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.
In an opinion piece in Saturday’s New York Times titled “The Conversion of a Climate-Change Skeptic,” Muller writes: “Three years ago I identified problems in previous climate studies that, in my mind, threw doubt on the very existence of global warming. Last year, following an intensive research effort involving a dozen scientists, I concluded that global warming was real and that the prior estimates of the rate of warming were correct. I’m now going a step further: Humans are almost entirely the cause.”
...Some leading climate scientists said Muller’s comments show that the science is so strong that even those inclined to reject it cannot once they examine it carefully. Michael E. Mann, director of the Earth System Science Center at Pennsylvania State University, said 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.