Transcript International Impacts of American Household Consumption

Food, Its Environmental
Consequences, and
Carrying Capacity
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Christopher L. Weber
Civil and Environmental Engineering
Carnegie Mellon University, Pittsburgh, PA USA
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
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RESEARCH OVERVIEW:
PAST AND CURRENT PROJECTS
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International trade and climate
change
Household “carbon
footprinting”
Uncertainty in LCA
Energy use and
Life Cycle
economic structural
Accounting
change
Corporate GHG
management
China’s rise in energy
Environmental Dimensions of
food and diet
Energy and Climate
Uncertainty
Assessment
Economic Assessment
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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
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THE IMPACTS OF FOOD
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Large focus on “localizing” food supplies recently
Production of Food also very GHG-intensive
(CO2, CH4, N2O)
Which is more important for climate change?
Study goal: Model freight transport and its
impacts throughout production, compare to nontransport GHGs
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An example—GHGs from food
Red Meat
Other Misc
Delivery
Oils/Sweets/Cond
Other Freight,Dom
Fruit/Vegetable
Other Freight,Int
Dairy Products
Production,CO2
Production,CH4
Chicken/Fish/Eggs
Production,N2O
Cereals/Carbs
Production,HFC
Wholesale/Retail
Beverages
0
0.5
1
1.5
2
Climate Impact, mt CO2e/yr
2.5
•Red Meat and Dairy particularly large impacts due to
methane, nitrous oxide emissions
•Shares of different gases and processes vary—transport
largest for produce
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ANOTHER EXAMPLE—LAND USE
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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
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Relative Intensity
Beverages
Cereals/Carbs
0.75
Chicken/Fish/Eggs
0.5
Dairy Products
Fruit/Vegetable
0.25
Oils/Sweets/Cond
0
Red Meat
CO2/hh
CO2/$
CO2/kCal
CO2/kg
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CURRENT GLOBAL TRENDS
120
Meat consumption
going up very quickly,100
mostly due to
80
developing world
60
 US leveled off ~100
40
kg /person
 China doubled in last 20
decade, expected to
0
increase further to 85
World
kg/person by
2030(currently ~50
kg/person)
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99
90
47
103
52
37
38
44
27
2000
2030
Developing Countries
2050
Industrialized Countries
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Discussion Points: Regional vs. Global
Carrying Capacity
Can food be limiting in one place?
 Food is a tradable good, between regions and nations
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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?
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Discussion Points: Personal Choice
Different diets lead to different carrying
capacities
 One doesn’t need more land or water-intensive
foods to survive
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Issue of choice/freedom?
 Or issue of economics?
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