Thaindian News

Washington, Dec 9 (IANS) The climate may potentially change for the worse this century, triggering many metres of sea level rise, if global warming is not controlled, said an American scientist, basing his finding on new research into the planet’s paleoclimate history.

By looking at how the Earth’s climate responded to past natural changes, James E. Hansen, director of NASA’s Goddard Institute for Space Studies, sought an insight into a fundamental question raised by ongoing manmade climate change: “What is the dangerous level of global warming?”

Some international leaders have suggested a goal of limiting warming to two degrees Celsius from pre-industrial times in order to avert catastrophic change, according to a NASA statement.

But Hansen told journalists at the American Geophysical Union in San Francisco Tuesday that warming of two degrees Celsius would lead to drastic changes, such as significant ice sheet loss in Greenland and Antarctica.

Based on Hansen’s temperature analysis work at the Goddard Institute, the earth’s average global surface temperature has already risen 0.8 degree Celsius since 1880, and is now warming at a rate of more than 0.1 degree Celsius every decade.

This warming is largely driven by increased greenhouse gases in the atmosphere, particularly carbon dioxide, emitted by the burning of fossil fuels at power plants, in cars and in industry.

At the current rate of fossil fuel burning, the concentration of carbon dioxide (CO2) in the air will have doubled from pre-industrial times by the middle of this century. A doubling of CO2 would cause an eventual warming of several degrees, Hansen said.