Climate's Dark Forcings

• Published in: Science (American Association for the Advancement of Science) Vol. 340; no. 6130; pp. 280 - 281
• Main Authors: Andreae, Meinrat O., Ramanathan, V.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 19.04.2013; The American Association for the Advancement of Science
• Subjects: Air pollution; Applied sciences; Atmospheric models; Atmospheric pollution; Atmospherics; Biofuels; Biomass burning; Black carbon; burning; Carbon; Carbon black; Climate; Climate change; Climate effects; Climate models; Clouds; coal; Combustion; Combustion and energy production; cooking stoves; Cooling; Earth, ocean, space; Electromagnetic absorption; Estimates; Exact sciences and technology; External geophysics; Global climate; Global climate models; Global warming; lungs; Meteorology; Nose; Nuisance; Particles and aerosols; PERSPECTIVES; pollutants; Pollution; Pollution sources. Measurement results; radiative forcing; Regional; Solar radiation; Soot; Trucks; women; Combustion residue; Carbonaceous materials; Pollution control; Soot; Regional scope; Aerosols; Planetary scale; Air pollution; Effect on climate; Pollution abatement; Pollutant effect; Forcing
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1235731

Uncertainties about the properties and amounts of atmospheric black carbon complicate efforts to understand its regional and global effects on climate. The black soot coming out of the tailpipes of diesel trucks is a nuisance familiar to every highway traveler. Soot also endangers the health of untold numbers of women and their families exposed to smoke from traditional cookstoves burning biofuels and coal. But in addition to irritating our noses and lungs, this pollutant, also known as black carbon (BC), is the strongest absorber of solar radiation in the atmosphere. The magnitude of global warming from BC, as well as its regional effects, has been the subject of intense debate. In a recent comprehensive assessment, Bond et al. ( 1 ) have synthesized available model results and observations, and propose a "best estimate" for BC's global climate forcing. Their estimate is almost twice as high as values commonly discussed ( 2 ). What causes such large discrepancies between estimates, and what are the implications for the global and regional climate effects of BC?