Q&A With Richard Muller: A Physicist and His Surprising Climate Data

Lawrence Berkeley Laboratory

Richard Muller of Lawrence Berkeley National Laboratory in California has gained a solid scientific reputation for his work in astrophysics and particle physics. He's waded into policy debates over nuclear weapons and terrorism as a member of the secretive JASON panel. And his introductory course, Physics for Future Presidents, is popular among undergraduates at the University of California, Berkeley.

But that impressive track record of research, teaching, and service wasn't why the science committee of the U.S. House of Representatives invited Muller to testify last week. The topic was climate change research and policy, and Republicans wanted Muller to discuss his recent reanalysis of global temperature records. Republicans expected Muller to challenge the accepted wisdom that the earth has warmed 0.7˚C since the 1880s. But to the dismay of skeptic bloggers, his preliminary analysis supports that canonical view.

Muller first delved into paleoclimate research in the 1980s to counter what he calls "a lot of B.S." in the field. Over a decade, his papers in Nature, Science, and other journals questioned standard explanations of the ice ages involving eccentricities in the planet's orbit.

"He is a very, very independent thinker. He does not take it for granted when he is told something. His instinct is to go check it out for himself," says fellow Berkeley physicist Raymond Jeanloz, who has served with Muller as a JASON panelist. "He's a very eclectic, very broad scientist. He'll apply physics to earth science, and apply earth science to physics or astronomy."

He also began to question what scientists were saying about the likely impacts of present-day climate change, and in November 2009 he became concerned about what he regarded as the imperial behavior shown by some climate scientists in leaked e-mails released as part of what's become known as Climategate.

So in 2009, Muller assembled a team of physicists and statisticians and launched the Berkeley Earth Surface Temperature project.

The project has sought to use new techniques to analyze temperature data to see whether problems like the bad stations could bias the results. Muller says he admires the work of prominent skeptic blogger Anthony Watts, a bête noire for most climate scientists, who has published photographs that document problems with hundreds of official U.S. government temperature stations. (Whether those problems affect reported climate trends is controversial.)

Muller spoke twice with ScienceInsider after testifying on 31 March before the science committee. Here are excerpts from those conversations.

Q: You testified that the scientists maintaining the three climate temperature sets—maintained by NASA, the U.S. National Oceanic and Atmospheric Administration, and the U.K. Met Office—have done "excellent" work. So how did you feel when the e-mails from the University of East Anglia emerged?

R.M.: I felt like a woman who's just learned her husband was cheating on her. It doesn't mean he's a bad husband in all ways, but that trust is lost. ... The e-mails didn't relate at all to the temperature work. … It was all the [paleotemperature] proxy data. [But] that disillusioned me.

Q: What does your initial examination of 2% of world temperature stations find in terms of world climate?

R.M.: Some [readings] are going down—but more are going up. The average is going up.

Q: You compared U.S. climate trends from some 300 stations deemed well or moderately-well located with 800 stations that are poorly sited. What did you find?

R.M.: There was no statistical difference [in the data] between the good groups and the bad groups.

Q: Why was that surprising?

R.M.: Because the stations were so bad. … You see stations right up against buildings, next to heat sources.

Q: How is your technique different than the methods used by the teams analyzing the three major datasets?

R.M.: [Their goal is] to generate long continuous methods. … If there was a change, [like] a station moved, they would adjust the data to try to eliminate that. [But] it makes me very uncomfortable when you adjust the data. … [So] we just cut the data at that point [and create two shorter records]. It means we wind up in our analysis with [not very many] continuous records.

Q: Did you have any trouble getting access to data? Access was central to the fight that led to the East Anglia e-mail flap.

R.M.: We believe we have 95% of the data that the U.K. [Met Office] is not releasing. ... Merging the data—from 16 sources—we found there is a great deal of overlap.

Q: You say that "openness and transparency" are central to your project. So why present your findings to Congress before describing your methods in a publication that everybody can read?

R.M.: We were originally planning to submit a paper at the same time as the testimony, to a journal which would allow simultaneous publication of the draft online. ... This is a problem that causes us great concern. What do you do when you are working on [something] and Congress asks you to testify? It's a difficult issue.

Q: Did photos on [skeptic] Anthony Watts' Web site showing official temperature gauges in flawed locations like parking lots inspire you to get involved in the debate over the accuracy of the weather stations ?

R.M.: I realized that Watts was doing something that was of importance. The issues he raised needed to be addressed. It made me seriously wonder whether the reported global warming may be biased by poor station quality. Watts is a hero for what he's done. So is [prominent skeptic blogger] Steve McIntyre.

Q: What are you hoping to accomplish with Berkeley Earth?

R.M.: There's a huge penumbra of scientists who have … heard from prominent scientists that the debate is over, it's all been settled and so on. … [So] when they stumble across things like the Watts pictures they're disturbed. ...They feel that many of these questions haven't been answered. What I'm hoping to do is calm the debate.

Q: What's next for your project?

R.M.: Very soon we hope to have both the data and the programs online. And if you don't like our results, my [advice] is to change the program, but be open and transparent about it. Let us know what you changed. If there's some assumption we make that you think is invalid than change the assumption and run the programs and see what answer you get. I'm hoping that if we make it that open and that accessible that the people who are interested in the answer … will be won over.

Q: Are there any other lines of research that you want to pursue?

R.M.: We're applying for funding to study the ocean temperature data. That will allow us to get a true global picture of temperature trends.

*This item has been corrected. Anthony Watts was originally identified as Andrew.