1. Climate and Economic Drivers of Land Use Change http://globalchange.mit.edu/ John Reilly, Niven Winchester, Adam Schlosser, Qudsia Ejaz MIT Joint Program on the Science and Policy of Global Change Massachusetts Institute of Technology Questions or comments? Contact: John Reilly jreilly@mit.edu North American Carbon Cycle Meeting, Albuquerque, New Mexico 4-6 Feb., 2013

2. http://globalchange.mit.edu/ 2 Population and Income Growth—greater demand, changing consumption patterns—more meat, more land. Agricultural productivity growth—more food on less land. Price driven intensification of production—pasture to feedlots, dry-land to irrigated, more fertilizer, low value to high value Climate: Wetter in dry climates, drier in wet climates, or vice versa, warmer in cold climates, warmer in hot climates Atmospheric composition: CO 2 and crop increase but also weeds; ozone—damage; nitrogen deposition. Energy and Climate Policy: higher energy prices, higher fertilizer and energy costs for agriculture, costs of reducing methane from rice and livestock, nitrous oxide from use of fertilizers Land policy: Carbon sequestration/reforestation, forest protection Drivers

3. http://globalchange.mit.edu/ 3 MIT EPPA, 16 Region, multi Sector CGE model Downscaling Technique/ Spatial disaggregation algorithm DYNAMIC TERRESTRIAL ECOSYSTEMS MODEL (TEM) CH 4, N 2 O, Net CO 2 from land use Crop, pasture, bioenergy, forest productivity Spatial data (0.5º x 0.5º) for land use Economy-Global Land System Interactions GHG and Other Pollutants from energy and agriculture/land use Land use shares for crops, livestock, bioenergy, forestry CO 2, Tropospheric Ozone, Nitrogen deposition Temperature, Precipitation, Solar Radiation Coupled Ocean, Atmosphere Biogeophysical Land Processes

4. http://globalchange.mit.edu/ 4 Climate, CO 2 Concentrations, and Changes in Land Carbon Storage Land policy gets us another ½ degree of avoided warming. Not much difference between the no biofuels and biofuels policy. With land incentives, land is a major sink. The climate policy also helps largely because we need less land for crops because of less environmental (ozone) damage.

5. http://globalchange.mit.edu/ 5 Energy Results Energy-Only: All liquid fuels from biomass, large reduction in use, coal w/CCS Energy+Land: Less biofuels, some petroleum, less use. No-biofuels: similar, more petroleum

6. http://globalchange.mit.edu/ Land Use Main difference in Energy only from No- Policy is more land biofuels, less to cropland. Reason is mostly less damage to crops from ozone. With Energy+Land significant reforestation, with biofuels further push into crop and pasture land. This at cost of higher commodity prices.

7. http://globalchange.mit.edu/ Regional patterns of change in land carbon Much loss, especially Africa, Asia Mostly gain

8. http://globalchange.mit.edu/ Big Effects on Food Prices When Land Carbon priced Solid: no-policy Short Dash: Energy-Only Dots: No biofuels Long Dash:Energy+ Land Surprising result: No-policy and energy only about the same. Less environmental damage w/ energy policy, but higher energy and GHG control costs offset benefit to crops. Energy+Land has big price impacts. w/o biofuels some pressure off.

9. http://globalchange.mit.edu/ Summary This is a complex system with many interactions Climate policy affects climate/atmospheric composition Which affects crop/forest/pasture productivity And, energy and fertilizer inputs And, costs of controlling methane and nitrous oxide It also affects incomes and food prices. And these determine both the amount of land used and where crops are grown. Biofuels and land carbon sequestration are still another element. Understanding these linkages is critical to designing policies that don’t have unpleasant surprises. Data and models well calibrated to data are needed. Models must represent physical processes and economic/social response that will occur through markets and policy