To fight global warming, it is easy to insist the government implement new laws and policies. It is also relatively easy (albeit expensive) to change to a more fuel-efficient car. None of these affect one's personal life in any significant way, however.
If one takes the threat of global warming seriously, the most powerful personal step you can take may well be choosing a vegetarian diet. As pointed out in the Baltimore Sun (July 19, 2007; reproduced here):
We're getting "greener": Recycling, energy-saving light bulbs and fuel-efficient hybrid cars are now a part of our culture and economy. But most people are neglecting one of the most important steps toward stopping global warming: adopting a vegetarian diet.
It is not just animal advocates making the connection between what we choose to eat and the future of the Earth. In November of 2006, the United Nations issued a press release that stated:
Which causes more greenhouse gas emissions, rearing cattle or driving cars?
According to a new report published by the United Nations Food and Agriculture Organization, the livestock sector generates more greenhouse gas emissions as measured in CO2 equivalent – 18 percent – than transport. It is also a major source of land and water degradation.
Says Henning Steinfeld, Chief of FAO’s Livestock Information and Policy Branch and senior author of the report: “Livestock are one of the most significant contributors to today’s most serious environmental problems. Urgent action is required to remedy the situation.”
This conclusion is backed up by research (pdf) at the University of Chicago. As reported by ABC News:
Eshel and Martin collected that data from a wide range of sources, and they examined the amount of fossil-fuel energy -- and thus the level of production of greenhouse gases -- required for five different diets. The vegetarian diet turned out to be the most energy efficient, followed by poultry, and what they call the "mean American diet," which consists of a little bit of everything.
There was a surprising tie for last place. In terms of energy required for harvesting and processing, fish and red meat ended up in a "virtual tie," but that's just in terms of energy consumed. When you toss in all those other factors, such as bovine flatulence and gas released by manure, red meat comes in dead last. Fish remains in fourth place, some distance behind poultry and the mean American diet, chiefly because the type of fish preferred by Americans requires a lot of energy to catch.
Can changing your diet really have much of an impact?
"It is comparable to the difference between driving an SUV and driving a reasonable sedan," said Eshel, who drives a Honda Civic, and only when he has to....
When they looked at only carbon dioxide emissions associated directly with energy consumption, they came up with the vegetarian diet far less damaging to the planet than the others.