Showing papers on "Atmospheric methane published in 1987"
TL;DR: A global data base of wetlands at 1° resolution has been developed from the integration of three independent global, digital sources: vegetation, soil properties and fractional inundation in each 1° cell as discussed by the authors.
Abstract: A global data base of wetlands at 1° resolution has been developed from the integration of three independent global, digital sources: (1) vegetation, (2) soil properties and (3) fractional inundation in each 1° cell. The integration yielded a global distribution of wetland sites identified with in situ ecological and environmental characteristics. The wetland sites have been classed into five major wetland groups on the basis of environmental characteristics governing methane emissions. The global wetland area derived in this study is ∼5.3 × 1012m2, approximately twice the wetland area previously used in methane-emission studies. Methane emission was calculated using methane fluxes for the major wetland groups, and simple assumptions about the duration of the methane production season. The annual methane emission from wetlands is ∼110 Tg, well within the range of previous estimates (11-300 Tg). Tropical/subtropical peat-poor swamps from 20°N-30°S account from ∼30% of the global wetland area and ∼25% of the total methane emission. About 60% of the total emission comes from peat-rich bogs concentrated from 50°-7O°N, suggesting that the highly seasonal emission from these ecosystems is the major contributor to the large annual oscillations observed in atmospheric methane concentrations at these latitudes.
1,061 citations
TL;DR: In this article, an analysis is presented of possible worldwide production of methane from anaerobic decay of organic municipal and industrial wastes in landfills, and the amount of methane released to the atmosphere from this source may now be in the range of 30-70×106 T/yr, which is between 6% and 18% of the total CH4 source.
Abstract: An analysis is presented of possible worldwide production of methane from anaerobic decay of organic municipal and industrial wastes in landfills. The amount of methane released to the atmosphere from this source may now be in the range of 30–70×106 T/yr, which is between 6% and 18% of the total CH4 source. By far, most of this emission comes from the industrialized world. Release rates from these countries have been increasing steadily during the past decades, but growth rates are now gradually stagnating. In the future, the contribution from developing nations is expected to grow rapidly because of increasing population and urbanization. Consequently, methane release from landfills may become one of the main sources of atmospheric methane in the next century.
295 citations
TL;DR: In this article, the authors investigated the evolution rate of carbon dioxide and methane in four subarctic fens over one summer and found that carbon dioxide was more sensitive to peat temperatures than methane.
Abstract: Rates of net methane and carbon dioxide evolution from four subarctic fens over one summer ranged from 0 to 7 mmol CH4 m−2 d−1 and from 2 to 29 mmol CO2 m2 d−1. Average molar ratios of carbon dioxide to methane ranged from 3 to 10. Partially because of the high spatial variability in evolution rates, the temperature dependence of carbon dioxide was weak, but stronger for methane, with significant (P < 0.05) positive correlations at two sites, especially with peat temperatures. Annual flux of methane is estimated to be 0.1–0.6 g C m−2 which, although low compared to other wetlands, becomes a substantial atmospheric contribution when the large area occupied by subarctic peatlands is taken into account. Key words: Methane, carbon dioxide, peatlands, fens
87 citations
TL;DR: In this paper, the authors constructed a record of atmospheric methane (CH 4 ) over the last 10,000 γ which shows that CH 4 has increased to more than double the natural levels of a century ago.
87 citations
01 Sep 1987
1 citations
TL;DR: A group of scientists gathered at the American Chemical Society meeting in Denver to try to understand why the concentration of methane in the atmosphere is increasing about 1% per year as discussed by the authors, and to give each other an appreciation of the possibilities and limitations of various approaches to the complex problem.
Abstract: Systematic global measurements have firmly established that the concentration of methane in the atmosphere is increasing about 1% per year. Last month at the American Chemical Society meeting in Denver, an interdisciplinary group of scientists gathered to try to understand why. Pinning down responsibility for the increase is a difficult problem, as methane is formed both by thermocatalytic reactions in Earth's crust and by many bacteria. Scientists working in atmospheric chemistry, microbiology, biogeochemistry, stable-isotope chemistry, and radiocarbon dating met and exchanged ideas at a five-day symposium sponsored by the Division of Geochemistry. Researchers from the various disciplines aimed to give each other an appreciation of the possibilities and limitations of the various· approaches to the complex problem, according to symposium organizer Ronald S. Oremland, a microbial geochemist with the U.S. Geological Survey. The increase in methane is a concern because methane is a green-house gas that trap...
1 citations
01 Jan 1987
TL;DR: In this article, the effect of infrared absorbing trace gases other than CO2 in the atmosphere was investigated. But the effect was limited to two radiatively important trace gases, i.e., CH4 and tropospheric O3.
Abstract: Infrared-absorbing trace gases other than CO2 are accumulating in the atmosphere. The climatic effect of these gases will be comparable and will add to that expected from CO2. Tropospheric chemistry plays an important role in the budgets and trends of two radiatively important trace gases, i. e., CH4 and tropospheric O3.