I don’t like mistakes, but I do make them. In the climate wars I really don’t like mistakes because they clutter up the conversation and give Konsensus Kooks ammunition they cheerfully use against me and other Lukewarmers.
Anderegg, Prall et al is a paper published in PNAS 2010. It purports to show that scientists who support the consensus are more expert than those who oppose it. They do this by counting publications.
I have criticized the paper since the day it came out. My criticisms were:
- They made serious errors in counting publications and classifying scientists. Many of them.
- They used Google Scholar instead of one of the databases created specifically for housing academic publications.
- They only used one database, when it would have been easy to use more than one to cross check their work.
- They searched only in English, despite the fact that climate change is researched worldwide.
- Their analysis of the findings of their research contains serious errors.
- They made it possible for anyone to find out who they had studied and who they had tagged as climate change deniers. This is a very serious violation of research ethics.
I wasn’t alone in my criticism. Famed physicist Spencer Weart, author of The History of Global Warming, said on the day the paper was published that it shouldn’t have been published in ‘its present form.’
However, this year while doing a bit more study on the study, I found what I thought was a further reason to criticize the paper. The researchers searched through open letters that challenged the climate consensus and were signed by scientists and others. Anderegg, Prall et al combed through those open letters and took the names of signatories to serve as their database of deniers.
I found what I thought was one of those open letters–a relatively famous document called the Heidelberg Declaration of 1992. It was a fairly innocuous letter saying that the environment needed to be considered as a whole and 4,000 people signed it, including 73 Nobel Prize winners.
However, Anderegg, Prall et al used a different letter also published in 1992 that was signed by 47 skeptical climate scientists, 46 of whom they used in their denier database.
I regret the error.
I do not withdraw any of my previous criticisms of the paper. I consider it shoddy science, unethical research and wrong in its stated results.
Oh, do I regret the error.