Earth Is Barreling Toward 'Peak Glacier Extinction'

A new study estimates the planet is heading toward a midcentury peak in glacier loss, with thousands of ice masses set to vanish each year as temperatures climb. Researchers writing in Nature Climate Change modeled the fate of more than 200,000 glaciers worldwide and identified a period they call "peak glacier extinction"—the years when the highest number of individual glaciers are expected to vanish. A glacier was considered "extinct" once it shrank below 0.01 square kilometers in area, or less than 1% of its volume around the year 2000.

How quickly that peak arrives, and how severe it is, depends on how much the world warms. If global temperature rise is limited to 1.5 degrees Celsius above preindustrial levels—a target scientists say is already slipping out of reach—glacier loss would crest around 2041, with about 2,000 disappearing annually. On a path to 4 degrees of warming, the peak shifts to the mid-2050s and intensifies to roughly 4,000 glaciers a year, three to five times today's rate. Under the roughly 2.7-degree trajectory implied by current climate pledges, the world would lose about 3,000 glaciers annually between 2040 and 2060.

Smaller glacier regions are poised for some of the earliest and most dramatic changes. More than half the glaciers in the European Alps, parts of the Andes, and North Asia are expected to vanish within about 20 years, with extinction peaking around 2040. Areas dominated by larger glaciers, such as Greenland and the Russian Arctic, would see their peak later in the century. By 2100, only about half of today's glaciers are projected to survive at 1.5 degrees of warming; that share drops to roughly 20% at 2.7 degrees, and to near-total loss at 4 degrees.

Phys.org notes that in the Alps, if global temps see a rise of 2.7 degrees, only about 110 glaciers, or 3% of the area's current total, would remain in Central Europe by the year 2100; with temps rising 4 degrees, that number would drop to 20. Scientists warn the implications reach far beyond scenery. Glaciers provide critical water supplies, support tourism and ski industries, and hold cultural significance for many communities. Once they disappear, they're unlikely to return anytime soon, UC Irvine glaciologist Eric Rignot, who wasn't involved in the study, tells CNN. "Reforming a glacier would take decades, if not centuries," he notes.