Right now we’re more than halfway to 3.6 degrees (2 degrees Celsius) of warming from preindustrial temperatures, which scientists have long warned is the threshold for dangerous climate change. The reports of the UN’s Intergovernmental Panel on Climate Change are full of harrowing details of what might happen to our world with 3.6 degrees of warming, from collapsing ice sheets to crop-killing drought. But to nonscientists—which is to say, most humans on the planet—3.6 degrees of warming does not sound dangerous at all. Who can tell the difference between a 77-degree day and an 81-degree day?
