COS 89-7
Reducing greenhouse gas emissions caused by global diets and their predicted changes
Literature in two sub-disciplines is particularly relevant to the climate impacts of current and possible future dietary patterns: research on greenhouse gas footprints associated with particular foods and production systems, and projections of how diets will change in both developed and developing countries in coming decades. The first is based on life-cycle analyses (LCAs), of which several dozen have been published, and on spatially explicit global modeling of agricultural production systems. The second includes forecasting and projection methods based on economics, social psychology and the anthropology of food. I reviewed these literatures, including meta-analyes and reviews of LCAs and the output of agricultural model inter-comparisons, to identify the most important foods, regions, and trends in dietary patterns for future greenhouse gas emissions.
Results/Conclusions
Both the LCA and agricultural model intercomparison literatures show that animal protein sources, particulary land-extensive meats such as beef, are the most important foods for current and future emissions. Other kinds of "foods" (including agricultural sources of bioenergy) whose growth is likely to increase emissions substantially include vegetable oils (e.g. palm oil and soybean oil) and feed grains and legumes. Current consumption of these foods is quite unequal among regions and social classes, so that considerations of equity as well as climate mitigation effectiveness will require quite different policies and objectives depending on country and income level. Broad-scale generic approaches (e.g. increasing production of crops and livestock without distinction, or a global carbon tax on food) are unlikely to be either fair or successful in reducing emissions.