Sources Of Climate- And Health-afflicting Soot Pollution Over South Asia Identified

ScienceDaily (Jan. 25, 2009) —

A gigantic brownish haze from various burning and combustion processes is blanketing India and surrounding land and oceans during the winter season. This soot-laden Brown Cloud is affecting South Asian climate as much or more than carbon dioxide and cause premature deaths of 100 000s annually, yet its sources have been poorly understood.

In the journal Science Örjan Gustafsson and colleagues at Stockholm University and in India use a novel carbon-14 method to determine that two-thirds of the soot particles are from biomass combustion such as in household cooking and in slash-and-burn agriculture.

Brown Clouds, covering large parts of South and East Asia, originate from burning of wood, dung and crop residue as well as from industrial processes and traffic. Previous studies had left it unclear as to the relative source contributions of biomass versus fossil fuel combustion.

Read the full story