1. Agricultural/Forestry Greenhouse Gas Modeling Forum October 1-3, 2001
Top-Down Simulation of Energy, Agriculture, and Land Use
Ron Sands Joint Global Change Research Institute: University of Maryland and Pacific Northwest National Laboratory
Agricultural/Forestry Greenhouse Gas Modeling Forum
October 1-3, 2001

2. Acknowledgements Pacific Northwest National Laboratory
Jae Edmonds
Hugh Pitcher
Steve Smith
Chris MacCracken (former PNNL)
Marshall Wise (former PNNL)
Dartmouth College
Kenny Gillingham (intern)

3. Overview Uses for top-down economic models SGM background
Marginal abatement curves for energy
Applications
PNNL approach to agriculture and land use
Modular development of agricultural sector
Application to commercial biomass

4. Top-Down Economic Models
Project baseline greenhouse gas emissions over time for a country or group of countries
Find the least-cost way to meet any particular emissions constraint
Provide a measure of the carbon price, in dollars per metric ton
Provide some measure of the overall cost of meeting an emissions target

6. SGM Production Sectors

9. Return to 1990 ($ per ton C) 2010 2020 Full Global Trading 28 29
Annex I Trading
106
126
Annex I targets = 1990 carbon emissions
Carbon policy starts in 2005
SGM reference case

10. Return to 1990 ($ per ton C) 2010 2020 Full Global Trading 21 27
Annex I Trading 72
113
Annex I targets = 1990 carbon emissions
Carbon policy starts in 2005
EIA reference case

12. Mitigation at Least Cost
Consider all opportunities for reducing greenhouse gas emissions
Energy system efficiency
Non-CO2 greenhouse gases
Expansion of commercial biomass
Carbon sequestration in terrestrial ecosystems
Carbon capture and sequestration
Top-down models should be a tool for integrating knowledge of sector specialists

13. 1998 Administration Analysis
Analysis by Council of Economic Advisers
Reduced-form analysis
SGM was not run directly
Marginal abatement curves derived from many SGM model runs
Emissions baselines taken from a different source (U.S. Energy Information Administration)
Supply curve for non-CO2 greenhouse gases (U.S. Environmental Protection Agency)

14. Why Model Agriculture?
Carbon emissions from energy consumption are not the whole story
Carbon emissions from land-use change
Carbon mitigation using biomass fuels
CH4 and N2O emissions from agriculture
Impact of climate change on agricultural productivity

15. PNNL Approach to Agriculture
Modular development of Agriculture and Land Use (AgLU) component
Key Drivers
Population growth
Demand for food and forest products
Rate of increase in crop yield

17. Products in AgLU Crops (calories) Processed Crops (calories)
Rice and Wheat
Coarse Grains
Oil Crops
Other Crops
Processed Crops (calories)
Vegetable Oils
Sweeteners and Alcoholic Beverages
Animal Products (calories)
Beef and other Ruminant Livestock
Pork and Poultry
Commercial Biomass (calories or metric tons)
Forest Products (cubic meters)

18. 1990 Food Consumption

19. Land Allocation

20. Methodology Forest Dynamics Land Allocation
Trees in AgLU grow for 45 years
Two forest markets (current and future) needed for model stability
Land Allocation
Land owners compare economic returns across crops, biomass, pasture, and future trees
Underlying probability distribution of yields per hectare

21. Land Shares si = share of land in use i
= profit rate per hectare in land use i
l determines rate of change in land use (is a function of correlation within land-use nest)

24. Status of SGM Quick Turnaround Model Development Reduced form
Rely on marginal abatement curves from sector models
Model Development
Move AgLU into SGM
Rely on sector models to parameterize agriculture and forestry
Collaboration with Texas A&M University and Lawrence Berkeley National Laboratory