The Blackboard

RyanO wins, it seems, unless we are playing using Price-Is-Right rules.

Lucia:
Can you provide the trends for the entire UAH and RSS data record by way of comparing to the IPCC projection. I understand why you have the chosen 2001 – but I would certainly like to compare the satellite trend with the global land and sea trend(s). Eyeballing your charts it looks pretty close to .6C per Century.

Bernie: as of last month, the 1979-June 2009 slopes for the 4 main records were

Slope UAH: 0.123834799
Slope RSS: 0.152262236
Slope GISS: 0.159250092
Slope HadCRU: 0.156233412

In degrees C per decade.

Lucia: It is unlikely that this will be a super El Nino. July 1997 NINO3.4 SST anomalies (OI.v2 dataset) were 1.84 deg C. Preliminary July 2009 NINO3.4 SST anomalies are 0.93 deg C. But the big difference is subsurface. Here’s the equatorial subsurface temperature anomalies for June 1997 from ECMWF:
http://i28.tinypic.com/30sdhed.gif

And then there’s June 2009, comparatively wimpy:
http://i29.tinypic.com/2psopy0.gif

There aren’t any 6.5+ deg C subsurface anomalies this year (thankfully).

I’m not sure why July2009 being the second warmest July in UAH record is relevant, other than providing a sensationalist headline. There are plenty other months that have had higher anomalies. The bigger story is the jump from June’s non-anomaly. Obviously the El Nino has kicked in its impact to the LT temps.

Fred– Sure.

But I always compare this month to all similar month’s. The jump is very large.

Bernie– It’s difficult to make a direct comparison of RSS or UAH to IPCC projections because the time series for the lower troposphere have not been made available at The Climate Explorer. To compute the time series, I would need to download gridded data from PCDM and write a program to compute the time series for each model. I haven’t done that. (I was hoping Chad would. But, I think he got busy doing other things. Maybe a job!)

Oh– Bernie– The trend since 1979 is much higher than 0.6 C/century! It’s more like 1.5 C/century for RSS. See yesterday’s post with this graph click for larger.

For more: http://rankexploits.com/musing.....to-follow/

Bob–
I had seen some subsurface maps and I am inclined to suspect you are correct. But personally, I’m leary about predicting this because I have no particular experience with looking at all the various weather maps and knowing which ones predict what. So… we’ll see….

My previous statements regarding your channel 5 method of using real time data versus my method to predict the monthly anomaly are no longer operative

Lucia, I think you mean 1.5 degrees C per century, not .15

Oh and WOOT! I was close with my guess (although I had a HUGE margin of error)

Andrew– Yes. Thanks. Fixed.

Is El Nino even in play here considering the largest anomaly was in the southern hemisphere?

FYI there’s always this chart to reference.

http://www.weatherzone.com.au/.....p?c=nino34

These high MSU anomalies come at a time when there have been widespread record low temperatures reported across the northern hemisphere both in North America and Europe. The Canadian wheat crop looks likely to fail due to cold weather. The New York Times is talking about “the Summer that wasn’t”. The UK has been unusually wet and cold. Italians in Sicily were delighted by one of the coolest, mildest Julys in recent memory. Why the disconnect, I wonder, between record low temperatures on land and sharp high MSU anomalies?

Dale– The channel 5 AMSU temps have recently begun falling almost as rapidly as the rose in the beginning of June. We’ll have to wait to see how long that persists.

By the way, it’s cold here in Chicago.

Roy must have had a rounding error.

Dale McIntyre (Comment#17378) August 5th, 2009 at 9:02 pm
These high MSU anomalies come at a time when there have been widespread record low temperatures reported across the northern hemisphere both in North America and Europe. The Canadian wheat crop looks likely to fail due to cold weather. The New York Times is talking about “the Summer that wasn’t”. The UK has been unusually wet and cold. Italians in Sicily were delighted by one of the coolest, mildest Julys in recent memory. Why the disconnect, I wonder, between record low temperatures on land and sharp high MSU anomalies?

The disconnect is in your mind because you ignore anywhere that had record heat such as the Pacific NW:
http://www.msnbc.msn.com/id/32199224/
Texas: http://www.startribune.com/wea.....c:_Yyc:aUU
Parts of California: http://www.redding.com/news/20.....artner=RSS
Southern Europe:
http://www.startribune.com/wea.....iaec8O7EyU
Drought in India: http://news.bbc.co.uk/2/hi/south_asia/8178636.stm
etc.

Blah blah blah, Weather continues to be uncorrelated to climate, what else is new?

Here’s a question by the way-when does an arithmetic mean bear no resemblance to it’s individual components?

When the mean is the “Global Mean Surface Temperature (Anomaly)”.

What I love about this analysis is the way it perfectly illustrates the role of your hypothesis.

While we can’t reject an hypothesis that data are drawn from a process that is increasing at a trend rate of 2 degrees per century (for UAH and only just). We al can’t reject an hypothesis that the data are drawn from a process that is not increasing at all (or in fact decreasing at 2 degrees per century).

Geckko
I don’t think Lucia, or most other contributors, would deny that the planet has increased in temperature in the past 30 years. However most observers would argue that it has probably cooled since 2001. (See Lucia’s graphs above) They might also argue about the cause of the 30 years of heating and the recent decade of cooling – the evidence that it is CO2 induced is not strong.

Edbhoy-
“They” might argue anything. However, I think there is strong evidence CO2 causes warming and that it was an important contributor to warming over the past century.

The amount of short term cooling, combined with the variability of “weather” actually seen on earth (as opposed to model runs only), suggests that the recent observations are inconsistent with 2C/century.

Geckko– Over long periods, we can reject the hypothesis of zero warming. Failing to reject a hypothesis over the short term is not particularly meaningful. Rejecting one always is meaningful (provided the statistical model is valid and the data are not cherry picked.)

Lucia,

I was addressing the more germaine point about whether the recent experience (200/2001 to date) is “consistent with” hypotheses.

While being “consistent with” 2001 vintage IPCC forecasts, it would also be “consistent with” 2001 vintage no anthropogenic trend forecasts.

Longer trends (pre 2000/01) are back data, not forecasts.

Gekko– Data from 1988 onward is back data for the AR4 but forward data for Hansen.

AGW was proposed as a theory even before Hansen, so earlier data is forward data for the theory as a whole, though not for testing the specific predictive ability of models in the AR4.

Lucia,

If you can publish some quantified climatic forecasts and we can test them.

Otherwise we have data around which to build and partially test hypotheses.

Hansen provides us with some forecasts with a 1988 vintage and qualitatively doens’t stack up to well.

We are only now building a sufficient test bed for our hypotheses – in a properly quantified form of model output. It hasn’t been done to date.

Geckko– Of course if I publish quantified climate forecasts, we could test them. I don’t publish long term climate forecasts though. I just test other peoples — which I consider a useful way for me to determine whether they have any predictive abilty.

Hansen’s forecasts qualitatively correct in that he predicted warming rather than cooling. However they do no better than extrapolation based on the trend that preceded them. (It had been warming for years prior to 1988.)

We have to give him credit for getting the sign correct and doing no worse than linear extrapolation based on the, then, current trend. This is better than nothing though. Some might have predicted regression to the mean anomaly over the past few centuries which might have included cooling.

Dear Lucia,

Thank you for your kind comment in #17381. Your comment that the satellite data are showing large swings is intriguing. In fact there are signs of that in the surface data too. Here in my town in Oklahoma, we had one day which tied a record high, in July, and one day which tied a record low, on the first of August. I see similar large swings in the surface temperatures in Alaska, in the UK and in Italy as well, so it seems quite a widespread pattern.

No need to post this but Mr. Phil, #17389, needs to mind his manners. The tone of his post is quarrelsome and disrespectful. It is quite out of tune with the general tenor of your blog, which is one of the most civil places for discourse in the climate blogosphere. I was not questioning the RSS and UAH MSU data; I have no reason to doubt that the anomaly is what they have stated it to be, and these data sets have been quite plausible in the past. I was not ignoring anything. I was merely curious at the simultaneous presence of sharp high MSU anomalies when so many record low temperatures were being noted around the world. Your thought about the sharp drop in satellite data may be the answer; it is simply a highly variable season.

All best wishes and thank you again for your thoughtful comment.

Lucia,

There is no way around this.

To prove an hypothesis we MUST quantitatively test forecasts built on that hypothess. It is no use pointing to historical trends. This point is beyond debate.

When I said “you must provide forecasts”, I didn’t mean your forecasts, I meant any properly quantified forecasts. Hansen 1988 is only part way there.

On the basis of a correct sign you give him credit for skill.

I give him credit for a coin toss.

Beyond that his forecasts (which of course have a conditional probability distribution) do not have sufficient data to properly test (note the lack of aggrement on the blogosphere about what his assumptions actually meant). But qualitatively we know for a fact that Hansen forecast higher temperatures than actually occurred – even under erroneous assumptions of “drastically reduced greenhouse emissions”.

For a modelled hypothesis producing forecasts based on assumptions of “drastically reduced greenhouse emissions” that subsequently overshot actual temperature trends over 30 years is a qualititive fail.

Gekko–
I agree models must be tested against future data, not hindcasts.
Yes. Getting the sign right is credit for predicting a coin toss– 50%-50%. That’s why more testing is needed.

But still, if a psychic claimed they could predict coin tosses, and they predicted one, I’d give them credit for that toss. I still keep in mind it’s one coin toss. I don’t count it as 10, but if people want to count it as zero, I tell them no, it’s one.

Lucia,

Thanks for your reply. This gets to the knub of my point.

What is you null hypothesis for the claimed psychic?

If it is N0: Psychic genuine, then you would say that the result (single toss) could not reject the hypothesis that the psychic was genuine.

But, if it was N0 Psychic fake, then you would say that the result could not reject the hypothesis that the pschic was indeed fake.

Back ot this thread. Why exactly are we working from N0: AGW is driving a trend of 2 degree per C), leading to; data since 2000 can not reject null hypothesis of AGW.

rather than:
N0: There is no AGW trend, leading to; data since 2000 can not reject hypothesis of no AGW.

Thank you, Phil (#17389). I think some folks simply have been spending a bit too much time on climatedepot, wattsupwiththat, iceagenow, etc.. I start to feel a chill just thinking about reading those sites. How can global temperature data be right when the only weather that’s happening, as reported by these fine objective blogs / media outlets, is cold weather? Clearly there must be some scamming going on.