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.
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.”
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)