Global Warning On Global Warming

Scientists warned Tuesday that a long-term, four-degree increase in the average global temperature could threaten Latin American water supplies, reduce food yields in Asia and result in a rise in extreme weather conditions in the Caribbean.

The warnings came in a report released by a group of European scientists on the sidelines of an annual U.N. conference on climate change.

The study aimed to determine the impact of climate change in select areas around the global and to assess how much change may be "tolerable," said Carlo Jaeger, the head of the Global Change and Social Systems at the Potsdam Institute for Climate Impact Research in Germany.

"Long-term temperature increases of more than two degrees constitutes dangerous interference with the climate system," said Jaeger, who helped assemble the report entitled "What is Dangerous Climate Change?"

The planet's temperature is used as a guideline by environmentalists and government official seeking to control the amount of greenhouse gas emissions blamed for global warnings.

"This can lead to sea-level rise of several meters and involve a whole range of major risks to human well-being and environmental integrity," said Jaeger.

Its release came as representatives from almost 200 nations refined details of the Kyoto Protocol, a landmark global warming treaty to be implemented in February. The accord commits major industrialized nations to curbing gases from factories, cars and coal-burning power plants blamed for trapping heat in the atmosphere by 2012.

Under the Kyoto pact, governments of 30 richer nations are to set quotas for their industries' emissions to meet specified national targets. But China, India and other poorer nations were exempted from Kyoto's short-term targets.

The United States has rejected the plan, with President Bush in 2001 objecting to the exemptions and saying it would damage the U.S. economy

Many environmentalists are alarmed by what they consider mounting evidence of global warming's destructive toll. American scientists reported last April that global temperatures rose an average of just over 1 degree Fahrenheit over the past century.

Jaeger said the report's calculations were based on the assumption that if average temperatures rose about four degrees Fahrenheit above those from a century ago, it could lead to a collapse in the Amazon rain forests ecosystem and lead to rising sea levels affecting Greenland.

In Peru, where almost 70 percent of power comes from hydroelectric plants, water supply for the Peruvian capital could be threatened if warming continues, Jaeger said.

Other vulnerable areas include China, where an increase in global temperatures could affect rice yields, and in the Caribbean, a region already hit by an increase in extreme weather such as hurricanes, Jaeger said. China is the world's second largest emitter of greenhouse gasses, with the United States ranking first.

In other developments Tuesday, government and private groups said they are rushing a new generation of more sophisticated satellites into space to monitor greenhouse gas emissions and track changing sea levels, thinning polar ice and as well as rising temperatures on the planet.

The effort aims at better understanding the impact of heat-trapping gases on the climate.

"We are developing a new generation of observational and environmental satellites. Each is increasingly advanced and more complex. We have satellites now capable of measuring many aspects of the environment," said Espen Volden of the European Space Agency.

The European Space Agency, together with the European Union, is taking part in an earth-monitoring program that is tracking everything from polluting forest fires in Borneo to changes in farmland in Europe and the thinning of polar ice caps.