An employee walks through a cold room filled with cattle carcasses at a Bindaree Beef facility in Inverell, Australia, on March 24. (Carla Gottgens/Bloomberg News)

The meat industry contributes more to greenhouse gas emissions than the combined exhaust from every form of transportation on Earth — a whopping fifth of the total. Beef is the biggest culprit, and it requires almost 30 times as much land and 11 times as much water to produce as pork or chicken.

Denmark's Council of Ethics, a government think tank, said that in light of these facts, Danes are ethically obligated to change their eating habits and that a sliding-scale tax should be imposed on foods that are proportional to their "climate impact."

The proposal now goes before lawmakers. Under the plan, a tax would first be imposed on beef, then would be expanded to all red meat, and possibly further food sources based on the sliding-scale model. Denmark is a small country, and the effect of a tax on climate-change mitigation would be negligible, but the nation's size allows for "greener living" to be built into people's lifestyles more easily. More than a third of the residents in Copenhagen, Denmark's capital, bike to work, and only 29 percent own a car. The government has a comprehensive plan to make the country independent from fossil fuels by 2050.

Mickey Gjerris, a spokesman for the Council of Ethics, emphasized that part of the goal of the tax was to raise awareness, if not reduce emissions. “An effective response to climate-damaging foods that will also contribute to raising awareness of climate change must be united, which requires that society sends a clear signal through regulation,” he said in a news release.

A British think tank, Chatham House, recommended in November that the United Kingdom do the same, but the proposal in Denmark is more serious — if only because a government-sponsored group made the push.

Americans eat about 200 pounds of meat per capita annually, which is more than double the global average, although overall meat consumption is increasing across the board worldwide, especially in the developing world. Knowing which habits — eating meat, driving cars, living in a suburb — contribute most to climate change is empirically difficult, and making personal decisions is inherently fraught. In a Washington Post column, Tamar Haspel, a food and science writer, laid out the conundrum in stark terms:

"Even if climate impact is your top priority, it’s important to look at the food data in the context of other lifestyle factors. Eating beans is definitely better than eating beef. Driving a Prius is better than driving a Hummer. But one decision trumps every other — potentially by orders of magnitude — and that’s how many children you have. No amount of bean-eating or Prius-driving will compensate for reproducing, and it’s the childless, not the vegetarians, who are more likely to save the planet. Which doesn’t mean that we should ignore the benefits of beans and Prii — or that we shouldn’t have kids — it just means that we should acknowledge that human survival takes a climatic toll."

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