President Herbert Hoover promised “a chicken in every pot and a car in every garage.” With warnings about global warming reaching feverish levels, many are having second thoughts about all those cars. It seems they should instead be worrying about the chickens.

Last month, the United Nations published a report on livestock and the environment with a stunning conclusion: “The livestock sector emerges as one of the top two or three most significant contributors to the most serious environmental problems, at every scale from local to global.” It turns out that raising animals for food is a primary cause of land degradation, air pollution, water shortage, water pollution, loss of biodiversity, and not least of all, global warming.

That’s right, global warming. You’ve probably heard the story: emissions of greenhouse gases like carbon dioxide are changing our climate, and scientists warn of more extreme weather, coastal flooding, spreading disease, and mass extinctions. It seems that when you step outside and wonder what happened to winter, you might want to think about what you had for dinner last night. The U.N. report says almost a fifth of global warming emissions come from livestock (i.e., those chickens Hoover was talking about, plus pigs, cattle, and others)–that’s more emissions than from all of the world’s transportation combined.

For a decade now, the image of Leonardo DiCaprio cruising in his hybrid Toyota Prius has defined the gold standard for environmentalism. These gas-sipping vehicles became a veritable symbol of the consumers’ power to strike a blow against global warming. Just think: a car that could cut your vehicle emissions in half – in a country responsible for 25% of the world’s total greenhouse gas emissions. Federal fuel economy standards languished in Congress, and average vehicle mileage dropped to its lowest level in decades, but the Prius showed people that another way is possible. Toyota could not import the cars fast enough to meet demand.

Last year researchers at the University of Chicago took the Prius down a peg when they turned their attention to another gas guzzling consumer purchase. They noted that feeding animals for meat, dairy, and egg production requires growing some ten times as much crops as we’d need if we just ate pasta primavera, faux chicken nuggets, and other plant foods. On top of that, we have to transport the animals to slaughterhouses, slaughter them, refrigerate their carcasses, and distribute their flesh all across the country. Producing a calorie of meat protein means burning more than ten times as much fossil fuels–and spewing more than ten times as much heat-trapping carbon dioxide–as does a calorie of plant protein. The researchers found that, when it’s all added up, the average American does more to reduce global warming emissions by going vegetarian than by switching to a Prius.

According to the UN report, it gets even worse when we include the vast quantities of land needed to give us our steak and pork chops. Animal agriculture takes up an incredible 70% of all agricultural land, and 30% of the total land surface of the planet. As a result, farmed animals are probably the biggest cause of slashing and burning the world’s forests. Today, 70% of former Amazon rainforest is used for pastureland, and feed crops cover much of the remainder. These forests serve as “sinks,” absorbing carbon dioxide from the air, and burning these forests releases all the stored carbon dioxide, quantities that exceed by far the fossil fuel emission of animal agriculture.

As if that wasn’t bad enough, the real kicker comes when looking at gases besides carbon dioxide–gases like methane and nitrous oxide, enormously effective greenhouse gases with 23 and 296 times the warming power of carbon dioxide, respectively. If carbon dioxide is responsible for about one-half of human-related greenhouse gas warming since the industrial revolution, methane and nitrous oxide are responsible for another one-third. These super-strong gases come primarily from farmed animals’ digestive processes, and from their manure. In fact, while animal agriculture accounts for 9% of our carbon dioxide emissions, it emits 37% of our methane, and a whopping 65% of our nitrous oxide.

It’s a little hard to take in when thinking of a small chick hatching from her fragile egg. How can an animal, so seemingly insignificant against the vastness of the earth, give off so much greenhouse gas as to change the global climate? The answer is in their sheer numbers. The United States alone slaughters more than 10 billion land animals every year, all to sustain a meat-ravenous culture that can barely conceive of a time not long ago when “a chicken in every pot” was considered a luxury. Land animals raised for food make up a staggering 20% of the entire land animal biomass of the earth. We are eating our planet to death.

What we’re seeing is just the beginning, too. Meat consumption has increased five-fold in the past fifty years, and is expected to double again in the next fifty.

It sounds like a lot of bad news, but in fact it’s quite the opposite. It means we have a powerful new weapon to use in addressing the most serious environmental crisis ever to face humanity. The Prius was an important step forward, but how often are people in the market for a new car? Now that we know a greener diet is even more effective than a greener car, we can make a difference at every single meal, simply by leaving the animals off of our plates. Who would have thought: what’s good for our health is also good for the health of the planet!

Going veg provides more bang for your buck than driving a Prius. Plus, that bang comes a lot faster. The Prius cuts emissions of carbon dioxide, which spreads its warming effect slowly over a century. A big chunk of the problem with farmed animals, on the other hand, is methane, a gas which cycles out of the atmosphere in just a decade. That means less meat consumption quickly translates into a cooler planet.

Not just a cooler planet, also a cleaner one. Animal agriculture accounts for most of the water consumed in this country, emits two-thirds of the world’s acid-rain-causing ammonia, and it the world’s largest source of water pollution–killing entire river and marine ecosystems, destroying coral reefs, and of course, making people sick. Try to imagine the prodigious volumes of manure churned out by modern American farms: 5 million tons a day, more than a hundred times that of the human population, and far more than our land can possibly absorb. The acres and acres of cesspools stretching over much of our countryside, polluting the air and contaminating our water, make the Exxon Valdez oil spill look minor in comparison. All of which we can fix surprisingly easily, just by putting down our chicken wings and reaching for a veggie burger.

Doing so has never been easier. Recent years have seen an explosion of environmentally-friendly vegetarian foods. Even chains like Ruby Tuesday, Johnny Rockets, and Burger King offer delicious veggie burgers and supermarket refrigerators are lined with heart-healthy creamy soymilk and tasty veggie deli slices. Vegetarian foods have become staples at environmental gatherings, and garnered celebrity advocates like Bill Maher, Alec Baldwin, Paul McCartney, and of course Leonardo DiCaprio. Just as the Prius showed us that we each have in our hands the power to make a difference against a problem that endangers the future of humanity, going vegetarian gives us a new way to dramatically reduce our dangerous emissions that is even more effective, easier to do, more accessible to everyone and certainly goes better with french fries.

Ever-rising temperatures, melting ice caps, spreading tropical diseases, stronger hurricanes… So, what are you do doing for dinner tonight? Check out www.VegCooking.com for great ideas, free recipes, meal plans, and more! Check out the environmental section of www.GoVeg.com for a lot more information about the harmful effect of meat-eating on the environment.