As greenhouse gases go, methane that escapes into the atmosphere without being burned is 21 times more potent per pound than CO2.

Raising livestock contributes to climate change and environmental degradation in other ways as well: it takes far more grain and land to produce a calorie of food for humans by feeding grains to animals than directly to people. That means more destruction of grasslands and forests for farming, more tractors burning fuel, and more pesticides seeping into the groundwater.