摘要：'Soot' or 'black carbon', which comes from incomplete combustion, absorbs light and
warms the atmosphere. Although there have been repeated suggestions that reduction of
black carbon could be a viable part of decreasing global warming, it has not yet been
considered when choosing actions to reduce climatic impact. In this paper, I examine four
conceptual barriers to the consideration of aerosols in global agreements. I conclude
that some of the major objections to considering aerosols under hemispheric or
global agreements are illusory because: (1) a few major sources will be addressed
by local regulations, but the remainder may not be addressed by traditional air
quality management; (2) climate forcing by carbon particles is not limited to 'hot
spots'—about 90% of it occurs at relatively low concentrations; (3) while aerosol science is
complex, the most salient characteristics of aerosol behavior can be condensed into
tractable metrics including, but not limited to, the global warming potential;
(4) despite scientific uncertainties, reducing all aerosols from major sources of
black carbon will reduce direct climate warming with a very high probability.
This change in climate forcing accounts for at least 25% of the accompanying
CO2 forcing with significant probability (25% for modern diesel engines, 90% for superemitting
diesels, and 55% for cooking with biofuels). Thus, this fraction of radiative forcing should
not be ignored.
