Agriculture, Climate Change and Water: Scenarios from the new IFPRI IMPACT Model

Transcription

1 Agriculture, Climate Change and Water: Scenarios from the new IFPRI IMPACT Model Sherman Robinson and the Impact Team Interna4onal Food Policy Research Ins4tute (IFPRI) July 2014

2 Outline Drivers of agricultural growth The AgMIP model comparison project AgMIP results (PNAS 2014) The IMPACT Model Modularity in a suite of models Base scenario results Climate challenges (IPCC 2014)

3 Drivers of Agricultural Growth and Food Security Demand drivers Popula4on growth: 9 billion people in 2050 Urbaniza4on: 50% in 2008, 78% in 2050 Income growth Oil prices Biofuels and bioenergy Conserva4on and biodiversity c=getobject&s=obj&objectid=101492

4 Drivers of Agricultural Growth and Food Security Rapid income growth and urbaniza4on effects on diets and payerns of agricultural produc4on Increased consump4on of fruits and vegetables Rapid growth in meat consump4on and demand for grains for feed Change in diets to convenience foods, fast foods Higher food energy, more sugar, fats and oils Half of growth in grain demand will be for Livestock feed Increased pressure on land and water File:Fast_food_( ).jpg

5 Drivers of Agricultural Growth Supply drivers and Food Security Climate change Water and land scarcity Investment in infrastructure Investment in agricultural research Policy drought18-8b9a6db718dda8f9f968da97316f9c0 a2daa3655-s40-c85.jpg btcotton_rice.jpg

6 AgMIP: 10 Global Economic Models Six general equilibrium models AIM, NIES ENVISAGE, FAO/World Bank EPPA, MIT FARM, USDA GTEM, ABARES MAGNET, LEI/Wageningen Four par4al equilibrium models GCAM, PNNL GLOBIOM, IIASA IMPACT, IFPRI MAgPIE, PIK Plus several crop modeling groups!!! 6

7 Key policy- relevant ques4ons What is the future of agricultural prices? No change or slight decline Doubling How will agricultural produc4on evolve? Land expansion Yield growth and intensifica4on How will climate change alter Prices Land use Trade Undernourishment

8 The climate modeling chain: From biophysical to socioeconomic Nelson, et al., PNAS

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10 Price changes over 4me, , no climate change General equilibrium Par4al equilibrium 10

11 World Crop Yields Annual Average Growth Rate Source: IFPRI IMPACT Model

12 Historical climate change impacts on yields Source: IPCC AR5 WG2 SPM, Figure 2(C), 31Mar

13 Rainfed Maize: Impact of climate change in 2050 (MIROC/A1B) Overall produckon change in shown exiskng areas: % Source: IFPRI IMPACT simulakons

14 Rainfed Maize: Impact of climate change in 2080 (MIROC/A1B) Overall produckon change in shown exiskng areas: % Source: IFPRI IMPACT simulakons

15 AgMIP Results Convergence across models on rates and poten4al sources of technological change Closer agreement across CGE and PE models BeYer understanding on differences in land supplies Discussion of the role of different land use models Importance of irrigated versus rainfed land supply Some convergence is specifica4on Demand side Methodological heterogeneity across models Very different treatment in CGE and PE models Wide varia4on in price and income elas4ci4es. 15

16 The IMPACT Model Interna4onal Model for Policy Analysis of Agricultural Commodi4es and Trade Global par4al equilibrium model Food model Water models Crop models Malnutri4on model

17 IMPACT Model SchemaKc

18 IMPACT Suite of Models 18 SPAM - Spa4al Produc4on Alloca4on Model Land- Use Model DSSAT Crop Models Biofuel Model Livestock Model Hydrology Model Water Basin Management Model Water Stress Model Mul4market Model: crops, sugar, oilseeds, livestock/meat

19 IMPACT version Countries Water Basins Food Production Units 58 Agricultural commodi4es 1

20 Desiderata for Modular Model Systems A module should be designed to: Read its own parameters; IniKalize its own variables; Accept variables passed to it from other modules and the environment; Pass variables that are computed within the module to other modules or the main model; Own its set of state variables; Operate in standalone mode.

21 Modules in the IMPACT Model System Water models: hydrology, water basin management, crop stress Crop models: DSSAT, etc. Land use models (including SPAM) Livestock models, including fisheries Crop processing: sugar, oil seeds, cassava Biofuels

22 IMPACT A Suite of Models Modularity = a la carte model system Use the models you need, turn off those you do not need Separate models can be run independently Modules can run on different Kme steps Standardize data transfer InformaKon Flows Dynamic or IteraKve interackon Data driven model specificakon IMPACT model can be run at any level of aggregakon without changing the model code Change input data and sets only: user need not even see the GAMS code 22

23 Advantages of Modularity Component models can be built by different modelers and reflect different disciplines Example modules: economy, water, land use, livestock, fisheries, biofuels, oil seed/sugar processing Design component models to be used in standalone mode No need to compromise on model structure and features in order to incorporate modules E.g. water models with bad economics and economic models with inadequate water Models that operate on different 4me steps Models wriyen in different languages (e.g., GAMS, Fortran, C) Let each model do what it is good at, in its own environment 23

24 Linking Modules Three ways to link modules: Exogenous: InformaKon flows in one direckon Hydrology, DSSAT, GCMs, SPAM Linked dynamically: Two- way informakon flow between years Water basin management, water stress on crops Land use Endogenous: Module equakons are solved simultaneously Livestock, sugar processing, oilseeds/oils Land allocakon to crops 24

25 Water Models in IMPACT Global hydrological module (GHM) assesses water availability IMPACT Water SimulaKon Module (IWSM) opkmizes water supply according to demands Monthly Kme step DomesKc, industrial (linked to GDP/populaKon) Livestock Environment IrrigaKon Water stress module Delivers crop yields to the IMPACT food module 25

26 Water Models Hydrology: wrifen in Fortran IWSM: Water basin management model One reservoir per FPU. Simplified version of a large class of water basin management models OpKmizaKon model: quadrakc program Wrifen in GAMS Water stress model FAO model: reduced- form regression model (Ky, Kc coefficients) Includes opkmizakon model to allocate crops across land types Converted to GAMS

27 27 Summary of IMPACT Water

28 Water: Two- Way Model IntegraKon Solve Food Model in Stand Alone Mode Fix Areas and Livestock Numbers and call the Water Model Resolve the Food Model using Fixed Areas and Livestock with new yields including Water Stress Food Model Crop Areas Population GDP Livestock Numbers Prices Water Model Water Stress Shock on Crop Yields

29 Linking to Modules Modules need not be wriyen in a common language Water models: IWSM class of water basin management models: GAMS SWOT: Fortran, open source RiverWare: proprietary, C Water stress models FAO Ky,Kc: rewriyen in GAMS FAO AquaCrop: proprietary. CliCrop version in MATLAB DSSAT crop models: Fortran 29

30 What about climate change? Global annual average surface temperature Source: IPCC AR5 WG2 SPM, Figure 4(B), 31Mar

31 Projected climate change impacts on yields Source: IPCC AR5 WG2 Ch7, Figure 7-7, 31Mar

32 Projected climate change impacts on yields over Ime Source: IPCC AR5 WG2 Ch7, Figure 7-5, 31Mar

33 Impact on InternaKonal Food Prices (2010=100) Average of four GCM, A1B, A2,B1, B2 Scenarios no CC 2050 CC Wheat Maize Rice Source: IFPRI IMPACT simulakons

34 AgMIP climate scenarios to 2050 Source: Nelson et al., PNAS (2014) 34

35 Price increase scenario results (%), , Baseline economy and demography, IMPACT 2010 Minimum and maximum effect from four climate scenarios 35

36 Thank you