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| Titel |
An ensemble approach to simulate CO2 emissions from natural fires |
| VerfasserIn |
A. V. Eliseev, I. I. Mokhov, A. V. Chernokulsky |
| 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 ; 11, no. 12 ; Nr. 11, no. 12 (2014-06-17), S.3205-3223 |
| Datensatznummer |
250117469
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| Publikation (Nr.) |
 copernicus.org/bg-11-3205-2014.pdf |
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| Zusammenfassung |
| This paper presents ensemble simulations with the global climate model
developed at the A. M. Obukhov Institute of Atmospheric Physics, Russian
Academy of Sciences (IAP RAS CM). These simulations are forced by historical
reconstructions of concentrations of well-mixed greenhouse gases (CO2,
CH4, and N2O), sulfate aerosols (both in the troposphere and
stratosphere), extent of crops and pastures, and total solar irradiance for
AD 850–2005 (hereafter all years are taken as being AD) and by the Representative Concentration Pathway (RCP)
scenarios for the same forcing agents until the year 2300. Our model
implements GlobFIRM (Global FIRe Model) as a scheme for calculating
characteristics of natural fires. Comparing to the original GlobFIRM model,
in our implementation, the scheme is extended by a module accounting for
CO2 release from soil during fires. The novel approach of our paper is to
simulate natural fires in an ensemble fashion. Different ensemble members in
the present paper are constructed by varying the values of parameters of the
natural fires module. These members are constrained by the GFED-3.1 data set
for the burnt area and CO2 release from fires and further subjected to
Bayesian averaging. Our simulations are the first coupled model assessment of
future changes in gross characteristics of natural fires. In our model, the
present-day (1998–2011) global area burnt due to natural fires is
(2.1 ± 0.4) × 106 km2 yr−1 (ensemble mean and
intra-ensemble standard deviation are presented), and the respective
CO2 emissions to the atmosphere are
(1.4 ± 0.2) Pg C yr−1. The latter value is in agreement with
the corresponding GFED estimates. The area burnt by natural fires is
generally larger than the GFED estimates except in boreal Eurasia, where it
is realistic, and in Australia, where it is smaller than these estimates.
Regionally, the modelled CO2 emissions are larger (smaller) than the
GFED estimates in Europe (in the tropics and north-eastern Eurasia). From
1998–2011 to 2091–2100, the ensemble mean global burnt area is
increased by 13% (28%, 36%, 51%) under scenario RCP 2.6
(RCP 4.5, RCP 6.0, RCP 8.5). The corresponding global emissions increase is
14% (29%, 37%, 42%). From 2091–2100 to 2291–2300,
under the mitigation scenario RCP 2.6 the ensemble mean global burnt area and
the respective CO2 emissions slightly decrease, both by 5%
relative to their values in the period 2091–2100. In turn, under scenario RCP 4.5
(RCP 6.0, RCP 8.5) the ensemble mean burnt area in the period 2291–2100 is higher by
15% (44%, 83%) than its mean value, and the
ensemble mean CO2 emissions are correspondingly higher by 9%
(19%, 31%). The simulated changes of natural fire characteristics
in the 21st–23rd centuries are associated mostly with the corresponding
changes in boreal regions of Eurasia and North America. However, under the
RCP 8.5 scenario, the increase of the burnt area and CO2 emissions in
boreal regions during the 22nd and 23rd centuries is accompanied by the
respective decreases in the tropics and subtropics. |
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