The latest evidence puts the threat of climate change beyond doubt, says Vanessa Houlder Published: February 23 2001 19:50GMT | Last Updated: February 23 2001 19:56GMT In The Snows of Kilimanjaro, Ernest Hemingway's hero has a vision of the ice-capped summit "as wide as all the world, great, high, and unbelievably white in the sun". The description will soon be unrecognisable. The ice field on top of the Tanzanian mountain will have disappeared by 2020, it was predicted this week. A third of the ice has melted over the last 12 years alone. According to Lonnie Thompson, professor of geological sciences at Ohio State University, all tropical glaciers are retreating at an accelerating pace. They are, he says, "an indicator of massive changes taking place". Prof Thompson's study, coupled with the recent findings of the United Nations-sponsored International Panel on Climate Change, marks a turning point in the controversy over the existence of man-made global warming. The IPCC's view that "there is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities" is now accepted by all but a very small group of sceptics. The IPCC, a body of climate scientists who advise the world's politicians on global warming, has found widespread evidence of climate change, ranging from the thawing of permafrost, longer growing seasons in certain latitudes, decline of some plant and animal populations, earlier flowering of trees and egg-laying in birds. But the changes that have already happened pale in comparison with those that could take place this century. In the 20th century, the planet heated up by about 0.60C. This century, the IPCC predicts, temperatures will rise 1.40C-5.80C , the fastest rate of change for 10,000 years. The IPCC's latest report, written by 426 authors and reviewed by 440 government and expert reviewers, predicts spreading deserts and a decline in agricultural production in Africa, floods and droughts in Latin America, storm surges and coastal erosion off the eastern seaboard of the US and water shortages in Australia and New Zealand. Europe will suffer widespread flooding and a decline in many traditional holiday resorts because of heat waves and unreliable snow conditions. In southern Europe more droughts could reduce agricultural productivity. Much of Asia will suffer a decline in agricultural productivity, while sea level rises and an increase in the intensity of tropical cyclones could displace tens of millions of people in low-lying coastal areas. The small island states, which are particularly vulnerable to increases in sea levels and storms, will suffer the worst effects of all. But if the scientific evidence is increasingly clear-cut, the political response remains uncertain. "How much more evidence do we need before governments take real action to tackle climate change?" says Russell Marsh of WWF, the conservation group. Negotiations to complete the 1997 Kyoto Protocol on cutting greenhouse gas emissions seem likely to remain stalled unless countries can agree to make a genuine commitment to reducing the use of fossil fuels. Yet the attitude of many politicians, especially in energy-hungry countries such as the US, is that the cost of taking action to curb global warming exceeds the electoral gains. The countries that need to put the most effort into curbing global warming are not, by and large, those that have the most to lose from it. "The impact of future changes in climate extreme are expected to fall disproportionately on the poor," says the IPCC. A modest increase in temperatures might even benefit the developed world: crop and timber yields would be higher, deaths from cold weather would be reduced, as would energy demand. But if temperatures rise by more than a few degrees Centigrade there would be no advantages for anybody. The IPCC now believes that its 1995 prediction of a 10C-3.50C rise this century is an underestimate, largely because scientists exaggerated likely future emissions of sulphur dioxide, an air pollutant that offsets warming. The revised forecast predicts that temperatures could rise by up to 5.80C. The possibility of a steep and prolonged increase in temperatures raises the possibility of what the IPCC scientists call "large-scale and possibly irreversible impacts". Examples include: large reductions in the Greenland and western Antarctic ice sheets; significant slowing of the thermohaline ocean circulation that transports warm water to the North Atlantic; and a huge release of greenhouse gases from melting permafrost and dying forests. The consequences could be catastrophic. The disintegration of the ice sheets could raise global sea levels by up to 6m over the next 1,000 years. A slowing of the ocean circulation could have a significant cooling effect on parts of Europe. And the release of greenhouse gases from permafrost and forests could amplify climate change, creating a runaway effect. The likelihood of these changes is "probably very low", the IPCC says, but adds: "Their likelihood is expected to increase with the rate, magnitude and duration of climate change." In spite of all the remaining uncertainties, the central message is clear: a warmer planet is likely to have implications for everybody. "No country can afford to ignore the coming transformation of its natural and human environment," says Michael Zammit Cutajar, a senior UN official. Moreover, global warming will inflict the most harm in the parts of the world that are the poorest, the least prepared - and the least responsible for causing it. FT.com _______________________________________________ CrashList website: http://website.lineone.net/~resource_base
