Melting glaciers and sea ice

The Arctic is warming four times faster than the rest of the planet, and this means that glaciers, which sit on land, and sea ice, which floats on the ocean surface, are melting rapidly. Two-thirds of Arctic Sea ice has disappeared since 1958 when it was first measured. Between 2000 and 2019, the world's glaciers lost 267 billon tons of ice each year. Himalayan glaciers are on a trajectory to lose one-third of their ice by 2100, and Alpine glaciers are projected to lose half of theirs.

"I can tell you from our research that the bedrock underneath the ice will become exposed at a much higher speed than we think," said Joerg Schaefer, a climate geochemist at the Columbia Climate School's Lamont-Doherty Earth Observatory who is researching the Greenland ice sheet. "All of the predictions are way too conservative in terms of change—the change will be much faster. That's true globally. But Greenland might be one of the areas where these predictions of ice change are way, way, way too conservative because of a variety of climate factors."

Because of the global warming human activity has already caused, Greenland's melting will cause sea levels to rise 10.6 inches, according to a new study. This amount of melting is already locked in, said the study authors. They added that 10.6 inches is a low estimate; if emissions continue and Greenland's record-breaking melting of 2012 becomes the norm, we could be facing 30 inches or more of sea level rise. The loss of ice from the West and East Antarctic ice sheets and from other glaciers would add to this.