Vegetarians often cite both animal rights and environmental issues as motivations for their decision to give up meat. While raising animals, processing them into meat, and transporting that meat to the store, the livestock industry generates 12 percent of global greenhouse gas emissions, NPR reports. A notable portion of those emissions come from growing animals' feed and converting land to grow those crops.
Not everyone is keen on giving up meat. In developing countries, demand for meat is rising, NPR says, and will likely double by 2050.
This does not have to mean an increase in greenhouse gas emissions, however. NPR:
The study's authors say there's a better path: Help farmers produce livestock more efficiently, and reduce the incentive to snap up new land to graze their animals.
A whopping 30 percent of the globe's land area already is used, one way or another, to raise livestock. The key is to prevent that area from expanding as countries like China, India and Brazil ramp up their meat production.
The key, paradoxically, is to get animals to eat more grain.
Raising animals on grass can require more land and, as a result, cause more greenhouse gas emissions than using grain, NPR explains. So a factory-farm diet of grain—along with techniques that get more meat from each animal and improving waste processing—could actually help reduce emissions.