF’s reply #93368, because it might not be obvious how to reconcile the varying figures of human energy use.
You gave world-wide energy consumption as 143,000 terawatts in #93329. That’s not right — the terawatt is a unit of power, not energy. The correct value is 143,000 terawatt-hours (TWh). If you convert 143,000 TWh per year into an equivalent average power, then (accounting for ~8766 hours per year), you get an average human power usage of around 16 TW = 1.6 x 10^13 W. This is pretty close to SteveF’s value in #93368 of 1.5 x 10^13 W — well, the energy usage figures in Wikipedia aren’t perfectly consistent. One place shows 143,851 TWh (gotta love that false precision), another 132,000 TWh; Steve’s average power figure was derived from the latter value.
SteveF:
Other than “Killing them through reckless behavior” I agree with this.
You have to ask if their agenda is what they say their agenda is, why they don’t go for the low-hanging fruit first.
Wait I know the answer!
My Rabbet haz Pancakez. Your argument is invalid!
Lucia: as of about 35 minutes ago, betting was ended by your autopost script. So, when you tell it “end betting on Mar.17”, as soon as it sees the time in Greenwich England is one second after the end of March 16, it does the post.
As of this minute, I am getting:
US Naval Observatory Master Clock Time
Mar. 17, 00:47:27 UTC Universal Time
Mar. 16, 08:47:27 PM EDT Eastern Time
Mar. 16, 07:47:27 PM CDT Central Time
Mar. 16, 06:47:27 PM MDT Mountain Time
Mar. 16, 05:47:27 PM PDT Pacific Time
These are all “Daylight Time Zone” (except UTC)
The spread between UTC is one hour greater when we are in “Standard Time Zone” mode.
AFPhys and others:
You may wish to start here http://www.webcommentary.com/docs/jo120314.pdf
Kindly read the paper and quote Section or FAQ numbers (for the benefit of others) if you have any enquiries.
I do have a dedicated thread on tallbloke’s talkshop where I would prefer to handle genuine enquiries, but I don’t respond to any who have merely assumed what I might have said without reading the paper. I trust you consider that reasonable.
.
SteveF (Comment #93368),
You said.. “Humans just don’t generate much heat (fossil, nuclear, geothermal) compared to the energy flow from the sun.”
That’s a really bizarre statement to make.
Any heat humans generate is heat in excess of earth’s natural energy budget. I’m assuming you’ve heard of the concept of earth having an energy budget. You then chose to spread this heat out over the entire planet to come up with a figure of “~0.026 watt/M^2” in an attempt to make it look insignificant. You might not be aware of this… but the heat is NOT generated evenly over the entire planet. The vast bulk of it is generated in the Northern Hemisphere… and in urban areas.
I’m beginning to wonder if you’re actually thinking for yourself, or just taking guidance from an IPCC instruction manual.
Skeptikal (Comment #93394),
Of course I am aware of an energy budget. I was aware of system level energy budgets more than 40 years ago when I first took some courses in engineering; and aware of the basic concept of energy balances in high school. I understand that more heat is generated in the norther hemisphere and in more developed areas than the southern hemisphere and less developed areas. But look at the magnitude of the total effect… ~0.011% of solar energy is still pretty small, even if it is generated on a smallish fraction of the total surface area; no doubt it makes some modest contribution to urban heat island effects, but contributes nothing significant to the global heat balance. In any case, the atmosphere does a reasonable job of transporting heat away from any local heat source (you have heard of atmospheric convection, Hadley cells, Ferrel cells, and polar cells, right?). Your sarcasm does not make you understand the basic concepts any better.
.
I think the chance is high that the IPCC has rather grossly overestimated Earth’s sensitivity to GHG forcing, and this shows up in the divergence between measured and projected warming rates. I think it is clear the IPCC is mainly driven by leftist politics, not science. I’ve never heard of any instruction manual from the IPCC, but if there were such a manual, I would not bother to read it.
.
Glad to see that my prediction of your response turned out to be about right. Oh well, I tried. You are utterly lost my friend, convinced that a bunch of nonsense is correct, and worse that that, apparently unwilling to learn. A very bad combination.
Carrick (Comment #93380),
You are right, I should have added to my first two, “Third, stop killing them for ‘sport’ or their body parts.”
HaroldW (Comment #93379),
Thanks for spelling out the difference between energy flow and total energy. It is easy to forget that many just don’t understand these simple concepts.
Skeptikal, you’re in no position at this point to make speculation as to whether others are capable of thinking.
Prove to us your own ability by admitting you are quite obviously wrong with respect to UHI being an even interesting driver of global temperature change. (Ironically when all land usage changes are factored in, the net effect is a slight cooling between 1850 and now.)
Just in case it isn’t obvious, the title of this thread is
And in case anybody is in any doubt, the thread was completely derailed by Doug Cotton #93173.
Carrick,
Thanks for sharing those internet memes. My children think I’m cooler now. 🙂
julio (Comment #93411),
I liked the ‘bird-hair’ guy. He looks a lot like Nicolas Cage after a really bad night in Las Vegas. 😉
You let your children see this thread? Well, I guess it is better than sitcoms. Come to think of it, the kind of open intellectual discourse you find here might be educational. None of my kids would ever have given a hoot… too many superficial interests. And yes, you are very cool.
Re: SteveF (Comment #93412)
No, no, I just showed them the bird-hair guy. They loved it, and then said “you are at knowyourmeme.com? Your coolness rating has gone up!” or something to that effect.
I’m afraid my kids are not that different from yours, but then again, that’s OK. You probably *are* expected to live in a world of your own as a teenager…
Anteros (Comment #93410),
Are you counting your winnings already?
Skeptical –
The sad thing is, I’ve already spent them..
julio:
I’m just the conduit. My teenage kids show me this stuff. Kids think up the craziest stuff.
I don’t know which is more funny about the Nic Cage photoshop, the photoshop or the idea that it so accurately reflects the level of some of the arguments we see on the internet.
The bunny’s name is Oolong, by the way (deceased).
He even has his own wiki entry.
Skeptikal (Comment #93351)
[“Yes, CO2 absorbs radiation and radiates it back out… but calculated predictions don’t match what’s happening in the real world. Radiative physics is not the issue, the issue is whether or not calculated values represent the real world values… and they don’t. My conclusion is that the warming effect of CO2 is tiny, if at all measureable.”]
Skeptikal, that statement is completely correct. I note that those who are trying to ridicule you are ignoring the substance of your posts and, as usual on this site, arguing from an assumption – without real evidence – that the radiative properties of a trace gas (namely CO2) are somehow enough to make a significant contribution to the ‘Greenhouse Effect’. They like to argue that the known ‘basic radiative physics’ of a single molecule of CO2 is enough to make the giant leap of faith that, globally, CO2 has the ability to significantly warm the atmosphere. The fact that there is no real-world evidence to support such an assertion seems to have escaped their notice.
.
I may not agree with everything you say but you are bang on with the statement above. Unfortunately, no-one knows just how much CO2 contributes to the GE. All anyone can say is that CO2 should, theoretically, have made an unknown (and unknowable) contribution to the 0.8C warming seen since accurate records started in 1850 (IPCC). This contribution could be anywhere between tiny (insignificant) and huge (catastrophic). It is unfair of anyone to argue against your valid point without supporting evidence.
Arfur Bryant (Comment #93418),
Some people see the sun as the only source of heat and greenhouse gases as the only mechanism for warming the planet.
I don’t think that man made heat is the only contributor to the recent warming, but it is real and has to be accounted for. I also believe that geothermal plays a fairly significant role. Nobody knows how much the oceans are heated geothermally.
It amazes me that people will say that there is science behind the theory of CO2 warming, yet they can’t adequately explain why the theory doesn’t match real world observations. That’s the kind of science that needs questioning.
Anteros (Comment #93415),
Now that’s what I call confidence.
A quick analysis of this months bets:
MAX 0.800
MIN -0.750
MEAN -0.025
MEDIAN -0.037
STD DEV 0.171
MEAN 1-27 -0.042
MEAN 28-56 -0.009
Of the 55 bets, 20 were positive and 33 were negative, but the predicted temperatures increased slightly during the course of the betting.
Given the continued rise in AQUA CH5 temperature, those bets at the higher end would appear to stand the best chance at the moment.
Lucia, it doesn’t look like you have had a WAG this month, unless your’s is the bet without a name, which coincidentally, is the same as your bet last month.
Ray,
My bet’s not looking too good right now.
Lucky I only bet 3 quatloos.
Skeptikal (Comment #93352)
March 16th, 2012 at 1:05 pm
“CO2 levels are still increasing yet the world has stopped warming… explain that!”
—————————————–
The world has not stopped warming. Quite the contrary. An energy imbalance due to the enhanced greenhouse effect is causing the entire climate system to warm. The warming of the atmosphere may have temporarily slowed, but the oceans are continuing to warm and absorb huge amounts of thermal energy (see http://imageshack.us/photo/my-images/837/02000mohca.jpg/ ). Land ice, another important part of the climate, is undergoing a massive phase change due to the energy imbalance (see http://imageshack.us/photo/my-images/703/greenlandgraceicemelt20.jpg/) (Also see http://imageshack.us/photo/my-images/703/greenlandgraceicemelt20.jpg/). Finally, sea ice is melting (see http://nsidc.org/images/arcticseaicenews/20111004_Figure3.png) and sea ice volume is rapidly decreasing.
Ray –
Good to see your analysis as usual.
I saw the two bets 0.8 and -0.75 as decimal point errors just because they are outside the range the UAH anomaly has been at any time since its inception. Leaving those out would change your SD a bit but leave the mean and median much as they are.
Interestingly, bar those two extremes only one bet had something other than a zero or a one after the decimal point – Tim W’s 0.23 (which is either going to need some spectacular warming or an extra digit inserted after the decimal point..)
You might be right about the implications of the recent ch5 data, but then again, it might be at its zenith and about to head south for the next fortnight…
As the blind man said to the deaf dog “We shall see”
Owen (Comment #93423),
OK. But a it of perspective is needed.
How much warming does that ocean heat represent? (For example, what is the average annual temperature increase over the average depth of 4000 meters?)
How fast is that Greenland melting versus the total of Greenland Ice? Will it melt in 200 years? 500 years? 2,000 years? 10,000 years? It makes a difference. My last read was that Greenland was adding about 0.7 mm per year to sea level rise, so that is a rate equal to 10,000 years to melt all of Greenland.
Yes, heat continues to accumulate (how could it not?) but the numbers matter….. a lot.
SteveF,
My point was to rebut the notion that warming has stopped as CO2 increases, giving credence to the notion of Skeptikal and others that CO2 has no effect on warming. I claim no foreknowledge of how quickly the ice will melt, only to note that the melting is accelerating (as measured by mass bugeting and GRACE: http://ps.uci.edu/scholar/velicogna/files/rignot_etal_grl2011.pdf) and is probably not amenable to a linear extrapolation.
Additionally, the possibility always exists of a huge warming-induced release of carbon from the tundra or from methane hydrates that is not figured into models or calculations of sensitivity (as far as I know, anyway). Just as it is not clear that we will have catastrophic warming, it is also not clear that we will have only mild warming – the very uncertainties (aerosols, clouds, humidity feedback, etc) that argue against certain catastrophe also argue against the certainty of its most benign alternative.
Owen (Comment #93426),
“My point was to rebut the notion that warming has stopped as CO2 increases, giving credence to the notion of Skeptikal and others that CO2 has no effect on warming.”
.
Fair enough, rising CO2 most definitely has to cause warming, and will accelerate melting of ice in Greenland, the Antarctic peninsula region, mountain glaciers, and ice caps.
.
With regard to huge future warming induced by a release of methane hydrates: the depth and location of the land hydrates (as far as I can tell from reading on the subject) is such that they will not quickly release methane under any circumstances… I mean, warming of the permafrost over several hundred meters depth is not going to happen quickly, and in much of the arctic it will never happen, since the average temperature is too low. Will some marginal stability hydrates at the southern limits of permafrost be released? Sure, it is likely warming will cause some release… but whatever the current release rate is, it is small compared to other sources of methane.
.
Release of substantial quantities of methane hydrates from the continental shelves is more credible, but that requires quite a lot of warming of the ocean below a few hundred meters depth, and we are a long way from that.
Owen:
The problem with Skeptikal’s logic is it isn’t CO2 forcings alone that causes temperatures to tend to increase, it’s net radiative forcings, and we don’t even know that the sign of the change in radiative forcings from 2002 to now is even positive, primarily due to the uncertainty in aerosol forcings (as I noted here).
Adding CO2 to the atmosphere tends to increase temperature. But it’s a mistake to transmogrify tends into must.
Steve,
I was curious to hear your response to the other point I had made: Just as it is not clear that we will have catastrophic warming, it is also not clear that we will have only mild warming – the very uncertainties (aerosols, clouds, humidity feedback, etc) that argue against certain catastrophe also argue against the certainty of its most benign alternative.
Do you agree? If so, how do we balance the need to address a potential problem vs the cost to address such a problem? Wait and do further research? What if the amelioration of the potential warming problem involves a similar set of solutions needed to address other looming problems (peak oil, reliance on foreign oil, supporting dictators or cultures antagonistic toward western values, etc.)?
Skeptikal,
[“It amazes me that people will say that there is science behind the theory of CO2 warming, yet they can’t adequately explain why the theory doesn’t match real world observations.”]
I understand your amazement!
Anteros,
Extreme outlier bets are always a problem, and I never know whether to leave them in or not. Anyway, excluding the two extreme bets, the results are as follows:
MAX 0.230
MIN -0.180
MEAN -0.027
MEDIAN -0.037
STD DEV 0.091
MEAN 1-26 -0.048
MEAN 27-53 -0.006
As you say, very little difference to the mean, but a much reduced SD.
NB the previous figures should have said MEAN 28-55.
@Arfur Bryant (Comment #93432)
Nothing in science is ever perfectly explained.
The climate is explained adequately. You perhaps don’t understand the explanation.
Owen,
[“My point was to rebut the notion that warming has stopped as CO2 increases, giving credence to the notion of Skeptikal and others that CO2 has no effect on warming.”]
Where has Skeptikal said that CO2 has no effect on warming?
Owen,
[“Quite the contrary. An energy imbalance due to the enhanced greenhouse effect is causing the entire climate system to warm. The warming of the atmosphere may have temporarily slowed, but the oceans are continuing to warm and absorb huge amounts of thermal energy…”]
And there is the assumption: “due to the enhanced greenhouse effect…”. Do you have any proof of that?
SteveF is quite right to ask for some perspective, but he’s not right to say “OK”. Lets take your imageshack graph:
http://imageshack.us/photo/my-images/837/02000mohca.jpg/
1. Why does that graph start around 1955 when the 2000m data doesn’t start until 2005?
2. Have you looked at the data supposedly used to make the graph?
3. How do you explain the anomaly that, according to the data, The Atlantic and Pacific Ocean Heat Content has increased by about 13% but the Indian Ocean Heat Content has increased by about 550% in 5 years?
4. Why does the 700m data show the Indian Ocean Heat Content increasing by about 30% in the same 5 yeas?
5. What does any of it have to do with CO2?
6. Do you really believe that a small portion (backradiation) of the radiation re-emitted by a trace gas in the atmosphere has the capability to increase the Heat Content of the Indian Ocean by 550% in 5 years whilst, at the same time, leading to no warming of the atmosphere or the surface of the world’s oceans? Really?
In this case, Owen, Skeptikal is correct when he/she said that the effect of CO2 was tiny, not non-existent.
Objectivity.
bugs (Comment #93435)
Bollox.
Owen #93429,
My position is that we need much more certainty to justify vast public costs, and that certainty must extend to very bad consequences, not just certainty of a specific level of warming. The value of avoiding those very bad consequences needs to be weighed against the present day cost using economically reasonable discount rates. If very bad consequences are projected for 100 years in the future, then the present day value is hugely discounted, and so it is likely difficult to justify vast current investment. Which is nothing more than accepting the reality that we face lots of problems with a limited amount of available capital. A reasonable hedge is publicly funded research into energy sources other than fossil fuels, including but not limited to standardized, inherently safe breeder reactors, thorium reactors, advanced battery design, etc. Rather than subsidize non competitive solar and wind, we should spend that money in the best ways we can to eliminate the terrible poverty that remains in much of Africa (and other places), poverty that drives rapid population growth, destroys natural habitats, and that leads to endemic diseases and terrible suffering. It is a far better investment if you care about the future than subsidizing id*otic banks of windmills.
.
Humanity must (and so will) ultimately stop using fossil fuels as a primary erergy source. The only question is how and when that transition will happen. IMO, the proposed means to that ultimate end which are primarily driven by political inclination are by far worse than doing nothing. Offer a reasonable plan, factually rather than politically informed, and people will support it. What has been proposed so far (with a few exceptions, like some of Roger jr’s) are counterproductive claptrap which are never going to happen.
Owen,
It makes no sense to argue with Arfur, any more than with skeptikal.
“Adding CO2 to the atmosphere tends to increase temperature. But it’s a mistake to transmogrify tends into must.”
SteveF,
Talk about ‘from the sublime to the ridiculous’!
SteveF (Comment #93438) = sublime. I agree almost completely. Well done on not mentioning CO2.
SteveF (Comment #93439) = ridiculous. Groupthink at its most unjust. What have I said in my posts above that gives you cause to say that? Do you not agree that Owen’s graph is fabricated?
Arfur #93443,
I will break my own rule about interacting with you and answer.
You have demonstrated (and continue to demonstrate) an extreme case of unwillingness to listen to reason. When you say things like “And there is the assumption: “due to the enhanced greenhouse effect…â€. Do you have any proof of that?”, it is clear that you continue (as in the past) to reject even the most basic and well known physical science. The direct radiative impact of CO2 is well known, and there is a broad consensus among physical scientists (covering everyone form Richard Lindzen and Roy Spencer to Peter Gleick and Gavin Schmidt… and at the Blackboard, trained physical scientists like Carrick, Julio, Lucia, many others, and me) that the effect of a doubling of CO2 is close to 1.2C, absent any feedbacks. The null hypothesis is, and ought to be, warming of about 1.2C for radiative forcing equal to a doubling of CO2. So long as you continue to reject that notion, I can only conclude that you know nothing of what you speak.
.
Owen’s graphic is a reproduction of the NOAA graphic for 0-2000 meter warming. Since there is only limited data below 2000 meters prior to Argo, for sure the graphic is based on some kind of model of ocean warming, combined with limited available data. But that fact does not mean the NOAA hind cast is not correct. My own best estimate (based on my model for vertical ocean diffusion, which is calibrated against the available 0-700 meter data) is within about 10% of the NOAA estimate. Is the NOAA estimate perfect? For sure not! But it is probably a very reasonable estimate, and certainly better than nothing.
.
Finally, I have lots of personal failings, but “group think” is most certainly not one of them. I judge the quality of your comments based only on their content… and I find that they consistently reflect a lack of basic technical understanding. And that is why I am usually reluctant to interact with you.
SteveF,
Thanks for your post. I am perfectly willing to engage. I wasn’t aware you had a rule about engaging with me but I know we’ve had our moments in the past. I have no problem with you thinking I ‘know nothing of what I speak’, even if that comes across as slightly melodramatic. You are entitled to your opinion, as are we all. Please allow me to answer your concerns:
.
1. “…it is clear that you continue (as in the past) to reject even the most basic and well known physical science…”
Now I don’t normally quote Wikipedia, but I agree with this: “To be termed scientific, a method of inquiry must be based on gathering empirical and measurable evidence subject to specific principles of reasoning.” So, whereas you can quote as many ‘big names’ as you like, until you can provide some empirical evidence that supports your ‘basic science’, I am quite happy to argue against your assertions using the principles of logic and reasoning. For example, Schmidt (and Trenberth and Lacis and scienceofdoom) reckons that CO2 contributes 26% to the Global Greenhouse Effect. Do you agree with this figure? I don’t, and I’m happy to discuss it with you.
2. I have no problem with the ‘basic physics’ of the radiative properties of a single molecule of CO2. I have a huge problem with the assumption that those properties are likely to have a significant effect on global temperature. The figure of 1.2 C for no-feedback sensitivity is not based on empirical evidence but on models. This makes it, in effect, a guess. I do not know the real figure. Nobody does. However, based on observed data I suspect it is much less. It is interesting to note that the figure has been reduced markedly over the years (didn’t Arrhenius first suggest 6 deg C?), so at least the ‘big names’ are heading towards my end of the scale. If you insist on supporting the notion that 0.04% of the atmosphere can have such a significant effect without giving supporting real-world empirical evidence then I can only assume you (and they) are incapable of objective assessment.
3. Feedbacks. There is no empirical evidence to suggest these ‘positive feedbacks’ exist. Period. They are a figment of imagination and assumption.
4. Owen’s graph. You base your estimate on the 700m data. Great! Unfortunately Owen’s graph was entitled ‘2000m data’. Yet the 2000m dataset, according to the NOAA link on the graph, shows that 2000m data didn’t start until 2005! This means Owen’s graph was a splicing of 700m data from 1955 to 2005 with the 2000m data from 2005 to 2011 – and presented as a graph of 2000m data! In addition, the last 5 years showed a massive increase when, had the 700m data continued to be used, the last 5 years’ rise would have been much shallower. Now where have we seen someone in ‘climate science’ splicing two datasets together to bolster a preconception? Hmmm… let me think. And that’s not all. You say that the NOAA 700m data is accurate, but Owen decided to try to persuade readers that the 2000m Global Ocean Heat Content anomaly has tripled since 1998 because of the backradiation from CO2. Do you agree with him?
.
Finally, you and others on this blog display groupthink when you automatically assume that I have a ‘low level of technical understanding’ just because I don’t accept your dogma. Either provide some empirical evidence to support the notion that 0.04% can have a significant effect on global temperature, or stop criticising me for questioning your belief. Science is proof without belief, religion is belief without proof.
.
Just so that we’re clear on my stance:
I accept that a molecule of CO2 has the ability to absorb and re-emit radiation. I question the ‘consensus’ estimate of the quantitative effect.
I note that the global temperature has warmed by about 0.8 deg C since accurate records began in 1850.
I note that CO2 has increased by about 40% in the same time.
I note that this gives an overall trend of less than 0.06 per decade, and is currently decreasing.
I do not consider this trend significant.
I do not care for sanctimony, however many letters you may have after your name.
Politely yours,
Arfur
Re: Arfur Bryant (Comment #93455)
In other words, lacking any additional information, the global temperature increase is consistent with a climate sensitivity of about 1.6 C for a doubling of CO2:
0.8 = 1.6*log2(1.4)
To assert that the effect of CO2 is less (or more) than this, you need additional information. What do you know that we don’t?
Arfur Bryant (Comment #93455),
Oh well, I tried. Back to no engagement…. and no wasted time.
Arfur,
The ARGO floats were deployed in roughly 2002, and the 2003 coverage was close to worldwide. The 2005 data was evidently considered the first full comprehensive set for 0-2000 meters. If you look at a plot of NOAA data for 0-700m and 0-2000 meters, they are essentially the same for most of the time course. The 0-700 m layer has been showing warming since 1970 and, as might be expected, heat is only recently making its way down below 700 m. I would guess that NOAA assumed that OHC from 0-2000 m was essentially equal to OHC in the 0-700 m zone until the last seven years or so. The flattening profile for 0-700 m (ca. 2005-present), along with the concomitant increase in 0-2000 m in the same time period, may reflect an emerging steady state in which thermal energy gained at the surface is becoming balanced by heat transfer to the 700-2000 m zone.
In any case, 0-2000 meters is a better measure of ocean heat uptake than 0-700 m, as the latter is becoming increasingly more incomplete. The ARGO float system has measured an increase of approximately 35-50% in the OHC anomaly since 2005. The climate system is clearly continuing to warm, your protestations notwithstanding.
SteveF,
We are still left with a big step change in OHC in 2003. I note that the satellite data shows no increase in radiative imbalance at that time – in fact quite the contrary. We were supposed to be ENSO neutral IIRC. Your sea-level work showed no surprise change at that time either. That’s a big slug of energy going in at that time, when coincidentally ARGO deployment was rapidly increasing. Do you have any thoughts on the accuracy or otherwise of that step?
Owen (Comment #93423),
You said… “Finally, sea ice is melting (see http://nsidc.org/images/arcticseaicenews/20111004_Figure3.png) and sea ice volume is rapidly decreasing.”
That’s a bit misleading. Your link goes to a graph showing ARCTIC sea ice. What about Antarctic Sea Ice? Your use of the words “sea ice” would give people the impression that ALL sea ice is melting away. I’ve uploaded a graph of the latest (February) Data for the Antarctic Sea Ice Extent. It shows February data from 1979 to 2012. It also shows a trendline (courtesy of excel).
http://img534.imageshack.us/img534/1725/southiceextent.jpg
Given that the Earth reaches its aphelion (greatest distance from the Sun) when the Arctic is experiencing summer and perihelion (least distance from the sun) when the Antarctic is experiencing summer, you would expect the Antarctic to be experiencing the same or an even greater melt than the Arctic… yet this is not happening. The Antarctic Ice Extent is in an upward trend (it’s gaining ice).
If your premise of CO2 causing “an enhanced greenhouse effect” is right, then why is Antarctica not losing it’s ice extent at the same rate as the Arctic? Moreover, why is there no loss of its ice extent at all? Surely the rate of rise in CO2 would be similar in Antarctica to the rest of the planet.
Paul K,
My best guess is that prior to 2003, NOAA had assumed that heat was entering only the 0-700 m zone (they had no significant data below 700 m). When they began to get the 0-2000 m ARGO data in 2003, they then plotted the new 0-2000 meter data as essentially an add-on to the 0-700 meter time course (or perhaps they modeled the transition years?). The 0-2000 m zone was most certainly picking up some heat prior to 2003 but had to be taken as zero uptake as no data was available. Thus when the first 0-2000 m measurements were plotted as an extension to the 0-700 m time course, we saw a step-change artifact.
That’s my best guess.
Paul K 93462,
The apparent step at the beginning of Argo does look suspicious, and was clearly not present in the model I used. That size step is inconsistent with a diffusion based model, unless you postulate that the rate of diffusion undergoes rapid changes. The most plausible explanation is difficulty in joining the old and new data. I note that the level of short term variability in the 0 – 700 M OHC prior to Argo was quite high, and considering the thermal mass involved, at least some portion of that high variability was probably due to the quality/coverage of the pre-Argo data. Warming data below 700 M is really limited to the last 7years. It will be interesting to see how that evolves over the next decade; the 700 – 2000 M trend should be smoother than the 0 – 700 M trend, and dominated by accumulation in the upper half of the deeper region. If the deep data looks noisy, then that will probably say more about the data quality than changing rates of deep warming.
Owen 93461,
35% increase in OHC anomaly? Compared to what base period? The 0 – 2000 M data shows a considerable increase, but there is only a modeled estimate for the earlier 0 – 2000 OHC, so that 35% figure needs to be taken with some grains of salt. The 0 – 2000 M trend since Argo was fully in place is a lot more solid, and suggests a continuing global imbalance in the range of 0.4 watt/M^2….. a number that I hope the modeling community will accept as a meaningful test of the ocean part of their models. Pronouncing doom based on a model with a 50 – 100% error in the rate of OHC change is unwise.
Owen (Comment #93461)
March 18th, 2012 at 8:32 pm
I would guess that NOAA assumed that OHC from 0-2000 m was essentially equal to OHC in the 0-700 m zone until the last seven years or so.
To get below 1,000 meters using XBT’s the deploying ship would have to be going a maximum of 6 knots.
XBT Capabilities –
http://www.sippican.com/stuff/contentmgr/files/0dad831400ede7b5f71cf7885fdeb110/sheet/xbtxsv92005.pdf
So the amount of data that exists below 700 meters pre-argo is ‘sparse’ at best.
julio (Comment #93457)
Julio,
Well, I know two things that you are ignoring…
1. You say “In other words, lacking any additional information, the global temperature increase is consistent with a climate sensitivity of about 1.6 C for a doubling of CO2…. In doing so, you ignore the fact that, to reach that conclusion, you have assumed (there’s that word again!) that ALL of the 0.8 C warming is due to CO2. In making that assumption, you are effectively denying that any natural variation could exist. This is obviously incorrect. Even the IPCC doesn’t think that ALL the warming is due to CO2. The global temperature has both risen and fallen at times since 1850, so ‘something’ can counteract any CO2 effect. So… how much of the 0.8C warming is down to CO2? Nobody knows. That’s the point! It could be 0.1, or 0.4 or 0.7 but it is definitely not 0.8 and it is probably not 0. Maybe we could say 0.4 (=50%)? So now do your log calculation using 0.4 instead of 0.8 as the target. What do you get? But the point is nobody knows. Its just a guess.
2. The other thing you ignore is that the 0.8C includes all forcings and feedbacks (if they exist)! This means that SteveF’s suggestion overestimates the ‘no-feedback’ CS, with the implication that the end result (ECS) will be higher. Please lets have no nonsense about thermal inertia lag etc. If you can provide any real-world evidence for either lag or feedbacks, please do so.
.
I repeat, all anyone can say is that CO2 should, theoretically, have provided some contribution to the observed warming of 0.8C. Nobody knows how much. Unless you insist that ALL the warming is due to CO2, all you have is an unknown contribution.
SteveF (Comment #93459)
That’s fine. Your inability to provide any evidence is duly noted, as is your desire to avoid any further engagement. I wish you every happiness for the future and hope your life is full of bunnies and puppies and fluffy clouds. And chocolate. And no difficult questions…
I will, however, continue to offer my support when you say something relatively intelligent which, to be fair, is reasonably regularly.
Owen (Comment #93461)
[“I would guess that NOAA assumed that OHC from 0-2000 m was essentially equal to OHC in the 0-700 m zone until the last seven years or so.”]
You’d guess they assumed? Wow, that’s science for you!
.
According to their data, the anomaly for 2005.5 for 700m is 8.4 units (= x 10 to the power of 22 joules). The anomaly for 2005.5 for 2000m is 10.2 units. So it’s not equal and your guess/their assumption is wrong.
.
Also, you have ignored my point about the Indian Ocean. Why do you think the data shows a 550% rise in OHC in 5 years when the Pacific and Atlantic oceans show a rise of about 13%? Do you really think that rise is caused by backradiation from CO2? Seriously?
.
Please explain how the Indian ocean OHC at 2000m depth can increase by 550% (due to CO2 according to you…) when, in the same period, the global atmosphere has cooled by about 0.3C and the global Sea Surface Temperature has shown a similar cooling.
SteveF (Comment #93438)
March 18th, 2012 at 6:18 am
“A reasonable hedge is publicly funded research into energy sources other than fossil fuels, including but not limited to standardized, inherently safe breeder reactors, thorium reactors, advanced battery design, etc. Rather than subsidize non competitive solar and wind, we should spend that money in the best ways we can to eliminate the terrible poverty that remains in much of Africa (and other places), poverty that drives rapid population growth, destroys natural habitats, and that leads to endemic diseases and terrible suffering. It is a far better investment if you care about the future than subsidizing id*otic banks of windmills.
————————————————
While I certainly can’t disagree with much of the above, especially about the desirability of eliminating third world poverty [are you sure you are not a closet liberal? ], I thought you might be interested in the following article from Business Week about the make-or-break German energy policy (throwing out nuclear and advancing wind and solar) – http://www.businessweek.com/news/2012-03-18/germany-s-270-billion-renewables-shift-biggest-since-war
The entire world will watch with interest to see if they can swing this.
Owen: “While I certainly can’t disagree with much of the above, especially about the desirability of eliminating third world poverty [are you sure you are not a closet liberal?]”
Why would anybody disagree with eliminating third world poverty? We would of course all benefit from that. Do you think non-liberals are evil monsters?
Niels A Nielsen (Comment #93495)
March 20th, 2012 at 12:53 am
“Do you think non-liberals are evil monsters?”
—————————————————–
Actually I was just teasing SteveF. You seem to be a bit sensitive on that issue.
Owen,
I appreciate that you were teasing. The truth is, my wife and I have always helped to support about half a dozen poor kids in developing countries (basic education, a mid-day meal and help with clothing) for the last 20+ years. And right now we are also sending a poor girl in Honduras to pharmacy school. What I have consistently observed is that conservative/libertarian people are usually generous with their own money, while liberals are usually generous with other people’s money. Liberals have no monopoly on morality, even though most seem to believe they do; I think a reasonbly strong contrary argument can be made.
Owen,
WRT the German loonecy, I can’t imagine a more silly and futile exercise. They will end up importing power from their more sane neighbors, and lowering their living standards for no good reason. Germany seems a place were crazy stuff gets tried, and it doesn’t always turn out well.
SteveF (Comment #93499)
March 20th, 2012 at 6:19 am
I have found many of the libertarian voices on this site to be rational, informed, and solutions-oriented (certain exceptions apply). I appreciate the opportunity to test my at times inchoate ideas on climate, politics, and even morality in these online debates with more than worthy adversaries.
Owen,
One final thought on Germany. The most recent birth rate is ~1.4 children per woman, and there is essentially no net immigration. The population is projected to fall by somewhere near 12-15 million (out of 82 million) by mid century, making the retirement system unable to support a rapidly aging population. I sat at dinner a few years ago with a group of educated (professional) Germans, and asked why they thought this was happening. The only reply I could get was that most Germans think having children is too expensive and do not think having children is “the right thing to do”. It kind of dovetails into the windmill decision.
Steve,
I have always thought that we should push forward on alternative energy development for multiple reasons (warming, peak oil, loss of the reduced carbon resources, general environmental contamination), but I must admit that the German proposal seems too aggressive even for me. But I am interested to see how strong their national will is to accomplish this transition which is primarily a technological one. If they succeed, the payoff will be big in terms of energy independence. A failure will be colossal.
Re: Arfur Bryant (Mar 18 18:57),
FYI. The rule is: Do Not Feed the Troll.
Back in the days of USENET, one would close a note to a troll by adding *plonk*. That was the sound of your name being added to the readers killfile list. Messages in the newsgroup from that person would not be downloaded from the server by the newsreader. Unfortunately, killfile utilities seem to have not made a successful transition to blogging.
*plonk*
Re: SteveF (Mar 20 08:18),
So they’re all planning to die in their 60’s or 70’s while they’re still relatively healthy? Sounds like a complete lack of forethought on consequences. But then ignoring unintended consequences seems to be endemic in liberals.
A 65 year old German male in 2002 had a life expectancy of 16.0 years (slightly worse than the 16.6 for a US male) and a 65 year old German female 19.6 years (the same as a US 65 year old female). Having one parent that passed away at age 97 and another who’s still around at 100, I can tell you that it takes substantial resources to have a comfortable lifestyle at that age. I wouldn’t bet that the German government will provide that, or even try, twenty years from now. Especially if they’ve trashed the economy by trying to switch to ‘renewable’ energy. I foresee warehouse style nursing homes with the inmates drugged to the gills in the future for a lot of Germans.
DeWitt Payne (Comment #93507)
Ah, DeWitt, my dear chap…
Yes, that is what you should do. It is the standard response when the group is threatened. Mark the outsider as a heretic and pretend he just doesn’t understand simply because he has none of ‘our’ faith.
.
You guys are pathetic. Skeptikal made a few decent points and you decide that its your sworn duty to belittle him and make fun of him. When anyone questions your beliefs and asks for some EVIDENCE to support your assertions your only escape is to ignore him and just carry on with the dogma which must not be questioned. ‘scienceofdoom’ ran away from a ‘difficult question’, just as you want to. You wouldn’t know objectivity if it slapped you in the face.
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cAGW is a scientific fraud of such colossal proportions a hollywood scriptwriter couldn’t get it accepted. If it makes you feel better by referring to yourselves as ‘lukewarmers’ because you’re too scared to take the ‘CO2 radiative forcing = significant warming’ theory full on and treat it with the contempt it deserves, you’re no better than the Emperor’s courtiers.
.
But go ahead, DWP. Preach to your buddies that I and other ‘disbelievers’ should be ostracised. That’s the real mark of an intelligent religious order…
And the classic response of a troll. If I didn’t already think you were one before, that confirms it. You have no interest in dialogue, only preaching. You’re not merely a troll but an extremely boring troll to boot.
DWP,
I’m not interested in dialogue?
Read the posts to Owen. Read about how he made the truly ridiculous assertion that the global oceans are ‘absorbing enormous amounts of energy’ (from CO2) and then proudly presented a completely fabricated graph to demonstrate his point. Then read where I tried to engage him in dialogue about how the data was not only spliced from two datasets and presented as one but contained the incredible (literally) anomaly of the Indian Ocean OHC increasing by 550% in 5 years, when the Atlantic and Pacific Oceans only increased by about 13% in the same time. He has not bothered to address that specific anomaly. I suppose he thinks the anomaly will go away. Just like the nasty troll. But, like cheap-shot politicians, he’s made his sound bite and, well, never let the truth stand in the way of good propaganda, eh?
.
No, DWP, I am not the one preaching. You can accuse me of being an annoying troll if it makes you feel big, but I’m not the one running away from the discussion. Your entire contribution has been to attack me personally. You have provided no constructive debate; nothing of any substance. You guys love to dish it out but you can’t stand taking it…
Arfur,
Settle down, think of your your blood pressure. That simple plot of data posted by NOAA (http://data.nodc.noaa.gov/woa/DATA_ANALYSIS/3M_HEAT_CONTENT/DATA/basin/3month/ohc2000m_levitus_climdash_seasonal.csv) certainly seems to be a burr under your saddle. I only plotted official NOAA data – no fabrication involved.
You do get fixated on things, don’t you. You were looking at the Indian ocean 3 month data for 2005, the first reported data by NOAA and it was very low. I don’t know the exact reason for that first year being excessively low, but it is most certainly not the “gotcha” that you think it is, that you badly want it to be. If you look at 2005 on the annualized Indian Ocean data (http://data.nodc.noaa.gov/woa/DATA_ANALYSIS/3M_HEAT_CONTENT/DATA/basin/pentad/pent_h22-i0-2000m.dat), no such anomaly is present. My guess would be that the first year involved data from only a portion of the floats. What’s the matter with you, Arfur, don’t you trust the scientists at NOAA?
Owen, DeWitt,
It is not worth the effort. Ignore those who know essentially nothing… and worse, are utterly unwilling to learn.
Arfur,
I think I have discovered the problem. You are confusing the anomaly being low with total heat content being low. Thus your statement “the Indian Ocean OHC increasing by 550% in 5 years” should read that the anomaly itself (not the OHC) increased by 550% in 5 years. This is entirely normal. Look at the data for the 0-700 meter zone that goes back many years (http://data.nodc.noaa.gov/woa/DATA_ANALYSIS/3M_HEAT_CONTENT/DATA/basin/3month/h22-i0-700m10-12.dat), the anomaly jumps all around noisily as it continues its upward trend.
DeWitt,
“I foresee warehouse style nursing homes with the inmates drugged to the gills in the future for a lot of Germans.”
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Actually, I can think of much worse German history to use as a president. They need to come to grips with the reality of their demographic choices. Sadly, there is no sign of that. Bad things will happen. Demographics are destiny.
General observations:
“Mark the outsider as a heretic and pretend he just doesn’t understand simply because he has none of ‘our’ faith.”
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No the ‘heretic’ is nothing more than a babbling id*ot who knows nothing of science. That is why people ignore the rants.
.
“You guys are pathetic. Skeptikal made a few decent points and you decide that its your sworn duty to belittle him and make fun of him.”
There is nobody on this thread more deserving of belittlement….OK maybe there is one person more deserving; you might imagine who that is.
.
“When anyone questions your beliefs and asks for some EVIDENCE to support your assertions your only escape is to ignore him and just carry on with the dogma which must not be questioned.”
.
Nope, nothing like that; there is no dogma. There is an expectation of basic understanding of science. Nobody knows how to respond reasonably to the ravings of an id*ot who knows nothing. That is why it is an awkward exchange.
.
“‘scienceofdoom’ ran away from a ‘difficult question’, just as you want to. You wouldn’t know objectivity if it slapped you in the face.”
Odd comment to make to practicing scientists of many years experience. DeWitt and I most certainly were dealing with reality and ‘objectivity’ before you were slapped in the butt at birth. Get a grip on it.
Re: SteveF (Mar 20 17:19),
Oh, indeed. In fact, that’s the first thing I thought of, but decided it would be too close to a violation (or is it a confirmation?) of Godwin’s Law to mention it.
Johnathan Swift in Gulliver’s Travels anticipated something similar with the Struldbrugs. Struldbrugs are immortal, but not ageless. They are declared legally dead at age 80.
Sounds familiar, doesn’t it.
What the Germans have forgotten is that children are a form of long term care insurance.
Re: SteveF (Mar 20 16:48),
Oh, it’s no effort because I don’t expect to accomplish anything.
I know people who try to keep telemarketers on the line as long as possible. It’s no fun if they hang up on you right away. I don’t have the mind set to do that, but it’s amusing sometimes to poke these people with a sharp stick to see the reaction, i.e. baiting the trolls rather than feeding them. Nasif Nahle is much more fun than AB, though.
Germans have had gastarbeiter in the past in the auto industry for example. I can see that happening in the health field.
Re: BarryW (Mar 20 18:24),
Yes, but in the auto industry they were creating products for sale, or in the parlance, a profit center. In health care they will be a drain on the economy or a cost center.
Some people think capitalism is doomed in the long term because it requires a continually expanding economy. A social welfare state has a much worse problem with this, IMO. Greece and California are the tip of the iceberg.
Quick thoughts on the German plan:
(1) If anybody can pull it off, it’s Germany–but I still would not bet on it.
(2) the goal is actually only to increase the percentage of renewable energy from 20 to 35%, which is a big step from a certain perspective but a relatively small one from another. It also looks like a dead end to me: I don’t think they could possibly expect to get much more from wind power after this. To get the next 15%, they’ll have to think of something else.
(3) if what they are planning to do is mostly to replace existing nuclear plants, their CO2 emissions will essentially not be reduced at all.
It’s an impressive undertaking and potentially a very valuable experiment, for the lessons everybody stands to learn from it…
DeWitt
Anytime the number of takers exceeds the number of producers the system eventually will collapse, especially when the takers control the government or are paid off by government largess. Was true in Rome, is true today.
“I know people who try to keep telemarketers on the line as long as possible. ”
hehe. I do that
I sometimes do too. And some of the people who’ve been phoning trying to get me to vote for their candidate. (Primary over! Yay!)
DeWitt
Greece is merely the “beak” at the end of the “neck” of the economic and financial “vulture” that is coldly staring the collective European welfare states in the face.
In the US it’s not just California but any state where public sector entitlements exceed those of private sector employees. I.e. cost centers costing more than the profit centers make.
Arfur Bryant (Comment #93509),
I think SteveF summed it up nicely when he said…
I think that they probably get annoyed when people ask them questions which neither they nor anyone else can answer. That’s not to excuse their conduct. I think resorting to ridiculing and name calling is appalling behaviour.
To say something like… “Odd comment to make to practicing scientists of many years experience. DeWitt and I most certainly were dealing with reality and ‘objectivity’ before you were slapped in the butt at birth”, shows that they are so far up their own ivory towers that they are shocked that we can even see them.
They just can’t accept that when we question the science, we are genuinely questioning the science. Calling people trolls or id*ots for asking questions doesn’t help the science at all.
We’re probably asking our questions to the wrong people.
“I think that they probably get annoyed when people ask them questions which neither they nor anyone else can answer.”
Yes, the Good Ol’ Boy Network at The Blackboard has a rich tradition of such reactions.
Andrew
Skeptical 93530,
“We’re probably asking our questions to the wrong people.”
No, the problem is that you are not willing or able to understand and accept the most basic and well understood parts of physical science, like blackbody radiation, so you reject any answer that is based on that well understood physical science. The problem is not with the answers you are getting, nor with the people giving you those answers, it is with your poor understanding of the simplest of scientific concepts. If you want people to support your rants, comment at a blog were most of the readers have your level of understanding of the basics. There will be high-fives all around, and you can feel comfortable in your misunderstandings.
.
‘Ivory tower’ normally refers to academic elitism. I never worked for a university or college, only industry and self employment.
“I know people who try to keep telemarketers on the line as long as possible. It’s no fun if they hang up on you right away. I don’t have the mind set to do that, but it’s amusing sometimes to poke these people with a sharp stick to see the reaction, i.e. baiting the trolls rather than feeding them. Nasif Nahle is much more fun than AB, though.”
I agree with SteveF that it is a waste of time and even gets the more reasonable amongst us off the track where a poster can learn and be challenged by the discussion.
I do the same with telemarketers, but with a few exceptions going back in time. I answered the phone to a particularly agressive telemarketer during a weekday and had this sudden thought of posing as a young kid left at home by his parents. I am capable of doing a young kid imitation so when the telemarketer asked to speak to my mother I told him that she was not home and had not been for a couple of days. He asked if my father was around and I told him that he had left over a year ago. The telemarketer’s demeanor was changing from agressive to very sympathetic and he said something like you poor kid and is there any thing I can do. I told him that I was used to being alone and not to worry. He told me to hang in there kid and said good bye. I was fully expecting that I would have to explain my hoax to a social service representative within the hour, but the call never came.
julio (Comment #93523),
“if what they are planning to do is mostly to replace existing nuclear plants, their CO2 emissions will essentially not be reduced at all”
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I agree, that is the issue. The program is driven by a desire to replace the most practical method of generating electricity that does not emit CO2 with a much less practical (and much more expensive) method. It has zero impact on global warming… and in the end, probably will lead to more CO2 emissions when the Germans end up using electricity generated using fossil fuels whenever the wind doesn’t blow. The program is purely a political rejection of nuclear power as an alternative to fossil fuels, and IMO, terribly misguided. There are lots of more useful things they could do with that money.
SteveF (Comment #93533),
Steve, If you had read my previous posts you would have noticed that I said in (Comment #93351)…
I then went on to say
Yes, I DO understand and accept the science, BUT the measured CO2 warming in the lab doesn’t appear to be translated into what’s happening in the atmosphere. That’s not a rant, that’s reality.
Skeptikal (Comment #93546),
OK I will try again.
.
I did read your original comments. A molecule of CO2 does not know where it is located. Its radiative properties are identical in the atmosphere or inside a laboratory instrument. If you don’t understand this, then you are simply uninformed. When you talk about “CO2 warming in the lab” it suggests that you don’t understand what is being measured. CO2 absorbs infrared radiation (mainly at 14 microns wavelength); that is what is measured, not “warming in the lab”. Warming due to CO2 in the atmosphere is calculated based on how CO2 molecules along the atmospheric column (from the ground to space) will absorb and re-radiate at 14 microns wavelength. The expected warming is a direct result of the absorption and re-radiation, and represents the influence of a change in CO2 concentration on radiative energy balance, which is calculated independent of changes in other processes (like changes in convection, changes in atmospheric water vapor, changes in clouds, etc.). To learn more, see for example http://en.wikipedia.org/wiki/MODTRAN and the Modtran web site.
.
A doubling of CO2, based on these radiative-only calculations, leads to warming at the surface of ~1.2C, which is the “base case”, where no feed-backs (negative or positive) are considered. That is, ~1.2C warming is the “null hypothesis” for a doubling of CO2. If you don’t want to dig that deeply, you can consider an even simpler analysis: the net ‘back radiation’ from a doubling of CO2 in the atmosphere is ~3.71 watts per M^2. Considering an ‘average’ emission temperature to space of ~255K (on average well up in the troposphere), which is the temperature that will emit to space a net IR flux equal to the solar flux of ~240 watts/M^2, the change in black-body temperature associated with 3.71 watts extra forcing is about 1.0 C. The higher quoted value (~1.2C) is due to a more accurate calculation. I hope you can accept that the “null hypothesis” of ~1.2C is agreed to by a wide range of technically trained people on both sides of the global warming debate, because it is the LEAST doubtful technical issue. Pretty much only the very uninformed do not accept this value as the “base case”.
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The real technical argument, and there is a real technical argument, is in all the other factors (AKA feedbacks); the argument has nothing to do with the known radiative properties of CO2. If someone believes the sensitivity to forcing is higher or lower than 1.2C per doubling, then they need to prove net feedbacks (negative or positive) which change the 1.2 C value.
Owen (Comment #93513)
Owen (Comment #93515)
Owen, just to show you that the ‘troll’ is someone who understands the concept of integrity (something sadly lacking on this blog), I will apologise to you for one error in my earlier post. But just one. I will grant that you are correct about the 550% being an OHC anomaly figure (your post #93515). You have my apologies for that misconception. The error, although there is no excuse for making it, does not change the the main point of my complaint about your graph. I trust that my other detractors on the site will note that I have the capacity not to run away from a valid point! Now to address your graph and comments in the other posts…
Owen, ok, now we have a dialogue.
You are wrong on the first post (#93513) and you are moving the goalposts by talking about different graphs from the one that you posted at #93423.
Let me remind you of that graph and what you said about it:
Owen (Comment #93423)
“An energy imbalance due to the enhanced greenhouse effect is causing the entire climate system to warm. The warming of the atmosphere may have temporarily slowed, but the oceans are continuing to warm and absorb huge amounts of thermal energy…”
Owen, ok, now we have a dialogue.
1. Please don’t worry about my blood pressure. I had it checked (coincidentally) yesterday and the nurse pronounced it ‘perfect’. (I think she fancied me…)
2. When you plotted your graph, you stated that the data was taken from http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/basin_data.html
I went to that page and used the yearly (not three monthly) data for the ‘world’. I noticed that there was a massive jump in the data in the last 5 years, so I looked at the individual basin data. There, you can clearly see that the Indian Ocean OHC anomaly has increased by 550%, whereas the Pacific and Atlantic have increased by about 13% each. Your comment that such a jump is normal is nonsense. There is nothing normal about a 550% increase, especially compared to the other basin data. And yet, the graph is plotted (by you and noaa) seemingly without question. So yes, I don’t trust the noaa scientists on this particular graph and I would still like you to explain how the IO can increase by such a staggeringly large amount when the neighbouring ocean anomalies have increased by much smaller amounts. I also notice that you seem to have spliced several data sets together but which ones I don’t know because I can’t match some of the readings. Maybe you could help me out here – where is the anomaly of 2001/2 at around 1x 10p22joules listed in the noaa data?
3. Finally, you still haven’t responded to my question regarding ‘how’ CO2 radiation can heat the ocean depths to such a degree without heating the sea surface or the temperature above. Could you give me a steer here? To keep SteveF happy, maybe you could aim it a very low level of technical understanding…
Thank you for pointing out the error of the anomaly but I would appreciate your answers to my questions.
SteveF (Comment #93517)
SteveF,
Your arrogance is truly boundless. Will you please make your mind up and either interact with me or not? Throwing personal insults (replacing an i with an asterisk is rather pathetic) without interacting directly is sooooo lower school…
Skeptikal (Comment #93530)
[“They just can’t accept that when we question the science, we are genuinely questioning the science. Calling people trolls or id*ots for asking questions doesn’t help the science at all”]
Yes, agreed. The problem is that, somewhere, in the darkest recesses of their faith, they realise that they don’t want to ask themselves these questions.
But there’s no point just asking questions of people who agree with us. We have to ask the opposing side, otherwise we are just guilty of the same ‘groupthink’ mentality. Good on yer…
Andrew_KY (Comment #93532)
Hi Andrew!
Agreed:)
I am impressed with your stamina…!
Arfur,
“Your arrogance is truly boundless.”
Not nearly as boundless as your lack of basic scientific understanding. By the way, try writing id*ot in a comment without the substitution of ‘*’ for ‘i’.
SteveF (Comment #93551)
Oh…My…God…
And you think Skeptikal and I don’t understand?
You do realise that MODtran is a computer model program, right? I’ve asked you for real, empirical evidence to support your assertions and all you can do is regurgitate the output from a model?
Who has said that the properties of a molecule are different in the lab and in the atmosphere? Did you not read what I wrote above? “2. I have no problem with the ‘basic physics’ of the radiative properties of a single molecule of CO2. I have a huge problem with the assumption that those properties are likely to have a significant effect on global temperature. The figure of 1.2 C for no-feedback sensitivity is not based on empirical evidence but on models. This makes it, in effect, a guess. I do not know the real figure. Nobody does.”
.
The problem is not the individual properties of a molecule, it is the quantification of these properties in the atmosphere. Just how much of the global Greenhouse Effect is contributed by CO2? The IPCC thinks the GE is 33C. I tend to agree. What do you think? So how many degrees C do you attribute to CO2? If you can’t answer that extremely basic question, how can you hope to estimate the impact of increasing the CO2 levels?
.
No sceptic I know (including me!) argues that a molecule of CO2 cannot absorb and re-emit radiation. Why can’t you move away from the ‘calculations’ and try to find a CO2 signature in the observed data? The temperature today is at least 0.4C lower than 1998 in every global dataset (much more in some)! In spite of the CO2 increasing steadily. Where is the evidence for positive feedback? Where is the evidence for lag? Where is the evidence that the radiative properties of CO2 has actually made a difference?
.
No need for personal insults, SteveF. You think I’m a troll, and I think you’re blinded by faith. So what? In the end, time will tell whether or not CO2 has, is or is ever likely to make a significant difference to global temperature. Have some objectivity… please.
SteveF (Comment #93556)
March 21st, 2012 at 3:38 pm
Arfur,
“Your arrogance is truly boundless.â€
Not nearly as boundless as your lack of basic scientific understanding. By the way, try writing id*ot in a comment without the substitution of ‘*’ for ‘i’.
.
.
I wouldn’t stoop so low…
Arfur Bryant (Comment #93552)
March 21st, 2012 at 3:21 pm
” Your comment that such a jump is normal is nonsense. There is nothing normal about a 550% increase, especially compared to the other basin data.”
—————————————————-
Regarding the magnitude of change expected in an OHC anomaly, please look at the more established 0-700 meter data set (http://data.nodc.noaa.gov/woa/DATA_ANALYSIS/3M_HEAT_CONTENT/DATA/basin/yearly/h22-i0-700m.dat), for the Indian Ocean. When you open the link, please look at the anomaly values for 2001.5 (0.118) and 2003.5 (1.143), this is a 9.7-fold (970%) increase in 2 years. Now look at 1986.5 (0.075) to 1987.5 (0.627) – an 8.4 fold increase. Now look at 1995.5 (0.454) to 1996.5 (-0.556), a big drop from positive to negative. Keep looking, there are many more such examples. You need to think a bit more about what anomalies actually are and why they therefore can show such large variation.
I’ll respond to your other questions later.
Arfur,
“If you can’t answer that extremely basic question, how can you hope to estimate the impact of increasing the CO2 levels?”
That is anything other than a basic question. The influence of CO2 depends on lots of factors. The point is not what the total effect of CO2 is (since it can’t be separated from water vapor and other GHG’s), the point is how much a doubling of CO2 from the present level is expected to have, absent any feedbacks.
You are correct, I agree with DeWitt that your are nothing but a troll. I don’t care much if you think I am blinded by faith. And this is really the very lost time I write anything to you.
Arfur,
“I would still like you to explain how the IO can increase by such a staggeringly large amount when the neighbouring ocean anomalies have increased by much smaller amounts.”
——————————————-
With it’s far smaller mass and heat capacity, I would certainly expect that the Indian Ocean would show higher fluctuations than the Atlantic and Pacific
———————————————-
“I also notice that you seem to have spliced several data sets together but which ones I don’t know because I can’t match some of the readings. Maybe you could help me out here – where is the anomaly of 2001/2 at around 1x 10p22joules listed in the noaa data?”
—————————————————–
I did no splicing. I just downloaded the NOAA data (http://data.nodc.noaa.gov/woa/DATA_ANALYSIS/3M_HEAT_CONTENT/DATA/basin/3month/ohc2000m_levitus_climdash_seasonal.csv) to Excel. The data point you are looking for is 2001-6 (1.115)
Arfur,
“Finally, you still haven’t responded to my question regarding ‘how’ CO2 radiation can heat the ocean depths to such a degree without heating the sea surface or the temperature above.”
——————————————————-
Point 1. The ocean is not heated by CO2, it is heated by solar radiation. As it heats the ocean emits long-wave radiation to cool, attempting to achieve thermal equilibrium (it also cools by convective means, transferring energy to the atmosphere). Greenhouse gases (H2O, CO2, CH4, O3, N2O, and chlorofluorocarbons) in the atmosphere act as insulators (in the simplest analogy) to reduce the radiative cooling by emission of the long-wave (primarily infrared) radiation. Like the other greenhouse molecules, CO2 absorbs the outgoing infrared radiation, and while in its excited state CO2 immediately collides with O2 and N2 molecules in the air, transferring the absorbed energy to the air molecules, increasing their kinetic energies and raising the temperature of the air layer in which the absorbing CO2 resides. The ground state CO2 can collide again with O2 and N2 in the atmospheric zone, picking up energy and re-emitting IR radiation, but with lower intensity and in both upward (toward space) and downward (toward earth) directions. The net effect is to increase the temperature in successive layers of the atmosphere, making the blanket warmer (so to speak). The earth finally releases the IR radiation at the region of the tropopause at a much lower temperature (than the surface).
I’m sure that SteveF, Steve Mosher, DeWitt, Carrick, and several others can add clarifications and correct any errors I have made.
Point 2. Now, if more atmospheric CO2 better insulates against heat loss, the ocean temperature builds up in the surface layer that is most directly impacted and heated by solar radiation. As the surface layer warms, transfer of thermal energy from the warming 0-700 meter layer to the colder 700-2000 m layer eventually results in additional warming of that layer (but with a lag). I think you are forgetting that the 0-700 layer is included in the 0-2000 zone (they are not separate).
Also, as heat flows into the 0-700 from the sun, and out of that layer by transfer to the zone below, the temperature of the 0-700 zone becomes more static, while the 700-2000 zone increases.
Arfur Bryant
I think this is the basis of a rather large miscommunication here. When MODtran is used to determine the warming effect of CO2 in the atmosphere, it is performing a large but trivial calculation, not modelling, no more than a large addition performed by Excel spreadsheet is “modelling”. The General Circulation Models used to predict climate sensitivity in AR4 are entirely different and SteveF is one of their harshest critics.
SteveF (Comment #93551),
Okay Steve, now we’re getting somewhere.
Two questions…
Question 1: Are you saying that it is feedbacks alone which are causing the difference betweeen predicted values and real world observations?
Question 2: Is the calculation for the amount of warming based on CO2 having the same effect regardless of how far it is up the atmospheric column, or is it calculated with the effect diminishing with altitude and then averaged?
Skeptikal (Comment #93573),
Question 1,
No, there are a number of non-feedback factors, including aerosols and ocean heat uptake. The ~1.2C value is the radiative only contribution. Ocean heat uptake slows the response to any change in forcing, and aerosol effects (direct reflection of sunlight and potential changes in cloud albedo and lifetime) can reduce the net flux of solar energy, reducing the effect of forcing. These other contributions are both potentially very important and not well defined, especially in the case of aerosol effects.
.
Question 2,
I am not sure I understand this question. The pressure falls with altitude, so the volumetric concentration of CO2 falls as well. The ‘opacity’ at 14 microns wavelength declines at increasing altitude, which is to say, the probability of an emitted photon reaching space without further absorption increases with increasing altitude. The net influence at the surface is the ‘sum’ of the resistance to radiative flux all along the column.
Re: Skeptikal (Comment #93573)
As I tried to point out to Arfur the other day, the “real world observations” (the temperature increase over the past 150 years) are actually higher than what you would predict from CO2 radiative physics alone.
So yes, some of the difference is (probably) due to positive feedbacks; some is certainly due to increases in other greenhouse gases; and this is counteracted in part by the effect of aerosols, thermal inertia, natural variability, changes in solar irradiance…
There are many scientists who have spent many years working hard to try to sort all this out. You and Arfur seem to believe that they are all either hopelessly stupid or hopelessly corrupt, or both.
See, here’s a good example. If you can think of this, don’t you think that a professional atmospheric scientist would think of it too?
Of course the calculations take into account the decreasing CO2 concentration with altitude. The really precise calculations even include the change in the absorption spectrum of the individual molecules with temperature and pressure, which is why you need a program like MODTRAN to compute them. (Incidentally, matt (Comment #93570) is quite right about what MODTRAN does.)
Reality check: at sea level, there are about 10,000,000,000,000,000 (ten thousand trillion) molecules of CO2 in a cubic centimeter of air (the volume of a sugar cube). You seem to think this is a small number. Why?
“the “real world observations are actually higher than what you would predict from CO2 radiative physics alone.”
julio,
Could you explain how you arrived at “what you would predict”?
Because you don’t put a number or how you got it on “temperature increase”.
Andrew
julio,
Had I known you would answer Skepitkal, I would not have bothered. 🙂
julio
Well to be fair to Arfur who describes MODTRAN as a “model”, radiative transfer codes including MODTRAN appear to be commonly described as “models” everywhere, including by the people who coded them. There doesn’t seem to be a hard deviding line between a complicated calculation applied to the physical world and a “model”.
My understanding is that MODTRAN and other radiative transfer codes are fundamentally performing a large and tedious integral: – absolutely a job for a computer, but basically a trivial calculation with a reliable output. That’s in stark contrast to the GCMs that have made “model” a dirty word.
Well, MODTRAN [i]is[/i] a model. It performs the radiative transfer calculation on a set of grid points (spectral bands) given some assumptions about the stratification. Like all models (including GCMs), MODTRAN’s output is either “reliable” or “starkly dirty” depending on what you’re trying to do with the output.
julio:
Yep See, e.g., this from Inamdar & Ramanathan, 1998 which computes the GHG effect due to a column of air.
PDF
Bv(T) is Planck’s radiation law which can be found here.
Whether this helps somebody who doesn’t know math or not is the question. The tricky part is calculating the optical depth measured from top of atmosphere, but it should be a bit of a tip-off that they allow it to vary.
Re: Oliver (Mar 22 09:00),
But the calculated spectra from MODTRAN or LBLRTM can be compared immediately with measured spectra. You don’t have to wait decades.
Re: DeWitt Payne (Comment #93604)
I never claimed otherwise. 😉
(It is contingent of course on having a measurement at any given time and place that you’d care to make the comparison).
Owen (Comment #93566 and #93567)
Owen,
Thank you for pointing out exactly where the 2001 anomaly was. It might have saved my blood pressure if you had labelled your graph with the actual dataset you used, but I accept that that particular dataset fits the graph.
What it does not do, however, is link CO2 radiation to the OHC anomaly, which is what you implied in your original post. The OHC anomaly graph shows a rapid rise since 2001 (half as much again as the previous fifty years). There is no such rise in the global temperatures. How long is the lag you speak of? I understand that solar radiation is the primary mechanism for heating the surface but you are talking about the enhanced GE being responsible for the anomaly increase. Please explain the precise mechanism by which CO2 radiation can warm the ocean depths by such amounts. How far can radiation penetrate below the surface? How long does it take for the surface temperature (top 10m or so) to get to 2000m? How much heat capacity is in the atmosphere compared to the oceans? How much would a 0.8 C rise in atmospheric temperature (over 160 years) raise the ocean temperature? Do you really believe that a trace gas has the ability to do this?
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The point I’m making with those questions is that you can’t label OHC rise with a cAGW tag without looking at all the possibilities. If the anomaly readings from NOAA are so inconsistent, why do you think backradiation from the atmosphere is the cause? The backradiation isn’t inconsistent! Also, when you say that the smaller ocean (Indian) has the greatest anomaly, isn’t there a weighting for the ocean size built into the world anomaly figure? That would make more sense.
.
Now for the GHG lessons in your last post…
Point 1:
‘…while in its excited state CO2 immediately collides with O2 and N2 molecules in the air, transferring the absorbed energy to the air molecules…”
Yes, I understand that (see my posts to SteveF). What you are forgetting is that, in a well mixed atmosphere, each non-condensing GHG molecule is, at any one instant, effectively surrounded by appx 2500 inert molecules (N2 O2 and Argon). It cannot heat all of these molecules by low energy collisions. It can only heat a tiny percentage. So, yes, the blanket gets warmer but by a tiny (insignificant) amount. The addition of water vapour is a much more powerful tool, but it still relatively small. That is why, in 160 years, the addition of 40% CO2 has only led to an unknown portion of 0.8C
Point 2:
“…if more atmospheric CO2 better insulates against heat loss…”
That is a big ‘if’. The increase in insulation due to CO2 is tiny.
“Also, as heat flow into the 0-700 from the sun, and out of that layer by transfer to the zone below, the temperature of the 0-700 zone becomes static, while the 700-2000 zone increases.”
Er… so cAGW will not lead to warmer surface temperatures, but will lead to warmer abyssal temperatures?
.
Owen, the significant warming of the deep oceans by CO2 backradiation is too implausible to be taken seriously. If you think CO2 backradiation has the power to raise the OHC so significantly, why have the global temperatures stalled when the CO2 levels have continued to rise?
.
I am on the road for a couple of days, but will try to reply when I can.
SteveF (Comment #93564)
SteveF,
[“The influence of CO2 depends on lots of factors.”]
An evasive answer as I expected. The influence of CO2 depends on the main factor that there is not much of it!
.
You can’t separate CO2 effect from the other GHGs? Well, you’d better tell Kiehl, Trenberth, Lacis, Schmidt and scienceofdoom, because they seem to think you can…
.
A sensitivity figure? Tell you what, go for 1.2C including all feedbacks and you’ll be closer to the mark IMO. There is no evidence that ‘positive feedbacks’ have added anything to the theorised increase. Whatever natural variation or negative feedbacks exist are obviously more powerful than any radiative effect, otherwise the global temperature would be rising at an accelerative rate.
julio (Comment #93457 and #93578)
Julio,
[“julio (Comment #93457)
In other words, lacking any additional information, the global temperature increase is consistent with a climate sensitivity of about 1.6 C for a doubling of CO2:
0.8 = 1.6*log2(1.4)
To assert that the effect of CO2 is less (or more) than this, you need additional information. What do you know that we don’t?”]
And as I tried to point out to you, in that calculation you are assuming all the warming is due to CO2. You didn’t respond then; Why bring it up now?
[“Reality check: at sea level, there are about 10,000,000,000,000,000 (ten thousand trillion) molecules of CO2 in a cubic centimeter of air (the volume of a sugar cube). You seem to think this is a small number. Why?”]
.
Reality check: now calculate the total number of molecules of any sort in that cube. It doesn’t matter how big the CO2 molecule number is, it is still less than 0.04% of the whole.
matt (Comment #93586)
matt,
Thank you for being fair.:) To further the point, here is the description on MODTRAN.org:
.
“MODTRAN(R) is an atmospheric radiative transfer model…”
.
I take your point about the calculations but I suppose the devil is in the detail. A calculation is only as accurate as the data inputted. It does not reflect the continuously changing atmosphere with complete accuracy. The answer it gives is theoretical, not actual.
Oliver
The more I’ve thought about it, the more difficult it becomes to define what counts as a model. If I calculate the mass of water in my pool using length x width x depth x density, haven’t I just “modelled” the pool as a perfect cuboid and assumed the (lab measured) water density applies in the real world? How good a match the answer would be to the real world depends on the accuracy of my “model”, but nobody would condemn the process itself as fundamentally flawed, I hope.
MODTRAN is treating the atmosphere as a stack of layers and calculating energy transfer through them, based on the lab-determined radiative properties of gases (rock solid). The only possibly controversial inputa are the variations in pressure, temperature and composition with altitude through the atmosphere, which can be and have been determined by radiosonde balloons among other things. The calculated and measured spectra high in the atmosphere have been comparable since around 1970 and were within 10% of each other then, are even closer now. See http://scienceofdoom.com/2010/11/01/theory-and-experiment-atmospheric-radiation/ , first two figures.
Now, it is my understanding that the additional 3.71 W/sq m predicted from a doubling of CO2 is a “theoretical” figure that isn’t confirmed by direct measurement, but so is the mass of water in my pool!
Re: Arfur Bryant (Comment #93627)
I didn’t answer you back then because I asked what information you had and your only answer was “Nobody knows this! Nobody knows that! Nobody knows anything!”
That’s not information, that’s (in your case, willful) ignorance.
So is this bit here:
You are really hung up on this 0.04% figure, which has virtually nothing to do with what’s going on.
For a 15-micron photon, the nitrogen and oxygen molecules might as well not be there at all: all it “sees” is the CO2, and there is so much of it that the photon is almost certainly absorbed by a CO2 molecule before it can travel 10 m or so in the lower atmosphere.
Now, each of these molecules (10,000 trillion of them in a sugar cube, remember) collides with other air molecules at a rate of several billion times a second. Most of the collisions (obviously) will be with nitrogen and oxygen molecules, since those are the most abundant ones. So that is an extremely effective mechanism for CO2 to transfer the radiative energy it absorbs to the rest of the atmosphere, which then re-emits some of it as thermal radiation, about half of it downwards, towards the earth.
So again I ask you: why do you think that 10,000 trillion molecules per cubic centimeter, each colliding several billion times per second, are not enough to accomplish this? I’d like a technical answer, please.
(Of course, I already know your answer: “Nobody knows this! Nobody knows that! Nobody knows anything!” The truth is, this comment is not really meant for you, but for a hypothetical open-minded reader.)
julio (Comment #93641),
Humm…
My spidey sense says that you will soon be too frustrated to continue this very tortured dialog!
Arfur
Absolutely, but this applies to just about any calculation regarding the physical world, including my swimming pool example. The problem isn’t whether the result is an “output of a model” regurgitated or not, but how well that model reflects the real world. Note that you are allowed to simplify things in a model – you don’t have to paint a scale model town to see whether a truck can get around a particular corner, or even include anything that isn’t on the truck’s route.
I don’t think you could dismiss the result of my swimming pool calculation as “theoretical” and therefore a “guess” if my pool were rectangular and of constant depth. Kidney-shaped with a shallow end, and you’d have a point! When calculating the change in energy flux through the atmosphere when you add CO2 and keep everything else the same, MODTRAN and similar are like the rectangular constant-depth pool calculation – very solid. And keeping everything else the same, we get the 1.2 deg/doubling sensitivity. That isn’t faith or groupthink; it’s the baseline result before we start letting the devilish detail in to modify it.
Of course, in the real world, everything else isn’t going to stay the same. If it gets warmer, evaporation will increase, convection will increase, ice sheets will retreat, relative humidity might change either way (we don’t really know), humidity distribution could change, cloud distribution and albedo could change… that’s what’s the General Circulation Models are trying to account for, and quite frankly they do a poor job. There are also a few elephants in the climate ballroom – the present sulphate forcing is poorly quantified and the historical sulphate forcing really is little better than a guess. There may be a 50-70 year period pseudocycle in the temperature record – we have insufficient data to know for sure, and no mechanism to explain it if it IS real. We don’t really know what caused the 1930’s rise, we don’t know how much heat goes into the deep ocean. So yes, there’s a fair bit of wriggle room on the true sensitivity and whether the effects of added CO2 are cancelled or magnified by other factors, but if you dispute the 1.2 deg. C baseline figure, then we can’t really have any dialogue about the rest.
matt (Comment #93639),
You are absolutely right, most any scientific or engineering calculation we do is a “model” (and as DeWitt notes, even our direct temperature measurements are just ‘models’ of temperature). But there are models and then there are MODELS. The assigned credibility needs to be based on how reliable the various inputs/assumptions/guesstimates that go into the model are. In the case of GCM’s: woa!… lots of guesses, fudges, and estimates to be worried about, and no clear way to verify performance of projections with actual (real, honest, red-blooded) data. In the case of Modtran, you can check it with real data, right away. Does anybody really think Modtran and GCM’s are remotely similar in uncertainty? I don’t think so, despite all the arm waves about both being ‘models’.
matt (Comment #93643),
Correct, and more to the point, a perfectly clear explanation.
Re: SteveF (Comment #93581)
Oops, sorry… it looks like we may have been typing our answers almost simultaneously! But this way he gets more information, so that’s not bad.
I’m on the road these days, with only a few minutes of Internet a day. We have been visiting colleges: Yale on Tuesday, Harvard today… fun, but tiring. Enjoyed walking around Boston this morning, too.
matt (Comment #93639) 

Sure, that is a model. For example, even assuming the shape is correct, the lab measured water density doesn’t apply here unless you know the temperature and the dissolved (whatever) content everywhere in the pool!
As I said before, the fact of “modeling” isn’t a problem. It depends on what you plan to do with the output.
Those are pretty controversial inputs. Perhaps you overestimate the coverage provided by radiosondes.
You might find interesting this paper comparing radiative parameterizations in AOGCMS to line-by-line codes: http://www.atmos.washington.edu/~qfu/Publications/jgr.collins.2006.pdf
julio (Comment #93646),
I rather suspect that to Skeptikal imagines the evil cabal of julio and SteveF were conspiring by telephone (or maybe sixth sense) to write many of the same things in reply to his questions. See, that proves it, anyone who works in physical science is part of a grand conspiracy.
.
I haven’t been in Boston since last summer, when I called on a customer in Cambridge. Well, at least you had nice (if unseasonably warm) weather in Boston… wait… it must be global warming!
Oliver (Comment #93647),
Just to be clear: Are you really suggesting that the level of uncertainty in Modtran (and similar) calculations for a doubling of CO2 is comparable to the uncertainty in GCM projections of climate sensitivity? (Not a rhetorical question.)
SteveF (Comment #93649)
I’d like to know the answer to that, too. What’s controversial about “the variations in pressure, temperature and composition with altitude through the atmosphere”??
Maybe he was being facetious. In any case, if you look at. e.g., fig. 10 of the paper he linked to. you can see that the MODTRAN-like line-by-line (LBL) calculations are all right on top of each other, whereas the GCMs are all over the place…
Re: SteveF (Comment #93649)
I’m looking back to try and figure out where I suggested something like that, but I’m not really sure…
My point is that MODTRAN would have to be considered a “model,” and in fact not a “first principles physics” flavor of model but more of a “parameterization.” Therefore, the distinction you’re making between GCMs and MODTRAN is in some sense artificial.
Going back to matt’s swimming pool “model”: there’s obviously nothing “wrong” with calculating the volume of an idealized prism-shaped pool with certain length, width, and depths at various places. You could even go ahead and assume some simple density profile. That would be enough of a model to give you a number for the mass of water in the swimming pool. But as matt himself points out, does it apply to his real-world swimming pool? My answer would be that it’s completely dependent on what he intends to do with this number.
Re: julio (Comment #93675)
Well for one thing getting the real-world variations is a challenge. Where would we get these inputs of local profile of pressure, temperature, and composition? From a GCM?
Unless I’m mistaken, MODTRAN (the MODerate resolution atmospheric TRANsmission model) is expressly not an LBL code.
Oliver:
Depends on how accurately you need them (and over what time period). There are two empirically based products that provide exactly this…
ECMWF (commercial package like MODTRAN but with an annual license for non-European governments and their contractors) and G2S (not commercial but maybe not available to anybody but US government employees and their contractors, which would include most US climate scientists).
These packages work similarly to the surface temperature reconstruction software, they combine the various empirical software with empirical models. They have been tested, and for e.g. 6-hr averaged profiles are pretty decent.
Oliver,
“Therefore, the distinction you’re making between GCMs and MODTRAN is in some sense artificial.”
Maybe in some sense, but there are huge differences in complexity and in how easy it is to constrain and verify the results. I mean, do you think there are huge differences between the calculated values for a doubling between Modtran and the the two models that Carrick points to above? I kind of doubt that. The paper you referenced above sates:
and then shows in figures 11 and 12 that the several line-by-line calculations for WMGHG’s are virtually on top of each other. So I ask again, are you suggesting that the canonical value of ~1.2C per doubling, absent feed backs, has substantial uncertainty? And if so, why do you think that?
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There are very solid models, like PV = NRT, and there are doubtful models, filled with uncertain parameters and kludges. I don’t see the point of dwelling on whether we call PV = NRT a “model” or a “calculation”, or trying to draw some kind of equivalency between relatively simple and well verified models and models which are extremely complex and not well verified. What started all this discussion was the assertion (by several different people) that ~1.2C per doubling is a fair representation of the “null hypothesis” of no feedbacks. I still can’t tell from your comments if you agree with this assertion or not.
julio (Comment #93641)
[“I didn’t answer you back then because I asked what information you had and your only answer was “Nobody knows this! Nobody knows that! Nobody knows anything!â€]
That is a misrepresentation of my comment. I gave you two ‘bits of information’:
1. That you assumed ALL of the 0.8C warming was due to CO2, and
2. That the 0.8C warming included ALL forcings and feedbacks.
The only time I used “Nobody knows” was in reference to the question “How much of the 0.8C warming is due to CO2?”
.
I note you did not address any of these points. I certainly never said “Nobody knows anything!”, so why would you say stuff like that and yet not have the decency to answer my questions?
.
Now to 0.04%. You say it “has virtually nothing to do with what’s going on…”. I disagree. It has everything to do with what is going on! You keep talking about how many collisions there are with CO2 and yet you ignore the fact that there are thousands more collisions for every billionth of a second which do not involve CO2. You say it is an “extremely effective mechanism for CO2 to transfer the radiative energy it absorbs to the rest of the atmosphere…” and yet you cannot offer any real-world evidence to support that statement! If the radiation from CO2 was that effective in heating the atmosphere, why has there been an overall cooling of the atmosphere since 1998? If the transfer of heat to the rest of the atmosphere is mostly through conduction, why go on about the radiative effect of the non-condensing GHGs? By your argument, water vapour is many times over a greater GHG even though it does not re-emit radiation. It absorbs, and therefore conducts. However many trillions of ‘inert’ molecules get heated by an excited CO2, there are several thousand more inert molecules being heated by excited water vapour molecules. Water vapour doesn’t need the presence of non-condensing GHG molecules to heat neighbouring molecules (although they help in a small way); it can absorb LW radiation directly from the planet.
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Until you – and any other warmist or lukewarmist on this or any other blog – can come up with a sensible answer to the question ‘How much does CO2 contribute to the GE?’, all you can do is hypothesize with estimates based on the theory.
.
In direct answer to your last question (please note an actual answer to an actual question) why do you think that 10,000 trillion molecules per cubic centimeter, each colliding several billion times per second, are not enough to accomplish this? the answer is because there is no evidence for it!
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In the 160 years that ‘accurate records’ have existed, there have been several warming periods and several cooling periods. Overall, the warming has been 0.8C. Unless you assert that warming can only occur due to CO2 and cooling can only occur due to ‘natural variations’ then you must concede that warming can be caused by natural factors. You don’t know how much of the overall warming is due to natural factors but you argue as if it was all due to CO2. If so, the current cooling trend must be caused by natural factors that are so powerful they override any ‘radiative warming’ and lag and feedbacks. If so, how do you know the warming wasn’t due to these powerful natural factors in the first place? I’m not suggesting it was all natural factors, but I am questioning the ‘effectiveness’ of the radiative theory in reference to the atmosphere as a whole.
.
If you were to say that the climate sensitivity is 1.2C including feedbacks then I would have no problem agreeing with you. In which case, due to the log effect, the next doubling will lead to even less warming. What is the problem with that?
.
You and others are arguing from theory. I am arguing from observed data. I see no reason to accept the theory without some form of real, empirical evidence to support it.
matt (Comment #93643)
matt, I do not have any time right now.
…but if you dispute the 1.2 deg. C baseline figure, then we can’t really have any dialogue about the rest.”]
Could you just clarify please exactly how the 1.2C figure is calculated with reference to the radiation graph you linked?
I may not be able to respond for 24 hours or more…
Regards
Re: SteveF (Comment #93684)


Not “huge” but “some” differences. Perhaps more quantitative language would be helpful here.
I have no problem with the “canonical value.” I do have a bit of a problem with trying to demonstrate the “correctness” of the canonical value by arguing that the simple model works perfectly in an simple world. Since the earth doesn’t respond in an idealized, zero-feedback way, how are you going to “verify” the ideal response for e.g., Arfur and Skeptikal, based on “real” observations, without referring to higher-complexity models?
Well, I’ve already answered above, but I am curious why it matters at all what I agree with?
Re: Carrick (Comment #93681)
…and both are fine by me. However, if one insists on the “strong” position that there is a clear distinction between (simple, physically verified) models like MODTRAN and (complex, “less verified”) GCMs, then maybe a model reanalysis is not “verified enough” to provide the input for MODTRAN.
SteveF:
Yes definitely.
GCMs don’t actually generate much you can directly test against with measurement. Partly this is because of the coarse detail of the GCMs and partly due to the uncertainty in the forcings over time.
James Annan was telling me at some point, that “regional skill” is tested by looking at EOFs rather than e.g., US contiguous states. With EOFs you can restrict yourself to patterns with spatial scales that are resolvable by the models. But that’s pretty removed from the direct numerical measurements, or anything that we generally think of as climate.
(For non-attentive sorts, the “C” in GCM stands for “climate” so it stands to reason GCMs need to reproduce “climate” patterns, not EOF patterns derived form climates. Otherwise, why not call them GCEOFMs?)
Carrick,
I’ve always been taught that GCM stands for “General Circulation Model,” with the “Climate” usage appearing later.
For anyone who thinks that 400 ppm of CO2 couldn’t possibly make a difference, a good dye is detectable by eye at a concentration less than 100 ppb in water. See for example:
http://www.brightdyes.com/technical/StdBlue.html
Absorptivity is a function of the concentration, the path length and the absorption strength of the absorber (line strength). CO2 absorbs very strongly at 15μm and the path length can be on the order of kilometers.
Re: Oliver (Mar 23 14:01),
I think Oliver is correct. The C stands for circulation.
GCM’s have no regional skill. The downscaling experiments are a complete waste of time and money. In the real world, the climate is as much or more a bottom up sum over all local climates than a strictly top down model.
Re: Oliver (Comment #93679)
Yes, yes, I said MODTRAN-like, as in, input some static atmospheric profile (for the various GHGs) and integrate the Schwarzschild equations to the top of the atmosphere. No “circulation”, and no attempt to let the model itself calculate the concentrations (of, e.g, H2O).
Of course those input profiles cannot represent the real-world situation exactly, since that is changing constantly in space and time. They can only be an average of some sort. So, yes, there will always be some uncertainty even in the most “rock solid” part of the theory. If you play around with MODTRAN you can see what forcings you get for a CO2 doubling for different settings (tropical atmosphere, standard US atmosphere, etc.) and based on those results I would not be surprised if the “canonical” 1.2 C, no-feedback result were actually as low as 1 C. (I can easily get it that low or lower; I’ve never been able to get it higher than 1.2)
But we are talking about an uncertainty of at most 20%; the GCMs’ estimates of the climate sensitivity are uncertain by factors of 2!
Julio – uncertainty in the no-feedbacks (Planck response) number is very low, at most about 1% – see Table 1 and Table 2 of Soden and Held (2006) – more notes on that and a link here:
http://altenergyaction.org/Monckton.html#E72
– however, that’s the response part, the forcing part is definitely uncertain at the level of about 10%.
Oliver #93698
“Since the earth doesn’t respond in an idealized, zero-feedback way, how are you going to “verify†the ideal response for e.g., Arfur and Skeptikal, based on “real†observations, without referring to higher-complexity models?”
You verify that the model logic is simple and robust, the radiaitve properties of the species involved are well known, and that the atmospheric profile is (closely) consistent with measured data. And that is why most people accept the results as a credible null hypothesis. There is no appeal to a more complex model… that is the point.
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“Well, I’ve already answered above, but I am curious why it matters at all what I agree with?”
It matters because you seem to be suggesting some kind of equivalency between simple models that are grounded in basic radiative theory and measured values and GCM with are filled with a lot of doubtful cloud parameterizations, aerosol offsets, and suffer (most of them at least) from rather gross errors in ocean heat uptake. It is the false equivalency that you seem to be trying to draw that I object to.
Arthur Smith (Comment #93704),
+/- 10% uncertainty in CGCM’s would be like ‘died and gone to heaven’ compared to the current situation. Heck, +/-10% uncertainty in CGCM’s would yield forecasts that could be tested against data in less than a human lifetime.
Oliver:
As I understand it, both versions of the acronym are acceptable, though your version is more standard. For example “edGCM” stans the educational global climate model.
But thanks… I was cracking wise and you just had to ruin it! >.<
“James Annan was telling me at some point, that “regional skill†is tested by looking at EOFs rather than e.g., US contiguous states. With EOFs you can restrict yourself to patterns with spatial scales that are resolvable by the models. But that’s pretty removed from the direct numerical measurements, or anything that we generally think of as climate.”
Is not the interpretation of those EOFs often an exercise in subjectivity. Ryan O’Donnell did an exercise awhile back at CA where he generated EOFs for global temperatures using synthetic data to show how one could image teleconnections that truth said did not exist. I believe it was called PCA, Sampling Error, and Teleconnections and posted in December of 2010.
I’m sure he did. So what.
How well EOFs work depends on how noisy the data is. If you make the noise big enough, it quits working.
People generally look at the trend in the eigenvalues and make the cut where they start to approach an asymptote (the “knee point”). If the noise is bad enough, you don’t see a knee point, and should probably punt this approach.
And yeah I’m familiar with Ryan, Steve’s and Nick’s various postings on this. I think Nick was in his familiar “defend the team” mode so I didn’t feel it worth getting into too much of a fuss over whether Steig’s original EOF analysis was meaningful.
This one’s over your head bugs. No offense intended. (You might as well argue over the interpretation of the Fundamental Theorem of Calculus with only a remedial math education.)
This one is for you, Carrick, no offense.
http://rabett.blogspot.com.au/2012/03/climate-of-physics.html
The regional analysis is difficult with climate models, since they don’t have a high resolution. That’s the state of the art. People always want to know how climate change will affect them specifically, which is hard to do. The predictions for Australia seem to be surprisingly accurate, at large regional levels.
Bugs, if you think you have the math down, critique Ryan O.
Otherwise skip the snarky comments about things you know not.
Re: SteveF (Comment #93708)
I was thinking more along the lines of verifying the output of the model against the observations in some convincing way…
I’m not trying to draw any “false” equivalency. I’m just calling it as I see it, and as I see it, the two flavors of model differ in degree, not kind. Both are models with significant simplifications in the interest of practical use. MODTRAN is not a line-by-line code but we (yes, the royal “we”) love it because we can try some more useful things (e.g., somewhat realistic conditions) precisely because the physics are simplified. A GCM is coarse and has lots of parameterizations but we use it because it’s (arguably) useful to run it now instead of waiting until we have computers big enough to run everything with better resolution. To use the results from each model effectively, you need to keep in mind what each model does and doesn’t do well.
Re: Carrick (Comment #93715)
“But thanks… I was cracking wise and you just had to ruin it! >.<"
O.o
With regard to the topic discussed earlier on this thread, the German intent to go strongly in the direction of renewable energy, it appears that they plan to use fluctuating green energy surpluses to generate methane from CO2 for long term storage and carbon-neutral base load. Quoting from http://www.fraunhofer.de/en/press/research-news/2010/04/green-electricity-storage-gas.html :
————————————————–
“Throughout the world, electricity generation is based more and more on wind and solar energy. So far, the missing link for integrating renewable energy into the electricity supply is a smart power storage concept. Because when the wind is blowing powerfully, wind turbines generate more electricity than the power grid can absorb. Now, German researchers have succeeded in storing renewable electricity as natural gas. They convert the electricity into synthetic natural gas with the aid of a new process. The process was developed by the Center for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW), in cooperation with the Fraunhofer Institute for Wind Energy and Energy System Technology IWES. Currently, Solar Fuel Technology, the Austria-based partner company, is setting up the industrial implementation of the process. One advantage of the technology:it can use the existing natural gas infrastructure. A demonstrationsystem built on behalf of Solar Fuel in Stuttgart is already operating successfully. By 2012, a substantially larger system – in the double-digit megawatt range – is planned to be launched.
For the first time, the process of natural gas production combines the technology for hydrogen-electrolysis with methanisation. “Our demonstration system in Stuttgart splits water using surplus renewable energy using electrolysis. The result is hydrogen and oxygen,” explains Dr. Michael Specht of ZSW. “A chemical reaction of hydrogen with carbon dioxide generates methane – and that is nothing other than natural gas, produced synthetically.”
DeWitt Payne (Comment #93701), March 23rd, 2012 at 2:10 pm
“For anyone who thinks that 400 ppm of CO2 couldn’t possibly make a difference, a good dye is detectable by eye at a concentration less than 100 ppb in water.”
What little I know about climate science owes much to you. I especially appreciated that link to Rodrigo Caballero at University College, Dublin.
Nevertheless I respectfully disagree with what you are saying. My research field is quantum electro optics (lasers). I have built and operated lasers producing radiation from 10.6 microns to 11 MeV (gamma rays) so I have a reasonable understanding of absorption spectra.
I understand that carbon dioxide is a wonderful absorber of IR radiation in a range centered on 15 microns. (It is also a pretty effective emitter of 10.6 micron radiation).
Thanks to carbon dioxide, ozone and traces of other complex molecules, energy transfer in the upper atmosphere is dominated by radiation transfer. That is why the temperature gradient at high altitudes has the opposite sign compared to the troposphere where other energy transfer processes are dominant.
In the troposphere, convection, Coriolis eddies and latent heat associated with water phase changes dominate. Radiative transfer makes such a minor contribution that it can be ignored. Thanks to the effective mechanisms that transfer energy in the troposphere you can calculate the temperature gradient in the lower atmosphere as g/C(p) without bothering to make a correction for radiation transfer or gas composition.
So how does this simple physics theory measure up against observations? Pretty well:
http://diggingintheclay.wordpress.com/2012/03/13/unified-theory-of-climate/
Owen, your link is from may 2010. I don’t recall hearing any news about this project. Strange I think if this “smart” technology has solved the problem of storing power.
Niels,
Right. They say this year they had planned to “launch” something beyond a test facility. I don’t know what the efficiency is of electrolytic decomposition of water to produce hydrogen, but H2 storage has been used in conjunction with photovoltaic panels for on-site storage at the level of individual homes. The large scale chemical reduction process of CO2 to CH4 seems to be the German contribution. We’ll see. Here is a second more recent report, but still no major plants being built: http://www.brighthub.com/environment/renewable-energy/articles/78303.aspx
Owen,
Let me inject a little reality here. The energy content of the methane that would be generated would be only about 76% of the energy content of the hydrogen. The process that generates that methane takes place at high temperature using a nickel catylist. If you had a very good process and a way to store the resulting methane, you would be looking at an overall thermal efficiency of maybe 60%. If you add the efficiency factor for electrolysis (and you use the very best possible efficiency) you might reach an overall efficiency of 50%.
Then you have to start thinking about capital cost for all that equipment, recognizing that it will only be used when there is too much wind for the power grid to accept, and maintenance cost for a lot of very complicated equipment.
Finally, you must remember that the process produces natural gas whic is very costly and difficult to store, and that even the most efficient use of that natural gas is unlikely to be more than 50% efficient, no matter the application.
The capital costs alone make it a non-starter. And that is what the whole idea is. Not going to happen beyond some subsidized demonstration plant. Humm…. Windmills making electricity that costs three times as much, being converted to natural gas that costs 20times as much as the gas running in pipelines. Nope, it’s nutty.
DeWitt Payne (Comment #93701), March 23rd, 2012 at 2:10 pm
“For anyone who thinks that 400 ppm of CO2 couldn’t possibly make a difference, a good dye is detectable by eye at a concentration less than 100 ppb in water.”
I thank you and Leonard Weinstein for what little I know about climate. Especially that link you gave me to Rodrigo Caballero at University College, Dublin:
http://maths.ucd.ie/met/msc/PhysMet/PhysMetLectNotes.pdf
Even so I must disagree with you on this important issue. My research field is quantum electro optics and I have built or worked with laser based sources from 10.6 microns to 11 MeV (gamma rays). Given my background I understand absorption spectra and the transfer of energy via radiation.
Radiation is the dominant energy transfer process in the upper atmosphere thanks to carbon dioxide, ozone and traces of other complex molecules. As a result, temperature usually increases with height above the tropopause.
In the troposphere energy transfer is dominated by convection, Coriolis eddies and latent heat (phase changes involving water). Temperature falls with height according to the simple formula L = g/C(p) which is easily derived using gas equations and thermodynamics. No need to make even a small correction for gas composition or radiative transfer processes.
Lately I have been comparing observations with a pressure based model that ignores chemical composition and RTEs. My apologies for not mentioning you:
http://diggingintheclay.wordpress.com/2012/03/13/unified-theory-of-climate/
http://noconsensus.wordpress.com/2010/03/30/pca-sampling-error-and-teleconnections/#comments
Ryan did a lot of work for this post and did a great job of explaining exactly what he did. His comment here sums up well his point in the thread. He also notes how for the O(10) paper the authors attempted to put the selection (limit) of eigenvectors on a more objective basis and not use a single eigenvector to denote a climate pattern as in Steig (09).
“PCA is NOT the problem. The problem comes in when people begin assigning physical meaning to the eigenvectors. The distribution of points within an individual eigenvector are determined by the mathematical constraints used for the decomposition. Unless the physical processes are known ahead of time, it is likely that the resulting eigenvectors will not INDIVIDUALLY reflect physical processes…
..However, just as it is irresponsible to claim something that the data does not support, it is likewise irresponsible to throw out a legitimate tool because some people happened to use it improperly.”
Perhaps, bugs would care to read and critique it.
Re: gallopingcamel (Comment #93737)
Radiation is fundamental in setting up the temperature of the surface, which then drives all those other processes (convection, evaporation, etc) that you talk about. Therefore, the radiation-trapping effect of the atmosphere, which is what we are talking about here, is also critical.
It is true that in steady state, the radiation-trapping mechanism does not change the temperature of an atmospheric layer. The Schwarzschild equations are, in fact, energy-balance equations, much like the rate equations you could write for your laser. But just because nothing changes, in steady state, on a sufficiently coarse-grained scale, does not mean that a lot of things aren’t happening all the time on a microscopic scale (as you must know quite well), including all the photon emissions and absorptions and collisional energy redistribution that I talked about in an earlier post. And, ultimately, these equations determine the rate of energy loss out to space, which, combined with the known input flow, determine the surface temperature that you need to use as input for your lapse rate calculations.
“Nope, it’s nutty.” Thanks, Steve F. I thought so.
brief addendum to julio (Comment #93741):
Of course, it goes both ways: the temperature profile you get from convection, evaporation, etc… calculations, for a given surface temperature, needs to be fed into the radiative transfer equations to find the radiative energy balance that, in turn, determines the surface temperature. So, ideally, you need to find a self-consistent solution, to which all heat-transfer mechanisms contribute.
(In practice you take shortcuts: if you are interested only in the radiation-trapping part of the problem, for instance, you may just assume a “standard atmosphere” lapse rate, whichever way that came about.)
Owen, SteveF and Niels,
Anyone know if their efficiencies include the energy necessary to capture the CO2?
Good grief.
Just runs at 400 ppm CO2 I guess.
Carrick,
“People generally look at the trend in the eigenvalues and make the cut where they start to approach an asymptote (the “knee pointâ€). If the noise is bad enough, you don’t see a knee point, and should probably punt this approach.”
.
Which was the first thing I thought about when I saw the Steig et al cut point. It seemed to me they were cutting well before the number of eigenvalues which were conveying useful information. In fairness to Steig et al, there was no clear knee in the plot of eigenvalues (more a gradual curve), but you would think they would have compared the resulting temperature estimates for different numbers of eigenvalues with the known warming rate for the peninsula, and recognized that something was terribly wrong. It was a clear case of looking only for the ‘desired’ result of warming everywhere in Antarctica, and not considering any other possibilities. What is appalling is that Steig et al ever got past review and onto the cover of Nature; reviewers ought be more than cheer-leaders for ‘the cause’ of CO2 emissions reduction.
John M (Comment #93744) ,
For sure not. It really is not a process worthy of serious consideration.
Arfur
I’ll give it a go. First understand that the graphs show a comparison between calculated and measured upwelling IR radiation at a particular location (gulf of Mexico) and date. (Further details aren’t given, probably because the original source is a 1970s paper and we’re seeing them third hand.) What we can see is that the agreement appears to be rather good – the calculation is only around 10% off the measurement, even back in 1970. (Note the displacement of the two curves is deliberate, for visibility, and not the difference between the results.)
A more modern comparison between the line-by-line calcs and direct measurement is given in this paper: http://smsc.cnes.fr/documentation/IASI/Publications/CalbetAMT2011.pdf The experimental detail is quite interesting: the measurement is performed by satellite and a number of radiosonde balloons are launched before the satellite passes overhead to capture the composition-pressure-temperature-humidity profiles of the atmosphere column being measured. Those profiles are then used as inputs for the calculation. The results are shown as residuals in figures 6 and 7 – the observations with the calculations subtracted. The residuals are within +/- 0.5 milliwatts per sq. m. That’s a very good agreement.
Now, back to the original graphs. They show intensity vs wavelength so by integrating under the curves we can determine the energy flux. What we want to know is, how much effect does CO2 on its own have? So we run the calculation twice to the top of the atmosphere, using current levels of CO2 as one input and double that as a second input, and see how much the upwelling IR is reduced. It turns out to be 3.6 W/ sq m. Then you see how much warmer the Earth has to be on average to radiate away an additional 3.6W/ sq m, using the same calculation but with higher ground-level temperatures, and it turns out to be 1.2 K or a bit less, depending on tweaks and variations, see julio’s comment 93703.
Obviously, during the calc/measurement comparison experiments, they had the luxury of simultaneous sonde data for the column of atmosphere being measured to input into the calcuation. To run the calc for the planet as a whole, a lot of averaging and infilling has to take place and so there’s a fair bit of uncertainty in the 1.2K result, but it’s good enough to show that all other things being equal, CO2 should have a warming effect.
matt,
Thank you for your detailed answer. The link was interesting too.
If you read some of my earlier posts, you’ll note that I don’t have much argument with the idea of a climate sensitivity being 1 to 1.2K but that is inclusive of feedbacks. The reason I say that is because there is no evidence of feedbacks in the observed data. I would therefore have no argument with julio‘s canonical value of 1K. It appears that your linked paper still makes use of models to obtain the estimated answer. I have no problem with the graph. The problem is with the conversion of radiation to temperature. As you quite rightly say:
[“What we want to know is, how much effect does CO2 on its own have?”]
.
This is precisely the question that I have been asking SteveF and julio. To me, it is the single most important question in the entire cAGW debate. I asked them “What is the contribution of CO2 to the GE?” The answer has to be expressed either as a percentage of GE or in units of deg C (or units of K if you prefer). Unless we know the accurate answer to this question, we cannot establish how much of the observed warming can be attributed to CO2.
.
There is also a possible issue with your statement:
[“So we run the calculation twice to the top of the atmosphere, using current levels of CO2 as one input and double that as a second input, and see how much the upwelling IR is reduced.”]
When I refer to the term ‘climate sensitivity’ I use the IPCC definition of the doubling from pre-industrial levels of CO2, namely from 280 ppm to 560 ppm. http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch9s9-6.html
You appear to be talking about the doubling of levels from now. Would this lead to a different answer? I’m not sure. Either way, it is secondary to the question of feedbacks. If, as I assert, the CS includes all forcings and feedbacks, then an increase of 1 to 1.2K for a doubling of 280 to 560 ppm may well be likely but we can’t currently identify how accurately the theoretical CS is because we can’t answer the question regarding knowing CO2’s contribution.
.
Also, the modtran graphs that I have seen equate CO2 concentration with absolute global temperature. This obviously includes all forcings and feedbacks, so why invent feedbacks (as a means of increasing the ECS) in the first place?
.
Due to the theoretical nature of the estimation of 1.2K (or 1, if you use julio’s canonical value), I remain sceptical that the observed warming can be used to specify an attributable warming from CO2 (plus the other non-condensing GHGs).
Re: Arfur Bryant (Comment #93750)
“What is the contribution of CO2 to the GE?†The answer has to be expressed either as a percentage of GE or in units of deg C (or units of K if you prefer).
This question can be answered in at least a couple of ways.
(1) if CO2 was the only greenhouse gas on Earth, at its present concentration, the Earth’s temperature would be about 266 K, or 11 K warmer than it would be with no greenhouse gases at all.
(2) on the other hand, if you removed all CO2 from the current atmosphere but left in all the other greenhouse gases (especially water vapor) at their current concentrations, the temperature would go down by about 8 K.
The difference between (1) and (2) is because the absorption bands of CO2 and water vapor overlap substantially, so in case (2) the water vapor would fill in partly for the missing CO2.
Also, because the effect of increasing CO2, at reasonably high concentrations, is logarithmic, rather than linear (because of saturation), you cannot conclude that doubling the present concentration of CO2 would give you another 8 degrees of warming! So this information, by itself, is not immediately useful.
(With luck, the figures above may be accurate to within +/- 10 %. They were obtained playing with MODTRAN, a program that belongs to the family of radiative transfer codes that, as matt showed us above, have been shown experimentally to be quite good at predicting the outward radiation flux when fed accurate atmospheric profiles.)
Oliver 93727,
“A GCM is coarse and has lots of parameterizations but we use it because it’s (arguably) useful to run it now instead of waiting until we have computers big enough to run everything with better resolution.”
A tough argument to make, I would say. Not sure about the bigger computers thing. Bigger computers have not helped much so far. How small must the grid scale be to start accurately emulating clouds? 100 times smaller? 1000 times smaller? A computer a million times more powerful than today’s best would seem out of reach for the foreseeable future. I am not going to hold my breath. Besides no amount of computing power makes up for a lack of data on aerosols, or significant errors in ocean heat uptake.
Re: SteveF (Comment #93754)
Of course bigger computers have helped. Improved resolution has massively improved what you get out of numerical simulations. They do not solve fundamental problems in the model physics, which is why you continue to do process studies and try to improve what goes into the models. This goes right back to our discussion about models and their usefulness hinging on understanding what they do well and don’t do well. What do you propose instead, stop developing GCMs until we can simulate all important processes from first principles?
That’s why some of us actually work trying to measure this stuff and improve what goes into the models.
If carbon dioxide is a significant factor influencing global average temperatures the IPCC GCMs should have some success in backcasting.
On a good day, downhill and with the wind behind them, the IPCC can backcast any 30 year period since 1850 as long as you allow them to choose the start date (e.g. 1976).
Over longer periods, the IPCC can backcast the period from 1000 to 1850 A.D. as long as you let them deny the LIA and MWP.
When it comes to the 750,000 years covered by the Vostok and EPICA records the GCMs fail in embarrassing fashion as they can’t explain why atmospheric CO2 concentrations lag temperature by ~800 years.
Looking forward. the IPCC made a prediction in 2007 (AR4) that the temperature will rise by 2 to 7 degrees Centigrade by 2100 depending on the amount of CO2 added to the atmosphere. After only 5 years their “A2” scenario has a variance of about about six standard deviations from the observed value and this gap is likely to be even wider by the time the AR5 is published in September 2013.
How big does the IPCC prediction error have to get before the IPCC faithful admit their theory is false?
Oliver (Comment #93755),
“What do you propose instead, stop developing GCMs until we can simulate all important processes from first principles?”
Not at all. I suggest only that people stop acting as if there is reason to believe the GCM’s can make accurate predictions… Out hundreds of years. It actually boils down to your suggestion of differentiating between what a model can and can’t do well. IMO, basing public policy on the output of GCM’s is a perfect example of improper use.
gallopingcamel (Comment #93756)
March 24th, 2012 at 11:04 pm
“When it comes to the 750,000 years covered by the Vostok and EPICA records the GCMs fail in embarrassing fashion as they can’t explain why atmospheric CO2 concentrations lag temperature by ~800 years.”
—————————————————
Two questions: First, do the GCMs hindcast as far back as 750000 years as you suggest? Second, GCMs aside, are you sure there are no reasonable explanations of why CO2 might lag temperature change over the longer periods when the main forcings are related to orbital, precessional cycle?. My understanding is that the orbital forcings have initiated the longer term temperature changes, which changes in turn cause either release of CO2 (in a warming phase) or uptake in a cooling phase, and the CO2 concentrations then amplify the warming or cooling effects.
The big difference in 2012, is that CO2 has become the major forcing due to an massive release of oxidized carbon on a very short time scale – carbon that had been reduced and sequestered over a period of hundreds of millions of years may now be largely oxidized back into the atmosphere in a matter of several hundred years.
Arfur
My mistake. I think you’d get a slightly lower baseline sensitivity using doubling of concentration from now, because the effect of CO2 is logarithmic.
Agreed. The true CS should incorporate all forcings and feedbacks, and we don’t know what its value is. Most regulars at this site think that the IPCC range is on the high side, as is the IPPC’s confidence expressed in that range.
Here you have to be careful. MODTRAN graphs showing global temperature vs CO2 are based on the calculation I have described: stick in a figure for CO2 and keep everything else the same; this gives decrease in upwelling infrared energy at top of atmosphere; new higher surface temperature is that required to compensate for the decrease. They do not include all forcings and feedbacks; that’s what the General Circulation Models try to do.
For example, you could use MODTRAN to work out the temperature rise for a doubling of CO2, AND assume that the relative humidity everywhere on the globe stays constant. Since it gets warmer everywhere on average from the CO2 doubling, constant relative humidity means the specific humidity (grams of water vapour per cubic metre or whatever) goes up. Since water vapour is also a greenhouse gas, you then input this change into MODTRAN as well. Now you’ve incorporated a “positive feedback” from water vapour into your calculation! Question is, is it REAL, does it actually happen? Last papers I read on the subject seemed to say that the average global specific humidity has been observed to be rising in response to the temperature rise, but not enough to maintain constant relative humidity. I.e. there should be a water vapour positive feedback, but it’s not as large as was originally assumed.
.
Arfur
I think you’re right to be skeptical, we can’t really say how much of the observed warming is due to CO2. That’s not the same as saying that CO2 doesn’t cause warming, of course. Just that the expected amount isn’t that large and Nature can and does provide some fairly big temperature swings of her own. Teasing them apart is keeping a lot of people busy.
Owen,
Nicola Scafetta recently published a paper with a millennial scale backcast that fits paleo climate reconstructions very well. The critics had some objections:
1. It is just curve fitting.
Camel says: If curve fitting is so easy why can’t the IPCC do it?
2. Backcasting 5,000 years is not enough, you need to look back 1 million years or more. See this comment from Robert G. Brown (a professor of physics):
http://wattsupwiththat.com/2012/03/21/scafettas-new-paper-attempts-to-link-climate-cycles-to-planetary-motion/#comment-930682
Camel says: True but one must walk before trying to run.
3. Correlation does not imply causation. What is the underlying physical process?
Camel says: True again but Scafetta’s correlation is so striking that I for one am looking for physical processes. The fact that the Maunder minimum corresponds with the coldest period of the Holocene should be a clue.
You mention longer term orbital cycles that we call Milankovitch cycles. While most people believe these cycles were somehow responsible for the glacial/interglacial oscillation over the last 1,000,000 years I am not aware of any convincing predictions of the onset of the next glacial period. Can you point me to anything?
Intuitively, Milankovitch cycles can be linked to oscillations in our climate but you need something else to explain the 20 Kelvin temperature fall since the PETM (Paleocene-Eocene Thermal Maximum).
Re: matt (Comment #93759) 

If the forcing is approximately logarithmic, then doubling is doubling, i.e., ln(2C/C) = ln(2C1/C1).
gallopingcamel (Comment #93763)
March 25th, 2012 at 9:34 am
“You mention longer term orbital cycles that we call Milankovitch cycles. While most people believe these cycles were somehow responsible for the glacial/interglacial oscillation over the last 1,000,000 years I am not aware of any convincing predictions of the onset of the next glacial period. Can you point me to anything?”
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If you take a look at the following tool (http://www.brightstarstemeculavalley.org/science/climate.html), you can superimpose the temperature, CO2, and 100000 year orbital eccentricity cycle for the past 400K years. This recent data does show a visual correlation between temperature and eccentricity.
——————————————————–
“Intuitively, Milankovitch cycles can be linked to oscillations in our climate but you need something else to explain the 20 Kelvin temperature fall since the PETM (Paleocene-Eocene Thermal Maximum).”
——————————————————-
Wikipedia says that the PETM is characterized by a huge, rapid influx of C13 depleted carbon – i.e., combustion of sequestered reduced carbon (burning of peat deposits?). Long term carbon fixation and sequestration has reduced that carbon surplus.
julio (Comment #93752)
julio,
11K or 8K? Are you sure about that?
In case 1), do I understand that you are saying CO2 contributes 11K out of the current 33K GE?
In which case, this equates to 33% of the GE, agreed?
So lets have a closer look at that. In 1850 the GE was 0.8 deg C less than it is today, making it 32.2 deg C. If CO2 was responsible for 33% of the GE, then it was responsible for 10.6 deg C. This means that a 40% increase in CO2 has been responsible for a mere 0.4 deg C warming (11-10.6). Even if we assume a linear relationship (which it isn’t), then that means that a doubling of CO2 from pre-industrial levels would lead to a climate sensitivity of 1.0 deg C. Now this happens to coincide with your ‘canonical value’ but, as I said previously, this includes all forcings and feedbacks! THis does not strike me as being significant, especially as further doublings should lead to relatively smaller increases.
.
Now for case 2). Same logic, only this time the 40% increase in CO2 since 1850 leads to a warming of 0.3 deg C and therefore a doubling = 0.75 = CS. This figure is even lower than for your 11K estimate in case 1) but still includes all forcings and feedbacks.
.
So what is the problem? According to your radiative forcing figures the maximum warming is likely to be 1K (and very probably less) inclusive of all feedbacks! Given the logarithmic nature of CO2 absorption, the NEXT doubling will be even lower! That’ll be in about, what 350 years…?
.
I’d hardly count that as significant. And it is still as estimate, anyway!
matt (Comment #93759 and #93762)
.
matt,
Firstly, could I just say what a pleasure it is discussing this subject with someone who doesn’t call me either an id*ot or a troll? (I mean, you may think it but at least you don’t write it, which is a pleasant surprise for me on this site…)
.
I agree with you 100% when you say:
[“I think you’re right to be skeptical, we can’t really say how much of the observed warming is due to CO2. That’s not the same as saying that CO2 doesn’t cause warming, of course. Just that the expected amount isn’t that large and Nature can and does provide some fairly big temperature swings of her own. Teasing them apart is keeping a lot of people busy.”]
To be fair, this is what I have been saying for some time. Please see my reply to julio regarding his estimates of 11K or 8K. I believe that putting the contribution of CO2 up into the region of 20% or more of GE defies logic when compared to the observed measurements.
.
I also agree with you on:
[“I think you’d get a slightly lower baseline sensitivity using doubling of concentration from now, because the effect of CO2 is logarithmic.”]
Which basically means we could be talking about a warming of less than 2 deg C by the year 2350 or later, after two doublings from pre-industrail levels.
.
The problem is, nobody knows! I understand some might not like that phrase but, being objective about it, it is probably true.
.
Regards,
Re: Arfur Bryant (Comment #93774)
You seem to be assuming that if CO2 contributes, say, 33% of the GE today, it must also have contributed 33% of it in 1850, but there is no reason to believe that. There is nothing magical about that 33% figure.
Anyway, today it is more likely to be 8-9 C, or about 25% of the total GE. [This is not just me playing with MODTRAN; see G. A. Schmidt, R. A. Ruedy, R. L. Miller, and A. A. Lacis, Attribution of the present-day total greenhouse effect, J. Geophys. Res. 115 D20106 (2010).] But, as I said in my earlier post, this information by itself is not enough to predict what effect a different concentration would have.
Arfur
As Oliver pointed out, I actually messed up there! The logarithmic curve means that each additional same sized increment of CO2 has a progressively smaller warming effect. However, doublings always have the same effect as each other. Doubling from today’s level adds a bigger increment of CO2 than doubling from pre-industrial level, which exactly balances the reduced warming effect of the additional CO2.
I don’t think you’re a troll as it happens. This is about the most relentlessly technical climate change sites you can find – there are a lot of engineers and scientists here and they tend to be blunt as hell as a rule, often impatient, and not so diplomatic if they catch a mistake. Your comment 93774 for example has a few fundamental errors in it (I’ll take the blame for the incorrect effect of successive CO2 doublings!) and you’re going to be challenged on them. Don’t take it personally, they do it to each other all the time and you either tread carefully here or get used to being wrong occasionally. (Except for Lucia, who is a tolerant and gracious host, intimidatingly smart and never wrong. I just take comfort from the fact that she can’t proofread worth a damn.)
julio:
Correctamundo.
To start with, all that radiative physics tells you is, if you add more CO2 to the atmosphere, you get a larger radiative forcing. It tells you nothing about how the atmosphere responds to that.
So you have to put in the all-important water vapor feedback, if you’re going to be remotely close to a right answer.
Secondly, it’s not just CO2 radiative forcing that the atmosphere responds to, it’s the sum of all forcings. You have to include solar, which is the fundamental one of course. And anthropogenic aerosols, which is the big red question mark in the middle of this calculation.
Anyway the purple line in this graph is GISS Model E’s assumed forcings. I’m including this to illustrate just how different the net forcings can look relative to the anthropogenic CO2 radiative (direct) forcings.
(Not trying to get into an argument over what the right net forcings versus time should look like, just considering just CO2 forcings over time grossly oversimplifies the problem.)
Re: Carrick (Comment #93778)
Actually I had in mind something more like pure math, along the lines of: if I only give you one point, you don’t know what curve to draw through it.
With a linear relationship, of course, you can typically assume that it goes through the origin (zero concentration, zero effect), and people do this implicitly all the time. But with the logarithm, the zero concentration point is singular (so, clearly, the formula breaks down at some point before then), and a single data point elsewhere is not enough to pin the curve down, even if one could ignore all the feedbacks (which I agree you can’t).
julio, the logarithm relationship obviously breaks down at small concentration levels. Here’s a reference here you might find useful that deals with this.
It just seemed to me Arfur was assuming that CO2 is the only thing that drives climate (or assuming that’s what the modelers assume). I though it was important to point out that even if you knew the CO2 radiative forcings, you’re still a light year from knowing enough say anything about e.g. what doubling CO2 would change the climate.
Owen (Comment #93769), March 25th, 2012 at 10:54 am,
That Wikipedia comment impling that the PETM was caused by a spike in the atmospheric CO2 concentration is interesting but debatable.
The question I asked was “What caused the 20 Kelvin drop in temperature following the PETM”? Nikolov & Zeller say that the atmosheric pressure dropped by 53% while you seem to believe that CO2 was somehow involved. I won’t buy either explanation without a lot more evidence.
My main “project” right now is reviewing the AR5 ZODs. Some of the science looks pretty good:
http://diggingintheclay.wordpress.com/2012/03/24/more-unwelcome-light/
julio (Comment #93776)
julio,
I completely agree that my calculations above assume that same percentage effect in 1850 than today. So, the obvious question is, if you don’t accept that assumption, what percentage would you attribute to CO2 in 1850?.
Lets say the percentage contribution today is 25% (as you and Schmidt et al say) and the percentage in 1850 was less – say 20%? (I have no idea but just for the sake of argument…). Given those figures, then CO2 would have contributed 6.4 deg C (32.2 x 0.2) in 1850 and, today, CO2 would contribute 8.2 deg C (33 x 0.25). Therefore, according to the Schmidt et al argument, CO2 has been responsible for an increase of 8.2 – 6.4 = 1.8 deg C. This is obviously incorrect as the total warming has been only 0.8 deg C from ALL sources. So, using the argument that the percentage remains the same actually helps them, not me! Either way, the numbers don’t work. This is what I said to SteveF many posts ago – trying to quantify the radiative effect is from models (of any type) is totally impractical unless and until we can accurately establish what the CO2 effect is both today and back in 1850.
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The faith people put in the ‘radiative theory’ is not backed up with any real-world evidence! The numbers don’t make sense. At its most basic, science should make sense…
.
If CO2 was responsible for 6.4C of the GE in 1850, then a relatively large % increase in CO2 since then should have made more of a difference than ‘an unknown portion of 0.8C’. From observation, the late 20th century warming of about 0.7C could (I’m not saying it was, just could) just have easily been entirely due to natural factors, which makes the “radiative forcing of CO2 = significant warming” theory even less likely. Or, alternatively, the absorption of CO2 really has reached saturation and therefore there is no problem from radiative forcing in the future!
Carrick (Comment #93781)
Carrick,
Just for the record, I have never assumed that CO2 is the only driver and I have never assumed that that is what the modellers assume either.
matt (Comment #93777)
matt,
Thanks for that. OK, I take the point about ‘a doubling is a doubling’ from Oliver although I think it depends on the concentration level. This graph may help:
http://www.barrettbellamyclimate.com/userimages/MOD2.jpg
(I’m not advocating the site, but the graph seems pretty clear…)
So, at current concentrations, I agree with Oliver.
.
As to your comments about the technical nature of this site, I agree except for the bit about ‘don’t take it personally’. I do not take constructive criticism personally, but I do take personal attacks critically. If you look back at the posts around the 20th March, you’ll see what I mean. However, just because it is a ‘technical’ site doesn’t mean they can get away with appealing to scientific authority without some sort of evidence to back up their statements.
Regards,
Re: gallopingcamel (Mar 25 09:34),
How about continental drift. There was no physical connection between North and South America, allowing circulation between the Pacific and Atlantic oceans. Antarctica was probably still connected to South America, preventing the formation of the Antarctic Circumpolar Current. The thermohaline circulation would then look very different than it does today. And, ignoring the PETM spike, baseline temperature didn’t start to decline until well after the PETM.
Re: Arfur Bryant (Comment #93785) 

Schmidt et al. (2010) find that the model CO2 contribution under a doubling is more or less the same as it is now, so if you accept their results, then the percentage contribution can be taken to be reasonably constant.
A temperature change is a signed quantity, so it is not true that all contributors to a temperature change must be less than the total. You could hypothesize a CO2 contribution of +10.8 °C if you wanted, and this would not be “obviously incorrect” so long as there were a reasonable explanation for the other -10.0 °C.
Re: Arfur Bryant (Comment #93786) 
March 26th, 2012 at 6:10 am
But your argument above seems to depend upon such an assumption. Either CO2 is the only driver, in which case the (single) number doesn’t add up, or else there are other drivers which each have their own numbers, in which case the numbers may well add up.
Oliver:
Yep. Arfur if you haven’t already, look at the graph of forcings I posted that are assumed by GISS Model E.
Aerosols give negative contributions by all accounts.
The purple curve (sum of all forcings) is smaller than the CO2-only curve.
That’s what I thought too, which is what lead to my comment above.
It’s of course possible for people to make implicit assumptions without realizing they’re making them, that in fact is more common in science than seeing people write out all of the assumptions that went into an analysis.
Re: Carrick (Comment #93781)
Thanks for the reference. I’ll have to study it carefully, whenever I find a minute (I am now back at work, so what little leisure I had last week is gone).
I am intrigued by the figure you linked at Comment #93778. I have looked at the GISS model E forcings before, and they used to have sharp volcanic spikes. Have they decided those were wrong, somehow? They were certainly hard to fit to the temperature record.
Carrick (Comment #93793) ,
The GISS assumed aerosol effects, ~ -2.2 watts/M^ in 2003, are quite a bit higher than the IPCC “most likely” estimates, which come to about -1.2 watts/M^2 in 2003.
http://en.wikipedia.org/wiki/File:Radiative-forcings.svg
That is partially offset by higher black carbon (~+0.4 watt/M^) for GISS versus the IPCC best estimate.
.
Who is right? Who knows, maybe nobody. (But you already knew how much credibility I place in all these aerosol estimates, right? 😉 )
As I pointed out recently on the Real Climate thread where they were all bitching about Lindzen, the current best estimate ocean heat accumulation rate, combined with the total “credible range”, and “most probable” values for aerosol effects (IPCC AR4), means any climate sensitivity between 1.4C per doubling and an infinite increase per doubling (with a most likely value of about 2.2C per doubling) is consistent with the observed warming. Or in other words, just about anything goes. Choose the aerosol offsets that fit your model, or if you prefer, adjust your model to fit the aerosol offsets you like. Don’t worry, be happy… ’cause nobody can prove you wrong… at least not during your lifetime!
Arfur I think some of the difficulties you have been experiencing here are because you raise arguments that require a whole body of background knowledge and concepts to address effectively. It’s a big and diverse body, I’m still learning it myself and I find I’ve been wrong about things or missed the point a depressing amount of the time. It’s a slog! You have in fact answered some of your own objections in your recent posts, and may not have realised it.
If I may summarise your argument here, you are saying that if 280ppm CO2 was responsible for 6-plus-change K of greenhouse warming in 1850 (your own for-example guess), today’s 380ppm should have given us a whole lot more of an increase than the 0.8 K seen, yes? So either the whole theory is wrong, or CO2 warming has reached saturation and we don’t need to worry about it anymore. That seems superficially reasonable, but then you link to BarettBellamy’s graph that actually tells a different story.
You appear to be familar with the idea of saturation, so you uunderstand that the warming effect of adding CO2 is greatest when there isn’t any present at the start and it becomes a case of diminishing returns as you add more. So from the graph, with CO2 at zero, temperature is 278K. Add a mere 50 ppm CO2 and you get a whole 6K of warming to 284K! Double that to 100 ppm gets you only an additional 1K, and redouble to 200ppm gets you one more… that’s what a climate sensitivity of 1K/doubling means. That’s the whole implication of a logarithmic response.
Doubling from 280 to 560 should only give 1 K or so of warming, absent feedbacks. Going from 280 to today’s 380ppm should only give about 0.6K warming, absent feedbacks. So the warming we’ve seen is actually pretty much in line with the no-feedback calculation!
The IPCC of course promotes a higher climate sensitivity, a range of possibilities with 3K/doubling median value. This is supported by the outputs of general circulation models and assumptions about the degree of water vapour positive feedback. The lower-than-expected warming level is justified by assumptions of temporary negative feedback from sulphate aerosols masking the true warming, and lag in the warming due to the heat capacity of the ocean. You will find plenty of criticism of the GCMs, sulphate assumptions and lag assumptions here – that’s what lukewarmers like to do.
julio (Comment #93794),
I believe those are the man-made forcings only.
Re: SteveF (Comment #93799)
Oh. That’s too bad. 🙁
It makes sense, though. Thanks!
julio:
They have those too. Sorry I forgot what my graph was about. It was intended to show just anthropogenic forcings, and again it’s just to give a “flavoring” of what impact the other anthropogenic forcings have on climate.
Anyways, that’s my bad. I should have a label on the graph stating that (don’t get confused if you look at the figure in the future…when I get a chance, I intend to add one.)
Julio, you might find this useful:
Here is the URL for the forcings.
Here are anthropogenic forcings. (This also includes O3, I had omitted this from the previous graph.)
And natural versus anthropogenic versus total forcings
Regarding the Lam paper, I definitely understand about not having the time right now. I believe there are at least two mistakes in the paper (doesn’t handle feedback, I also don’t believe he properly computes the radiative GHG effect at the level that Rammananthan calculates it), but I think he does get right what is responsible for the approximately logarithmic relationship between CO2 concentration and radiative forcing.
Carrick #93805,
There is a problem with the first link (a typo I think). The second link shows black carbon as a negative forcing, but I am pretty sure it is actually positive, since it reduces albedo, no matter where it is (atmosphere, on land, on snow/ice).
Carrick,
You fixed the link before I posted my comment. 🙂
Carrick,
You seem to have mislabeled land use and black carbon on the graphic.
Re: Carrick (Comment #93805)
Thanks! So they have updated the forcings to go all the way to 2010. That’s interesting.
I believe the feedbacks may be hidden in Lam’s parameter “mu”, but I need to look at it more closely.
Here’s a recent paper that some here may find interesting (behind a paywall, sorry): “Simple model to estimate the contribution of atmospheric CO2 to the Earth’s greenhouse effect,” American Journal of Physics, Volume 80, Issue 4, p. 306 (April 2012). [No feedbacks are considered, though, so the title may be a bit misleading, in that it seems to promise more than the paper delivers.]
If you want the inputs for Ar5 they are at the RCP data portal.
in excell.
Ask for a link if google is not your BFF
Steven Mosher: “in excell”
Better check for transcription errors. Sometimes the data gets “shifted and scrambled a bit in the process of being converted to an excel spreadsheet or upon being downloaded or opened”
Julio – congratulations on your paper, it looks very nice. And thanks for the acknowledgement and citation!
Re: Arthur Smith (Comment #93820)
Thanks, Arthur!
julio,
Let me second Arthur’s congrats…. and thanks for the (probably undeserved) shout-out!
Oliver (Comment #93791)
[“Schmidt et al. (2010) find that the model CO2 contribution under a doubling is more or less the same as it is now, so if you accept their results, then the percentage contribution can be taken to be reasonably constant.”]
So, if the Schmidt contribution is constant, then CO2 is responsible for 25% of whatever the GE is at the time of observation. Which means that it is responsible for 8.25 deg C today and was responsible for 8.05 deg C in 1850. Which means that CO2 has ’caused’ a 0.2 deg C warming in 160 years! Hence my (and Skeptikal’s) original assertion that, contrary to popular belief, the radiative forcing of CO2 is insignificant when taken in the atmosphere as a whole. In order for anyone to argue otherwise, they would have to assume that a much larger portion of the 0.8 deg C warming since 1850 has been caused by CO2. There just is no evidence for this.
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[“A temperature change is a signed quantity, so it is not true that all contributors to a temperature change must be less than the total.
But Schmidt et al used a percentage. This, in effect, is a net final figure, after any ‘signs’ are added up. Therefore, 25% is exactly what it says. There is no get-out clause.
.
[“But your argument above seems to depend upon such an assumption.
I don’t accept that conclusion. I have at no time indicated that CO2 is the main driver. I have always mentioned it as one driver, and a fairly insignificant one at that. Schmidt et al have made it a significant one, and even they do not claim it is the only one. However, it should be remembered that ALL the non-condensing GHGs amount to less than 0.04% of the atmosphere. Of these, CO2 is way out there as the main one.
.
The fact is that all the arguments put forward about the ‘effectiveness’ of CO2 forcing are based on estimates which are based on some form of computer model. I am arguing based on empirical evidence (or as close as it gets in this debate). At some point someone has to decide whether the evidence tends to validate or falsify the ‘radiative forcing’ theory. I say that, so far, it has tended to falsify it.
DeWitt Payne (Comment #93788), March 26th, 2012 at 6:56 am :
I had a look at Scotese.com. It seems the continents were pretty close to their present positions 45 million years ago.
Any thoughts on the timing of the next glacial or what might cause it?
matt (Comment #93798)
[“I think some of the difficulties you have been experiencing here are because you raise arguments that require a whole body of background knowledge and concepts to address effectively.”]
.
matt, with all due respect, I don’t feel as if I am having difficulties here(!), unless you are referring to the tone of some of the comments. I am quite happy to discuss the subject, learn where necessary, and yes, I too have had some disappointments along what has been a pleasurable if sometimes frustrating heuristic experience! 🙂
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[“If I may summarise your argument here, you are saying that if 280ppm CO2 was responsible for 6-plus-change K of greenhouse warming in 1850 (your own for-example guess), today’s 380ppm should have given us a whole lot more of an increase than the 0.8 K seen, yes? So either the whole theory is wrong, or CO2 warming has reached saturation and we don’t need to worry about it anymore. That seems superficially reasonable, but then you link to BarettBellamy’s graph that actually tells a different story.”]
.
That is a fairly good summary, matt. However, the Barrett Bellamy graph actually only tells the story according to the radiative effect. To relate it, as you do, to the observed warming is to effectively assert that ALL the warming since 1850 is due to CO2. This effectively negates the presence of natural factors. Now, since – according to Carrick’s forcings graph (eg) – the CO2 forcing didn’t really start increasing until after 1950, then how do you explain the 0.7 deg C warming between 1910 and 1945? It appears fairly obvious that natural factors are capable of causing a 0.7 deg C rise, so we cannot say with any certainty that the overall warming has been due to CO2. But we can say that it may have been due to natural causes! Barrett Bellamy’s graph is not based on observation; it merely gives an estimated amount of warming per doubling from CO2 alone. If the observations invalidate the estimate, then yes, maybe the theory IS wrong!
Regards,
gallopingcamel (Comment #93828)
The isthmus of Panama was almost certainly quite open until about 3-4 million years ago, which would have a major impact on ocean circulation and global climate. ( http://en.wikipedia.org/wiki/Isthmus_of_Panama ) The closing of the isthmus appears to be coincident with the cyclical glaciation of Greenland. http://en.wikipedia.org/wiki/File:Five_Myr_Climate_Change.svg
Re: Arfur Bryant (Comment #93826)
The concept of “positive feedbacks” explains how a small CO2 forcing is amplified to produce a larger overall climate response. In other words, CO2 concentration acts like your stereo system’s “volume knob” and may be seen as the initial “cause” for a total temperature change which is larger than the effect of CO2 forcing acting alone.
Schmidt et al.’s percentage tells you the fraction of the total greenhouse forcing (positive, units of W/m^2 not temperature) which is directly attributed to CO2 radiative forcing (also positive). It does not say whether any other forcings (such as aerosols) may counteract part of the increase in greenhouse forcing, leading to a smaller net positive temperature change.
If I understood correctly, your objection was that the theoretical temperature change attributed to CO2 forcing was larger than the total observed change. From this you concluded that radiative physics are contradicted by observations. Carrick, and later I, explained why your numbers were incorrectly used.
Arfur
Well no worries then!
julio:
Yeah, I know that’s what he’s claiming. I don’t see how you are going to meaningfully model water vapor feedback in particularly without using a more realistic radiative model.
And by the way, congrats on the paper, julio. For some reason, I’m supposed to have a subscription for that journal and it keeps putting up the pay wall. Oh well, I’ll try again from work in the morning.
matt:
It’s possible that this warming period might be partly artifactual. Don’t see that as a defense of the models, it’s just there’s a basis for suspecting the data prior to 1950 (sparse coverage, change in measurement method, a war that disrupted normal measurement patterns, etc).
Julio, I had a chance to skim through your paper.
One thing I noticed was this comment
As you likely know, increasing CO2 is not strictly the same as increasing solar forcing, since CO2 forcing is (more or less) uniform around the globe, whereas solar forcing is concentrated at the equators. (h/t to James Annan for that point.)
Very interesting paper. I haven’t seen a physics-based derivation of the CO2 no-feedback forcing before.
Since you’ve been thinking about this particular problem, I’d especially be interested in your take on Lam’s paper now.
Carrick
Re: Carrick (Comment #93848)
Good point about the solar forcing. I hadn’t thought of that!
Yes, I was a bit worried when you pointed the Lam paper out yesterday. I was relieved to see it was unpublished! I may post a few thoughts on it later today.
BTW, please consider yourself included in the acknowledgments too. I have learned quite a bit here from people like you, DeWitt and Steve, just to name the most obvious ones. (Steve got singled out because I can point to a specific equation in the paper that I actually corrected as a direct result of working through one of his guest posts. Plus, I know his full name!)
Re: julio (Comment #93813) 

Thanks for the link, julio. I enjoyed this paper, and it clearly explains many of the “ambiguous” points for readers who have some understanding of radiative physics but still have questions about the radiative balance in the atmosphere.
Not sure what the idea that early 20th century warming was an artefact is based on. It’s pretty clear in the raw data in many places.
Oliver (Comment #93839)
[“The concept of “positive feedbacks†explains how a small CO2 forcing is amplified to produce a larger overall climate response.”]
.
And that is what it is. A concept. There is no real-world empirical evidence to support the concept. And yet the concept is used to dramatically increase the hypothesised radiative effect of non-condensing GHGs.
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Oliver,I would like you to consider the possibility that the radiative forcing effect is very very small, and that the positive feedback concept is non-existent. Then, accept that the 0.7 C warming between 1975 and 1998 is caused by whatever caused the identical 0.7 C warming between 1910 and 1945. You now have the situation we find ourselves in without invoking any hypothetical ‘significant’ radiative effect, any hypothetical feedbacks, any hypothetical thermal lag, and any need for the majority of climate change mitigation funding. Just a thought… 🙂
Regards
matt (Comment #93841)
matt, good post.
[“I DO assert that according to the radiative transfer calculations, it is feasible for CO2 to have caused the magnitude of warming seen since 1850…”]
.
Feasible. What a great word. Now I certainly don’t want to politicize this excellent discussion but “feasible” was not the term used when the radiative forcing theory was ‘sold’ to Joe Public back in c1998. The terms used were “very likely”, “accelerating” and “catastrophic”. But ‘feasible’ carries much less certainty with it. ‘Feasible’ implies that “we’re not really sure but it could be…”. That’s probably fair, as long as the uncertainty is highlighted and even emphasised.
.
Consider this (repeated from my post above to Oliver):
Consider the possibility that the radiative forcing effect is very very small (insignificant?), and that the positive feedback concept is non-existent (or also insignificant). Then, accept that the 0.7 C warming between 1975 and 1998 is caused by whatever caused the identical 0.7 C warming between 1910 and 1945. You now have the situation we find ourselves in without invoking any hypothetical ‘significant’ radiative effect, any hypothetical feedbacks, any hypothetical thermal lag, and any need for the majority of climate change mitigation funding.
Now that’s ‘feasible’! 🙂
.
[“These other factors explain why global temperatures fail to simply track with CO2 concentration or even with total greenhouse forcing. On the other hand, they make it extremely difficult to seperate man-made from natural warming.”]
I agree. That is why I like to consider that there may be an alternative explanation…
Regards
Paul Matthews (Comment #93858)
Agreed!
Re: Arfur Bryant (Comment #93875)
Of course there is empirical evidence. To start with, an increase in evaporation and absolute humidity are widely observed with an increase in temperature.
I am perfectly willing to give this possibility consideration. But for me to continue to take it seriously, I would want to see some physical justification for this “very very small” radiative forcing which is compelling enough for me to reject my existing understanding of CO2 forcing (see, for example, the paper discussed in recent posts).
It would be a bit like my weighing myself on a scale and getting a value 15 lbs. larger than expected. Yes, I would consider the possibility that the in situ value of gravity differs substantially from the laboratory tested value, but there are other, more plausible (and some more unfortunate) explanations for the discrepancy.
Can you give reasons for accepting this hypothesis over any other?
Paul:
I didn’t say the entire warming was an artifact. What I said part of it could be artifactual.
One is that the geographic distribution changes over time, and secondly we know that there is a bias in rate of temperature change with latitude.
Mean latitude of non-zero 5*x5* grid cells versus time for CRUTEM3.
Well it looks like the double-dip La Nina is finally waning and global Sat. temps have been heading for the roof all month. Quatloos are unlikely to be coming my way this time.
http://discover.itsc.uah.edu/amsutemps/
Oliver (Comment #93879),
Is observational data “physical” enough?
Re: Skeptikal (Comment #93900)
It is if you can provide some “justification” to go along with the “physical.”
Oliver (Comment #93879)
[“Of course there is empirical evidence. To start with, an increase in evaporation and absolute humidity are widely observed with an increase in temperature.”]
But that is not evidence that CO2 caused the warming in the first place! Any feedbacks ‘due to warming’ would happen irrespective of what caused the warming. Your comment was about positive feedbacks from CO2…
[“But for me to continue to take it seriously, I would want to see some physical justification for this “very very small†radiative forcing which is compelling enough for me to reject my existing understanding of CO2 forcing…”]
The physical justification is that the warmings were identical and subsequent coolings invalidate the CO2 approach! Some folk on this site think the latter warming is due to CO2 and the earlier warming is due to ‘other’ factors. There is no logic in that opinion. Anyone who supports the idea of radiative forcing leading to ‘significant’ warming would have to produce evidence to support how that hypothesis could induce warming in such discrete packages. It is as if they assert that any warming is due to CO2 and any cooling is due to ‘negative feedbacks’ of some other natural factors. This defies logic. Any factors which cause warming can obviously have an opposing setup. The warming periods are too random. If you objectively consider what I proposed you should concede that it is at least as feasible as the radiative forcing assertion. It just hasn’t got the hype!
[“Can you give reasons for accepting this hypothesis over any other?”]
I used the word ‘accept’ as part of the logical sequence. The main reason for doing so is that the end result is the same, so invoking the significant ‘radiative forcing effect’ (note that I don’t say it doesn’t exist for a single molecule, just that it isn’t significant globally) is not necessary.
Regards
Oliver (Comment #93904)
[“Re: Skeptikal (Comment #93900)
It is if you can provide some “justification†to go along with the “physical.—]
I believe this will do…
http://www.woodfortrees.org/plot/hadcrut3vgl/from:1850/to:2012
Note there are three distinct warming periods: c1860 to c1868; c1910 to c1945 and c1975 to 1998. Each was followed by a cooling period. If CO2 radiative forcing did not become effective until after 1950, what caused the very similar warming periods before 1950?
I think the land-only data over at the other thread
http://rankexploits.com/musings/2012/new-land-temp-comparisons-with-crutem4/
show some pretty clear differences between previous warming/cooling cycles (“natural variation”) and the current warming trend (starting around 1975): it is steeper than all the others, and it has lasted longer. We have not seen any significant, sustained cooling since about 40 years ago, unlike the earlier periods shown. This is just what we would expect if an external agent was at work, with enough strength to overpower “natural variation”.
We know from theoretical considerations that such an agent is, indeed, at work, and the observations provide experimental evidence.
The other thing, of course, is that, despite the relatively small cooling episodes, the overall trend is relentlessly upwards–as is the increase in CO2 (nobody “turned on” the CO2 in 1950, you know).
julio (Comment #93909),
The “overall trend” has been relentlessly upward since the last ice age. Are we to infer that CO2 emissions ended the last ice age?
Re: Skeptikal (Comment #93911)
You must mean since the “little ice age” (unless you believe that there was no “medieval warm period”?). But it’s rising faster now.
OK, this is for Carrick mostly. I have taken a closer look at the (unpublished) paper “Logarithmic response and climate sensitivity of atmospheric CO2”, by S. H. Lam, which I will henceforth refer to as [1], and compared it to the paper I mentioned in Comment #93813 above, henceforth referred to as [2] (note that the fact that one of the authors of [2] is named Julio may lead to some bias on my part :-)).
.
First the good news: the explanation [1] offers for the logarithmic dependence is essentially the same as in [2], as it should be. Ultimately this comes from the near-exponential decay of the strength of the (strongest) CO2 absorption lines with distance to the band center, as is evident, for instance, in Figure 1 of [2]. This is an intriguing feature; I have asked a couple of molecular spectroscopists about it and they were unable to provide any insights. [For anybody interested, I suspect a good starting point would be the classic paper by E. Condon, “A Theory of Intensity Distribution in Band Systems” Phys. Rev. 28, 1182–1201 (1926); at least, that’s where *I* would start, if I had time!]
.
Unlike in [2], the author of [1] makes no attempt to calculate the actual emission rate inside the absorption band (which in [2] is modeled as blackbody radiation from the top of the atmosphere). Instead, he introduces a parameter eta in his Eq. (15) that is supposed to take care of “any other relevant physics”. His Eq. (16) is more or less directly comparable to Eq. (25) of [2]: in [1], assume a doubling of the concentration, which gives you ln(2) in Eq. (15); in Eq. (18), replace eta and gamma at the edges by their average value (gamma in [1] essentially corresponds to r in [2]) and write the sum of B at the edges as twice the value of B at the band center. Then you get essentially Eq. (25) of [2], with an explicit expression for eta:
.
eta = 1 – B(Ttop)/B(Tsurface)
.
where B is the Planck function, Ttop the temperature at the tropopause, and Tsurface the temperature at the surface. This is clearly less than 1, as correctly claimed in [1].
.
[I gloss over details such as the fact that [1] works with wavelength and [2] works with wavenumber; one just has to use the correct form of the Planck radiation function in each case. Also, the parameter epsilon_e,0 in [1] is 1, more or less by definition.]
.
The author of [1] makes no attempt to evaluate his parameter alpha. He merely quotes Myhre et al. (also referenced in [2]) as providing a value of 5.35 W/m^2. A big part of [2], of course, was to provide an estimate for precisely this quantity, which is done immediately after Eq. (25) of (2): according to this estimate, alpha*ln(2) = 4.3 W/m^2, or alpha = 6.2 W/m^2. This is “within 15%” of the result by Myhre et al.
.
This is all about the forcing, now for the change in temperature. The authors of [2] essentially re-derive the so-called “Planck response” in their Eq. (5), which gives a temperature change of 0.3 K per W/m^2 of forcing (as Arthur Smith reminded us upthread, comment #93704, the “canonical” value for the reciprocal of this quantity is 3.216 W/Km^2, so 1/0.3 = 3.33 is (almost) within the bounds (about 4% error). The corresponding equation in [1] is (2), which throws all the “feedbacks” including the Planck response into the parameter mu.
.
Comparing Eq. (2) of [1] to Eq. (5) of [2], one can see that [2] assigns the value (T/T0)^4 to the quantity mu. (In [2], T = 288 K is the current surface temperature, and T0 = 255 K the effective radiation temperature.) This gives (almost) the correct Planck’s response, as indicated above, and suggests that a proper “no feedback” starting value for mu is not 1, as claimed in [1], but more like (288/255)^4 = 1.6.
.
It is true that to get from 5.35 ln(2) = 3.71 W/m^2 of increased forcing per CO2 doubling to something like a climate sensitivity of 2 C/doubling, you’d need mu to be even larger, of the order of 2.9; this is what the author of [1] means when he says (top of p. 9) that “the IPCC’s likely beta range needs the Earth’s effective Stefan-Boltzmann exponent of Tsa to be between 0.6 and 1.3 (instead of the classical 4).” My contention would be that the authors of [2] have shown that there is nothing “classical” about a value of 4, and just by considering the Planck response, before any other feedbacks, the “Stefan-Boltzmann exponent” should be reduced to 4/1.6 = 2.5.
.
(Yes, this is still larger than 1.3, by almost a factor of 2; but this all comes back to the old observation that “no feedbacks” predicts a climate sensitivity of about 1.1 C/doubling, which is about a factor of 2 smaller than the lower end of the IPCC’s “likely” range of 2 to 4.5. There are no new insights in this observation.)
.
Long story short: use of Eq. (2) of [1] with mu = 1 is misleading because it does not even properly account for the “no feedback” “Planck” response. Properly accounting for that requires mu = 1.6 or so, which would bring things into agreement with [2].
nice julio!
Thanks, Mosher. If nothing else, it took a long time to write! 🙂
Re: julio (Mar 29 09:57),
But the Stefan-Boltztmann equation only applies if the emissivity is constant over all wavelengths. That’s more or less true for radiation from the surface at 288K, but far from true for radiation to space. I therefore question your use of μ = (T/To)^4. It seems to be circular logic in that you must define To using the SB equation when the actual emission temperature varies all over the map, depending on the effective altitude of emission. Even T isn’t really accurate as it neglects energy transfer from the surface by convection. So, in effect, you’re assuming that convective energy transfer is not a function of temperature. That seems to me to be a very large assumption.
Re: DeWitt Payne (Comment #93929)
You’d have to read [2] to see how the (T/T0)^4 comes about, but the crucial assumption is that the fraction of the power (radiated by the surface) which is blocked by the other greenhouse gases does not change significantly as the CO2 concentration is increased.
This seems to work well, at least for relatively small changes in temperature.
I could write more about this, but I have a class to teach right now!
OK, I’m back, here’s the rest of the story:
Actually the model in [2] allows you to do a (limited) self-consistency check of this hypothesis. Equation (22) of [2] is the result of (approximately) integrating the radiative transfer equations, with a given temperature lapse rate, to find the total flux out to space at any frequency. It includes contributions from the surface, and contributions from the top of the atmosphere, and it looks just like your standard MODTRAN curve, only smoother.
So now you can integrate that expression over frequency to get the total flux out to space, and see how that depends on the surface temperature, assuming that the lapse rate does not change. The result is not quite proportional to T^4 (as you point out, there’s no reason why it should), but neither is it too far off; for instance, in the range 278 < T < 298 K (a 7% change in T), the ratio of flux out to sigma*Tsurf^4 varies between 0.861 and 0.875, a change of about 1.6%. So the approximation of a relatively temperature-independent ratio of emitted to transmitted flux is not too bad, at least according to this model.
Julio, thank you very much for the write-up!
Re: Carrick (Comment #93935)
You’re welcome!
julio (Comment #93908)
julio,
You are cherry-picking. Anyone can play ‘graph ping-pong’. By choosing a land-only graph melange shows you are being subjective, not objective.
The HadCRUt data is the only one that starts in 1850. It was considered global. Now we have satellite data which matches the shape of the HadCRUt perfectly. This shows the HadCRUt data is a reasonable attempt at showing a ‘global’ temperature, in the absence of any satellite data before 1979.
http://www.woodfortrees.org/plot/uah/from:1979/to:2012/plot/uah/from:1979/to:2012/trend/plot/hadcrut3vgl/from:1979/to:2012/plot/hadcrut3vgl/from:1979/to:2012/trend
Look how the graph shapes match, and note that the OLS trend is very nearly identical. The trend since 1975 is around 0.12 deg C per decade. You have stated that the “the current warming trend (starting around 1975): it is steeper than all the others…”
Now look at the HadCRUt data since 1850:
http://www.woodfortrees.org/plot/hadcrut3vgl/from:1850/to:2012/plot/hadcrut3vgl/from:1858/to:1880/trend/plot/hadcrut3vgl/from:1910/to:1945/trend/plot/hadcrut3vgl/from:1975/to:1999/trend
You can clearly see that the trend since 1975 (plotted to 1999 when the warming stopped) is most certainly NOT “steeper than all the others”. It is matched by the warming trend from 1910 to 1945 which was well before the supposed ‘effective start of CO2 warming’ around 1970 or so (according to some).
As for this:
[“julio (Comment #93909)
March 28th, 2012 at 3:50 pm
The other thing, of course, is that, despite the relatively small cooling episodes, the overall trend is relentlessly upwards–as is the increase in CO2 (nobody “turned on†the CO2 in 1950, you know).”]
The overall trend is certainly one of warming. No argument there. However, the overall trend since 1850 is about 0.06 C per decade and it is shallower now than it was in 1880!. It is also shallower now than it was in 1998, so there is NO acceleration in the warming, as would be implied if an increase CO2 was as effective as you seem to think.
Arfur:
Then there is the problem of data quality. If not you, others, selectively worry about data problems. The substantial lack of coverage prior to 1950 is no issue for them, microscopic effects in the last 20 years however are.
The sloper is slightly steeper from 1975-2010, but the older temperature trend had a larger uncertainty. There is no question that the null test is passed in this case (“is the slope 1975-2010 the same as the slope 1905-1945”), but it’s partly because of the greater systematic uncertainty in the early data—one shouldn’t make too big of a story about the fact they appear to agree.
Re: Arfur Bryant (Comment #93938)
You know, eyeballing is not a very precise science 🙂 That’s why when I first became interested in global warming, over two years ago, I spent some time analyzing the HadCRUt and GISTemp data numerically.
The best fit to the data that I could get with simple functions was the sum of a sinusoidal oscillation and a parabola. The sinusoidal may represent a “real” oscillation or not, but in any case it is neutral from the warming/cooling point of view. The parabola, on the other hand, indicates that the overall rate of warming has been increasing steadily over the course of the past century (or century-and-a-half).
That’s for the overall picture. Regarding the decadal trends, I will agree with you that the similarity between those warming trends you highlighted, as well as the recent slowdown, are hard to reconcile with a very large climate sensitivity.
Julio,
Humm.. ~1.6 degrees per doubling, where have I seen that number before? 😉 (hint: http://rankexploits.com/musings/2011/a-simple-analysis-of-equilibrium-climate-sensitivity/)
.
Joking aside, as Paul_K notes, there is plenty of evidence of at least a linear/short term response to forcing in that range. I observe only that eliminating uncertainty about aerosol contributions seems key to resolving the climate sensitivity conundrum.
Julio,
“You know, eyeballing is not a very precise science”
I don’t know. I have been accused by more than one woman of being able to see a change of 1% in mass by eyeball alone.
SteveF, it depends on the latitude and longitude of the mass change.
but ya.
Arfur.
Pay close attention to what carrick says.
1979 to present we have good global coverage.
in the earlier periods you have
1. Oversampling in the NH relative to the SH ( sampling bias)
2. Few stations ( increased measurement error)
3. More missing data ( increased error )
As carrick notes you have to take these into account. That is NOT to say that the early period warming isnt important.
A) hardcore warmist like to armwave about it.
B) contrarians try to make too much out it.
It’s a interesting phenomena. Understanding it is important. It could simply mean that some are discounting internal variability too much. In short, its not a smoking gun and its not something to just wave away.
Re: SteveF (Comment #93941)
Um… I know it was a long and confusing post, but… that 1.6 was not meant to be the CS all by itself, you know.
All the same, I would not be surprised if the transient climate response was in that ballpark, with the equilibrium CS in the 2.5 – 3 range.
Arfur Bryant (Comment #93938)
“from 1910 to 1945 which was well before the supposed ‘effective start of CO2 warming’ around 1970 or so (according to some).”
Well, maybe some. But it’s not really true. Here is a plot of the GHG forcing (mainly CO2) against Hadcrut3.
Nick:
Are you claiming that net anthropogenic forcings were important prior to 1970 or something different?
Here is assumed GISS Model E forcings.
You’ve probably seen this figure before too.
Are you saying the proper interpretation of this figure is that anthropogenic forcings are required to explain the observed temperature change prior to 1970?
Do you have a counter example of a model where net anthropogenic forcings were important prior to 1970?
One has to look at net anthropogenic forcings (and that includes aerosol forcings which is negative of course) when looking at anthropogenic impact on climate, and what Arfur says here is definitely the consensus view in climate science—the beginning of the AGW age was circa 1970, not prior to that.
Carrick,
Yes, your first figure shows the CO@ forcing that I was trying to superimpose on the Hadcrut3 record, though I’m not sure how well it came through. It rises from 0 in 1880 to somewhere near 1 W/m2 in the 60’s, and then another 2 W/m2 since. The earlier rise is smaller, but it isn’t nothing.
I don’t think anthropogenic effects are absolutely required to explain either temperature change. My take is that we know CO2 has increased in both periods, we’d expect warming, and indeed warming is seen, so the expectation is not contradicted. It may well be that something else added to the warming pre-1940, and something else again modified it later, perhaos with cooling effect.
No serious scientist claims that anthropogenic CO2 forcing is the only thing going on. But it’s new and sustained.
Nick, I was trying to say it’s a mistake to compare solely anthroopogenic CO2 forcings to global mean temperature… that’s not a meaningful comparison.
It’s only the sum of anthropogenic forcings that matters in terms of net influence of human activity on global mean temperature.
I believe the general consensus is we can explain the warming prior to 1970 in terms of natural variability, but not the warming since…and this is a consensus statement among the various modelers.
That’s the point of the IPCC figure I enclosed. I don’t dispute CO2 forcing is important, it’s just not the sole factor at play.
Carrick,
Does the line for CO2 on your graph of GISS forcings represent only CO2, or does that line include other man made GHG forcings?
SteveF, it’s all anthropogenic GHGs (direct effect).
Another mislabel. I’ll fix it when I get time.
julio,
I still think that using radiant energy transfer only to determine the magnitude of the greenhouse effect is wrong. When you include net convective energy transfer from the surface to the atmosphere, then:
μ = 492/255 = 1.93
Re: DeWitt Payne (Comment #93959)
I’m sorry this was a bit too cryptic for me.
I agree if you don’t include convection in some way (implicitly or explicitly) you get the wrong answer, but I’m not sure how this applies to my criticism of paper [1] above, or to your (apparent) criticism of the estimate of the Planck response in paper [2].
Here’s what I think we are talking about. From Bony et al., “How Well Do We Understand and Evaluate Climate Change Feedback Processes?” Journal of Climate, vol. 19, pp. 3445–3482, appendix A:
“The most fundamental feedback in the climate system
is the temperature dependence of LW emission through
the Stefan–Boltzmann law of blackbody emission
(Planck response). For this reason, the surface temperature
response of the climate system is often compared
to the response that would be obtained (Delta T_s,P) if
the temperature was the only variable to respond to the
radiative forcing, and if the temperature change was horizontally
and vertically uniform”
Note the explicit assumption that the lapse rate does not change with surface temperature for the purpose of this calculation. Later on they write
“The Planck feedback
parameter lambda_P is negative (an increase in temperature
enhances the LW emission to space and thus reduces R [the Earth’s radiation budget at the TOA, under the assumption of an unchanged lapse rate indicated above])
and its typical value for the earth’s atmosphere, estimated
from GCM calculations (Colman 2003; Soden
and Held 2006), is about 3.2 W/m^2 K.”
Let’s stop here for a second and look at [1] again. From his Eq. (1), one gets (Delta F/Delta T) = 4 sigma T^3/mu = 5.7/mu W/m^2 K (using T=293 K, as he does). So this clearly does not give you the right Planck feedback parameter. To get something close to 3.2, you’d have to make mu of the order of 1.78. If you use T = 288, as I did above, you still need mu = 5.4/3.2 = 1.68, which is pretty much what I said in Comment #93926:
Now, about how to get that 1.6, or at least in the right ballpark, Bony et al. go on:
“(a value of 3.8 W/m^2 K is obtained by defining lambda_P simply as 4 sigma T^3, by equating the global mean OLR to sigma T^4 and
by assuming an emission temperature of 255 K)”
In terms of the formula above, this amounts to using mu = (T/T0)^3 = 1.44 or 1.52, depending on whether T = 288 or 293 is used.
On the other hand, the method indicated in [2] yields mu = (T/T0)^4 = 1.63, and a Planck parameter of 4 sigma T0^4/T = 3.32 W/m^2 K, much closer to the accepted value of 3.2. It is derived in a way I find plausible and it works, so I’m not sure what else to say…
Owen,
Thanks for your comments on glacial cycles.
By happy conincidence my wish was granted. Here is a very interesting web site by “iya” who I have encountered on John Spencer’s blog:
http://most-likely.blogspot.com/2012/03/milankovitch-cycles-and-glaciations.html
Carrick (Comment #93949), March 30th, 2012 at 12:29 am,
Thank you for so graciously admitting that CO2 is not the major driver of our climate as many learned people have claimed in the past.
Have you anything to say about the relative importance of natural versus human induced climate change?
When one sees striking correlation between Milankovitch and shorter term planetary cycles it can seem as if natural factors will explain almost every change once we properly understand them.
julio,
I think the assumption that you can have a system where:
My suspicion is that doing this will cause a surface radiative imbalance because you’re increasing the concentration of the emitter and raising the temperature of the atmosphere while only increasing the temperature of the surface.
Let’s look at numbers:
MODTRAN US standard atmosphere, clear sky, constant water vapor pressure, 100-1500 cm-1.
375 ppmv CO2, 288.2 K surface temperature
0 km looking down: 360.472 W/m²
0 km looking up: 258.673
12 km looking down (tropopause):264.262 W/m²
The IR radiative imbalance is: 101.799 W/m²
560 ppmv CO2, 288.77K surface temperature
0 km looking down: 363.298 W/m²
0 km looking up: 262.253 W/m²
2 km looking down: 264.262 W/m²
IR radiative imbalance: 101.045 W/m²
Obviously, I adjusted the surface temperature offset to restore upward flux at the tropopause, assuming that the stratosphere can take care of itself (which it doesn’t in MODTRAN).
difference: 0.754 W/m²
That’s 27% of the change in surface emission, which seems fairly substantial to me.
There is no “the”. At various times, various parts of the climate system could be could “the” major driver, depending on the circumstances. At the moment, it is CO2, because the concentration of CO2 is rising so quickly. No doubt this will change in time, but at this time, which is where we live, it’s CO2.
bugs (Comment #93970)
I think you might be off by a derivative.
Re: DeWitt Payne (Comment #93969)
I’m sorry I am being so obtuse, but I’m still trying to pinpoint the problem. Please bear with me!
As I see it, the problem of getting the no-feedback CO2 climate sensitivity can be broken up into two steps. Step A is not specific to CO2, whereas step B is.
(A) Take the Earth as it is right now (with its given concentration of GHGs, and its lapse rate) and determine the change in (surface) temperature that would result from a change in radiative forcing only, all other things remaining equal. That’s the (reciprocal of the) “Planck parameter”.
(B) Calculate the change in radiative forcing equivalent to a doubling of the concentration of CO2, again all other things remaining equal.
According to Bony et al., the reciprocal of the number you want in (A) is about 3.21 W/m^2 K. According to Myhre et al, the number you want in (B) is 5.35 ln 2 = 3.71 W/m^2. Arthur Smith, upthread, gave error estimates for (A) of the order of 1% and for (B) of the order of 10%.
Now multiply A and B: 3.71/3.21 = 1.16 K/doubling +/- 10%
So: is your problem with (A), (B), or both? Or the whole procedure?
Mathematically I think both (A) and (B) are well-defined problems. Your objection therefore must be physical. It cannot be simply that convection is neglected, because it is not: to lowest order, convection is accounted for in both cases by using the current lapse rate. I could, however, think of other objections:
(O1) keeping the lapse rate constant (in the prescription for A? for B? for both?) is physically unrealistic for some reason (which could be, but the retort would be simply that that’s how we choose to define what we mean by “no feedbacks”).
(O2) the estimate of (A) in the paper [2] is not really done by following the prescription in (A) in detail (which could really only be done with a radiative transfer calculator, or even a GCM), but rather by treating the atmosphere as a sort of attenuation filter with a transmissivity that–at constant GHG concentration and lapse rate–is approximately independent of the surface temperature (incidentally, this was more or less inspired by a model of SteveF’s, which he posted here long ago).
Re: julio (Mar 30 14:23),
Doing the inverse of step A, determining the change in radiative forcing at the tropopause for a change in surface temperature: If I increase the surface temperature offset by 1 degree, using the same conditions as above, surface emission increases to 365.182 W/m² for an increase of 4.71 W/m² and downward emission increases to 261.625 W/m². So the radiative imbalance increases to 103.557 W/m², a difference of 1.778 W/m². The emission at 12 km increases to 267.811 W/m², or an increase of 3.549 W/m², pretty close to Bony’s number of 3.21 W/m² for a 1 K change.
Now for step B. Doubling the CO2 from 375 to 750 ppmv reduces emission at the tropopause to 260.777 W/m² or a reduction of 3.485 W/m², pretty close to 3.71 W/m². That reduces the radiative imbalance at the surface to 98.879 W/m².
As I pointed out above, combine steps A and B and you don’t get back to the status quo ante with just the surface and atmosphere temperature higher. Therefore the calculation of a Planck only feedback is flawed. It gets you a ballpark number at best, certainly not ± 10%.
Re: DeWitt Payne (Comment #93981)
I think I’m beginning to see. But you don’t really, physically, combine A and B; you only combine them mathematically. The idea is to use the information you gather from A to predict the temperature change at the surface caused by B.
In your case, it looks like (A) a reduction in upward flux at the tropopause of 3.549 W/m^2 *could* be compensated by an increase of 1 K at the surface, and it also looks like (B) a doubling of CO2 would be equivalent to a reduction in upward flux at the tropopause of 3.485 W/m^2. So to compensate for that you would have to raise the surface temperature by … 3.485/3.549 = 0.98 K.
(This looks more or less like what I always get from MODTRAN, a sensitivity of about 1 K.)
In fact, I just tried the “experiment,” and it works: with 375 ppm of CO2, the flux out from 12 km is 264.262 W/m^2. Doubling CO2 brings it down to 260.777 W/m^2, or a reduction of 3.485 W/m^2, as you said. Then, increasing the surface temperature by 0.98 K brings it back up to 264.2 W/m^2… which is almost right where I started.
Carrick (Comment #93939)
Carrick,
A fair post. However, that logic means that the last 15 years or so have had less uncertainty than before. Therefore the lack of warming lately is a more accurate representation than any temperature set beforehand. Therefore the lack of correlation between CO2 rise observed and the warming (and cooling) observed in the last 15 years is further refutation of the CO2 = significant warming ‘theory’. 🙂
I do take your point about uncertainty, but it is a shame that that argument wasn’t more stringently pursued back in 1998 when MBH98 was lauded as ‘fact’.
Steven Mosher (Comment #93944)
Steven,
I DO take account of what Carrick says. We sometimes disagree but I know that he, like SteveF and many others here, has a great deal of knowledge.
.
And of course ‘warmists’ and ‘contrarians’ will always try to enforce their own slant on data. This is why I always ask that people are objective about data. Now the argument that uncertainty was greater in the early days has to have some merit, although I suppose it can be countered by the argument that – just possibly – the measurements in the early days were both highly accurate and more objective (if the charge of bias is worthy of debate). Against that, maybe the number of stations was either insufficient or too random. I’m really not sure. I do think the people who took the measurements 150 years ago were both proud and professional in their work.
.
Please see my answer to Carrick ref uncertainty and data recently.
Carrick and Steven…
There is also the point that the HadCRUt data (shape) is virtually identical with the UAH satellite data since 1979. It might therefore seem churlish (although it may be a valid point here, that the HadCRUt data before 1979 was far from accurate.
Carrick (Comment #93947)
[“…and what Arfur says here is definitely the consensus view in climate science—the beginning of the AGW age was circa 1970, not prior to that. “]
Just to be clear, I did say ‘according to some’. I wasn’t saying it myself, although I’m not saying it is wrong; but maybe unproven.
Interestingly, the IPCC states that the beginning of the AGW age was circa 1750!
julio (Comment #93940)
[“Regarding the decadal trends, I will agree with you that the similarity between those warming trends you highlighted, as well as the recent slowdown, are hard to reconcile with a very large climate sensitivity.”]
Thanks julio. That is the main point of my argument.
Nick Stokes (Comment #93946)
[“Well, maybe some. But it’s not really true. Here is a plot of the GHG forcing (mainly CO2) against Hadcrut3.”]
Noted. But now re-plot that graph back to 1850. The CO2 levels are virtually flat but there is significant warming around 1860-1880. Very significant. That cannot be attributed to CO2.
Last post on this, I promise! It’s just that I just thought of a really simple way to look at this. I’m thankful to deWitt for helping me to think about it the easy way, which is to say backwards 🙂
So: to get the Planck parameter we just need to answer the following question. If you increase the surface temperature of the Earth by 1 K, how much extra radiation goes out to space?
If the Earth radiates as a blackbody at temperature Ts = 288 K, the increase in radiation at the surface will be approximately 4*sigma*Ts^3 = 5.42 W/m^2.
Setting mu =1 in the paper [1] amounts to assuming that all this extra energy goes straight out to space. This is absurd, on the face of it, since we know that currently, with the GHG being what they are, the flux out to space is only about 61% of the flux radiated by the surface.
The approach taken by the authors of [2], instead, amounts to saying that a more logical starting point is to assume that only approximately 61% of the extra 5.42 W/m^2 will make it out to space. This gives 0.61*5.42 = 3.3 W/m^2 K for the Planck parameter, pretty close to its “official” value.
arfur.
the early data is sparse.
Yes. the “warming” you see in 1850-1880 is probably not due
to C02.
That has nothing to do with the physics of what happens when you increase C02.
Finding warming when C02 is constant says nothing whatsoever about the effect that increasing C02 has.
What it points to is what we all know:
warming results from many factors. Including C02.
julio (Comment #93989),
Simpler is usually better. 😉
Gives the right answer is good too.
julio,
One final thought. So the canonical value (1.1C – 1.2C per doubling, absent feedbacks) is agreed to by almost everyone. The next important factor is the assumed increase in specific atmospheric humidity with rising surface temperature (the worst case being constant relative humidity… at best uncertain) which might double the equilibrium sensitivity value to 2.2C – 2.4C per doubling. It is only if one also believes clouds are strongly positive on average, and there is only weak/uncertain evidence, that you can plausibly reach the middle of the IPCC range.
So what do you think, can reasonable people agree the upper part of the IPCC range (>3.1C – 4.5C per doubling) is extremely unlikely?
Re: SteveF (Comment #93992)
Well, I consider myself reasonable, and I find it very unlikely, but I’m not a climate scientist! 🙂
James Annan strikes me as reasonable and he seems to think that the large values are becoming less and less likely, but he would probably still not exclude 4 C/doubling at this point.
You may like this picture here: http://julesandjames.blogspot.com/2012/03/bayesian-estimation-of-climate.html
Also, you know what I always say: if you have an asymmetric distribution and you need to bet, bet on the mode, not the mean!
Steven Mosher (Comment #93990)
Steven,
I agree with your last sentence. I have always said that CO2 can cause ‘some’ warming. But I also agree with Skeptikal that the attribution of CO2 to the GE is very small. It is the significance of the warming that is in question. I’ll repeat what I said at the start of my posts on this thread:
The physics of what happens with one single CO2 molecule is not in doubt. The physics of what ‘global’ CO2 will contribute as a component of the atmosphere is very much in doubt in a quantitative sense.
But thanks for your input.
Nick Stokes (Comment #93946)
March 29th, 2012 at 10:40 pm
——————————————–
Thanks for doing the interactive plotter – very useful.
Thanks, Owen,
I’m hoping to get Ver2 out this month.
julio (Comment #93993),
Thanks for the James Annan link. Maybe he is beginning to come to his senses? 🙂
.
But seriously, there is a good argument to be made to work towards lower CO2 emissions per unit GDP. There is no reasonable argument to be made for impoverishing people to avoid CO2 emissions… whether they are already rich or still poor. As Bill Gates correctly notes, what poor people need is cheaper and more reliable energy, not more expensive energy.
.
So IMO, the real conundrums we face are: 1) how do we make energy cheaper and more reliable for the world’s poor? and 2) how do we keep the nut-cake extremists from damaging the global economy in the guise of saving us from utter destruction/doom?
“Arfur Bryant (Comment #93999)
April 1st, 2012 at 1:55 am
Steven Mosher (Comment #93990)
Steven,
I agree with your last sentence. I have always said that CO2 can cause ‘some’ warming. But I also agree with Skeptikal that the attribution of CO2 to the GE is very small.”
##########
I am amazed at the certitude skeptics have WRT the small effect of c02.. when so little is known. Im also amazed at the certitude that the effect is Large.. when so little is known.
here is how I think about the problem.
Julio ( and others ) have some nice work from first principles
that shows an effect ( without slow feedbacks ) of somewhere in the neighborhood of 1-1.6C per 3.7Watts of forcing.
And we know that doubling C02 gives us ~3.7Watts of forcing.
For me, that means, to a first order we can say that a doubling
will lead to 1-1.6C.
Now what about feedbacks. For this, there is no simple analytical solution. Thats just a fact. There are only a few ways to estimate it.
1. observation ( long wait here)
2. Paleo ( noisy data)
3. Models. ( incomplete understanding)
All three lines of evidence point to final numbers > 1.5C.
And I think the probablity of it being > 3C is less than 50%
Now whether that is ‘big’ or unprecedented or dangerous is an entirely different conversation. First order, first principles, lands you between 1 and 1.6. Estimates ( guesstimates if you like) all point to numbers greater than 1.5. So in my mind our “best” knowledge says > 1.5C. is this knowledge good enough for policy?
Dunno. What policy? dunno. But, those questions dont change what our best knowledge is. Our best knowledge is what it is.
And that best knowledge says the effect is > 1.5C per doubling of c02. Questions about the the policy implications of that are not really relevant to the discussion about what the best knowledge actually is.
Steven.
I agree that our “frist order” understanding of the climate will lead to a >1.5 degree warming for a duobling of co2.
But since the climate is far from “first order” the obove is only relevant when comparing a future world with a doubling of co2 to a future world without a doubling of co2.
What i’m trying to say is that 1.5 deg warming doesn’t necesserily mean 1.5 deg warmer than now. It only means 1.5 deg warmer than a world without a doubling of co2. Based on current knowledge you can’t rule of cooling. I say predicting future temps is still a WAG or at best a SWAG even concerning the +- sign.
Andreas,
The current forcing from man made GHG’s is in the range of 3watts per M^2, while a doubling of CO2 represents about 3.7watts per M^2. That includes contributions from halocarbons, methane, N2O, tropospheric ozone and others. The trajectories for each of these are independent of CO2, although all except halocarbons will tend to increase with growing energy use unless steps are taken to reduce them. So looking at only CO2 does not accurately portray the situation. By the time CO2 reaches double its preindustrial level, the total GHG forcing will be significantly greater than 3.7watts per M^2. A reasonable estimate is somewhere near 5watts per M^2 or more….. but that depends on how much people try to control non-CO2 emissions.
Steve, the 90% CI in the work cited by James Annan includes values for CS <1.5C. I'm curious why you rule it out.
http://julesandjames.blogspot.com/2012/03/bayesian-estimation-of-climate.html
Steve, in the study James Annan mentions (thanks Julio) the 90% CI includes values for CS less than 1.5C. I’m curious why you rule out lower values than 1.5C.
Steven Mosher: I am amazed at the certitude skeptics have WRT the small effect of c02
Yep. “We really don’t know” is not the same thing as “we know it’s small”.
Re: Steven Mosher (Comment #94009)
Just to be precise, I do not know of any way to get 1.6 C/doubling without including water vapor feedback.
On the other hand, the existence of water vapor feedback is not in doubt, and as Steve pointed out above, it might well be enough to double the effect CO2 has by itself, so I personally think that reasonable estimates for the climate sensitivity should start at about 2 (and they probably should end around 3).
Re: Niels A Nielsen (Comment #94015)
That was an estimate based on a “uniform prior”, which is to say “assuming we don’t know anything at all about the climate sensitivity except the results of this study”. But there are probably hundreds of other studies, and the majority appear to exclude the 1-1.5 range.
Carrick.
It’s interesting to watch the difficulty skeptics have when you note the “certainty” they have about the effect being small. I’m seeing
the emergence of 4 distinct groups
1. Slayers and other nuts: GHGs have no effect. ( of course they
have no experimental data showing this )
2. Minimalist: they cannot deny tyndall experiements, or working
devices, so they must say c02 has an effect. They claim certainty that it is small. with no evidence.
3. Luke warmers: GHGs have an effect. sensitivity is somewhere
between 1.5 and 3. But it could be higher.
4. Alarmist. Sensitivity is between 1.5 and 6, but we need to be
worried about values above 3. and do something ( like waste money in the near term) because of that fear and uncertainty.
It’s hard being a rational creature and there are few lukewarmers in public, but the ranks are growing.
Steven Mosher (Comment #94009)
I am amazed at the certitude skeptics have WRT the small effect of c02.. when so little is known.
And, without wishing to do the whole ‘debating in the same style as your opponent’ thing, I am amazed that people who believe in the veracity of the radiative forcing theory cannot separate the theory from reality.
here’s how I think about the problem (well, actually, what exactly is the problem?).
We (ie you) have no proof of:
1. The portion of the the 0.8 C warming that has been observed since 1850. It could be anything from 0.01C to 0.79C. If anyone has proof of a particular figure, please produce it.
2. The quantitative figure for the warming effect of a doubling of CO2. All anyone has is a theoretical calculation.
3. The idea that the theoretical calculation of CS is then further increased by ‘feedbacks’. I remind everyone here that the 0.8C warming includes ALL forcings and feedbacks.
4. The idea that, somehow, the effect of CO2 (which, according to Schmidt et al, was powerful enough to contribute 26% of the GE) is subject to some sort of ‘thermal inertia lag’.
.
If you guys are so interested in the ‘basic science’, why can you not be objective in your assessment of the lack of real-world evidence (or at least something close to proof) that supports your theory?
.
There has been an increase in global temperature of 0.8C in the last 160 years. In the same time but not necessarily causal there has been a 40% rise in atmospheric CO2. The CO2 rise has a slight acceleration. The warming has no such acceleration. The CO2 rise has no periods of decrease. The warming has several. Logic would dictate that whatever has caused the cooling (or the flattening) periods is of sufficient power to counteract the theoretical effect of CO2. Logic would further dictate that the ‘whatever’ must have the ability to cause warming as well as cooling, in which case the warming periods between the cooling periods since 1850 could have been caused by the ‘whatever’. In which case the quantitative CS could be significantly lower than the 1-2 or 3C figures that have been mentioned here.
.
You say [“Our best knowledge is what it is.
And that best knowledge says the effect is > 1.5C per doubling of c02.”]
I say that your best knowledge is effectively a guess. That is not me being intentionally rude. It may be that the final ECS figure for a doubling of CO2 is in the region of 1-1.5C; unless we find out what the contribution is from CO2 to the current warming and the current GE, we simply don’t know. As we don’t know, why support the theoretical? I simply ask for some objectivity without presumption.
Steven Mosher (Comment #94024)
“..3. Luke warmers: GHGs have an effect. sensitivity is somewhere
between 1.5 and 3. But it could be higher.
4. Alarmist. Sensitivity is between 1.5 and 6, but we need to be worried about values above 3. and do something ( like waste money in the near term) because of that fear and uncertainty.
It’s hard being a rational creature and there are few lukewarmers in public, but the ranks are growing.”
I agree that the major difference between luke-warmers and alarmists is as you note above, but I really think what separates them is that generally alarmists see no major and troubling unintended consequences from government mitigation and thus they need no uncertainty limits on the amount of warming or the beneficial/detrimental effects of future warming. The luke-warmers are, on the other hand, in the political camp that generally sees unintended consequences from government attempts at mitigation and while they may see a wide range of possibilities for warming they need a good deal more certainty of the amount warming and potential detrimental effects of that warming before proceeding with government mitigation – as it would likely proceed given the current political climate.
There are others who are luke-warmers not so much from a political leaning but rather they would prefer government to allocate resources for what they see as more pressing programs, but they to want more certainty before diverting those resources to mitigation of AGW.
The science is what it is and is rather straight forward when advocacy remains on the sidelines. The politics are where it gets a bit crazy and primarily I think because people want to argue the politics based on the science instead of based on political philosophies.
For some reason, my edit did not take for this post. The above post should read thus:
Steven Mosher (Comment #94009)
[“I am amazed at the certitude skeptics have WRT the small effect of c02.. when so little is known.”]
.
And, without wishing to do the whole ‘debating in the same style as your opponent’ thing, I am amazed that people who believe in the veracity of the radiative forcing theory cannot separate the theory from reality.
.
OK, so here’s how I think about the problem (well, actually, what exactly is the problem?).
.
We (ie you) have no proof of:
1. The portion of the the 0.8 C warming that has been observed since 1850. It could be anything from 0.01C to 0.79C. If anyone has proof of a particular figure, please produce it.
2. The quantitative figure for the warming effect of a doubling of CO2. All anyone has is a theoretical calculation.
3. The idea that the theoretical calculation of CS is then further increased by ‘feedbacks’. I remind everyone here that the 0.8C warming includes ALL forcings and feedbacks.
4. The idea that, somehow, the effect of CO2 (which, according to Schmidt et al, was powerful enough to contribute 26% of the GE) is subject to some sort of ‘thermal inertia lag’.
.
If you guys are so interested in the ‘basic science’, why can you not be objective in your assessment of the lack of real-world evidence (ie proof) that supports your theory?
.
There has been an increase in global temperature of 0.8C in the last 160 years. In the same time but not necessarily causal there has been a 40% rise in atmospheric CO2. The CO2 rise has a slight acceleration. The warming has no such acceleration. The CO2 rise has no periods of decrease. The warming has several. Logic would dictate that whatever has caused the cooling (or the flattening) periods is of sufficient power to counteract the theoretical effect of CO2, feedbacks and lag. Logic would further dictate that the ‘whatever’ must have the ability to cause warming as well as cooling, in which case the warming periods between the cooling periods since 1850 could have been caused by the ‘whatever’. In which case the quantitative CS could be significantly lower than the 1-2 or 3C figures that have been mentioned here.
.
You say [“Our best knowledge is what it is.
And that best knowledge says the effect is > 1.5C per doubling of c02.”]
.
I say that your best knowledge is effectively a guess. That is not me being intentionally rude. It may be that the ECS figure for a doubling of CO2 is in the region of 1-1.5C; unless we find out what the contribution is from CO2 to the current warming and the current GE, we simply don’t know. As we don’t know, why support the theoretical? I sort of agree with Carrick that ‘I don’t know is not the same as ‘very small’ but there just is no evidence to support a large figure. I simply ask for some objectivity without presumption.
Steven Mosher (Comment #94024),
I agree with everything but #4. I think the accepted range for those folks is 2 C to >6 C per doubling, but more importantly, they believe the danger of catastrophic consequences is so great (the end of the human race is often suggested!) that any cost is easily justified…. including forced large reductions in energy use, economic activity, total wealth, and human population. They are actually just neo-malthusians like Tobis who have latched onto global warming as a means to reach their desired goals (the Club of Rome, zombie-like, seems never to die!).
“we had to destroy civilization in order to save it!” 🙂
to paraphrase a Viet-Nam-era general, I believe.
There is also the issue of conduction and convection.
The radiative forcing calculations are based on the “radiation” component only. The calculation is that backradiation should increase by 3.7 W/m2 more than outgoing longwave radiation increases as CO2 doubles and temperatures increase.
But the majority of energy flow in the lower atmosphere occurs through conduction and convection. How do these components change when the radiation component increases by 3.7 W/m2.
If the majority of energy flow in the lower atmosphere occured through radiation, then the Earth would cool off very rapidly at night – when the outgoing longwave radiation exceeds the backradiation by 50 joules/second. But it doesn’t.
Re:Bill Illis (Comment #94035)
This is not true. They are based on the current thermal equilibrium of the atmosphere, which indeed is primarily (though not exclusively) determined by convection.
That’s a good question, but it is a “feedback” question.
Steven Mosher, the other part of the equation, is nobody ever thinks they have any burden of proof themselves. Arfur’s little rant upstream of here is a good example of that.
Arfur Bryant (Comment #94027) said
“Logic would further dictate that the ‘whatever’ must have the ability to cause warming”.
Please explain this. Surely there are many possibly cooling agents that cannot cause warming.
And use “logic” in your explanation, since that is what you are claiming. Just saying “it’s obvious” wont do.
Arfur Bryant (Comment #94027)
4. The idea that, somehow, the effect of CO2 (which, according to Schmidt et al, was powerful enough to contribute 26% of the GE) is subject to some sort of ‘thermal inertia lag’.
The thermal capacity of the Earth (mainly the oceans) is not a property uniquely unlocked by CO2. Try to explain the shape of the global annual cycle of surface and lower-troposphere temperatures without incorporating a slower transient response of ocean surface temperatures to a change in forcing.
steveta_uk (Comment #94038),
If you want a ‘whatever’… look no further than the pacific ocean. It has warming and cooling cycles. It’s just ended a warm cycle and is now beginning to cool. Have a look at the sea surface temperature anomaly…
http://www.weatherzone.com.au/climate/indicator_sst.jsp?lt=global&lc=global&c=ssta
Notice the blue areas in the pacific ocean?… that’s cooling at work. But it doesn’t stop there. The pacific’s heat makes its way to the atlantic and the arctic through thermohaline circulation (the ocean conveyor belt). The last warm phase of the pacific is the reason the atlantic and artic are warmer than normal now. It takes a while for the water to circulate, but eventually the atlantic and artic will receive cooler water from a cooler pacific. When that happens, you’ll see just how insignificant a role your increased level of CO2 really plays.
Skeptikal,
The SST (which is what you’ve shown) doesn’t really reflect the overall “heating” and “cooling” of the Pacific Ocean. Also, the thermohaline circulation doesn’t do much to transport the near-surface heat in the Pacific to the Atlantic, etc.; certainly not on the time scale of the intradecadal “warm cycles.”
Skeptical (94040) I wasn’t asking for an example of a “whatever” that can produce warming and cooling.
I was asking for a logical explanation that shows that any conceivable “whatever” must have the ability to cause warming, which is what Arfur claimed that logic dictates.
Julio (94036) – Thank you. I’ve been reading this thread off and on, and that is the best simple explanation of that point that I’ve ever heard.
SteveF (94028) – “they believe the danger of catastrophic consequences is so great (the end of the human race is often suggested!) that any cost is easily justified”
My parents (aging Catholic hippies, if there is such a thing) subscribe to the progressive Catholic magazine Commonweal, which features this quote, which if not taken out of context, is more scary than climate change itself (particularly the last sentence):
“What happens if we take a less radical—and more politically palatable—emissions-reduction path? ….. then the world will likely warm by nearly 4°C by 2100. And this analysis, from Alice Bows and Kevin Anderson of the Tyndall Centre for Climate Research …. Kevin Anderson has expressed the gravity of our situation, calling our chances (in a world 4°C warmer) of avoiding mass death—the loss of more than 90 percent of human beings—“extremely unlikely.†This is not the opinion of a crackpot, but rather the judgment of the director of a major international climate center.”
Full article here: http://commonwealmagazine.org/%E2%80%98global-suicide-pact%E2%80%99
Re: BillC (Comment #94043)
Glad that helped! The article you quote is indeed really scary, but you can gauge its accuracy by how it starts: “And scientists are forecasting another 5 to 7°C (9 to 12.6°F) of warming over the remainder of this century.” 5 to 7°C ???
julio – agreed, just a minor point that you could probably discard the whole article and just read the Kevin Anderson quote as it is presented, as an expert opinion from a climate scientist that 90% of the human race will be wiped out by 4C warming. Whether or not that’s what he actually meant is almost beside the point…it’s even couched almost in IPCC-speak “extremely unlikely” – what’s that – 5% chance? So we have a 95% chance that 90% of us won’t make it…
steveta_uk (Comment #94038)
steveta_uk,
That is a fair question. When I said “Logic would further dictate that the ‘whatever’ must have the ability to cause warming.”, I was not referring to one single cause of warming or cooling but the ‘net’ effect of ‘whatever natural factors’ were in play at the time. The logic is that If any combination of natural factors are able to cause cooling, or at least a flattening, another combination of those factors has to be able to cause a warming. Otherwise we are left with the scientifically implausible explanation that only CO2 can cause warming, and only natural factors can cause cooling. No-one can say that there have not been periods of warming in the past when CO2 was not increasing, or at least not according to the available data. Closer to today, just look at the HadCRUt graph:
http://www.climate4you.com/images/HadCRUT3%20MAATand3yrAverage%20Global%20NormalisedFor1979-1988.gif
Most of the pro-radiation theory supporters on this blog will tell you that CO2 did not start being an effective warming agent until post 1950. And yet there are two distinct warming periods prior to that – starting 1875 and 1910. They were followed by cooling periods. If CO2 did not cause those warmings, then ‘whatever’ caused them. Similarly, ‘whatever’ caused ALL the cooling periods on the graph (according to warmists and luke-warmists). Therefore logically ‘whatever’ has some combination of factors which can either warm or cool, depending on the distribution of those factors. Either way, the natural warmings are, at times, identical to the supposed CO2 warmings. This indicates that no-one (repeat no-one) can say with any certainty that the ‘radiative forcing theory’ is valid. There is no evidence.
Paul S (Comment #94039)
[“The thermal capacity of the Earth (mainly the oceans) is not a property uniquely unlocked by CO2. Try to explain the shape of the global annual cycle of surface and lower-troposphere temperatures without incorporating a slower transient response of ocean surface temperatures to a change in forcing.”]
.
I quite agree. I did not say that thermal lag was impossible, just that it has not been proven that it is linked to CO2. Just out of interest, what is the lag (in years) of the slower transient response of the ocean surface temperature?
Carrick (Comment #94037)
April 2nd, 2012 at 7:06 pm
Steven Mosher, the other part of the equation, is nobody ever thinks they have any burden of proof themselves. Arfur’s little rant upstream of here is a good example of that.
.
What, you want me to prove that fairies don’t exist? 🙂
Re: BillC (Comment #94045)
You are right–I wonder how he calculates his probabilities?
In any case, I feel sorry for your parents (and all the other readers of Commonweal): they don’t deserve that kind of stuff. [At least, I don’t think they do. It’s true that some people seem to relish hearing predictions of doom as much as some other people enjoy making them… there’s a market for that sort of thing out there.]
julio,
Humm… I think you are correct about that. The weird thing (for me at least), is the divergence between the demonstrable improvement in humanity’s average situation and the howls of impending doom. Let’s see…. humanity is better fed than ever before (OK, too much better fed in many countries), humanity has never suffered endemic tropical diseases less, average wealth (indexed for inflation) has never been higher. Being poor in India or China today offers infinitely more opportunities than being poor in India or China 50 years ago offered. I could go on, of course. There are lots of things responsible for these improvements in humanity’s lot (the good will and effort of brilliant and thoughtful people like Norman Borlaug not least among them), but green hysteria and GHG warming ‘scare stories’ are, IMO, diametrically opposite; whatever they have done, it has impoverished and injured the poor… shame on them.
.
I sometimes think that a significant fraction of people believe it is morally required and ‘correct’ that people suffer horribly, and those self-same people seem truly shocked (and even saddened) when humanity’s lot is continuously improved.
.
Were I a religious person, I would guess the Malthusians are doomed to Hades…. but I am not.