The key witness in the Republican congressional committee's case against global warming shocked his hosts with preliminary evidence confirming that global warming is caused by human activities. Dr. Richard Muller, Professor of Physics at UC Berkeley, the most credible climate change skeptic the Republicans could find, showed that his random sampling methodology, designed to remove possible sampling biases, gave preliminary confirmation of the global temperature records developed by NOAA, and Dr. James Hansen of NASA, GISS. The British Hadley CRU dataset, repeatedly maligned by Republicans in the "climategate" incident, was also given preliminary confirmation by Dr. Muller.
Figure: Land average temperatures from the three major programs, compared with an initial test of the Berkeley Earth dataset and analysis process. Approximately 2 percent of the available sites were chosen randomly from the complete set of 39,028 sites. The Berkeley data are marked as preliminary because they do not include treatments for the reduction of systematic bias.
Dr Muller told the congressional committee he was surprised that his preliminary results were in agreement with the global temperature data sets he was evaluating.
In our preliminary analysis of these stations, we found a warming trend that is shown in the figure. It is very similar to that reported by the prior groups: a rise of about 0.7 degrees C since 1957.
Then he told the committee that the "poor quality temperature stations" identified by climate skeptics, had no effect on measured global warming trends.
Many temperature stations in the U.S. are located near buildings, in parking lots, or close to heat sources. Anthony Watts and his team has shown that most of the current stations in the US Historical Climatology Network would be ranked "poor" by NOAA's own standards, with error uncertainties up to 5 degrees C.
Did such poor station quality exaggerate the estimates of global warming?
We've studied this issue, and our preliminary answer is no.
The Berkeley Earth analysis shows that over the past 50 years the poor stations in the U.S. network do not show greater warming than do the good stations. Thus, although poor station quality might affect absolute temperature, it does not appear to affect trends, and for global warming estimates, the trend is what is important.
He concluded that his concerns about biases in the temperature record were reduced by his results.
Based on our initial work at Berkeley Earth, I believe that some of the most worrisome biases are less of a problem than I had previously thought.
Paul Krugman's New York Times editorial
today tells how professional climate change denier, retired weather personality Anthony Watts, became apoplectic and flipped flopped faster than Mitt Romney.
But back to Professor Muller. His climate-skeptic credentials are pretty strong: he has denounced both Al Gore and my colleague Tom Friedman as "exaggerators," and he has participated in a number of attacks on climate research, including the witch hunt over innocuous e-mails from British climate researchers. Not surprisingly, then, climate deniers had high hopes that his new project would support their case.
You can guess what happened when those hopes were dashed.
Just a few weeks ago Anthony Watts, who runs a prominent climate denialist Web site, praised the Berkeley project and piously declared himself as "prepared to accept whatever result they produce, even if it proves my premise wrong." But never mind: once he knew that Professor Muller was going to present those preliminary results, Mr. Watts dismissed the hearing as "post normal science political theater".
The book "Merchants of Doubt" showed that many of the same paid scientists that denied that smoking causes cancer are denying anthropogenic climate change. Cancer and climate collapse are a full time job.
Why would scientists dedicated to uncovering the truth about the natural world deliberately misrepresent the work of their own colleagues? Why would they spread accusations with no basis? Why would they refuse to correct their arguments once they had been shown to be incorrect? And why did the press continue to quote them, year after year, even as their claims were shown, one after another, to be false?
And the press is either incompetent, corrupted by advertising money, or both.
The full written and spoken testimony of Dr Muller can be found here. The actual spoken testimony of Dr. Muller follows is quoted here:
Testimony of Richard A. Muller
Thank you Chairman Hall and Ranking Member Johnson for this opportunity to testify before the Committee. I am a Professor of Physics at UC Berkeley and Faculty Senior Scientist at the Lawrence Berkeley Laboratory. I founded the Berkeley Earth Surface Temperature project under the auspices of Novim, a non-profit public interest group. My testimony represents my personal views and not those of the above organizations.
I begin by talking about
Global Warming
Prior groups at NOAA, NASA, and in the UK (HadCRU) estimate about a 1.2 degree C land temperature rise from the early 1900s to the present. This 1.2 degree rise is what we call global warming. Their work is excellent, and the Berkeley Earth project strives to build on it.
Human caused global warming is somewhat smaller. According to the most recent IPCC report (2007), the human component became apparent only after 1957, and it amounts to "most" of the 0.7 degree rise since then. Let's assume the human-caused warming is 0.6 degrees. The magnitude of this temperature rise is a key scientific and public policy concern. A 0.2 degree uncertainty puts the human component between 0.4 and 0.8 degrees - a factor of two uncertainty. Policy depends on this number. It needs to be improved.
Berkeley Earth is working to improve on the accuracy of this key number by using a more complete set of data, and by looking at biases in a new way.
I'll now talk about potential
Bias in Data Selection
Prior groups selected for their analysis 12% to 22% of the roughly 39,000 available stations. They believe their station selection was unbiased. Outside groups have questioned that, and claimed that the selection picked records with large temperature increases. Such bias could be inadvertent, for example, a result of choosing long continuous records.
To avoid such station selection bias, Berkeley Earth has developed techniques to work with all the available stations. This requires a technique that can include short and discontinuous records. In an initial test, Berkeley Earth chose stations randomly from the complete set of 39,028 stations. Such a selection is free of station selection bias.
In our preliminary analysis of these stations, we found a warming trend that is shown in the figure. It is very similar to that reported by the prior groups: a rise of about 0.7 degrees C since 1957.
The Berkeley Earth agreement with the prior analysis surprised us, since our preliminary results don't yet address many of the known biases. When they do, it is possible that the corrections could bring our current agreement into disagreement.
Why such close agreement between our uncorrected data and their adjusted data?
One possibility is that the systematic corrections applied by the other groups are small. We don't yet know.
Let me now address the problem of
Poor Temperature Station Quality
Many temperature stations in the U.S. are located near buildings, in parking lots, or close to heat sources. Anthony Watts and his team has shown that most of the current stations in the US Historical Climatology Network would be ranked "poor" by NOAA's own standards, with error uncertainties up to 5 degrees C.
Did such poor station quality exaggerate the estimates of global warming?
We've studied this issue, and our preliminary answer is no.
The Berkeley Earth analysis shows that over the past 50 years the poor stations in the U.S. network do not show greater warming than do the good stations. Thus, although poor station quality might affect absolute temperature, it does not appear to affect trends, and for global warming estimates, the trend is what is important.
Potential Legislation
I was asked what legislation could advance our knowledge of climate change. After some consideration, I felt that the creation of a Climate Advanced Research Project Agency, or Climate-ARPA, could help.
Without the efforts of Anthony Watts and his team, we would have only a series of anecdotal images of poor temperature stations, and we would not be able to evaluate the integrity of the data. This is a case in which scientists receiving no government funding did work crucial to understanding climate change. Similarly for the work done by Steve McIntyre. Their "amateur" science is not amateur in quality; it is true science, conducted with integrity and high standards. Government policy needs to encourage such work.
Climate-ARPA could be an organization that provides quick funding to worthwhile projects without regard to whether they support or challenge current understanding.
In Summary
Despite potential biases in the data, methods of analysis can be used to reduce bias well enough to enable us to measure long-term Earth temperature changes. Data integrity is adequate. Based on our initial work at Berkeley Earth, I believe that some of the most worrisome biases are less of a problem than I had previously thought