Regional trends in land use/land cover change emissions of CO 2 in Asia

Transcription

1 Regional trends in land use/land cover change emissions of CO 2 in Asia Leonardo Calle, Benjamin Poulter, Prabir Patra N.S.F. USA East Asia Pacific Summer Institute (EAPSI) Japan Society of the Promotion of Science (JSPS)

2 RECCAP/IPCC: Budget equations To atmosphere The South Asian Carbon Budget: Patra et al To land The net land to atmosphere C flux (F c ) for carbon budget : F C = F NPP + F RH + F LUC + F Fire + F river + F FF C flux changes in the biospheric (NPP net primary production, RH heterotrophic respiration), land use change (LUC), fire emissions, riverine export, fossil fuel (FF) 1PgC = g 1TgC = g

3 Synthesis of regional land fluxes from TDIs and DGVMs Top down (Inversion) fluxes include all CO2 component Bottom up (DGVMs dynamic global vegetation models) do not include LUC Figure 6.15, IPCC AR5 WG1, analysis by P. Patra

4 DGVMs: Leaf to Globe Plant & Soil Biophysics, Biogeochemistry ( carbon, water, and nutrient budgets ) H 2 0 CO 2 CO 2 H 2 0 Nutrients H 2 0 Leaf level photosynthesis (Farquhar 1980) Temp. feedbacks (todo: H 2 O) N limitations (rubisco) Canopy light modeled differently Leaf level energy budget Latent & sensible heat flux

5 The Anthropocene

6 Stocker et al Land Use Change and LM

7 Geographic areas for this study Defined by the Asia Pacific Network (APN) for Global Change Research (Project id: ARCP CMY Patra/Canadell). East Asia South Asia Southeast Asia

8 Carbon Emissions from Land Use and Land Cover Change (LULCC)

9 Carbon Flux: DGVM variability Southeast Asia Land Use Flux Pg C yr Models JULES LPJ LPJG LPX VISIT 0.0 Calle et al., ERL, submited

10 Carbon in total biomass (above + below ground) Estimated by the DGVMs The Forest Resource Assessment report (FRA2010), Tier 1 methods

11 Carbon in aboveground biomass Estimated by the DGVMs ; Baccini et al (2012) biomass dataset The Forest Resource Assessment report (FRA2010), Tier 1 methods Calle et al., ERL, submited

12 Carbon Emissions from Land Use and Land Cover Change (LULCC) IPCC AR5 CO 2 Flux Someone on Day 1 mentioned Myanmar is 3 rd on the list of forest loss (FRA2015) Calle et al., ERL, submited

13 JAMSTEC: Benchmark DGVM C fluxes 1. C fluxes from 8 DGVMs (TRENDY) as boundary conditions in the CCSR/NIES/FRCGC atmospheric circulation model (ACTM) 2. Compare to: Up looking TCCON observations of X CO 2 Down looking GOSAT (IBUKI) Satellite observations of X CO 2 3. Evaluated Seasonal Amplitude and Inter hemispheric flux rate 4. Evaluate confidence in detecting Land Use Change signal from models

14 Conclusions Land use and land cover change (LULCC) now modelled by the DGVMs We estimated the LULCC emissions from 3 populous Asia regions LULCC in Southeast Asia is among the highest in the world (20%) This reduces the gap in our understanding of the regional carbon budget, reported in IPCC AR5 We are now trying to find ways to evaluate the DGVM fluxes for LULCC, separately from NEE

15 Thank you

16 DGVM Carbon Fluxes Carbon fluxes due to LUC are calculated as the difference between a simulation with and without LUC o This method of calculation helps isolate carbon fluxes from LUC, while accounting for effects due to a changing climate and increases in CO 2 Legacy fluxes are delayed carbon fluxes that occur after LUC o These include carbon fluxes from soil respiration and decomposition of downed wood, for example, after deforestation and before the forest regrows to previous levels o Legacy fluxes are implicitly included in the DGVM LUC flux estimates, but currently, none of the DGVMs quantify the magnitude of legacy versus immediate fluxes Biomass Turnover o Carbon in Soil and Litter decomposes to CO 2 at daily or annual rates which vary with temperature and soil moisture o A few models include coupled Carbon Nitrogen cycles that modify the decomposition rates

17 DGVM Carbon Fluxes from LULCC Deforestation o Generally, the majority of the carbon in vegetation (wood, leaves, roots) gets converted to CO 2 in one year, but a fraction goes to Litter pool for delayed decomposition Wood Harvest o 40% of harvested woody carbon (incld. all of leaves and roots) goes to Litter for decomposition o 60% of woody carbon is split into product pools, decomposing at annual rates of 1, 10, and 100 yrs Product pools reflect wood products of fuel wood, paper products, wood for furniture or homes (i.e., short term and long term storage) Crop and Pasture (Managed Lands) o Many models treat crop and pasture as annual grasslands, with annual harvest of the vegetation. o Only a few models simulate fertilization and irrigation, fewer models include crop plant functional types

18 Disturbance : Competition : Climate How do plants respond to change? Rate of Carbon Assimilation Lambers et al Plant Phys. Ecology.

19 Carbon Flux: Land Use Change LULCC flux: Regional / Global (%) All Regions East Asia South Asia Southeast Asia 44% of Global Emissions Calle et al., ERL, submited