Now Professor Muller, professor of physics at UC Berkeley, goes even further, arguing, “Humans are almost entirely the cause.”
He attributes the turnaround in a relatively short period of time to his study of the “careful and objective analysis by the Berkeley Earth Surface Temperature project.”
The results there show that the average temperature of the earth’s land has risen by 2.5 degrees over 250 years, and 1.5 degrees over the last 50 years.
He writes, “It appears likely that essentially all of this increase results from the human emission of greenhouse gases.”
As this morning’s LA Times notes, “Muller is a long-standing, colorful critic of prevailing climate science, and the Berkeley project was heavily funded by the Charles Koch Charitable Foundation, which, along with its libertarian petrochemical billionaire founder Charles G. Koch, has a considerable history of backing groups that deny climate change.”
The LA Times reports that Tonya Mullins, spokesperson for the Koch Foundation, “said the support her foundation provided, along with others, had no bearing on the results of the research.”
“Our grants are designed to promote independent research; as such, recipients hold full control over their findings,” Ms. Mullins said in an email to the LA Times. “In this support, we strive to benefit society by promoting discovery and informing public policy.”
The LA Times reports, “Michael E. Mann, director of the Earth System Science Center at Pennsylvania State University, said that Muller’s conversion might help shape the thinking of the ‘reasonable middle’ of the population ‘who are genuinely confused and have been honestly taken in’ by attacks on climate science.”
On his facebook page, Professor Mann writes, “There is a certain ironic satisfaction in seeing a study funded by the Koch Brothers – the greatest funders of climate change denial and disinformation on the planet – demonstrate what scientists have known with some degree of confidence for nearly two decades: that the globe is indeed warming, and that this warming can only be explained by human-caused increases in greenhouse gas concentrations. I applaud Muller and his colleagues for acting as any good scientists would, following where their analyses led them, without regard for the possible political repercussions.”
At the same time, the Times reports that Professor Muller’s words have failed to sway other climate skeptics such as Marc Morano, a producer for Rush Limbaugh and communications director for the Republicans on the Senate Environment and Public Works Committee, who now runs the website climatedepot.com.
“Muller will be remembered as a befuddled professor who has yet to figure out how to separate climate science from his media antics. His latest claims provide no new insight into the climate science debate,” Mr. Morano said in an email.
“What has caused the gradual but systematic rise of two and a half degrees?” Professor Muller asks. “We tried fitting the shape to simple math functions (exponentials, polynomials), to solar activity and even to rising functions like world population. By far the best match was to the record of atmospheric carbon dioxide, measured from atmospheric samples and air trapped in polar ice.”
The LA Times notes that, while Professor Muller believes his findings are stronger than the UN’s, he has not published any of the research in peer-reviewed journals.
This troubles both climatologists and contrarians.
For example, Benjamin Santer, who is the lead climate researcher at the Lawrence Livermore National Laboratory, said, “If you go into the public arena and claim to have generated evidence that is stronger than the IPCC [Intergovernmental Panel on Climate Change], where is the detailed, scientific evidence? Has he used fundamental new data sets? Publish the science and report on it after it’s done.”
He added: “I think you can do great harm to the broader debate. Imagine this scenario: that he makes these great claims and the papers aren’t published? This (op-ed) is in the spirit of publicity, not the spirit of science.”
Professor Muller’s daughter, Elizabeth Muller, explained that the papers have been peer-reviewed but not published. She told the LA Times, “The Berkeley team decided to place its papers online, in part to solicit comment from other scientists.”
Writes Professor Muller, “Four of our papers have undergone extensive scrutiny by the scientific community, and the newest, a paper with the analysis of the human component, is now posted, along with the data and computer programs used. Such transparency is the heart of the scientific method; if you find our conclusions implausible, tell us of any errors of data or analysis.”
“I believe the findings in our papers are too important to wait for the year or longer that it could take to complete the journal review process,” Elizabeth Muller wrote in an email. “We believe in traditional peer review; we welcome feedback [from] the public and any scientists who are interested in taking the time to make thoughtful comments. Our papers have received scrutiny by dozens of top scientists, not just the two or three that typically are called upon by journalists.”
Instead, the research and analysis is laid out at BerkeleyEarth.org.
Professor Muller concludes, “What about the future? As carbon dioxide emissions increase, the temperature should continue to rise. I expect the rate of warming to proceed at a steady pace, about one and a half degrees over land in the next 50 years, less if the oceans are included.”
He warns, “But if China continues its rapid economic growth (it has averaged 10 percent per year over the last 20 years) and its vast use of coal (it typically adds one new gigawatt per month), then that same warming could take place in less than 20 years.”
The work by Professor Muller, should it pan out, is a blow to climate skeptics who had hoped that by funding independent research they could debunk the commonly held belief in the scientific community that recent warming of temperatures was linked to human activity.
Professor Muller writes, “I embarked on this analysis to answer questions that, to my mind, had not been answered. I hope that the Berkeley Earth analysis will help settle the scientific debate regarding global warming and its human causes.”
He adds, “Then comes the difficult part: agreeing across the political and diplomatic spectrum about what can and should be done.”
—David M. Greenwald reporting