University of Chicago: Global Warming
Vegan diets healthier for planet than meat diets - 04/13/06
The food that people eat is just as important as what kind of cars they drive when it comes to creating the greenhouse-gas emissions that many scientists have linked to global warming, according to a report accepted for publication in the April issue of the journal Earth Interactions.
Both the burning of fossil fuels during food production and non-carbon dioxide emissions associated with livestock and animal waste contribute to the problem, the University of Chicago's Gidon Eshel and Pamela Martin wrote in the report.
The average American diet requires the production of an extra ton and a half of carbon dioxide-equivalent, in the form of actual carbon dioxide as well as methane and other greenhouse gases compared to a strictly vegetarian diet, according to Eshel and Martin. And with Earth Day approaching on April 22, cutting down on just a few eggs or hamburgers each week is an easy way to reduce greenhouse-gas emissions, they said.
"We neither make a value judgment nor do we make a categorical statement," said Eshel, an Assistant Professor in Geophysical Sciences. "We say that however close you can be to a vegan diet and further from the mean American diet, the better you are for the planet. It doesn't have to be all the way to the extreme end of vegan. If you simply cut down from two burgers a week to one, you've already made a substantial difference."
The average American drives 8,322 miles by car annually, emitting 1.9 to 4.7 tons of carbon dioxide, depending on the vehicle model and fuel efficiency. Meanwhile, Americans also consume an average of 3,774 calories of food each day.
In 2002, energy used for food production accounted for 17 percent of all fossil fuel use in the United States. And the burning of these fossil fuels emitted three-quarters of a ton of carbon dioxide per person.
That alone amounts to approximately one-third the average greenhouse-gas emissions of personal transportation. But livestock production and associated animal waste also emit greenhouse gases not associated with fossil-fuel combustion, primarily methane and nitrous oxide.
