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| Titel |
The carbon budget of South Asia |
| VerfasserIn |
P. K. Patra, J. G. Canadell, R. A. Houghton, S. L. Piao, N.-H. Oh, P. Ciais, K. R. Manjunath, A. Chhabra, T. Wang, T. Bhattacharya, P. Bousquet, J. Hartman, A. Ito, E. Mayorga, Y. Niwa, P. A. Raymond, V. V. S. S. Sarma, R. Lasco |
| 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 ; 10, no. 1 ; Nr. 10, no. 1 (2013-01-25), S.513-527 |
| Datensatznummer |
250017486
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| Publikation (Nr.) |
 copernicus.org/bg-10-513-2013.pdf |
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| Zusammenfassung |
| The source and sinks of carbon dioxide (CO2) and methane
(CH4) due to anthropogenic and natural biospheric activities
were estimated for the South Asian region (Bangladesh, Bhutan, India,
Nepal, Pakistan and Sri Lanka). Flux estimates were based on
top-down methods that use inversions of atmospheric data, and
bottom-up methods that use field observations, satellite data, and
terrestrial ecosystem models. Based on atmospheric CO2
inversions, the net biospheric CO2 flux in South Asia
(equivalent to the Net Biome Productivity, NBP) was a sink,
estimated at −104 ± 150 Tg C yr−1 during
2007–2008. Based on the bottom-up approach, the net biospheric
CO2 flux is estimated to be
−191 ± 193 Tg C yr−1 during the period of
2000–2009. This last net flux results from the following flux
components: (1) the Net Ecosystem Productivity, NEP (net primary
production minus heterotrophic respiration) of
−220 ± 186 Tg C yr−1 (2) the annual net carbon
flux from land-use change of
−14 ± 50 Tg C yr−1, which resulted from a sink
of −16 Tg C yr−1 due to the establishment of tree
plantations and wood harvest, and a source of
2 Tg C yr−1 due to the expansion of croplands; (3) the
riverine export flux from terrestrial ecosystems to the coastal
oceans of +42.9 Tg C yr−1; and (4) the net
CO2 emission due to biomass burning of
+44.1 ± 13.7 Tg C yr−1. Including the emissions
from the combustion of fossil fuels of 444 Tg C yr−1
for the 2000s, we estimate a net CO2
land–atmosphere flux of 297 Tg C yr−1. In addition
to CO2, a fraction of the sequestered carbon in terrestrial
ecosystems is released to the atmosphere as CH4. Based on
bottom-up and top-down estimates, and chemistry-transport modeling,
we estimate that 37 ± 3.7 Tg C yr−1
were released to atmosphere from South Asia during the 2000s. Taking
all CO2 and CH4 fluxes together, our best estimate
of the net land–atmosphere CO2-equivalent flux is a net
source of 334 Tg C yr−1 for the South Asian region
during the 2000s. If CH4 emissions are weighted by radiative
forcing of molecular CH4, the total CO2-equivalent
flux increases to 1148 Tg C yr−1 suggesting there is
great potential of reducing CH4 emissions for stabilizing
greenhouse gases concentrations. |
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