gerald nelson senior research fellow, ifpri theme leader, ccafs

Gerald NelsonSenior Research Fellow, IFPRI

Theme leader, CCAFS

Forestry and Agriculture Greenhouse Gas Modeling ForumWednesday, September 27, 2011

Food Security and Climate Change: Current IMPACT Results and Future

Plans

OverviewFood Security and climate change

results from IMPACTHow we got themHow do we compare with othersShould you believe any of us

FOOD SECURITY AND CLIMATE CHANGE RESULTS

Nelson, Gerald C., Mark W. Rosegrant, et al. 2010. Food Security, Farming, and Climate Change to 2050: Scenarios, Results, Policy Options. Washington, D.C.: International Food Policy Research Institute.

Food security challenges are unprecedentedMany more people in developing

countries◦Between 2000 and 2050, 50 percent

globally; almost all in developing countriesWith higher incomes comes more

demand for quantity and qualityClimate change – a threat multiplier

with uncertain outcomes◦Reduced productivity of existing varieties

and cropping systems

Income and population growth drive prices higher(price increase (%), 2010 – 2050, Baseline economy and demography)

Nelson et al, 2010

Climate change increases prices even more(price increase (%), 2010 – 2050, Baseline economy and demography)

Minimum and maximum effect from four climate

scenarios

Nelson et al, 2010

Developed Country, Change in Net Exports of Cereals, 2010-2050 (million mt)

With climate change, DC net cereal exports grow less or decline.

With perfect mitigation, DC net cereal exports change little between 2010 and 2050.

Countries with more than 1 million hectares of crop area increase, 2010–2050 (000 hectares)

Countries with more than 1 million ha of crop area decline, 2010–2050 (000 hectares)

2010

2015

2020

2025

2030

2035

2040

2045

2050

Pessimistic scenario

Perfect miti-gation

2010

2015

2020

2025

2030

2035

2040

2045

2050

1,800

2,000

2,200

2,400

2,600

2,800

3,000

3,200

3,400

3,600

Optimistic scenarioKc

als/

day

Developedcountries

All developingcountries

Low-income developing countries

Assessing food security and climate change outcomes

WHERE DO THE RESULTS COME FROM:THE IMPACT MODELING SUITE

The IMPACT Modeling Environment

Hydrology and Water Supply Demand Models

Climate Scenarios

Crop Models

Partial equilibrium economic model

Supply Side Spatial Resolution:281 Food Production Units

Global Food Production Units (281 FPUs)

Change in average annual precipitation, 2000-2050, CSIRO GCM, A1B (mm)

Change in average annual precipitation, 2000-2050, MIROC GCM, A1B (mm)

Current process for incorporating climate effects on crops into IMPACT

FPU level yield and area projections

FPU boundaries

GCM/SRES scenario climate results are down scaled to 0.5 degree/5 minute resolution


FPU boundaries

2000 June average minimum temperature

2050 CSIRO/A2 June average rainfall

Planting months are chosen based on current and future climate conditions


FPU boundaries

2000 Rainfed planting month

2050 CSIRO/A2 Rainfed planting month

Soils are represented by 27 generic soil profiles based on the harmonized FAO soil datasets


FPU boundaries

Soil profiles color coded by location

The remaining inputs fall under management practices


FPU boundaries

Choice of crop variety

Rainfed versus irrigated sources of water

Planting densities, row spacing, and transplanting details

Fertilizer types, amounts, and application dates

DSSAT generates projected yields for each location


FPU boundaries

2000 Rainfed maize yield

2050 CSIRO/A2 Rainfed maize yield

SPAM 2000 areas are used to weight the projected yields when aggregating to FPUs


FPU boundaries

Rainfed maize physical area in 2000

FPU boundaries and crop model pixel results


FPU boundaries

2000 Rainfed maize yield with FPU boundariesin South Asia

Projected yields from DSSAT are aggregated up to the FPU-level for use in IMPACT


FPU boundaries

By crop and rainfed/irrigated...

Find total SPAM area within FPU

Find total production (SPAM area × DSSAT yield) within FPU

Compute area-weighted-average yield as total production / total area

Yield Effects, Rainfed Maize, CSIRO A1B (% change 2000 climate to 2050 climate)

Nelson et al, 2010

Yield Effects, Rainfed Maize, MIROC A1B (% change 2000 climate to 2050 climate)

Nelson et al, 2010

Corn Yield Change, 2000-2050 (%)CNR GCM, A1 GHG Scenario

Illinois -10.1 Indiana -4.1 Iowa -21.3 Minnesota -10.4 Ohio 2.2

Corn Yield Change, 2000-2050 (%)CSI GCM, A1 GHG Scenario

Illinois -5.9 Indiana -12.1 Iowa -3.6 Minnesota 12.1 Ohio -10.3

Corn Yield Change, 2000-2050 (%)ECH GCM, A1 GHG Scenario

Illinois -8.3 Indiana -12.0 Iowa -9.5 Minnesota -0.9 Ohio -12.0

Corn Yield Change, 2000-2050 (%)MIR GCM, A1 GHG Scenario

Illinois -42.7 Indiana -41.3 Iowa -39.6 Minnesota -30.5 Ohio -43.1

HOW DO WE COMPARE WITH OTHERS: COMPARINGIMPACT, ENVISAGE, LEITAP

Alternate Perspectives on Price Scenarios (perfect mitigation), 2004-2050

IMPACT has substantially greater price increases

Alternate perspectives on agricultural area changes, 2004-2050

IMPACT Area Response, at FPU Level

Atni = crop areaα = crop area interceptPStni = producer price ε = area price elasticityWATtni = water stress = exogenous area growth rate

( ) ( ) (1 ) ;ijniintni tni tni tnj tni tni tni

j iA PS PS ga A WAT

tniga

Selected CGE Area Supply Functions• Envisage (World Bank/FAO)

• LEITAP (Wageningen)

• - Asymptote• Ɛ - Price elasticity

1 P

SSe

S S P

Aggregate land supply parameters for ENVISAGE and LEITAP

Expansion potential

Initial supply elasticity

Region ENVISAGE

LEITAP ENVISAGE

LEITAP

China 1.298 1.174 0.250 0.100India 1.145 1.050 0.250 2.317Canada 2.446 7.870 1.000 1.384United States 2.244 1.843 1.000 1.384Brazil 8.657 3.045 1.000 2.000Russia 2.383 4.461 1.000 0.902Sub-Saharan Africa 5.624 1.893 1.000 1.162EU27 & EFTA 2.019 1.149 0.250 0.170Middle East & North Africa 1.079 1.020 0.250 0.000Australia & New Zealand 3.149 1.380 1.000 0.115High income countries 2.109 1.442 0.472 0.494Developing countries 2.410 1.698 0.537 1.316East Asia & Pacific 1.651 1.891 0.554 0.557Europe & Central Asia 1.896 2.800 1.000 0.968LAC less Brazil and Mexico 8.719 2.017 1.000 1.410World total 2.288 1.594 0.511 0.982

Ratio of all land rated very suitable, suitable, moderately suitable land and marginally suitable land to actual arable land in use

SHOULD YOU BELIEVE ANY OF US:EXAMPLES OF THE QUALITY OF DATA

How much irrigated area in India?Intl. Water Management Inst.

113 M ha (net)Government of India

57-62 M ha

Source: Thenkabail 2009

Where do land cover maps disagree on forest and cropland? All colored areas below.

Source: FAO and ILRI (forthcoming 2011)

Where do MODIS v. 5 and GlobCover disagree on crop area globally? All colored areas below.

Source: FAO and ILRI (forthcoming 2011)

COMPARING LAND COVER DATA IN AFRICA

Globcover 2005 – (300m)GLC2000 2000 – (1km)MODIS 2001 – (5km)Africover 1999-20 01 – (30m)

Globcover

MODIS

GLC2000

Africover

Kenya

Zhe Guo, HarvestChoice 2011 (unpublished).”

All maps use the same

legend

MODIS

GLC2000Globcover

Uganda Rwanda


Africover


legend

MODIS

GLC2000Globcover

Tanzania


Africover


legend

Ethiopia

MODIS

GLC2000Globcover



legend

What is needed?Regular observations

◦Observations year after yearRepeated observations

◦Multiple observations within a year and across years

Appropriate spatial resolution ◦Similar to field size

Discrimination◦Minimum spectral frequencies to detect

agricultural and natural resource change

Thank you

www.ifpri.orgwww.ccafs.cgiar.org

http://www.ifpri.org/

http://www.ccafs.cgiar.org/

gerald nelson senior research fellow, ifpri theme leader, ccafs

Documents

climate change resultspage

climate effects

food security challenges

climate scenariosnelson

income growth

rice price mean increase

wheat price mean increase

maize price mean increase