Researchers Find Key To Measuring Effects On Global Climate From Humans Burning Trees, Sooty Industrial Fuels

Greenbelt, MD (AHN) - Researchers in the United States and Israel teemed up to re-examine the role of soot in world climate and discovered a key to helping to determine the true impact on the climate of human activities such as burning trees or sooty industrial fuels.

Scientists discovered that soot can help heat the climate up as well as cool it down and they developed a model to be able to forecast whether soot will provide a cooling or heating effect at any given time.

Tons of soot from forest fires around the world rises up into the climate to interact with clouds every year. Soot is classified as an airborne particle, collectively airborne particles are referred to as aerosols.

Scientists used to think that the main effect of soot was a cooling one because it can rise up into the clouds, increasing the size and lifespan of the cloud and reflecting some solar energy back into space.

However, researchers from Israel's Weizmann Institute of Science; the University of Maryland, Baltimore County and NASA's Goddard Space Flight Center in Maryland have found that soot's interaction with clouds is more complex than that.

Now they know that soot can both have either a cooling or heating effect on the atmosphere, depending on conditions.

"On the one hand, water droplets form around the aerosol particles, which may extend the cloud cover. On the other hand, particles, especially soot, absorb the sun's radiation, stabilizing the atmosphere and thus reducing cloud formation," researchers wrote in a statement released Thursday.

The scientists developed a model to forecast whether soot will extend or reduce cloud formation and during testing have discovered it works. This model provides scientists with a missing key to figuring out what the true scope and climatic consequences of human-induced climate change from burning trees or sooty industrial fuels are.

Findings from the study appear in the Aug. 15 issue of Science.