Deriving global quantitative estimates for spatial and temporal distributions of biomass burning emissions

Since the 1980’s biomass burning has been recognized as a major source of global air pollution (Seiler and Crutzen, 1980; Andreae et al., 1988; Crutzen and Andreae, 1990). The majority of the emissions occur in the Tropics, due to the conjunction of anthropogenic pressure, level of development, climate, and availability of fuel. In these regions, biomass burning remains the main source for energy supply even if the contribution of fossil fuel which used to be relatively low in many countries (figure 1), has been increasing since the 1980’s (for example from 1980 to 1995 fossil fuel consumption in South Africa has doubled). Because of the intensity of photochemistry and convection in tropical latitudes, biomass burning emissions in this region have an important atmospheric chemical and radiative impact. This was pointed out by numerous studies on the tropospheric ozone budget (Andreae et al., 1988; Chatfield et al., 1996; Thompson et al., 1996; Chandra et al. 2002), on the CO2 sources and sinks (Prentice et al., 2002), and on regional and global radiation budgets (Kaufman et al., 1991; Penner et al., 1991; Cox et al. 2000; Jacobson, 2002). Recently, Wotawa and Trainer (2000) found that emissions from fires in temperate and boreal fires in the northern hemisphere may occasionally have a regional and long-range impact comparable to the emissions from fossil fuel combustion.