A whopping 83 percent of the surface of the Earth is dedicated to human activities — farming, mining, fishing, or just plain old living — according to a report released this week by the Wildlife Conservation Society and Columbia University’s Center for International Earth Science Information Network. Human use leaves wildlife with just a fraction of the terrestrial surface of the globe still untouched, mostly in Alaska, Canada, Russia, Tibet, Mongolia, and the Amazon River Basin. The report also found that close to 100 percent of the land that can be farmed for rice, wheat, or corn is already being cultivated by humans. Eric Sanderson, a landscape ecologist and the leader of the report, called it “a clear-eyed view of our influence on the Earth” that provides “a way to find opportunities to save wildlife and wild lands in pristine areas.”