Looming Floods, Threatened Cities.
THE RISK IS CLEAR: Antarctica’s collapse has the potential to inundate coastal cities across the globe.
Over tens of millions of years, thin layers of snow falling on the continent — in many places, just a light dusting every year — were pressed into ice, burying mountain ranges and building an ice sheet more than two miles thick. Under its own weight, that ice flows downhill in slow-moving streams that eventually drop icebergs into the sea.
If that ice sheet were to disintegrate, it could raise the level of the sea by more than 160 feet — a potential apocalypse, depending on exactly how fast it happened. Recent research suggests that if society burns all the fossil fuels known to exist, the collapse of the ice sheet will become inevitable.
Some scientists point out that during the last ice age, ice sheets similar to West Antarctica’s formed in other ocean basins. But as the ice age ended and the oceans warmed, all of them collapsed. These experts have started to think that West Antarctica, as a fragile holdover, is basically a disaster waiting to happen — and that if human-caused global warming has not already set the calamity in motion, it may soon do so.
“We could have a substantial retreat on a time scale of 10 years,” said Robert A. Bindschadler, a retired NASA climate scientist who spent decades working in Antarctica. “It would not surprise me at all.”