Our appetite to pork and beef is not just clogging our arteries; it’s grilling the Earth too.

Eating one kilogram of beef produces more greenhouse gas emissions than driving for three hours while leaving the lights on at home, according to a new study that examines the CO2 emissions resulting from bringing an average beef cow to market.

These startling conclusions come out of a recent study lead by Akifumi Ogino of the National Institute of Livestock and Grassland Science in Tsukuba, Japan. Mr. Ogino and his team assessed the effects of beef production on global warming, water quality, and energy consumption.

The problem is that rearing livestock uses a lot of grain that could otherwise directly feed people. It takes 8 or 9 kilos of grain to produce 1 kilo of beef, for example. Similarly, it takes around 20 square metres of land to produce each kilo of beef while only 0.3 square metres can produce the same amount of vegetables. As China and India, the world’s two most populous nations, increasingly turn to meat, the strain is also showing on world food supplies.

Ranching is also one of the main drivers of deforestation worldwide, while overgrazing is turning a fifth of all pastures and rangeland into desert. And it takes a staggering 990 litres of water to produce just 1 litre of milk.
Most of the greenhouse gas emissions are in the form of methane released from the animals' digestive systems. What is even more alarming is that over two-thirds of the energy goes towards producing and transporting the animals' feed. In fact this study did not include the impact of managing farm infrastructure and transporting the meat, so the total environmental cost is much higher than the study suggests.

Rajendra Pachauri, the head of the U.N.'s Nobel Prize–winning Intergovernmental Panel on Climate Change, urges people around the world to cut back on meat in order to combat climate change.

He suggests cutting down on meat at least for one day a week, at least initially. In the short term this will have the biggest impact.

Going vegetarian and buying your fresh local produce is obviously the better option. But perhaps it’s not too much to ask that when the choice is to eat meat, it should be in moderation and with some regard for the needs of the poor and the planet, neither of which have any choice at all.