Climate Science Subject to 'Irreducible Uncertainties'

In a New York Times blog, Roger A. Pielke Jr., a political scientist at the University of Colorado, explained his position on whether recently disclosed emails and files would likely erode confidence in the Intergovernmental Panel on Climate Change's conclusion that most climate change since 1950 was the result of human activity.

In the Green Inc. blog, Pielke said some of the overall climate change trend was due to how adjustments were made to the raw data to account for biases. Different investigators made these adjustments in different legitimate ways. The adjustments and the principles behind them could be used to minimize or maximize the effects of human activity.

Pielke was quoted as saying: "Presumably once the data is readily available how these legitimate scientific choices are made about the adjusting would be open to scrutiny and debate. People will then be much more able to cherry pick adjustment procedures to maximize or minimize the historical trends, but also to clearly see how others make decisions about adjustments."

The implications would be that if the adjustments made by CRU, GISS and NOAA were those that would maximize historical climate trends, the credibility of their conclusions would be damaged, but it would be enhanced if their adjustments trended somewhere in the middle. A critical measurement, said Pielke, was surface temperatures, which were the key to estimates of climate sensitivity in climate change models. Debates over what adjustments were made would help us understand that some uncertainties remain, and will remain, in climate science, he said.

Concluded the Green Inc. blog: "So, in the end, Dr. Pielke appears to say, closer scrutiny of the surface-temperature data could undermine definitive statements of all kinds -- that human-driven warming is an unfolding catastrophe or something concocted. More uncertainty wouldn't produce a climate comfort zone, given that poorly understood phenomena can sometimes cause big problems. But it would surely make humanity's energy and climate choices that much tougher."