Thanks to humans and our addiction to meat, the majority of mammals on Earth are livestock, and it’s ruining the planet.

A new study published this week in the Proceedings of the National Academy of Sciences sought to catalog the mass of all living things on Earth and found that humans have pretty much ruined most of it despite making up only a small sliver of the biosphere. Humans make up just 0.01 percent of the biomass on Earth, but have managed to wipe out 83 percent of all wild mammals and cut the plant biomass in half during our time on this planet, according to the study. When you look at mammals specifically, humans make up 36 percent of all the mammals on the planet, with just 4 percent being wild animals like lions and bears.

“Today, the biomass of humans and the biomass of livestock far surpass that of wild mammals,” the study states. “This is also true for wild and domesticated birds, for which the biomass of domesticated poultry is about threefold higher than that of wild birds. In fact, humans and livestock outweigh all vertebrates combined, with the exception of fish.”

Most mammalian livestock are cows and pigs, though cows slightly surpass pigs, meaning that by massively expanding our global industrial meat production, human beings have turned Earth into Planet Cow.

Cows are great and all (seriously, if you ever get the chance to give a cow some ear scritches, do it), but the problem is that animal agriculture produces more greenhouse gas emissions than all land transportation combined. It also contributes to deforestation—we lost global forests equivalent to the size of Portugal in just the 1990s—and puts endangered animals at risk. Then there’s the fact that we don’t really treat those cows so well.

“I would hope people would take this [work] as part of their world view of how they consume,” Ron Milo, a researcher at the Weizmann Institute of Science in Israel and co-author of the study, told The Guardian. “I have not become vegetarian, but I do take the environmental impact into my decision making, so it helps me think, do I want to choose beef or poultry or use tofu instead?”