20th Century FoxA scene from the movie The Day After Tomorrow, an ever-so-slightly hyped up take on “abrupt climate change.”

Twenty years ago, scientists atop the Greenland ice sheet pulled up an ice core that both excited their curiosity and scared the pants off of them. They had discovered definitive evidence that Earth’s climate can change quickly, dramatically, and unpredictably, rearranging the planet’s energy balance and plunging Europe and North American into bitter, 1,000-year cold snaps. It wasn’t quite like they played it in The Day After Tomorrow, but it was damn scary nonetheless.

Though there is now ample evidence that our planet has seen dozens of these sudden climatic changes, the Intergovernmental Panel on Climate Change — the official, consensus-building arbiter of climate science — rates the probability of humans causing another abrupt climate change in the next century as low: less than 10 percent. Still, a one-in-10 chance of pushing the climate over a cliff is enough to sober you up. Should we be as scared as those scientists were?