NEWS

Clean-Air Policies May Accelerate Warming Trend, Scientist Says

10/09/2008

By Jeremy van Loon

 (Bloomberg)—Cleaning air in Beijing and in other large cities suffering from pollution problems by limiting car and power-plant emissions may raise global temperatures instead of lowering them, according to a German scientist. 

Aerosols, or particles suspended in air, have a cooling effect on the Earth, countering global warming linked to carbon dioxide, said Hans-Joachim Schellnhuber, director of the Potsdam Institute for Climate Research. A drop in aerosols in the atmosphere could cause a ``rapid’’ rise in temperatures, he said. 

Airborne pollutants act as an umbrella worldwide while CO2 provides insulation, trapping heat attempting to escape into the atmosphere. A rise in temperature because of declines in aerosols in the atmosphere can be offset by slashing CO2 emissions, he said. By not reducing carbon output, humanity ``is closing the last door we have through which we can possibly influence the global climate,’’ Schellnhuber said. 

There’s a 50-50 chance of limiting the global temperature rise to 2 degrees Celsius (3.6 degrees Fahrenheit) before 2100, which would avert some of the worst damage of climate change, Schellnhuber said. It’s ``urgent’’ that the United Nations- sponsored climate-change talks this December in Poznan, Poland, and next year in Copenhagen reach an agreement to limit CO2, he added. 

``There is really no time to spare,’’ he said today in a Berlin interview. ``Technology will play a decisive role in limiting carbon but we have to move to a carbon-free world by the end of the century.’’

To contact the reporter on this story: Jeremy van Loon in Berlin at jvanloon@bloomberg.net