Biomass burning in the tropics: Impact on atmospheric chemistry and biogeochemical cycles

Journal Article · Fri Dec 21 04:00:00 EST 1990 · Science (Washington, D.C.); (United States)

DOI:https://doi.org/10.1126/science.250.4988.1669· OSTI ID:6079232

Crutzen, P J; Andreae, M O ^[1]

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1. Max Planck Inst., Mainz (West Germany)

Biomass burning is widespread, especially in the tropics. It serves to clear land for shifting cultivation, to convert forests to agricultural and pastoral lands, and to remove dry vegetation in order to promote agricultural productivity and the growth of higher yield grasses. Furthermore, much agricultural waste and fuel wood is being combusted, particularly in developing countries. Biomass containing 2 to 5 petagrams of carbon is burned annually (1 petagram = 10{sup 15} grams), producing large amounts of trace gases and aerosol particles that play important roles in atmospheric chemistry and climate. Emissions of carbon monoxide and methane by biomass burning affect the oxidation efficiency of the atmosphere by reacting with hydroxyl radicals, and emissions of nitric oxide and hydrocarbons lead to high ozone concentrations in the tropics during the dry season. Large quantities of smoke particles are produced as well, and these can serve as cloud condensation nuclei. These particles may thus substantially influence cloud microphysical and optical properties, an effect that could have repercussions for the radiation budget and the hydrological cycle in the tropics. Widespread burning may also disturb biogeochemical cycles, especially that of nitrogen. About 50% of the nitrogen in the biomass fuel can be released as molecular nitrogen. This pyrodenitrification process causes a sizable loss of fixed nitrogen in tropical ecosystems, in the range of 10 to 20 teragrams per year (1 teragram = 10{sup 12} grams).

• OSTI ID: 6079232
• Journal Information: Science (Washington, D.C.); (United States), Journal Name: Science (Washington, D.C.); (United States) Vol. 250:4988; ISSN SCIEA; ISSN 0036-8075
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
092000* -- Biomass Fuels-- Combustion-- (1990-)
095000 -- Biomass Fuels-- Environmental Aspects-- (1990-)
BIOMASS
CHEMICAL REACTIONS
COMBUSTION
DATA
ENERGY SOURCES
ENVIRONMENTAL EFFECTS
EXPERIMENTAL DATA
HYDROLOGY
INFORMATION
NITROGEN CYCLE
NUMERICAL DATA
OXIDATION
PARTICLES
RENEWABLE ENERGY SOURCES
THERMOCHEMICAL PROCESSES
TROPICAL REGIONS