Short-term cooling but long-term global warming due to biomass burning particles and gases

Biomass burning is the burning of evergreen forests, deciduous forests, woodlands, grassland, and agricultural land, either to clear land for other use, to stimulate grass growth, for forest management, or as a ritual. Biomass burning releases both gases (e.g.,CO2, CO, CH4, NOx, SO2, C2H6, C2H4, C3H8, C3H6) and aerosol particle components (e.g., black carbon, organic matter, K+, Na+, Ca2+, Mg2+, NH4+, H+, Cl-, H2SO4, HSO4-, SO42-, NO3-). The global-scale climate response of controlling emissions of these gas plus particle constituents during biomass burning has not been examined to date. Whereas biomass-burning particles enhance global cooling in the short term, it is found that this cooling is partially suppressed by black carbon and more than offset in the long term by the warming effect of long-lived biomass-burning gases. The emissions of the most important of these gases, CO2, is only partially offset by biomass regrowth each year. As such, a reduction in biomass burning, not considered under the Kyoto Protocol, should slow global warming, contrary to common perception. Control of biomass-burning should also improve human health.