Cattle ranch on former Amazon rainforest land in Brazil. Photo by Daniel Beltrá.

Humans make up only about 0.01 percent of all life on Earth. While our planet is 4.5 billion years old, we have been around for a mere speck — 200,000 years or so. Yet in our short time here, we have managed to set in motion the worst era of mass extinction since the dinosaurs. In the past 50 years alone, we have caused wildlife populations to decline by a catastrophic 60 percent.