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| Titel |
Global fire emissions and the contribution of deforestation, savanna, forest, agricultural, and peat fires (1997–2009) |
| VerfasserIn |
G. R. Werf, J. T. Randerson, L. Giglio, G. J. Collatz, M. Mu, P. S. Kasibhatla, D. C. Morton, R. S. DeFries, Y. Jin, T. T. Leeuwen |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 10, no. 23 ; Nr. 10, no. 23 (2010-12-10), S.11707-11735 |
| Datensatznummer |
250008948
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| Publikation (Nr.) |
 copernicus.org/acp-10-11707-2010.pdf |
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| Zusammenfassung |
| New burned area datasets and top-down constraints from atmospheric
concentration measurements of pyrogenic gases have decreased the large
uncertainty in fire emissions estimates. However, significant gaps remain in
our understanding of the contribution of deforestation, savanna, forest,
agricultural waste, and peat fires to total global fire emissions. Here we
used a revised version of the Carnegie-Ames-Stanford-Approach (CASA)
biogeochemical model and improved satellite-derived estimates of area
burned, fire activity, and plant productivity to calculate fire emissions
for the 1997–2009 period on a 0.5° spatial resolution with a monthly
time step. For November 2000 onwards, estimates were based on burned area,
active fire detections, and plant productivity from the MODerate resolution
Imaging Spectroradiometer (MODIS) sensor. For the partitioning we focused on
the MODIS era. We used maps of burned area derived from the Tropical Rainfall
Measuring Mission (TRMM) Visible and Infrared Scanner (VIRS) and Along-Track
Scanning Radiometer (ATSR) active fire data prior to MODIS (1997–2000) and
estimates of plant productivity derived from Advanced Very High Resolution
Radiometer (AVHRR) observations during the same period. Average global fire
carbon emissions according to this version 3 of the Global Fire Emissions
Database (GFED3) were 2.0 Pg C year−1 with significant interannual
variability during 1997–2001 (2.8 Pg C year−1 in 1998 and
1.6 Pg C year−1 in 2001). Globally, emissions during 2002–2007 were relatively
constant (around 2.1 Pg C year−1) before declining in 2008
(1.7 Pg C year−1) and 2009 (1.5 Pg C year−1) partly due to lower deforestation
fire emissions in South America and tropical Asia. On a regional basis,
emissions were highly variable during 2002–2007 (e.g., boreal Asia, South
America, and Indonesia), but these regional differences canceled out at a
global level. During the MODIS era (2001–2009), most carbon emissions were
from fires in grasslands and savannas (44%) with smaller contributions
from tropical deforestation and degradation fires (20%), woodland fires
(mostly confined to the tropics, 16%), forest fires (mostly in the
extratropics, 15%), agricultural waste burning (3%), and tropical peat
fires (3%). The contribution from agricultural waste fires was likely a
lower bound because our approach for measuring burned area could not detect
all of these relatively small fires. Total carbon emissions were on average
13% lower than in our previous (GFED2) work. For reduced trace gases such
as CO and CH4, deforestation, degradation, and peat fires were more
important contributors because of higher emissions of reduced trace gases
per unit carbon combusted compared to savanna fires. Carbon emissions from
tropical deforestation, degradation, and peatland fires were on average 0.5 Pg C year−1.
The carbon emissions from these fires may not be balanced
by regrowth following fire. Our results provide the first global assessment
of the contribution of different sources to total global fire emissions for
the past decade, and supply the community with an improved 13-year fire
emissions time series. |
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