09/06/2007 10:30 pm ET Updated Nov 17, 2011

Memo to Environmentalists: It's Time to Seriously Address the Number One Cause of Global Warming

In the August 27 New Yorker, there is a cartoon showing two men on a private plane. Off to the side is a recycling bin; as one man tosses a piece of paper into the bin, he explains, "I try to do my part." This cartoon made me think of environmentalists who urge people to drive less, switch to hybrid cars, use energy-efficient light bulbs, and make other similar changes, while they ignore the global warming, waste, and pollution that is produced by funneling crops through chickens, pigs, and other farmed animals.

Last week, The New York Times ran an article about the animal protection community's efforts to convince the environmental community to break its silence on the critical fact that almost 20 percent of all greenhouse gas emissions are the product of our national addiction to chicken nuggets and other animal products. That's more than all the cars, trucks, and planes in the world combined, according to the 2006 U.N. report, "Livestock's Long Shadow."

And the environmental problems with eating animals transcend global warming: The U.N. report concluded that the meat industry is "one of the ... most significant contributors to the most serious environmental problems, at every scale from local to global." The U.N., in its 408-page indictment of the meat industry, specifically addressed the contribution of eating meat to "problems of land degradation, climate change and air pollution, water shortage and water pollution, and loss of biodiversity."

Since the best thing you as an individual can do for the environment is to adopt a vegetarian diet, wouldn't you think that the environmental community would be addressing the issue in a significant way? Sadly, Al Gore doesn't discuss the issue at all. According to Mr. Gore's deputy press secretary, however, the suggestion to "modify your diet to include less meat" appears on Page 317 of An Inconvenient Truth (though it's not in the movie at all). And the Sierra Club, when listing "10 things you can do to help curb global warming," ignores this number one issue completely.

There are signs of change, fortunately. Although Environmental Defense neglects the issue in its main global warming brochure, it does address it on its global warming Web page, noting that "If every American skipped one meal of chicken per week and substituted vegetables and grains, for example, the carbon dioxide savings would be the same as taking more than half a million cars off of U.S. roads... Having one meat-free day per week would be the same as taking 8 million cars off American roads." So imagine the impact of adopting a fully vegetarian diet!

Greenpeace has done just that. The group both walks the walk and talks the talk, serving only vegetarian food at all the organization's events. And they call attention to the connection between meat and environmental degradation on their Web site, noting that a vegetarian diet means "saving vital chunks of rainforest, consuming less raw materials, saving water and generating less pollution." Greenpeace has also targeted KFC for the destruction of the rainforests because the Amazon is being razed to grow feed for KFC's chickens.

Don't get me wrong: I have a deep respect and admiration for Al Gore, Leonardo DiCaprio, Carl Pope, and all the others who selflessly trying to make the world a better place. I know that they genuinely care about ending global warming and all environmental issues.

But evidence shows that eating animals is the number one individual cause of global warming and that it's in the top three causes of every significant environmental problem, from the smallest to the largest. So it's past time for the environmental movement to tell people the truth--that adopting a vegetarian diet is the most important action any of us can take, both to decrease our support for global warming and also to address our support for all the rest of the "most significant contributors to the most serious environmental problems, at every scale from local to global" (to quote the United Nations).

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