Antarctic Cooling Down; The Antarctic Ice Sheet is Growing; Hansen Downgrades Warming Threat

January 22, 2002
Cooler Heads Coalition

Antarctic Cooling Down

A forthcoming study in Nature, that has appeared on its website as an "advance online publication," has found that the Antarctic has been cooling for some time now ( This contradicts the findings of the climate models upon which the case for global warming is built. They predict that the Earths poles will warm more rapidly than the rest of the Earth.

According to the study, "Climate models generally predict amplified warming in the polar regions, as observed in Antarcticas peninsula region over the second half of the 20th century." The new study finds that "Our spatial analysis of Antarctic meteorological data demonstrates a net cooling on the Antarctic continent between 1966 and 2000, particularly during summer and autumn." The McMurdo Dry Valleys, for example, have cooled about 0.7 degrees Celsius per decade during this period of time.

The authors conclude that, "Continental Antarctic cooling, especially the seasonality of cooling, poses challenges to models of climate, and ecosystem change."

The research into the continents temperature record was motivated by the unexpected coldness of the summers, according to lead author Peter Doran with the Department of Earth and Environmental Sciences at the University of Illinois. "Two or three years ago when we were waiting for the big summers, we noticed that they didnt come," said Doran. We were thinking that warm summers were the norm, and we were saying, Its going to get back to normal, but it never did" (Washington Post, January 14, 2002).

Michael Oppenheimer, chief scientist for Environmental Defense isnt buying it, however. "Id be very careful with this," he told the Washington Post. "My general view has been that theres simply not enough data to make a broad statement about all of Antarctica."

Of course, lack of data has never stopped Oppenheimer from making "broad" statements about the whole Earth. In November 2000, Environmental Defense press release he stated, for instance, "The 1990s, likely the hottest decade of the past thousand years, capped decades of shrinking glaciers, thinning Arctic ice, intensifying rainstorms, and rising seas," and that this means that, "The world must end its dependence on fossil fuels that are too dirty and too expensive. Governments must take action now."

It seems that the climate models have struck out. Strike one: they cant simulate the current climate. Strike two: they predict greater and more rapid warming in the atmosphere than at the surface. The opposite is happening. Strike three: they predict amplified warming at the poles, which are cooling instead.

The Antarctic Ice Sheet is Growing

A new study appearing in Science (January 18, 2002) concludes that the West Antarctic Ice Sheet (WAIS) is thickening, rather than thinning as was previously thought. Earlier studies found that in the Ross Sea Sector, "The grounding line (the point where the ice sheet loses contact with its bed and begins to float) has retreated nearly 1300 km along the western side of the Ross Embayment," since the last glacial maximum.

This led researchers to predict that the entire WAIS would collapse in 4000 years, implying a sea-level rise of 12.5 to 15 centimeters per century. This was based on a measurement of a loss of ice mass of 20.9 13.7 gigatons per year.

The authors of the new study, Ian Joughin and Slawek Tulaczyk, with the Jet Propulsion Laboratory at the California Institute of Technology, note, "The ice-discharge estimates of earlier studies relied on relatively sparse in situ measurements of ice-flow velocity. For some ice streams theestimates were based on only one or two velocity measurements."

The new study used satellite remote sensing to get better measurements. Contrary to earlier studies, the authors found "strong evidence for ice-sheet growth (26.8 14.9 gigatons per year)." They conclude, "The overall positive mass balance may signal an end to the Holocene retreat of these ice streams."

Hansen Downgrades Warming Threat

James Hansen, the director of NASAs Goddard Institute for Space Studies, has published a study in the Proceeding of the National Academy of Sciences (December 18, 2002) that downgrades the magnitude of global warming.

According to his analysis, the growth rate of climate forcing from greenhouse gases peaked in 1980 and has since declined from about 5 watts per square meter (W/m2) per century to about 3 W/m2 per century. When all forcings, both negative and positive, are taken into account total net forcing is about 1.6 1.1 W/m2. The Intergovernmental Panel on Climate Change assumes a 4 W/m2 forcing. As the study notes, "Most climate simulations, as summarized by the IPCC, do not include all of the negative forcings; indeed, if they did, and other forcings were unchanged, little global warming would be obtained."

Hansen and his co-author Makiko Sato, with Center for Climate Systems Research at the Columbia University Earth Institute, predict that "Global warming at a rate +0.15 0.05 degrees C per decade will occur over the next several decades." This is what the so-called skeptics have been saying all along.

Hansen and Sato put an interesting twist on their argument, however. They state that "the slowdown was caused mainly by phase-out of CFCs" (chlorofluorocarbons), which are also greenhouse gases, under the Montreal Protocol. The previous claim that sulfate aerosol emissions are masking the warming is no longer satisfactory since that has been cancelled out by the discovery of an equal but opposite forcing from black carbon.

Despite Hansens latest conclusion that the planet will only warm about 1.5 degrees C over the next century, a miniscule amount, he still argues for international cooperation to stop global warming. He calls for a "cooperative, not punitive" program of technology transfer from developed to developing world to reduce emissions.

News from Australia

Opponents of the Kyoto Protocol in Australia are clearly making progress in their campaign to defeat ratification. The Canberra Times (January 10, 2002) recently published an op-ed by Clive Hamilton of the Australia Institute that attacks the Lavoisier Group in vitriolic terms.

The Lavoisier Group provides the principal intellectual and organizational opposition in Australia to Kyoto and was organized by our colleague, N. Ray Evans of Melbourne. Hamilton accuses the Lavoisier Group of painting the UNs global warming negotiations as "an elaborate conspiracy in which hundreds of climate scientists have twisted their results to support the climate change theory in order to protect their research funding." Sounds plausible to us.

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