News Archive

posted 10/04/02

Researchers Use Goddard Institute to Examine Effects of Soot in China

NASA researchers Surabi Menon and James Hansen used resources at the Goddard Institute for Space Studies at Columbia University to discover that large amounts of black carbon particles, or soot, as well as other pollutants have been observed to cause changes in precipitation and temperature over China. Additionally, the scientists noted that the pollutants "may be at least partially responsible" for the tendency toward increased floods and droughts in the country during the last few decades.

At the Goddard Institute for Space Studies, researchers used climate computer model and aerosol data from 46 ground stations in China to conduct four sets of computer simulations to monitor the effects of black carbon on the hydrologic cycle over China and India. In the four sets, Menon and Hansen isolated such specific factors as sea surface temperature, other greenhouse gases and aerosols, and analyzed whether changes in the various factors would be responsible for hydrologic cycle changes.

Of the four scenarios, the researchers noted that the effect of increased amounts of soot over southern China created a "clear tendency" toward flooding in southern China and increasing drought in northern China during the last several years.

The study's findings, which appear in the latest issue of the journal Science, suggest that black carbon can affect regional climate by absorbing sunlight and heating the air, thereby altering large-scale atmospheric circulation and the hydrologic cycle.

"If our interpretation is correct, then reducing the amount of black carbon or soot may help diminish the intensity of floods in the south and droughts in the northern areas of China, in addition to having human health benefits," said Hansen.

Menon and Hansen said soot is typically generated by industry, traffic, outdoor fires and the burning of coal and biomass fuel in homes.

The Goddard Institute for Space Studies is part of The Earth Institute at Columbia University, which is the world's pioneer academic center for mobilizing the sciences and public policy in pursuit of a sustainable future, especially for the world's poor.