SciDev.Net: Burning biomass is the main cause of the dense ‘brown clouds’ that plague South Asia each winter, and both biomass and fossil fuel burning should be targeted to combat climate change and improve air quality. These are the conclusions of a study published today (23 January) in Science. The study, conducted at two sites in South Asia, attempted to find the main source of the carbon soot particles that comprise much of the clouds. While the brown cloud acts as a ‘global dimmer’ by …