Brown haze from burning biomass in Asia and Africa may contribute regionally as much as greenhouse gas emissions to anthropogenic climate warming according to reports in Nature. Designing efficient cookstoves for the poor could improve their livelihood, improve health, and the environment. How would investing in cookstoves compare to carbon sequestration?
“By 2001, it was realized that the thick brown haze discovered over the Arabian Sea during the Indian Ocean Experiment (INDOEX: 1997-1999) was a persistent dry-season feature above Southern Asia. A UNEP report in 2002 raised concerns of major climate disruption if the sources of the haze, including biomass burning, were not controlled. . . . Atmospheric solar heating and surface dimming due to ABCs both drive climate change, and to quantify that change we need direct measurements like the two datasets presented this week. . . . Climate modelling with the data suggests that ABC-induced atmospheric warming resembles that induced by greenhouse gases, a possible explanation for Himalayan glacier retreat. News and Views: Climate change: Aerosols heat up
Warming trends in Asia amplified by brown cloud solar absorptionVeerabhadran Ramanathan1, et al. Nature 448, 575-578
2 August 2007
“Atmospheric brown clouds are mostly the result of biomass burning and fossil fuel consumption1. They consist of a mixture of light-absorbing and light-scattering aerosols1 and therefore contribute to atmospheric solar heating and surface cooling. ” . . . “We found that atmospheric brown clouds enhanced lower atmospheric solar heating by about 50 per cent. Our general circulation model simulations, . . . suggest that atmospheric brown clouds contribute as much as the recent increase in anthropogenic greenhouse gases to regional lower atmospheric warming trends. We propose that the combined warming trend of 0.25 K per decade may be sufficient to account for the observed retreat of the Himalayan glaciers4, 5, 6“