Climate change is real. It’s caused by greenhouse-gas pollution released by human industrial activity. Its consequences can already be felt across every region and coastline of the United States—and, unless we stop emitting greenhouse gases soon, those consequences will almost certainly get worse. Those are the headline findings of the Climate Science Special Report, a sweeping and more than 800-page examination of the evidence. The report was published Friday by four agencies of the U.S. government and academics from across the country. “This is the most comprehensive assessment of climate science currently available in the world, and it reaffirms what we’ve already known,” said Robert Kopp, one of the lead authors of the report and a professor of climate science at Rutgers University who co-directs the Lab. “If we want to do something like stay under 2 degrees Celsius of warming, the window to do that is closing in the next couple decades.”