Number of wildlife has declined by half over past forty years

Vox - Earth has lost a lot of animals over the past four decades. A major new study by the World Wildlife Fund estimates that the overall number of mammals, birds, reptiles, amphibians and fish has declined 52 percent between 1970 and 2010.

The main culprits? Humans, who have been wiping out other animals through hunting, fishing, deforestation, pollution, and various forms of habitat destruction:

This doesn't mean we've wiped out half of all species. It means that, on average, the world's vertebrate species populations are about half the size they were in 1970.