04/25/2012
Using Land to Mitigate Climate Change and Implications for Food Prices
Summary
As the global population grows to possibly 10 billion by 2100, there will be greater demands for food, energy, and land. At the same time, world leaders have set a goal of restraining temperature to within 2°C of the pre-industrial level. This will become harder as energy use and emissions increase with population growth. Emissions strategies might also consider land changes, because deforestation accounts for almost 20 percent of annual greenhouse gas emissions, more than the entire global transportation sector. A new report by Massachusetts Institute of Technology researchers at the Joint Program on the Science and Policy of Global Change analyzes the effects of land-use emission mitigation and biofuels production. This study uses the DOE-sponsored Integrated Global System Model (IGSM), a linked system that represents the agriculture, energy, and forestry sectors in an economy-wide model. The report finds that if an aggressive global tax is applied to energy emissions alone, it would not be possible to achieve the 2°C target. However, if the tax also encompasses land-use emissions, and biofuels are used, the target becomes more realistic. Nevertheless, there is a significant tradeoff because prices for food, crops, livestock, and forest products rise substantially due to mitigation costs borne by the sector and higher land prices. While wealthier regions will continue to spend less of their income on food over time, the poorest regions will spend more of their income on food. The results suggest that environmental, food, and energy challenges are likely to put significant pressure on land resources over the century, especially if efforts to reduce greenhouse gases include land changes.
References
Reilly, J., J. Melillo, Y. Cai, D. Kicklighter, A. Costa Gurgel, S. Paltsev, T. Wallace Cronin, A. Sokolov, and C. A. Schlosser. “Using Land to Mitigate Climate Change: Hitting the Target, Recognizing the Tradeoffs,” Environmental Science and Technology, DOI: 10.1021/es2034729.