How we know that climate change is happening—and that humans are causing it

It's a matter of how, not if Pexels “People come to Asheville to retire,” says Deke Arndt, “and data comes to Asheville to retire, too.” He should know. Arndt and his colleagues sit atop a vast trove of current and historical climate data—data so valuable, it’s protected by multiple failsafes and even backed up on tape…