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| Titel |
Use of a process-based model for assessing the methane budgets of global terrestrial ecosystems and evaluation of uncertainty |
| VerfasserIn |
A. Ito, M. Inatomi |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 9, no. 2 ; Nr. 9, no. 2 (2012-02-15), S.759-773 |
| Datensatznummer |
250006766
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| Publikation (Nr.) |
 copernicus.org/bg-9-759-2012.pdf |
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| Zusammenfassung |
| We assessed the global terrestrial budget of methane (CH4) by using a
process-based biogeochemical model (VISIT) and inventory data for components
of the budget that were not included in the model. Emissions from wetlands,
paddy fields, biomass burning, and plants, as well as oxidative consumption
by upland soils, were simulated by the model. Emissions from ruminant
livestock and termites were evaluated by using an inventory approach. These
CH4 flows were estimated for each of the model's 0.5° × 0.5° grid cells from 1901 to 2009, while accounting for atmospheric
composition, meteorological factors, and land-use changes. Estimation
uncertainties were examined through ensemble simulations using different
parameterization schemes and input data (e.g., different wetland maps and
emission factors). From 1996 to 2005, the average global terrestrial
CH4 budget was estimated on the basis of 1152 simulations, and
terrestrial ecosystems were found to be a net source of 308.3 ± 20.7 Tg
CH4 yr−1. Wetland and livestock ruminant emissions were the
primary sources. The results of our simulations indicate that sources and
sinks are distributed highly heterogeneously over the Earth's land surface.
Seasonal and interannual variability in the terrestrial budget was also
assessed. The trend of increasing net emission from terrestrial sources and
its relationship with temperature variability imply that terrestrial
CH4 feedbacks will play an increasingly important role as a result of
future climatic change. |
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