Office-sharing company WeWork, which operates in 22 countries, is going meat-free and will ban its 6,000 staff from expensing meals containing meat in a bid to "leave a better world for future generations".

Environmentalists say livestock farming is a major contributor to global warming. Here are some facts:

- Livestock accounts for more than 14 percent of planet warming emissions, mainly from animal burping, manure and feed production.

- Production of animal-based foods accounts for two-thirds of agricultural greenhouse gas emissions and three-quarters of agricultural land use, while only contributing 37 percent of the global protein supply.

Image: World Resources Institute

- If cattle were a nation, they would rank third behind China and the United States among the world's largest greenhouse gas emitters.

- The livestock industry is responsible for more greenhouse gas emissions than the world's biggest oil companies.

- The combined emissions of the top 20 meat and dairy companies exceed the emissions of entire countries such as Germany or the United Kingdom.

- A quarter of the world's landmass, excluding Antarctica, is used for pasture.

- Cattle release methane, nitrous oxide and carbon dioxide. Methane, which traps far more heat than carbon dioxide, is released mainly through belching.

- Scientists are looking at how to make livestock less gassy by breeding animals that burp less or adjusting their diets - including feeding them seaweed.

- If the 2 billion biggest consumers of meat in the world shifted towards plant-based foods, it could save an area twice the size of India, making it easier to feed a growing world population without cutting down more forests.

- It takes 25kg of grain to produce 1kg of beef and roughly 15,000 litres of water.

- Per gramme of protein, producing beef takes 20 times as much land, and emits 20 times as many greenhouse gases, as producing beans.

- Producing chicken takes three times as much land, and emits three times as many greenhouse gases, as producing beans, per gramme of protein.

- Americans eat about 10 billion burgers each year. Replacing 30 percent of the beef with mushrooms would have the same impact as taking 2.3 million cars off the road.

- If everyone became vegetarian by 2050, food-related emissions would drop by about 60 percent. If they went vegan, the decline would be around 70 percent.