FIG. 2. Annual pre-industrial, expected contemporary, and contemporary emission estimates from biomass burning in the conterminous United States for: carbon dioxide (Tg x 10²), carbon monoxide (Tg), methane (Tg x 10^-1), nonmethane hydrocarbon (Tg x 10^-1), volatile organic compounds (Tg x 10^-1), nitric oxide (Tg x 10^-1), total particulate matter (Tg x 10^-1),10- micron particulate matter (Tg x 10^-1), 2.5-micron particulate matter (Tg x 10^-1), organic carbon (Tg x 10^-1), and elemental carbon (Tg x 10^-2). These are compared with 1995 fossil fuel emission estimates for carbon dioxide, carbon monoxide, volatile organic compounds, nitric oxide, and 10-micron particulate matter.