Elizabeth Kolbert is the author of the book The Sixth Extinction, which won this year’s Pulitzer Prize for general non-fiction. In an interview with National Geographic, Kolbert said that we humans have caused the sixth mass extinction by hunting, bringing in invasive species, changing the climate and changing the chemistry of all the oceans. We are also changing the surface of our planet. We cut down forests. We engage in agricultural activity that is damaging to other species. The list goes on and on.