Modeling Agriculture and Land
Use: Climate Impacts
Ron Sands
The 7th AIM International Workshop
15-16 March 2002, Tsukuba, Japan
Joint Global Change Research InstitutePacific Northwest National Laboratory and University of Maryland

Overview
Objective
Link Economic Model with Output from Crop andForest Productivity Models
 Response of Agricultural Production and Land Use
to Climate ChangeBackground on PNNL Agriculture and LandUse Model (AgLU)
Demand for food Land Use DecisionSensitivity on Global Crop Yields
EPIC and BIOME simulations for United States
Joint Global Change Research InstitutePacific Northwest National Laboratory and University of Maryland

Food Consumption by AgLU Region
kcal per person per day
01,000Crops

Processed Crops

2,000

3,000

United States
CanadaOECD EuropeJapan
Australia and New ZealandFormer Soviet Union
China and Centrally Planned Asia
Middle EastAfrica
Latin America
Other Asia
Eastern EuropeKorea
India
Animal Products

4,000

AgLU Land Allocation

unmanaged

foodgrainscoarsegrainspastureoilcrops

othercrops

biomass
crops

Joint Global Change Research InstitutePacific Northwest National Laboratory and University of Maryland

forestCalculation of Land Shares
1λπisi =1λπ∑ kkπ i = y i (Pi − Gi )Land share for land use i
is an increasing functionof profit rate (lambda ispositive).
Profit rate equals
average yield times
price received lessnon-land cost ofproduction.

Joint Global Change Research InstitutePacific Northwest National Laboratory and University of Maryland

Growth in Global Average Crop Yields
2.5

yield relative to 1990

2.0

1.5
Reference
Low Growth
1.0

0.50.01990

2005

2020

2035

2050

2065

2080

2095

Global Land Use Reference Scenario
1098billion hectares

7

Unmanaged Land

65
Managed Forest

43Pasture2101990

Crop Land
2005

2020

2035

2050

2065

2080

2095

Global Land Use: Reduced Growth in Crop Yields
1098
Unmanaged Landbillion hectares

765Managed Forest

4Pasture

32Crop Land

1019902005

20202035

2050

20652080

2095

Full-Out Corn Production (United States)
10.0
9.0
8.0
7.0
6.0
All LandAgricultural Land Only

tons per5.0
hectare
4.0
3.0
2.0
1.0
0.0
0

100

200

300

400
million hectares

500

600

700

800

Global Sensitivity Analysis
Global Change in Crop Yields+10% by 2080
 Reference Growth Rate -10% by 2080
Global Crop Production
Global Land Use for Crops

Joint Global Change Research InstitutePacific Northwest National Laboratory and University of Maryland

Global Crop Production in 2080
71015 kilocalories per year654

10% yield decrease
Reference scenario
10% yield increase

3210
Wheat and RiceCoarse Grains

Oil Crops

Misc. Crops

Global Land Use for Crops in 2080
800
700

million hectares

600
500
10% yield decrease
Reference scenario
10% yield increase

400
300
200
1000
Wheat and RiceCoarse Grains

Oil Crops

Misc. Crops

Impacts on Crop Yield
Climate Scenarios
CO2 at 365 ppmv and 560 ppmv
 GCMs: UIUC, UIUC+sulfates, BMRC
 Climate Sensitivity: 1.0° C and 2.5° C
EPIC crop growth model to represent
managed crops
BIOME to represent forest, pasture, andbiomass productivity
Joint Global Change Research InstitutePacific Northwest National Laboratory and University of Maryland

Soybean Yields (tons per ha)
Baseline
BMRC 1.0BMRC 2.5
UIUC 1.0
UIUC 2.5
UIUC 1.0 + sulfates
UIUC 2.5 + sulfates

dryland
365 ppmv
560 ppmv
1.56
1.88
1.45
1.76
1.23
1.49
1.53
1.84
1.44
1.72
1.53
1.84
1.47
1.77

irrigated
365 ppmv
560 ppmv
1.87
2.17
1.80
2.101.58
1.85
1.80
2.09
1.63
1.90
1.80
2.09
1.68
1.95

Yields are an average across 204 hydrologic unit areasin the United States, with agricultural land used asweights.
Joint Global Change Research InstitutePacific Northwest National Laboratory and University of Maryland

Soybean Yield (USA)
3.0

2.5

2.0
Baseline 365 ppm
BMRC 1.0
BMRC 2.5

tons per1.5
hectare1.0

0.5

0.0050100

150
million hectares

200

250300U.S. Crop Yields (BMRC 2.5; 365 ppm)
2.5

yield relative to 1990

2.0

1.5

Reference
U.S. wheat
U.S. corn
U.S. soybeans

1.00.50.01990

2005

2020

2035

2050

2065

2080

2095

U.S. Crop Yields (BMRC 2.5; 560 ppm)
2.5

yield relative to 1990

2.0

1.5

Reference
U.S. wheat
U.S. corn
U.S. soybeans

1.00.50.01990

2005

2020

2035

2050

2065

2080

2095

Corn Yield (USA)109876
Baseline 365 ppm
BMRC 1.0
BMRC 2.5

tons per5hectare
43
2
10050

100

150
million hectares

200250300

Full-Out Corn Production (United States)
10.0
9.0
8.0
7.0
6.0
All LandAgricultural Land Only

tons per5.0
hectare4.0
3.02.01.00.00100200300400
million hectares

500600700800Winter Wheat Yield (USA)7.06.05.04.0

Baseline 365 ppm
BMRC 1.0
BMRC 2.5

tons perhectare
3.02.01.00.0050100150
million hectares

200

250300Hay Yield (USA)
12108
Baseline 365 ppm
BMRC 1.0
BMRC 2.5

tons per6hectare420050100150
million hectares

200250300

Annual Net Primary Productivity (USA)
1400

1200

1000

800
gm

Baseline
BMRC 1.0
BMRC 2.5-2600

400

200

0050,000

100,000

150,000

Number of BIOME cells

200,000

250,000Intended Uses of AgLU
Carbon Emissions from Land Use Change andChanges in Land Management
Interaction with carbon policy through biomass
 Carbon sequestration in soils and forests


Climate Impacts
ENSO study for North America
 Change in crop yields from EPIC and General
Circulation Models


Non-CO2 Greenhouse Gases

Tracking emissions from agriculture over time Mitigation options


Joint Global Change Research InstitutePacific Northwest National Laboratory and University of Maryland

Conclusion
Recent Progress
Sensitivity Analysis on Global Scale Detailed Crop Simulation for USA
Model Development
Crop Simulation outside of USA Irrigated Agriculture Embed in Computable General Equilibrium
Framework
Joint Global Change Research InstitutePacific Northwest National Laboratory and University of Maryland