I've just read this report in the Climate Change Report of the journal Nature.
The full article has appeared in the journal Environmental Science & Technology:quoting the report:
Environ. Sci. Technol. 42, 3508–3513 (2008)
Worried about your food miles? With rising public concern over how individual lifestyle choices affect the climate, more attention is being paid to the notion that long-distance transport of goods can harm the environment.
But a new study by Christopher Weber and Scott Matthews of Carnegie Mellon University in Washington, DC, suggests that a dietary shift may be more effective in reducing your emissions than eating local produce. They conducted a life-cycle analysis of all greenhouse gas emissions, not just carbon dioxide, associated with the production of food consumed in the United States, compared against those associated with long-distance distribution. Food production far outstripped transport as a source of emissions, accounting for 83 per cent of the 8.1 tonnes of greenhouse gases that an average US household generates each year by consuming food. Although transport distances were considerable, they led to only 11 per cent of total emissions.
Different food groups varied widely in their emissions, with red meat, for example, producing 150 per cent more greenhouse gases than chicken or fish. The authors suggest that eating less red meat and fewer dairy products even one day per week would do more against global warming than becoming a 'locavore' who eats an entirely regional diet.-----------------
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