If you really want to go green, the conventional thinking goes, buy a hybrid. Practically speaking though, there is a faster and cheaper option: shift to a low-carbon diet. The meal plan of the average American family accounts for 2.8 tons of CO2 emitted annually, compared with 2.2 tons for driving. Worldwide agriculture contributes some 30% of global greenhouse-gas emissions, far more than transportation. So when it comes to cutting your carbon footprint today, the truth is that what you eat is as important as what you drive. "If you can't buy a Prius," says Jonathan Kaplan of the Natural Resources Defense Council, "you can certainly eat like one."
And here's better news: eating green is good for you. The very foods with a high carbon cost--red meat, pork, dairy products, processed snacks--also tend to be laden with fat and calories. A green diet would comprise mostly vegetables and fruits, whole grains, fish and lean meats like chicken--a diet that's eco- and waistline friendly. "[Eating green] can make a big difference for the climate and be more healthy," says Doug Gurian-Sherman, senior scientist for the food and environment program at the Union of Concerned Scientists.
It may be hard to believe that a meal at McDonald's produces more carbon than your trip to the drive-through--until you consider just how vast and energy-intensive the global food system is. More than 37% of the world's land is used for agriculture, much of it ground that was once forested--and deforestation is a major source of carbon. The fertilizer and machinery needed on a modern farm also have a large carbon footprint, as does the network of ships and trucks that brings the food from the farm to your plate. On average, it takes seven to 10 times as much fossil-fuel energy to produce and ship food as we get from eating it.
The most efficient way to shrink the carbon footprint of your menu is to eat less meat, especially beef. Raising cattle takes a lot more energy than growing the equivalent amount of grains, fruits or vegetables: most produce requires about 2 calories of fossil-fuel energy to cultivate per 1 calorie of food energy; with beef, the ratio can be as high as 80 to 1. What's more, the majority of cattle in the U.S. are reared on grain and loads of it--670 million tons in 2002--and the fertilizer used to grow that feed creates separate environmental problems, including surface runoff that leads to dead zones in coastal waters like the Gulf of Mexico. Those grain-fed cattle then belch methane, a greenhouse gas that is 20 times as potent as CO2. "Reducing beef is the first step to a green diet," says Michael Jacobson of the Center for Science in the Public Interest (CSPI).
That one step can make an enormous impact on the atmosphere and your arteries. A 2005 study by the University of Chicago found that one person switching from a red-meat-based diet to vegetarianism could save about the same amount of CO2 as trading in a Toyota Camry for a Toyota Prius. There's no shortage of evidence that reducing red meat--Americans eat more than 60 lb. of dead cow annually--is also good for your health. CSPI estimates that replacing one 3.5-oz. serving of beef, one egg and a 1-oz. serving of cheese each day with an equivalent amount of fruits, vegetables and grains would cut your daily fat consumption and increase your fiber intake, all while conserving 1.8 acres of cropland and reducing animal waste by 11,400 lb. each year.
And while locally grown has become some eco-eaters' mantra, what you eat matters more than where it comes from. Our food travels from 1,500 to 2,500 miles on average from farm to supermarket, but that journey typically accounts for just 4% of a food's carbon footprint. "Focus on eating lower on the food chain, with more plants and fruits and less meat and dairy," says Kate Geagan, a dietitian and author of the forthcoming book Go Green Get Lean. "It's that simple." Installing solar panels or buying a hybrid may not be possible for many of us, but we can change today what goes into our bodies--and those decisions matter, for the health of our planet and ourselves.
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