WASHINGTON-The
major source of potentially climate-changing soot in the air over south Asia is
home cooking fires,according to a team of Indian and American
researchers.
The burning of
wood, agricultural waste and animal manure for cooking is the largest source of
black carbon in the air in that region, according to the team led by C.
Venkataraman of the Indian Institute of Technology Bombay.
“We therefore
suggest that the control of these emissions through cleaner cooking
technologies, in addition to reducing health risks to several hundred million
users, could be of crucial importance to climate change mitigation in south
Asia,” the researchers wrote in a paper appearing in Friday’s issue of the
journal Science.
The effect of soot
in the air over the Indian Ocean is some 10 times that of the so-called
greenhouse gases, according to the researchers. The pollution causes the air to
absorb more sunlight, warming the atmosphere and cooling the surface beneath.
Such changes can affect rainfall patterns, contributing to intensity of floods
and droughts, the group said in their paper.
Worldwide, most
atmospheric scientists are concerned that increasing greenhouse gases, such as
carbon dioxide, from industrial processes are trapping heat increasing the
planet’s overall temperature in ways that could lead to climate
change.
The researchers
conducted tests, burning various fuels used in home cooking in India to
determine the type of soot produced, and measured soot in the air.
They calculated
that, of the black soot in the atmosphere, 42 percent originates from cooking
fires, 25 percent from burning fossil fuels and 13 percent from open burning
such as forest fires.
The research also
included scientists from the University of California, Los Angeles. The work
was funded by the Indian Space Research Organization; Center for Clouds,
Chemistry and Science,University of California, San Diego; U.S. National
Institute of Environmental Health Sciences; and U.S. Environmental Protection
Agency.