Atmospheric Brown Clouds: Regional Assessment Report with Focus on Asia
http://www.unep.org/pdf/ABCSummaryFinal.pdf
Represents a summary for policy makers of research into the cause and effects of large clouds from the burning of fossil fuels and biomass. The clouds pose major threats to the water and food security of Asia and have resulted in surface dimming, atmospheric solar heating, and soot deposition in Himalayan glaciers and snow packs. From the United Nations Environment Programme.