Statisticians Confirm: No Global Cooling Despite Skeptic Spin

Mon, 2009-10-26 12:41Brendan DeMelle
Brendan DeMelle's picture

Statisticians Confirm: No Global Cooling Despite Skeptic Spin

In a massive blow to the climate skeptic movement, the Associated Press has conducted a blind test of statisticians that unequivocally confirms that no global cooling trend exists

Despite the best efforts of a small handful of climate skeptics, who argue that the globe has cooled rather than warmed since the record hot year of 1998, no such cooling trend has taken place.

The Associated Press conducted the blind test by sending global temperature data from NOAA and NASA to four independent statisticians who were not told what the data represented, but simply asked to perform a common statistical analysis to look for trends in the data.

The statisticians “found no true temperature declines over time,” and in fact identified “a distinct decades-long upward trend in the numbers,” the AP reports.

Several statisticians quoted in the AP piece slam the climate skeptics who “cherry-pick” data in a “particularly suspect” attempt to denounce global warming.  Efforts to portray a global cooling trend since the record hot year of 1998 are “not scientifically legitimate,” and are the result of “people coming at the data with preconceived notions,” according to David Peterson, a retired Duke University statistics professor who analyzed the data for AP.

“To talk about global cooling at the end of the hottest decade the planet has experienced in many thousands of years is ridiculous,” said Ken Caldeira, a climate scientist at the Carnegie Institution at Stanford.

“Ridiculous” indeed, but that has not stopped the handful of loud-mouthed climate skeptics from spreading this false claim.  Their efforts have proven successful at confusing the public, thanks in large part to the Drudge Report, FOX News and lazy journalists who fail to fact-check the skeptic arguments, providing oxygen to their baseless claims.

The Associated Press conducted a simple exercise that any self-respecting news outlet concerned with the facts rather than the confusionist spin could duplicate easily.  Don’t expect this news to silence the skeptics, but if you are a journalist, please let the skeptics talk amongst themselves, rather than polluting the public discourse any further.  And if you are a concerned news consumer, please do hold accountable any news outlet that continues to ignore this starkly obvious fact: there is no global cooling.  There definitely is global warming. 

It really is that simple.  Now can we talk about the critically important matter of how to address climate change with just a few weeks left until the Copenhagen Climate Summit?

Previous Comments

Phew, finally this is confirmed! It’s a little absurd how people, even scientists, are allowed to make such significant claims without showing scientifically significant evidence to back up their claims. Of course, the damage is done and I’m sure it would take more than a report like this to convince the true believers of global cooling. This whole topic gets me pretty worked up. I have half a mind to go over to my local catalog printer and have some pamphlets printed up so that I could spread the word about the truth of global warming in my city. Hopefully that will help.


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No cooling, maybe slight warming since 98 as the stat guys see it.

I don’t think we’ll see this AP report splashed around that much. It’s not all that dramatic.

Independent? Associated Press?
Now there’s a non-sequitur !

I noticed you prefer AIGNews= Answers in Genesis to the AP, and to JGR, Journal of Climate, other research publications.
AIG is a creationist publication run by a guy named Ken Ham. Strangely, AIG also publishes swipes at global warming, disguised as scientific publications, which fools you.

Maybe you also believe the world is 6013 years old?

Oh no! Did I miss it’s birthday?

I like how they didn’t tell them what the data was – just asked them to look for the trend. That truly is how statistics work.

You say:

“The Associated Press conducted the blind test by sending global temperature data from NOAA and NASA to four independent statisticians who were not told what the data represented, but simply asked to perform a common statistical analysis to look for trends in the data.”

A common statistical test? Doh…. That would be a linear regression. They were NOT asked to explore the data (which is a severe NO NO in statistical analysis of any data set). So the answer was bound to come out they way the AP WANTED it to.

I have outlined in another post on this site that the data are not that straightforward. I have found structural changes in the data set whereby choosing 1998 as a start point is not cherry picking but a legitimate start point based on a more exploratory analysis of the data. An analysis that the four “independent” statisticians were not asked to do. In fact I am certain that they were not asked to review the data as a time series analysis with full autocorrelation and structural change analysis.

So you’re saying the AP and Seth Borenstein wanted a “kill the cooling” story so they fed the winning numbers to some statisticians.

Well I guess so, but I still say it doesn’t matter. Nothing spectacular is happening in climate up or down right now. We just have to wait.

No, they got the right data but not the right context. Such a blind test is basically rubbish. In fact, I don’t really think it was a true blind test as later in the press release they have the statisticians speaking of the data in it’s real context of temperature data viz a viz:

“Saying there’s a downward trend since 1998 is not scientifically legitimate, said David Peterson, a retired Duke University statistics professor and one of those analyzing the numbers.

Identifying a downward trend is a case of “people coming at the data with preconceived notions,” said Peterson, author of the book “Why Did They Do That? An Introduction to Forensic Decision Analysis.”

Well David Peterson is wrong. He obviously did a very sloppy job of exploring the data. He also must have known that the data were long term surface temperature data.

But I understand what you are saying. Seth Borenstein is trying to kill the cooling hypothesis by instituting a scientifically invalid test.

The participants found out what they were tasting AFTER they had made a choice. I suspect Peterson was commenting AFTER the blind test was over.

I love how you guys all claim global cooling by cherry-picking around 1998, and then cry “foul” when someone who knows statistics does it right. Raw temperature data was given to statisticians unconnected with NOAA or NASA, and they found no downward trend. It could have been gas prices or crop production or (alas!) my weight – but it was temperature. Get over it.

Heh. New weight-loss plan: the Reverse Hockey Stick Diet

okay, but what raw temperature data?

It seems a little general. Was it all number sets combined into an average or was it a specific number set or sets sourced specifically to get a favorable outcome?

My main point is - this is not news - unless data sets that previously showed cooling due to advocate statisticians(McIntyre for example) are now showing warming under neutral analysis.

Call me crazy, but my suspicion is that AP (Borenstein) wanted a certain result and provided number sets that would bring that about.

To answer your question “what raw temperature data?” here is an exerpt from the AP story:

The AP sent expert statisticians NOAA’s year-to-year ground temperature changes over 130 years and the 30 years of satellite-measured temperatures preferred by skeptics and gathered by scientists at the University of Alabama in Huntsville.

I would like to see an actual published study by the scientists involved. There is no link to research methology, etc. Without that, this is just a news story.

at the link embedded in the post, you will see that the stats used INCLUDED the 30 years of satellite data usually cited by deniers as support for cooling. As for whether the statisticians have published their results, maybe they should, but I suspect they have other things keeping them busy. In any case, there is nothing in the scientific journals that supports a cooling trend - no case to answer.

Let’s give your “independent”(what a joke) statisticians a set of Richard’s Lindzens data. I wonder if they are going to arrive at the same answer Femack? It should be called Not Evil Just Dumb. Femack do you realize there have been reports since the early 1900s about the Great Lakes dissappearing and glaciers melting. None of this is new, hurricanes occurred before the industrial revolution…nobody is going to sign legislation in the name of climate because it makes no sense.

Lindzen doesn’t produce data, he just cherrypicks other people’s data.

Lindzen uses one of the four datasets that everybody else also use, and which all show essentially the same. Note that the statisticians even looked at the UAH data, the one that shows the least warming (but only marginally lower than e.g. HADCRU).

Lindzen’s uses the ‘data’ to model (oh, *gasp*, a model!) what he believes describes atmospheric processes. It’s interesting to note that certain people so gladly follow this man and his model, and tramp on all those other models that they claim can “never” be a good representation, because we know so little…the irony is baffling.

You’re right – none of this is new. The industrial revolution began in the late 18th century and Arrhenius calculated the impact of increased CO2 concentrations in 1896.


This article, however, (which is not a true independent assessment if the study was completed by NOAA scientists) is not based on the much more robust metric assessment of global warming as diagnosed by upper ocean heat content. Nor does it consider the warm bias issues with respect to surface land temperatures that we have raised in our peer reviewed papers; e.g. see and see.

O whoops, guess Seth blew it again.

Failure of reading comprehension. The study was done by independent statisticians.

Rabett Run comments on the AP story, including some of the context on the new book by Dubner and Levitt:

“…Levitt is trying to roll it back to rescue some respectability, but, of course, the damage is being done both by the book, and it’s reception. In this blogs are playing an important roll. It is important to a) keep it up and b) realize that this has been effective on at least a personal level with Levitt. He knows that he has a long way to go before people he cares about take him seriously again…”

oh, gimme a break

“significant oversight” - well you had to know there would be objections.

This almost made me laugh off of my seat. Some one asked statisticians for their opinion? Why not just ask them to do the calculation? This looks like pure manipulation. Anyone can calulate a simple moving average. This is a good cover story but I doubt anyone will be fooled.

The fact remains a simple moving average from 1998 to present shows a cooling trend. For global warming to remain legitemate we need to see constant warming. Otherwise it may be time to relook the positive feeback loop that is supposed to create constant and accelerated warming.

Looks like global cooling is still a threat.

Maybe we can get somebody with a lot of credibility to say that he looked at the moving average and it looked like it was going up not down? Maybe Leonardo dicapprio at the very least that would help to win over the teenage girls.

maybe 98 was such an outlier that it doesn’t count that much - -that’s what I figure

They DID ask the statisticians to do the calculation! Hence their dismissal of using one very particular point as the starting point. Yes, you can cherry-pick yourself to a negative slope by choosing 1998 (in some data sets), but because choosing 1997 or 1999 as starting point results in a positive slope, it would be data manipulation to focus on 1998. That’s what the people who know about statistics and data fitting say. And in comes the lay man “RalphNader”, and he does exactly what the statisticians say would be unscientific.

Oh, and no climate scientist claims there should be constant and accelerated warming. That’s the mockery that the deniosphere has made out of climate science. Several models(!) expressly show flat/cooling periods on the decadal scale, such as those of Mojib Latif. Unfortunately for you, they also show VERY rapid warming in other decadal periods.


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