Whatever happens at the global green gabfest in Durban, greens will, no doubt, take comfort in assuring themselves that science is on their side.Well, not quite. It seems that Science — that is, one of the world’s most prestigious and influential scientific journals — is open to doubts about some of the more dire premises regularly trotted out by green hactivists to justify their doomsday predictions.The Economist reports on some new cutting-edge climate research published in a peer-reviewed article in Science that challenges some core green doom warnings. In particular, the study suggests that the probable sensitivity of the earth’s climate to increases in the concentration of carbon dioxide in the atmosphere is far lower than the assumptions traditionally used by the (already discredited) Intergovernmental Panel on Climate Change. Not only that, the authors find that the existence of a so-called “fat tail” — the notion that extreme temperature changes in response to increases in atmospheric CO2 are likely — is illusory.The Economist tells us that the conclusions of this study, if confirmed by others, have far-reaching implications for predictions about the climate.
The Intergovernmental Panel on Climate Change, in its most recent summary of the science behind its predictions, published in 2007, estimated that, in present conditions, a doubling of CO2 would cause warming of about 3°C, with uncertainty of about a degree and a half in either direction. But it also says there is a small probability that the true number is much higher. Some recent studies have suggested that it could be as high as 10°C.If that were true, disaster beckons. But a paper published in this week’s Science, by Andreas Schmittner of Oregon State University, suggests it is not. In Dr Schmittner’s analysis, the climate is less sensitive to carbon dioxide than was feared.
So much less sensitive, in fact, that the doomsday scenarios can be ruled out. Carbon dioxide just does not make the world as much warmer as the green Malthusians believe. The Economist continues:
The group’s most likely figure for climate sensitivity is 2.3°C, which is more than half a degree lower than the consensus figure, with a 66% probability that it lies between 1.7° and 2.6°C. More importantly, these results suggest an upper limit for climate sensitivity of around 3.2°C.
Via Meadia regards this study, like others, as limited in scope and subject to revision. We await new studies and new hypotheses that over time will help us understand the earth’s extremely complex climate system better than we now do. But the challenge to “established” assumptions shouldn’t surprise anyone. This is modern science in action: some of the best minds in the discipline probing the validity of others’ hypotheses in the interest of advancing our understanding of the world around us. But don’t tell the folks in Durban — for the unicorn chasers, the science is settled.