1. Food, Its Environmental Consequences, and Carrying Capacity Christopher L. Weber Civil and Environmental Engineering Carnegie Mellon University, Pittsburgh, PA USA 1

2. OUTLINE Food production and its environmental dimensions Why would food be limiting? Current Global Trends related to food availability Regional vs. Global Food production The issue of personal choice 2

3. RESEARCH OVERVIEW: PAST AND CURRENT PROJECTS International trade and climate change Household “carbon footprinting” Uncertainty in LCA Energy use and economic structural change Corporate GHG management China’s rise in energy Environmental Dimensions of food and diet 3 Energy and Climate Uncertainty Assessment Economic Assessment Life Cycle Accounting

4. Food and Agriculture and the Environment Why are food and agriculture important for carrying capacity? Land use—set amount of land available globally, yields can only be increased so far Water use—huge user of water, dominant in most regions of US Water quality—detrimental effects from runoff to already scarce resource Climate Change—large source of GHG emissions, particularly non-energy GHGs and land use change

5. THE IMPACTS OF FOOD Large focus on “localizing” food supplies recently Production of Food also very GHG-intensive (CO 2, CH 4, N 2 O) Which is more important for climate change? Study goal: Model freight transport and its impacts throughout production, compare to non- transport GHGs 5

6. An example—GHGs from food 6 Red Meat and Dairy particularly large impacts due to methane, nitrous oxide emissions Shares of different gases and processes vary—transport largest for produce

7. ANOTHER EXAMPLE—LAND USE 7

8. COMPARING FOOD GROUPS Hard to compare food groups No matter how its calculated, red meat and dairy worse than others Big difference in impacts of different food choices 8

9. CURRENT GLOBAL TRENDS Meat consumption going up very quickly, mostly due to developing world US leveled off ~100 kg/person China doubled in last decade, expected to increase further to 85 kg/person by 2030(currently ~50 kg/person) 9

10. Discussion Points: Regional vs. Global Carrying Capacity Can food be limiting in one place? Food is a tradable good, between regions and nations Unlike, say, water In era of globalization, what would limit food trade? Economics—subsidies, unwillingness to sell below a certain price? Changing climate decreasing global food supply? Others? 10

11. Discussion Points: Personal Choice Different diets lead to different carrying capacities One doesn’t need more land or water-intensive foods to survive Issue of choice/freedom? Or issue of economics? 11