Richard Muller is interviewed in the current issue of Physics World (H/T Jonathan Jones). The article is not online as far as I can tell, but there are some interesting comments that I will reproduce here.
Asked by he started the BEST project, Muller replies:
"I lost my trust," Muller says, referring to the alleged actions of the scientists at the centre of the "Climategate" scandal, which broke in 2009. The controversy centred on a series of e-mails leaked from the Climatic Research Unit (CRU) at the University of East Anglia in the UK that led to accusations about the conduct of these scientists, including the way that data were selected in their studies. Although all the CRU scientists involved have been exonerated by four independent inquiries, Muller, having read the leaked e-mails, is still scathing of these scientistsand he isconvinced that, while they did nothing illegal, they are still guilty of scientific malpractice and that big question marks remain over their scientific methods. "What bothers me is the way that they hid the data, and the way that they used the peer-review system to make sure that the sceptics' arguments - some of which I felt were valid-wouid not be published".
And he also has high praise for Anthony Watts:
Muller also had four specific concerns with the scientific consensus on global warming, which the BEST project was designed to address. The first - and most serious, he says - is the "stations issue", referring to a problem highlighted by controversial US blogger and former TV meteorologist Anthony Watts. In 2007 Watts initiated the Sur/acestatiQns.org project, which reported that 70% of temperature recording stations in the US were inaccurate to a level of 2--5°C. MulIer says that the BEST team has now cleared up this issue by showing that when it comes to specifically measuring change in temperature, the 30% of good stations are not significantly more accurate than the 70% of bad stations. "lf Watts hadn't done his work, we would not have reliable data today. The fact that he did that means he's a hero; he deserves some sort of international prize."
The other concerns are as follows:
The second concern Muller refers to i. the "data selection" employed by the three major groups collecting global temperature data: NASA; the National Oceanic and Atmospheric Administration in the US; and the Met Office's Hadley Centre in the UK. Muller says that the number of stations being used between 1980 and the present day has dropped from 6000 to less than 2000, with no explanation to be found anywhere in the literature. The third issue is that rapid urbanization in the regions surrounding temperature stations might have led to localized temperature increases, or what is known as the "urban heat island" effect. The fourth concern, which Muller calls "data correction", refers to the small adjustments that the climate groups make to temperature readings as a result of changes in instruments and locations. Muller says the records describing why individual corrections have been made are very poor.