As a number of folks already know, I’ve been working over the last year on a paper trying to quantify the magnitude of the urban heat island effect on temperature trends in the U.S. It builds on (and greatly expands) the approach outlined in a post here last March:Â http://rankexploits.com/musings/2010/uhi-in-the-u-s-a/
I’m happy to announce that our abstract has been accepted to present at the 19th Conference on Applied Climatology this summer in Asheville, North Carolina. We’re also planning on submitting the full paper to a journal in the next few months.
Assessing the urban heat island signal in the U.S. Historical Climatology Network monthly temperature data
Zeke Hausfather, Matthew Menne, David Jones, Ron Broberg, Troy Masters, and Claude Williams
Urbanization over the past century in the United States has contributed to a warming bias in some U.S. Historical Climatology Network (USHCN) temperature records.  While the impact of the urban warming bias is removed to some degree through data homogenization procedures, the extent to which the overall urban bias is corrected remains largely un-quantified.  As a result, additional urban-specific corrections are sometimes applied to the homogenized data.  In order to quantify the magnitude of urbanization bias in the dataset, and to quantify the extent to which the USHCN version 2 homogenization procedures correct for it, we examine minimum and maximum temperature trends from stations classified using four different proxies for urbanity–urban boundaries, satellite nightlights, population growth, and percent of impermeable surface, each created from publically available high-resolution GIS datasets. These urbanity proxies are used to segment stations into separate urban and rural sets, and temperature differences between the two are calculated using both spatial gridding and station pairing approaches. The analysis is performed on the USHCN version 2 time-of-observation-bias adjusted data and on data homogenized using NCDC’s pairwise homogenization algorithm.  Homogenized data that have been further adjusted using NASA GISS’s Satellite Nightlight urban adjusted data are also evaluated.  In addition, the pairwise homogenization algorithm is used to generate multiple versions of homogenized USHCN temperature data using comparisons solely with other COOP stations classified as rural according the four urbanity proxies and compared to homogenization results from the full COOP network.  The magnitude of the urbanization bias in the un-homogenized (TOB-adjusted) data and the degree to which this bias is mitigated with homogenization is discussed.
Congrats Zeke. Can’t wait to read it!
now if congress called you to testify would you pull a Muller?
Somehow I doubt any of us will be asked to testify. And our work is complimentary to but does not directly address surface station stuff. (I presume thats what pulling a Muller entails?)
That said, I am looking forward to playing around with interaction between CRN rating and instrument changes when Anthony releases the metadata. Would also be interesting to test the relationship between site quality and urbanity.
Cool! Who knows, maybe you will be invited to testify. If you do, you can let us know if ‘pre-interviews’ occur prior to the invitation.
No pulling a Muller is talking about preliminary results. That’s unheard of.
On site quality it would be interesting to look at the variablity over time, looking at daily data. If I’m right you would see a higher variability for poor sites.
Way to go Zeke! I look forward to reading it.
Congratulations to you Zeke! Now on to running the peer review gauntlet, though I’m sure it will be easier for you than me and everyone on Fall et al since you have the “right people” onboard. 😉
I’m pretty sure I ended up with at least one of those at NCDC as a reviewer.
Congrats to Zeke and fellow authors. But won’t the full paper require a title with an embedded pun (or pop-culture reference, literary allusion…)? Back to work!
🙂
it’s an interesting abstract, and partly for what it doesn’t address. You don’t give any results ! Presumably you will have results which demonstrate something, before you discuss their implications 🙂
can you give any hint, in broad brushstrokes, of whether different measurement methods make a difference, or if UHI is significant ?
per
Well done Zeke and coauthors.
Does your paper, like that of Anthony Watts, find no evidence of distortion of mean temperature trends over time?
I guess that would depend on what the meaning of the word distortion is.
http://pielkeclimatesci.wordpress.com/
Re: per
That abstract is simply the one submitted for the conference…I believe the one for the paper itself will contain actual results. Anyway, we still have some tests to run before the paper is ready for submission to a journal, so as Steven Mosher pointed out we don’t want to be discussing preliminary results. But I think it is safe to say that using different urbanity measures can yield different results, yes.
Anything else is up to Zeke if he wants to reveal 🙂
What it also found is
Which is what others have found already. Such a finding is to be expected, that the errors above and below the real temperature will tend to cancel each other out.
We will be discussing results at the conference. I can say that there is definitely some urbanity-related bias in the TOB data, and the big question (that we are working to address) is how much of this bias is removed by existing homogenization procedures (both the PHA and NASA’s nightlight correction).
One of the novel parts (inspired largely by Troy’s work) is:
“In addition, the pairwise homogenization algorithm is used to generate multiple versions of homogenized USHCN temperature data using comparisons solely with other COOP stations classified as rural according the four urbanity proxies and compared to homogenization results from the full COOP network.”
The idea is to test how much (if at all) the PHA “blends” the UHI signal by using urban co-op stations to adjust rural USHCN stations.
“The poor science that passes peer-review will eventually be shown to be incorrect. The good science that is incorrectly rejected initially has generally been published eventually and has, somewhat belatedly, contributed to the base of knowledge.”
-UK Science and Technology Committee review of peer review
Submission by the American Meteorological Society
[8 March 2011]
I wonder if anyone has any examples of this phenomenon they can point to? I’d like to see it/them, if anyone can come up with one/some.
Andrew
thanks for your helpful answers
per
bugs:
That’s not something, as an experimentalist, that you can count on. In fact, I’ve seen plenty of examples where the errors didn’t cancel.
If you had two errors, that were uncorrelated and equal in magnitude E, you’d expect to see an error in the mean introduced on the order of E/sqrt(2). The exact cancellation of errors is extremely fortuitous.
Troy and Zeke I’m really glad you guys joined forces.
@Carrick
Sure, there will be cases where the errors don’t cancel out. But in the relentless surface temps war waged by Watts, he has made it perfectly clear, the only bias could be up, and by a significant amount. His one sided presentation of the issue has been one, endless rhetorical question of ‘look at this picture, can the measured temperature rise be real?’. Eleventy, leventy. Pielke Senior makes sure that the !!!! is up the top of his post, but leaves the real meat in the middle that I highlighted. The errors pretty well balance out.
Bugs.
Guess what? watts gets to speculate ALL HE WANTS. you get to ignore it. others get to swallow it. some get to wait for the data to make a decision.
So today you get to say I told you so, others get to eat crow or spit some new nonsense, and some of us get to say ‘nice’ Now we know more.’
nothing will ever change that. so what’s your point
Steve:
Yep, absolutely correct. And even more to the point, people should state their biases up front.
I don’t view Watts as playing it down the middle (I’ve been known to criticize him at times), but then neither do I view Tamino in a different light. The only difference is Tamino is too big of a coward to actually engage people who don’t rubber stamp everything he has to say. At least Anthony lets people (who are reasonably behaved anyway) comment on his blog. (Let the tu quoque arguments begin.)
Also, for bugs, what I was really trying to say is… actually “the errors almost never balance out”. That is as uncommon as making the errors double in size.
If somebody is really trying to sell you that one, you might want to ask them if they have a deed for the Brooklyn Bridge or one for an Arizona beachfront property.
bugs, you wrote in #75899,
> Which is what others have found already.
This was in reference to Fall, Watts et al’s abstract,
My impression is that these authors are saying that this is a novel result. So, could you point to the others who have already shown this?
(Not a rhetorical question.) 🙂
Andrew_KY (Comment #75902) May 14th, 2011 at 1:15 pm
“The poor science that passes peer-review will eventually be shown to be incorrect. The good science that is incorrectly rejected initially has generally been published eventually and has, somewhat belatedly, contributed to the base of knowledge.â€
-UK Science and Technology Committee review of peer review
Submission by the American Meteorological Society
[8 March 2011]
I wonder if anyone has any examples of this phenomenon they can point to? I’d like to see it/them, if anyone can come up with one/some.
Andrew
The most obvious one that comes to mind is Maiman’s paper describing the first Laser, it was rejected by Physical Review Letters. When the editor,Goudsmit, wouldn’t change his mind the first laser was described in a short note to Nature.
The odiferous emanations from this stunt resemble that of the steam arising from fresh cow pies on a brisk morning. Let’s see, we are introducing some new material without previously releasing the data or results to a conference. We are using that good old USHCN v2 which claims to find a background signal of .6 while missing discontinuities at an average of .4. And most le-pew… we are presenting this UHI work at an adaptation conference. Is there a trick to hide the decline or find the missing heat in there somewhere?
@AMAC
I thought that was what Menne 2010 had already established, not to mention informal work from Zeke.
http://www1.ncdc.noaa.gov/pub/data/ushcn/v2/monthly/menne-etal2010.pdf
@AMAC
I would guess the novel result is Watts saying that all his work in making repeated accusations of fraud and malfeasance have come to naught.
Thank u phil. Anything climate related?
Andrew
Seriously what a dog and pony show.
Andrew & MikeC have you read this? http://noconsensus.wordpress.com/2011/05/08/delta-t/
Carrick and Mosher have already commented there.
Zeke, I look forward to reading your paper. Your announcement here allows me once again to pronounce my views on UHI. I will give my condensed version.
In my view, UHI adjustments fall directly into the category of homogeneity adjustments, since moving temperature measuring stations, even within a urban locale or changing the environment around a permanent urban station, can be more influenced by the micro climate then, let us say, the number of lights that are left on in an urban area at night and sited by satellites.
That you mention paired station differences and break points as used by USHCN for temperature adjustments and measuring homogeneity and referencing the Watts data on CRN ratings in the same breath as UHI is encouraging. I would hope you could make statements in your paper regarding uncertainty limits that effects like micro climates and lack of homogeneity can have on the historic temperature records. Better still would be using some artificial data to test the efficacy of paired station breakpoints in detecting non homogeneities. Looking at population changes and satellite images of the night lights would be not so exciting in my view.
Re: bugs (May 15 01:44),
Thanks, bugs. As I understand it, Menne 2010 analyzed a subset of the data collected by Watts’ group, so it makes sense that the results of the two studies would be similar.
From Menne’s abstract,
So Falls, Watts et al’s results seem consistent with but not identical to those of Menne et al.
liza,
Yes I did read it.
It further answers Lucia’s “What adjustment to the adjustments?” question of yesteryear.
Andrew
liza, I read it after you linked it. While Mosher is one of those guys who you have to watch like a hawk (McI would say keep your eye on the thimble) he is correct in his comment there. But the most informative part of that posting is how well carrick is coming along.
I hear ya MikeC. 🙂 Glad you finally got your answer AndrewKy 😉
Speaking of micro climate…it rained and was cold this morning…sun’s out now but wind is chilly. We’ve been running at up to 12 degrees below normal around here (last summer was below normal temps too). Be interested to know how all that came about with so much C02 and cement here. 😉 I’m an old California girl and have never see this kind of cold weather in the middle of May..when kids are getting ready to get out of school or graduate and head for the beach. 🙂 We should be swimming in our pool!! Happy Sunday!!
Folks who still worry about adjustments will have to wait for the BEST results.
I’ll make a prediction. The answer wont change. Same way I told you that the micro site effect was real, but small.
basically, you have 1 major adjustment That is the TOBS adjustment.
Since about 2007 people have raised a huge stink about TOBS. At first it made no sense to me. A reader at CA JerryB did some great work showing and explaining the adjustment in the US. There are two main takeaway points
1. The adjustment is needed. without it you get a biased answer. You can prove this to yourself by plowing thru Jerry’s data.
2. The UNCERTAINTY due to the error of prediction has never been included in the final error analysis.
The corrections are needed, the model that does them is sound, but they need to account for the additional error.
When BEST is done you’ll have a series that has no “artificial” adjustments.
Then we will be down to some really silly arguments, which silly people will still make.
Those silly people will not see that the real debate is open. what is the sensitivity. They are invited to that debate, but they will not partake. That would require them to get off their hobby horse and learn something new.
Re: Kenneth Fritsch (May 15 10:11),
go see troy’s work on his blog. when I saw his work on synthetic data I think I suggested that he and zeke talk, or maybe it was zeke who referred me to troy. doesnt matter. Troy was posting some solid work and I anxiously await the results from 4 guys who all do solid work. ron, zeke ,troy. and D Jones.
steven, you mean silly like when you said “we” had no evidence for the LIA in Death Valley? 😉
So who is participating in the real debate of what climate sensitivity is?
Re: liza (May 15 18:28), Sorry liza, you fact challenged. You still don’t get the argument. You can argue that it was colder in the death valley in the LIA than it is today. It was. But that belief commits you
to ACCEPTING the measurements today.
You cannot argue that it was colder there in the LIA and at the SAME TIME question the record today. Get it?
You cannot ( as you have) argue that we cant trust the temp record today AND also argue that the LIA was colder than a temperature you mistrust.
You want the LIA to be real. Nice, that commits you to these beliefs
1. Its warmer today
2. the concept of a global average is meaningful.
is mikeC your husband?
That’s a ridiculous response steven mosher. I could completely distrust the modern temperature record and still make claims about past temperatures in relation to present ones. I don’t need the modern temperature record to tell me there have been ice ages where it was colder than current times. It doesn’t matter whether temperatures in the last hundred years have gone up by .2, .8 or 1.4 degrees if I’m comparing now to a time when temperatures were five degrees lower.
One only has to accept the modern temperature record if one’s beliefs depend upon the precision of it. Otherwise, one’s beliefs are unaffected by it.
Whoever supports a weak effect of perturbations of the stations must assume the paper Böhm 2001 : http://onlinelibrary.wiley.com/doi/10.1002/joc.689/pdf
Who here is ready to accept the explanation of the origin of bias adjustments given page 1784 ?
Michael Hauber (Comment #75928) “So who is participating in the real debate of what climate sensitivity is?”
Roy Spencer would be an example on the “skeptical” side.
Brandon Shollenberger (Comment #75930) ” I could completely distrust the modern temperature record and still make claims about past temperatures in relation to present ones.”
Not without great difficulty and certainly it would be hard to put any sort of numbers on it. But you also missed Steven Mosher’s other point “the concept of a global average is meaningful.”
If you talk about things being colder IN GENERAL in the past (rather than say just colder in Birmingham or colder in Vladivostok) then you are accepting that it is meaningful to talk about global temperatures that way.
Perhaps there is some fingers-crossed sub-clause that makes it meaningful to talk about LIA with great creedence and still doubt the current instrumental record but it would be quite an acomplishment (and I’ve never seen anybody pull it off). But you certainly can’t claim there was some global Little Ice Age decline in temperature AND claim that global temperatures aren’t meaningful.
Heh. You are the ones who mostly don’t trust the modern temperature records. You have to adjust them. I admit I have a problem with saying you know the ave temperature of the entire state of Alaska in the early 1900’s when there was like two thermometers set up.
The evidence for the LIA in Death Valley was there. Steven pronounced there wasn’t any. That was silly. That was my point. And I agree that it is warmer today then during the LIA. I also suspect the MWP happened and the “warm” was similar to today and it had nothing to do with the C02 content of the atmosphere. Also I have provided evidence (ignored) that the climate can change much faster then you think it is doing right now. Who is fact challenged again?
The evidence for the LIA and many other glacial advances and retreats are recorded in Death Valley geology if you really care about a true Earth’s climate history. The evidence had to do with water and rainfall- not temperatures. But the patterns matched up with other evidences of glacial advances and retreats all over the world.
The concept of a “global average temperature” maybe useful to you and others (like to scare people) but your thermometers wouldn’t tell you that Death Valley had more or less water and rain during the LIA. I suspect more or less water and rain (clouds) has something to do with what the temperature will be like in Death Valley.
5,000 yrs ago the Sahara used to be green. Even if you had thermometers all over that area at that time of change, that data might be “useful” but it wouldn’t tell you anything meaningful. (Some scientists suspect a shift in the earth’s orbit was to blame.)
liza (Comment #75934)
May 16th, 2011 at 5:30 am
You have obviously never worked with raw data.
I feel a Kim moment coming on.
Data is not information.
Information is not knowledge.
Knowledge is not wisdom.
“You have obviously never worked with raw data.”
Yes I have. Temperature data as a matter of fact. For friction materials R&D in the automotive industry. Worked with it every day for over a decade. You obviously haven’t.
Hey, nobody for Böhm ? It’s about raw data and how they are adjusted. For wisdom, will probably leave the topic to find it.
Instrumental records from different sources show global temperature has been rising. I wish the records were wrong, and the temperature wasn’t trending up, but my wishing doesn’t make the records wrong.
IMO, if you don’t believe instruments, you shouldn’t be allowed to drive a car or fly an airplane.
Max_Ok it’s not about believing instrumental records or not. Its about knowing what the margin for error is between all those thermometers over all those years (not calibrated to each other) which I can reason and imagine being greater than or equal to the “warm” being reported on the graphs. Everyone is still arguing about fractions of just one degree. Then I read things like the latest installment on this website:http://www.drroyspencer.com/
Also whether that much “warm” is unusual or not for our planet and knowing what the NATURAL part of that warm is (and you can’t tell me natural is not a factor) important because the temperature has been “trending up” since the last glacial retreat about 18-12 thousand years ago when North America was half way covered with ice– up to 3 miles high. Sea level has been “trending up” since then too. Also “trending up” since the LIA …Oh no! 😉
I am not sorry for a warming earth; I am glad. It’s COLD in California and across the USA today…I am really tired of being cold.
liza (Comment #75939)
May 16th, 2011 at 7:18 am
I’ll repeat this for the hundredth time. They don’t need to be calibrated against each other. It’s about the changes they experience locally. That’s all. These local changes are callled anomalies. They are what is tallied up.
So repeat after me. The thermometers don’t have to be calibrated against each other.
Again.
The thermometers don’t have to be calibrated against each other.
Lisa,
If by not “calibrated to each other,” you mean some thermometers are consistently reading too high and/or some others are consistently reading too low, this need not be a problem when measuring change. Likewise, where the thermometers are located need not be a problem when measuring change.
Plus, you have consistency between the surface temperature trends (as measured by thermometers) and the sattelite-based temperature trends.
Max_OK ,
“Plus, you have consistency between the surface temperature trends (as measured by thermometers) and the sattelite-based temperature trends.”
Not for the land in the northern hemisphere. The divergence is 0.1 ° C per decade between UAH and CRUTEM.
“IMO, if you don’t believe instruments”
Max_OK,
This is how befuddled you Warmers are. It’s not about believing instruments. We can’t observe the instruments. It’s about believing what someone tells you. At that point you appeal to authority.
You got nothing, dude.
Andrew
“the thermometers don’t have to be calibrated against each other.”
You have no standards!
And Steven Mosher doesn’t know if the adjustments or the adjustments to the adjustments are justified. They are after-the-fact. Yet he pretends like he does.
Oh, lets see what numbers come in and we can change them if we don’t like them. Yeah.
Andrew
Andrew,
I doubt the four major global temp metrics are products of people trying to put one over on me.
“I doubt the four major global temp metrics are products of people trying to put one over on me.”
Max_OK,
Personal incredulity on your part does nothing to advance anyone’s knowledge.
Got anything else?
Andrew
Re: Andrew_KY (May 16 08:47),
Umm. Pot, kettle, dark color. Once again irony increases.
Adrew,
Common sense .
Max_OK,
“Common sense”
Appeal to Thomas Paine? 😉
We are kind of getting away from anything resembling evidence here. Which is where all discussions with Warmers eventually go.
Andrew
DWP,
OK, so it’s your personal incredulity vs mine. And there’s still no evidence of AGW for anyone to see.
Andrew
Andrew,
Evidence won’t make me believe something I have decided to refuse to believe. But so far in life, there isn’t anything I have decided to refuse to believe.
Re: steven mosher (May 15 22:54),
> You cannot argue that it was colder there in the LIA and at the SAME TIME question the record today. Get it?
Steven, you have gone over this ground with Liza in previous threads.
I have also covered this material with Liza in a comments to a prior Blackboard post.
The prospect of a “meeting of the minds” is somewhat less than the likelihood that increasing CO2 in the atmosphere will be shown to be a forcing for generalized cooling.
It might be more profitable to link to one of those threads, so any interested reader can review the parties’ arguments. (Liza, Steven — I don’t have a URL cached; do either of you?) Then, we could leave more room on this thread for Zeke.
“Evidence won’t make me believe something I have decided to refuse to believe.”
So much for science. And note this is from a Warmer. Not a coincidence.
Andrew
Andrew,
Now you are cherry-picking from my statements. There’s no need to pick . Everything I say is good.
“Everything I say is good.”
Don’t look like it from here, Max. FYI.
Andrew
“> You cannot argue that it was colder there in the LIA and at the SAME TIME question the record today. Get it?”
I am not questioning the record like you think I am questioning it I am questioning EVER SINGLE THING like…what you assume from it how it’s handled, where it came from, who used it and what you go on to push for its meaning…when you have NO CLUE and are just guessing. And the observations are NOT matching the parts of the hypothesis…so you fudge and make up more stuff! I say it’s pretty much meaningless at this point what the “global average temp” is or not and I say it doesn’t show what you think it shows when it goes UP OR DOWN. Holy cow, there are no standards. Just making it up as you go along you are! And the worst of it gets fed to the public faster then fast and the mistakes when they are found do not. This paper right here is trying to “quantify” the UHI effect AFTER this AGW hype has been fed to the public already. I don’t trust any of it any more and I’m not alone.
What did having these temp records help anybody with lately? How were they useful? Did they prepare anybody for anything? How about for these floods due to MORE SNOW this past winter? NOPE!
Whatever Amac!
Andrew,
Since we aren’t edifying one another, I will excuse myself, and catch up on some chores.
Re: liza (May 16 10:20),
Hey liza, can you by any chance link to that thread a couple of months back where you and I discussed this stuff? I thought we each took some care in putting our respective arguments forward. (I’m annoyed that I can’t find it…)
“You cannot argue that it was colder there in the LIA and at the SAME TIME question the record today. Get it?â€
Of course you can. Whatever Record you may mean (and it’s not obvious from your confused comments) may have be “better” representing the past than it represents today.
Simple.
Andrew
Amac..I will search later today. Gotta go live life (in a sweater in May!) right now. 🙂
Thanks AndrewKy@75960 🙂
Nyq Only, I’m afraid your response to me is no better than steven mosher’s response was:
You claim it would be very difficult to say the Little Ice Age (LIA) was cooler than current times without the modern temperature record. You didn’t address the explanation I provided, so I’ll try a slightly different one (which I hope you don’t ignore as you did the former).
There is proxy data used to make determinations about the LIA. This proxy data extends into the 20th century. Because it covers both the LIA and a portion modern times, we can use it to compare temperatures. There is no need for the modern temperature record in this.
I’m curious how you take me responding only to one issue as me missing another issue. It’s much simpler to think I didn’t respond to that issue because I wasn’t discussing it. It had no bearing on the topic I was discussing so I had no reason to discuss it.
Oddly enough, by claiming I missed the point, you create the assumption I dispute the point. This is setting up a false argument for you to argue against. In other words, you created a straw man.
All in all, your response is very strange.
Liza
I suspect Death Valley will remain hot and bone dry until such time valley floor rises and it no longer below sea level or until a big fizure forms connecting it to the ocean. If the former happens death valley might not be in a tremendous rain shadow; if the latter it will fill up with sea water.
Amac
Maybe I should set up the “Liza & Andrew_KY Cretaceous Wiggly-line” thread and just route all their comments there. When it hits 300 comments, I create “Liza & Andrew_KY Cretaceous Wiggly-line part II” ? It’s definitely a bit tiring to have nearly every comment thread become a debate involving whether or not one should believe in averaging or how we need to put current temperatures in context of the Cretaceous.
Lucia, setting up threads for repetitiously the same, off-topic, never anything new, comments (and responses to those comments) seems like a great idea to me.
Wondering if it would be difficult to add something like this in the original thread:
{comment and responses moved to url}
“Maybe I should set up the “Liza & Andrew_KY Cretaceous Wiggly-line†thread”
Sounds like a good idea to me.
You could also set up the “Carrick and bugs General Agreement Thread” and the assuredly dynamic “Steven Mosher ‘It’s All We Have’ Thread” and the “Lucia Documents and Understands All The Adjustments and Their Adjustments Thread.” 😉
Andrew
Andrew_KY– It’s my blog. 🙂
Carrick– If I set that up, I think I could do leave a message noting they left a comment. It’s a little work–but it’s a matter of creating just changing the comment-post id on the comment and then creating a fresh comment on the original post. I’d only show it the first time they commented on a thread. That would prevent someone from just leaving a long series of “X commented, visit url to read”.
If I did this, I’d just identify specific people and put them on a list a that automatically moves all their comments to the “wiggly line” thread until such time as I decide they have stopped mono-maniacally derailing thread to discuss things that happen on geological time scales or the theory of “wiggly lines”. Since their comments would never appear on any other threads, there would be no replies moved.
Brandon Shollenberger (Comment #75962) “There is proxy data used to make determinations about the LIA. This proxy data extends into the 20th century. Because it covers both the LIA and a portion modern times, we can use it to compare temperatures. There is no need for the modern temperature record in this.”
Proxy data is neccesarily NOT temperature data but something that has some correlation to temperature hence my comment “not without great difficulty”. Whatever proxy data you use you need some way of matching the proxy to actual temperatures and some way of knowing how much the proxy varies independently of temperature. Consequently you need some actual temperature data to match that with. Doing that WITHOUT modern instrumental data would be difficult. Impossible? No – you might have some fundamental substantive theory from which you can somehow deduce a temperature in the past based on this proxy data that somehow you’ve developed without looking at modern instrumental data. That would be clever.
“I’m curious how you take me responding only to one issue as me missing another issue. ”
My apologies – I assumed that when you said “That’s a ridiculous response steven mosher” that you meant his response was ridiculous not that you disagreed with one part of it. I’m sorry for any confusion caused.
Nyq,
“Proxy data is neccesarily NOT temperature data ”
Well… this is a new and exciting revelation! 😉
Andrew
Re: Brandon Shollenberger (May 16 11:02),
We don’t measure temperature directly, we use proxies. We measure thermal expansion, electrical resistivity, EM radiation emission, etc. We have solid physics to relate these physical properties to the thermodynamic concept of temperature. Yet for some reason, you want to believe that measurements using these properties which are directly related to temperature and have at worst only minor confounding effects are somehow less accurate than tree rings, isotope ratios, etc., all of which are only partially temperature related and which have large confounding effects like precipitation for tree rings and sea level for deuterium isotope ratios.
Andrew_KY (Comment #75971) “Well… this is a new and exciting revelation! ”
Glad you like it – I have also breaking news about the defecation habits of bears.
Bugs,
Your ‘Kim moment’ is good.
Why don’t you follow it?
Nyq Only, the modern temperature record is made up of data which has been processed and combined into a singular record through various means. This product and the underlying data are not the same things. This means your point here depends entirely upon changing the position held by those you disagree with. Obviously, that doesn’t make sense.
A person who has no no faith in the modern temperature record could easily have faith in (some) temperature data.
Calling a response ridiculous doesn’t mean I am calling every single sentence in it ridiculous. As it happens, I actually do disagree with that particular sentence, but I figured discussing it would just derail things further.
DeWitt Payne, I think you’ve misunderstood me. I haven’t advanced any positions of my own or said what my personal beliefs are. That I responded to steven mosher to point out why his argument was wrong doesn’t mean I agree with liza.
I’m relatively certain I haven’t ever said anything about what I (want to) believe on this blog.
Lucia: “I suspect Death Valley will remain hot and bone dry until such time valley floor rises and it no longer below sea level or until a big fizure forms connecting it to the ocean. If the former happens death valley might not be in a tremendous rain shadow; if the latter it will fill up with sea water.”
Why do you have to be insulting and on top of it actually think you know what you are talking about lucia?
Death Valley is lake when it is cold with lots of vegetation all around it. Native Americans were living there just fine not too long ago. All the valleys near there are lakes. Owens Lake is just north and overflows into Death Valley during cold periods. I posted papers and data for all this before …IGNORED.
then you say “It’s definitely a bit tiring to have nearly every comment thread become a debate involving whether or not one should believe in averaging or how we need to put current temperatures in context of the Cretaceous”
No just in context in the of 125,000 years ago when it was way warmer then now and sea level was 20 ft higher. Or in the context of Death Valley being a lake when the glaciers advanced when the Native Americans lived there! These are normal climate cycles on this planet that have happened over and over again and not some big joke.
Ok maybe my question about who is participating in the climate sensitivity debate might have been to vague for anyone to understand what I am trying to get at.
I do see that this debate is mostly the domain of the climate scientists with Spencer and Lindzen pretty much it for the low sensitivity side. Most of the blogosphere doesn’t really participate in this debate but picks a side and cheers it on.
Perhaps comparing the modelled temperature trend to the actual temperature trend can be considered a contribution to this debate. But observing that over a specific time period warming is less than modelled does not say anything about climate sensitivity until you can decide which of:
1 climate sensitivity is lower than the models predict
2 something other than Co2 has had a cooling impact
3 Some of both, Factor X has caused Y cooling and when adjusted for this means that warming is still less than predicted so warming can be at most Z.
is most likely to be true.
The fact that we are currently in a strong solar minimum is support for option 2. Or it could be option 3 if we could quantify the solar cooling and put limits on it, and be confident that nothing else like PDO or some mysterious oscillation in the South Atlantic that no one has hear of isn’t a factor.
Liza,
I think the longer Lucia has to pretend she believes in AGW, the less friendly she becomes. I mean there are no more fun Haiku threads, fewer interesting personal stories and stuff that normal people might find interesting- hence fewer people particpating.
Instead we get the Zeke Show and Carrick and DWP whining about comments they don’t like. Pardon me, but Global Warming Advocacy and perpetual lukewarmerism only topics is pretty boring. That’s my opinion.
Andrew
Michael Hauber (Comment #75981) “Most of the blogosphere doesn’t really participate in this debate but picks a side and cheers it on.”
Fair point. The climate sensitivity argument is a subtle one and one that doesn’t lend itself well to political positions. For those on the ‘nay’ side it concedes too much ground to the ‘ayes’ – whilst for those on the ‘aye’ side it puts too much emphasis on aspect of the science which has the most uncertainty about it.
Circular arguments about grape harvests in the English middle-ages are more fun.
Andrew_KY (Comment #75983) “Pardon me, but Global Warming Advocacy and perpetual lukewarmerism only topics is pretty boring. ”
Perhaps Lucia should also add some exciting chase sequences and some explosions to the discussions. Maybe a mystery guest star or a surprise ending. Ooh those freaky Silence monsters from Dr Who! Or robots…
Liza–Must have been melt run off. The geography guarantees low precipitation.
Micheal–
There are other options.
4) Climate models get mixing uptake from the ocean wrong. (i.e. time scales are wrong.)
5) Some important physics could be missing. Cosmic rays and Leprechauns have been proposed, but it could be something no one has even imagined.
liza (Comment #75944)
May 16th, 2011 at 8:23 am
You mean I am not going to be able to accurately say what the temperature is. That does not matter. All I need to do is see how much they go up and down from their own base, whatever that is.
If I have two thermometers, one reads 20C, one reads 21C, what is the right temperature? Not sure about that, but it doesn’t matter.
If they both go up by 1C, then it has warmed by 1C. If they both go down by 1C, then it has cooled by 1C. That is all I have to do to see if it is warming or cooling, which is what I am most interested in.
Sorry for the off-topic comment, Zeke…
Robots!
(I have no clue what the linked page is about. But its title brought it to the top of my Google search.)
🙂
Bugs,
But if your two thermometers are both faulty how do you have any idea of what the temperature is doing?
NCDC/NOAA data for the contiguous US doesn’t show a warming since 1996. If UHIE under-adjustment is significant, then there has been no heating from before 1996 and actual cooling in the last few years.
I hope your paper discusses the ramifications of your work on the hyped temperature record, at least for the contiguous US. Most non-fact checkers thinks that “global” warming is global.
@Dave Andrews.
They can both not be reading the temperature accurately, and we are still OK, we are only interested in the deviation relative to themselves that they record.
… we are only interested in the deviation relative to themselves that they record.
Not completely correct. We are also interested in WHY the deviation occurs.
Re: Dave Andrews (May 17 14:57),
That’s why thermometers are calibrated at regular intervals against standards. Standards can be a thermometer with a recent calibration traceable to NIST or against standards with known freezing points or boiling points. Distilled water ice in distilled water is going to be very close to 0 C and the boiling point of distilled water can be corrected for atmospheric pressure.
DeWitt, I’m guessing (minding reading time) Dave was referring to microclimate and siting effects on the thermometers, and since these change with anthropogenic activity, that’s a confounding effect.
Re: Carrick (May 18 09:32),
There’s a new post up at Pielke,Sr.’s that addresses just that issue. The KNMI observatory ran 5 parallel sites for 2 years.
Bugs,
The KNMI study shows the effect of local factors on temp measurements over a relatively small area.
We all know this of course because we live in the real world and temp varies considerably locally. So how can we support extrapolation across 1200 km as GISS does?
Lucia, I agree point 4 (models get ocean uptake wrong) is another important option.
Re: liza (May 16 16:43),
“Death Valley is lake when it is cold with lots of vegetation all around it. Native Americans were living there just fine not too long ago. All the valleys near there are lakes. Owens Lake is just north and overflows into Death Valley during cold periods.”
True. And if there were more C02 in the atmosphere during these times, it would be warmer than it was.
That’s the point liza. Nobody believes that the earth has gone through ups and downs. The point is this. AGW tells us that additional warming will be imposed ON TOP OF these variations. That is what the physics tells us. More GHGs, means it will warmer than it would have been without them. That says nothing about the historical record.
Now, to be sure, some silly people have tried to make the argument for AGW from the point of view of ‘unprecedented’ changes. I think these arguments are weak and unnecessary. We know all we need to know when we realize that more GHGs means warmer than it would be with less GHGs.
How much warmer? good question
How much danger? good question
What should we do? good question.
Is it warmer now than some time in the past? silly diversion.
Dave Andrews (Comment #76059)
May 18th, 2011 at 3:26 pm
It doesn’t matter.
There is something interesting which pops out of the analysis from Fall, et al.