There’s this notion among the climate denial community that somehow the entire professional climatology community has overlooked an obvious flaw in the science behind anthropogenic global warming. Their hypothesis is that too many of the thermometers used to record temperatures over the last 200 years have been located in or near cities, and so have produced a warming bias produced by the waste heat generated in urban areas.

It sounds plausible. The problem with the notion, of course, is that it’s so obvious a potential bias that climatologists long ago learned to take the “urban heat island” effect into account. Still, the idea persists, and so a bunch of still-open-minded-despite-reams-of-solid-evidence-scientists, known collectively as the Berkeley Earth Surface Temperature (BEST) project, and all but one of them new to the field, decided to conduct their own independent analysis of the data that NASA, NOAA and HadCRU say shows unequivocal evidence for global warming.

Today, that team released its findings. Can you guess what they found?

We observe the opposite of an urban heating effect over the period 1950 to 2010, with a slope of -0.19 ± 0.19 °C/100yr. This is not statistically consistent with prior estimates, but it does verify that the effect is very small, and almost insignificant on the scale of the observed warming.

And that result

supports the key conclusion of prior groups that urban warming does not unduly bias estimates of recent global temperature change.

So, will this be the nail in the coffin of the UHI canard? Probably not. Comparable analyses that show a complete lack of correlation between solar output and global temperature change has failed to shut down the pseudoskeptical argument that it’s really all about the sun.

The team has written four papers and submitted them for peer-review, which has yet to happen.

Members of the BEST team include Charlotte Wickham (University of California, Berkeley); Judith Curry (Georgia Institute of Technology); Don Groom and Arthur Rosenfeld (Lawrence Berkeley Laboratory, Berkeley), Robert Jacobsen, Richard Muller, Jonathan Wurtele and Saul Perlmutter (Lawrence Berkeley and University of California, Berkeley); Robert Rohde,(Novim Group); (Lawrence Berkeley Laboratory). Note that Curry is the only genuine climate scientists among the group.

It will be interesting to see what they each has to say about their paper. Curry already has spoken up, calling the work “initial steps in analyzing the data set.”

It will be even more interesting to see what some of the funders of BEST have to say. Those funders include Bill Gates’ Fund for Innovative Climate and Energy Research, the Ann and Gordon Getty Foundation, and, most notably, the Charles G. Koch Charitable Foundation, which has spent enormous sums funding climate denial propaganda.

Tom Peterson, who as chief scientist at NOAA’s National Climatic Data Center in Asheville, NC, knows more than a little about this issue, told me in an email that “it is always good to have additional groups take different analysis approaches. Even if the results just confirm earlier work, that is still of value.”

He did have some problems with the BEST team’s analytical approach, particularly their use of some of the oldest data, which are far from statistically meaningful. But, Peterson added, “Considering the perspective they seemed to have on why they started the project, the results they came up with clearly say good things about their integrity.”

Yes, well… reaction from other sectors can be found here, here, here and here and elsewhere.

Because the papers haven’t been peer-reviewed, there’s no telling whether their failure to falsify the no-UHI effect will even be added to the literature. The general practice in scientific journals is to not pay too much attention to papers that confirm what we already know.

Wickham, C., Curry, J., Groom, D., Jacobson, R., Muller, R., Perlmutter, S., Rohde, R., Rosenfeld, A., & Wurtele, J. (2011). Influence of urban heating on the global temperature land average using rural sites identified from MODIS classification. (yet to accepted)

Comments

  1. #1 Zeke Hausfather
    October 20, 2011

    I think your statement that “The problem with the notion, of course, is that it’s so obvious a potential bias that climatologists long ago learned to take the “urban heat island” effect into account” is a tad too simplistic. To my knowledge, the BEST study is the first global analysis of UHI using the MODIS proxy (which arguably is much better at uniformly detecting UHI than NASA’s previously used satellite nightlights proxy). That is actually found a slight negative UHI is interesting, though it may suffer from some spatial coverage issues in accurately comparing urban and rural stations. There should be a number of new papers coming out on this subject in the next year or two, though I imagine the picture won’t change all that much (e.g. the UHI effect may turn out positive, but likely won’t be that large).

  2. #2 Vince Whirlwind
    October 20, 2011

    The negative UHI *is* interesting – I have two local stations about 20km apart – one rural and one in a valley that’s been filled with suburbs. The rural one shows more warming than the suburban one.
    Perhaps UHI increases airflow, leading to some local cooling effect?

  3. #3 Harry Eagar
    October 20, 2011

    The real problem is that there are no global observations from a century ago to compare today’s observations with.

    I dunno how you get around that, but so far when I present this, all I get is handwaving. A globe and a little high school math and a knowledge of where people were in, say 1900, will reveal the scope of this problem.

  4. #4 Rattus Norvegicus
    October 20, 2011

    Harry, by 1900 or so the surface coverage was ~75% or so. So there were plenty of stations available back then.

  5. #5 Craig Thomas
    October 20, 2011

    Judith Curry explains:

    > the REAL problem with the surface temperature data set lies with the ocean data. I hope that the Berkeley group will be able to extend their efforts to include ocean data.

  6. #6 Marco
    October 21, 2011

    And when the ocean data has been analyzed, I’m sure Curry will find yet another “REAL problem”.

  7. #7 chek
    October 21, 2011

    Actually Marco, Open Water Heat Effect has barely been accounted for.

    Remember the not-at-all-nutty John O’Sullivan’s breathless expose about a year ago when NOAA-16 malfunctioned and reported temperatures in the hundreds of degrees in Lake Michigan?

    Luckily for us, fearless freedom fighters such as JohnO stopped that scam before the Warmist World Government had to step in to prevent us all boiling to death.

    As for Curry, surely all that’s required is to let it become generally known that Mike Mann hates and detests satellites and all their stinkin’ data products.

  8. #8 Dunc
    October 21, 2011

    Quick! Move those goalposts!

  9. #9 Neil Craig
    October 21, 2011

    Obviously the fact that you censor any pointing out of the obvious untruths in the alarmist case proves you know the case cannot survive honest debate.

  10. #10 chek
    October 21, 2011

    Equally obviously, your inability to specify any – in your own words – ‘obvious untruths in the alarmist case’ proves you’re just blowing smoke.

  11. #11 Neil Bates
    October 21, 2011

    OK. Anyone know then, why the UHI effect would be smaller than expected? Is it, more white reflective surfaces in the cities?

  12. #12 Neil Bates
    October 21, 2011

    Neil Craig: have some saved HTML pages with your comments there, that are now removed, to make your complaints credible? Note that other reasons can make something deserve to be removed.

  13. #13 mandas
    October 23, 2011

    Ahhh, so this is where Biel Roaig (a.k.a Neil Craig) is hiding out now!

    He was last seen illiterately ranting at all over at AFTIC for some months. The man is so deluded he can’t even spell his own name correctly.

    So Biel, how are you going with those 7 questions you keep asking? How are you going answering the ones that I asked with regard to some of the claims you made:

    How much is a ‘thrillion’?
    Where can I find these schoolfirl br5othels accross Europe?
    How much do our5 police make from the seel of a schoolfirl?
    What did Joe Biden do with the body org=fans that he obtained by dissecting 1300 living human beings?

    Nice to see you again Biel.

  14. #14 Wow
    October 24, 2011

    “using the MODIS proxy (which arguably is much better at uniformly detecting UHI than NASA’s previously used satellite nightlights proxy)”

    It can be argued such.

    It could also be argued that leprechauns eat your socks in the clothes drier.

    Can either be proven the case?

    And, given that this result is pretty much identical to the one NOAA did on their data when Anthony Watts set up surfacestations to show “proof” that the US dataset was wrong, and THEY didn’t use MODIS, it is rather more proven that MODIS isn’t a better proxy than the ones available earlier for discerning the trend bias (or lack).

  15. #15 Wow
    October 24, 2011

    “Perhaps UHI increases airflow, leading to some local cooling effect?”

    I believe it;s more likely that the UHI effect is being over-compensated, Vince. Or those urban stations showing a higher trend are being discarded in the mistaken belief they are seriously affected by UHI.

  16. #16 Confusio
    October 26, 2011

    What is Curry talking about? The BEST project is about urban areas bias. Are there many cities on the ocean?

  17. #17 Jade
    October 26, 2011

    Great post I hope to see more, keep at it.

  18. #18 Andrew
    December 31, 2011

    Luckily for us, fearless freedom fighters such as JohnO stopped that scam before the Warmist World Government had to step in to prevent us all boiling to death.

    As for Curry, surely all that’s required is to let it become generally known that Mike Mann hates and detests satellites and all their stinkin’ data products.

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