The Heat Death of American Dreams

A number of news reports and commentary on Hurricanes Katrina and Rita have linked the disasters to global warming. Almost nobody noticed a crucial scientific finding, two weeks earlier, that foreshadows disasters on a far greater scale in the decades to come.

According to August 11 articles in the magazine New Scientist and the British newspaper the Guardian, a pair of scientists, one Russian and one British, report that global warming is melting the permafrost in the West Siberian tundra. The news made a little blip in the international media and the blogosphere, and then it disappeared.

Why should anyone care? Because melting of the Siberian permafrost will, over the next few decades, release hundreds of millions of tons of methane from formerly frozen peat bogs into the atmosphere. Methane from those bogs is at least twenty times more potent as a greenhouse gas than the carbon dioxide that currently drives global warming. Dumping such a huge quantity of methane on top of already soaring CO2 levels will drive global temperatures to the upper range of increases forecast for the remainder of this century.

According to the most recent forecast by the UN's Intergovernmental Panel on Climate Change (IPCC), compiled in 2001, human industrial emissions are on course to raise global temperatures between 1.4 and 5.8 degrees Celsius by the year 2100. The IPCC models didn't account for methane releases from the Arctic, nor did they consider other natural sources of greenhouse gases that could be released by human activity. The agency judged Arctic methane releases to be a real but remote possibility, not likely to emerge for decades. Now we find that it could very well be happening today.

The news of melting Siberian permafrost means, in all likelihood, that global warming is accelerating much faster than climatologists had predicted. The finding from Siberia comes amidst evidence, presented at Tony Blair's special climate change conference last February, that the West Antarctic Ice Sheet could be in danger of disintegrating -- another warming-induced event once thought to be decades or centuries away.

Meanwhile, according to a September 29, 2005 report in the Guardian, scientists at the University of Colorado, Boulder's National Snow and Ice Data Center have measured a drastic shrinking of ice floes in the Arctic Ocean. Arctic waters are now expected to be ice-free well before the end of this century.

How many more milestones will there be? The prospects of a worst case scenario, with a temperature increase approaching or exceeding 5.8 degrees Celsius, are increasing dramatically, with all the attending disasters that would entail -- inundated coastlines, extreme storms and drought, disease pandemics, collapsing agriculture, massive environmental refugee flows.

And how far will it go? Climate forecasts have long noted that every increase in global temperature heightens the odds of runaway global warming, beyond any human control. Continued overheating could unlock more methane from Arctic regions beyond Siberia. It could cripple the vital ability of plants and oceans to absorb CO2 from the atmosphere, turning them into gushing sources of new CO2 that accelerate the superheating even further. The ice caps that help cool the Earth by reflecting sunlight into space could vanish. In the end, the relentless rise in temperature could induce a cataclysmic venting of billions of tons of methane from the oceans.

A paper by British scientists Michael J. Benton and Richard J. Twitchett, published in the July 2003 issue of Trends in Ecology & Evolution, shows how this could happen. 251 million years ago, at the end of the Permian era, a release of carbon dioxide from volcanic eruptions apparently heated the Earth's atmosphere by about 6 degrees Celsius.