BBC News reports on Richard A. Muller's decision to switch sides on the Climate Change political smokescreen, favoring reality over politics. Muller was a leading critic of the initial hockey stick results, one of the first people to cast widespread doubt on the issue and help stall a global discussion on what needs to be done to avoid killing billions of people.
In a piece authored for the New York Times, Prof Muller, from the University of California, Berkeley, said: "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."
In the New York Times piece, Muller insists that previous studies were insufficient and untrustworthy, but he makes it clear that his more robust research lines up completely with their claims -- the Berkeley Earth Surface Temperature group, the organization Muller organized to do this research, specifically repeated the experiments, accounting for all the popular denial arguments.
Our Berkeley Earth approach used sophisticated statistical methods developed largely by our lead scientist, Robert Rohde, which allowed us to determine earth land temperature much further back in time. We carefully studied issues raised by skeptics: biases from urban heating (we duplicated our results using rural data alone), from data selection (prior groups selected fewer than 20 percent of the available temperature stations; we used virtually 100 percent), from poor station quality (we separately analyzed good stations and poor ones) and from human intervention and data adjustment (our work is completely automated and hands-off). In our papers we demonstrate that none of these potentially troublesome effects unduly biased our conclusions.