From the high mountains to the vast polar ice sheets, the world is losing its ice faster than anyone thought possible. It’s no surprise that glaciers are melting as emissions from cars and industry warm the climate. The ice loss has outstripped the upward creep of global temperatures.
Scientists are finding that glaciers and ice sheets are surprisingly touchy. Instead of melting steadily, like an ice cube on a summer day, they are prone to feedbacks, when melting begets more melting and the ice shrinks precipitously.
Most glaciers in the Alps could be gone by the end of the century, Glacier National Park’s namesake ice by 2030.
The temperature threshold for drastic sea-level rise is near, but many scientists think we still have time to stop short of it, by sharply cutting back consumption of climate-warming coal, oil, and gas. Few doubt, however, that another 50 years of business as usual will take us beyond a point of no return.