Global wildlife populations plummeted by 58 percent between 1970 and 2012, according to the latest Living Planet Report published by conservation group WWF on Wednesday. The report — an analysis of data on more than 14,200 populations across 3,700 species of mammals, fish, amphibians, birds and reptiles — projected that if the trend continued, the world could lose more than two-thirds of wildlife by 2020. The worst affected are species living in lakes, rivers and wetlands — who have seen an 81 percent drop in populations over the past four decades, according to WWF. We are entering a new era in Earth’s history: the Anthropocene. An era in which humans rather than natural forces are the primary drivers of planetary change.