Wild fires and land use / land use change related fires for the 20th and the 21st century

Transcription

1 Wild fires and land use / land use change related fires for the 20th and the 21st century Marlies Gumpenberger (PIK), Kirsten Thonicke, Alberte Bondeau, Ursula Heyder, Kees Klein Goldewijk, Christoph Müller, Elke Stehfest (PIK / PBL)

2 What do we want to do and why? Biomass burning is part of the biosphere-atmosphere carbon balance, emits trace gases and aerosols, and impacts the vegetation's dynamic. Biomass burning is a land use practice, used for many different purposes. Biomass burning cause CO 2 emissions equal to 50% of those stemming from fossil-fuel combustion (2-4 Pg C yr -1 versus 7.2 Pg C yr -1 ) (e.g. Bowmann et al. 2009) Map server: active fires detected by MODIS, 30 Sept 7 Oct Marlies.Gumpenberger@pik-potsdam.de

3 Natural vegetation and agriculture in LPJmL: which fires? Natural vegetation fires: - lightning - human-caused => SPITFIRE (Thonicke et al. in revision) Land use fires: - deforestation - shifting cultivation / slash & burn - burning of crop residues - firewood consumption => Agricultural Fires LPJmL: Sitch et al. 2003, Gerten et al. 2004, Bondeau et al What is the role of fires for the carbon cycle under population growth, land-use and climate change?

4 Inputs for Climate: climate anomalies of the ECHAM5 and HadCM3 climate data provided for the IPCC AR4 (interpolated to 0.5 resolution), combined with CRU mean climatology. Population density: historical period (HYDE 3.1, Klein Goldewijk) + UN Median until 2100 (Klein Goldewijk) Land use: historical period (HYDE, Klein Goldewijk) + IMAGE land use scenarios driven by SRES B1, B2, A2 combined with crop distribution (Müller et al., 2007)

5 Land-use change: deforestation for permanent grazing or permanent cropland Deforestation occurs when natural vegetation is converted to agricultural land. Regional parameterisation for the fraction of biomass burnt (IMAGE)

6 Shifting cultivation / slash & burn agriculture Shifting cultivation is an agricultural system, in which plots of land are cultivated temporarily, then abandoned. Editions Didier Millet Period The land use input was modified using maps for non-permanent agriculture rural population density cropping/fallow periods etc. Olofsson & Hickler (2007): grid cells with non-permanent agriculture (orange)

7 Agriculture fires: crop residues used as biofuels and burnt in the fields A fraction of crop residues is burnt as biofuel or/and in the fields after the harvest. Regional parameters developing countries after Yevich & Logan 2003 industrialized countries, e.g. Korontzi et al. 2006

8 Domestic firewood consumption Firewood is extracted from natural vegetation according to the demand (per capita consumption x population density). Firewood is taken from available dead biomass and from leaving trees. In case of supply < demand, only the supply can be consumed. Regional per capita consumption rates: developing countries after Yevich & Logan 2003 FAO for industrialized countries (low income)

9 The SPITFIRE approach K Thonicke, A Spessa, IC Prentice, SP Harrison, C Carmona-Moreno Fire Danger Index Climatic conditions: fire danger index Wildfire initiation in natural vegetation Lightning & human-caused ignitions No. ignitions Spread Effects Emissions Fire spread area burnt BEHAVE fire spread model (Rothermel 1972) Fuel parameterisation of PFTs Fire behaviour Post-fire mortality Cambial damage, crown scorch Biomass burnt = surface fire + crown scorch EF (biomass) trace gases

10 Wildfires of natural vegetation: Simulated trace gas emissions Biomass Burnt CO 2 [Tg] CO [Tg] CH 4 [Tg] VOC [Tg] TPM [Tg] NO x [Tg] [PgC] Mean p.a. Std. Dev Thonicke et al., in review

11 Model evaluation EO data Seasonality: MODIS active fires Area burnt: AVHRR, MODIS area burnt etc. Fire statistics: confined to small regions, no global coverage

12 Model intercomparison Comparison against emission models GFEDv2: e.g. seasonality of biomass burning Agreement confirms assumptions of simulated wildfire regime Fire regime not dominated by wildfires Boreal Eurasia Boreal Asia Southern Hemisphere Africa South-East Asia

13 Deforestation and slash & burn agriculture Deforestation slash & burn ECHAM5, SRES A2

14 Crop residue burning in the fields and as biofuel burnt in the fields burnt as biofuel ECHAM5, SRES A2

15 Firewood consumption Simulated firewood (supply) Tg C yr Tg C yr -1 Firewood (demand) Tg C yr Tg C yr -1 Marlies.Gumpenberger@pik-potsdam.de ECHAM5, SRES A2

16 Wildfires and agricultural fires SPITFIRE ECHAM5, HadCM3, SRES B1, A2 ECHAM5, SRES A2

17 Global fire emissions comparison ECHAM5, SRES A2 [Tg C / year] Literature Wildfires (SPITFIRE) Deforestation (incl. slash & burn) (s&b) 299 (s&b) 1172 Domestic firewood consumption (charcoal) Crop residues burnt as biofuels (biofuels) Crop residues burnt in the fields Total Literature: Andreae & Merlet 2001, Van der Werf et al. 2003, Lauk & Erb 2009, Fearnside 2000, Crutzen & Andreae 1990, Fernandes et al. 2007, Houghton 2003, Yevich & Logan 2003, Bowmann et al. 2009, Schultz et al. 2008

18 Thank you for your attention!