The Earth today stands in imminent peril
…and nothing short of a planetary rescue will save it from the environmental cataclysm of dangerous climate change. Those are not the words of eco-warriors but the considered opinion of a group of eminent scientists writing in a peer-reviewed scientific journal.
By Steve Connor, Science Editor, The Independent, 19 June 2007

Six scientists from some of the leading scientific institutions in the United States have issued what amounts to an unambiguous warning to the world: civilisation itself is threatened by global warming.

According to Hansen et al, the IPCC is not dramatic enough for their liking. From other speaches by James Hansen, the most vocal beurocrat ever muzzled by the administration, sea levels will rise by 80 feet, not the 20 that Gore says or the 3 feet that the IPCC projects.

“Civilisation developed, and constructed extensive infrastructure, during a period of unusual climate stability, the Holocene, now almost 12,000 years in duration. That period is about to end,” the scientists warn. Humanity cannot afford to burn the Earth’s remaining underground reserves of fossil fuel. “To do so would guarantee dramatic climate change, yielding a different planet from the one on which civilisation developed and for which extensive physical infrastructure has been built,” they say.

Hansen et al dismiss the latest IPCC graph showing warmer times on the past 10,000 years, or maybe they just overlooked those findings. The small rub here is that civilization is not as fragile as Hansen believes and humans have survived warm and cold in the past as have the polar bears. And, if, as they say, the climate has been unusually stable, why should we expect it to stay that way? Climate variability is normal, not unusual or catastrophic.

Dr Hansen said we have about 10 years to put into effect the draconian measures needed to curb CO2 emissions quickly enough to avert a dangerous rise in global temperature. Otherwise, the extra heat could trigger the rapid melting of polar ice sheets, made far worse by the “albedo flip” – when the sunlight reflected by white ice is suddenly absorbed as ice melts to become the dark surface of open water.

Again with the 10 years, its always ten years. Hansen has been saying ten years for at least 10 years. Isn’t it time to pay up?

Their study looked back over more than 400,000 years of climate records from deep ice cores and found evidence to suggest that rapid climate change over a period of centuries, or even decades, have in the past occurred once the world began to heat up and ice sheets started melting. It is not possible to assess the dangerous level of man-made greenhouse gases.

Hansen et al admit that “It is not possible to assess the dangerous level of man-made greenhouse gases.” But they do make a lot of mileage out of something that cannot be assessed.

Read the whole article for more insight.

Lubos Motl has a good critique of Hansen’s paper at The Reference Frame. Most people ther think Hansen is delusional at best.