What if every pet was vegan? Here's how much it would help the planet

At least a quarter of all human-generated greenhouse gas emissions to date can be traced to the livestock industry. Vast tracts are used to grow feed crops and to graze the world's 92 billion cows, pigs, chickens and other animals slaughtered each year. This hunger for land means livestock farming is a leading cause of deforestation, as well as a significant drain on freshwater.