Antarctica’s ice loss is locked in, and extra snowfall won’t save it – that’s bad news for low-lying coastal areas elsewhere

A glacier front meets the sea in Antarctica. The ice sheet holds enough water to raise global sea level by about 190 feet (58 meters). Qiyue Sun Sea-level rise is one of the most visible signs of climate change, one that is threatening low-lying coastal communities around the world. Today, about 1…

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Antarctica’s ice threat

Antarctica holds enough ice to raise global sea levels by about 190 feet (58 meters) if it all melted, though this would take centuries.

Today, about 1 billion people live in coastal areas, with roughly 100 million living within 1 meter (3.3 feet) of sea level, making them highly vulnerable to flooding.

Over the long term, Antarctica’s ice loss is the biggest unknown in predicting future sea-level rise, as scientists have debated whether the continent will gain or lose ice this century.

The frozen continent’s fate depends on a chain of events linked to global warming, including ocean and air temperatures around Antarctica, the melting of ice shelves, and the speed at which glaciers slide into the sea.

Ice shelves are floating extensions of the ice sheet that act as barriers, slowing the flow of glaciers behind them.

When these shelves thin or collapse, glaciers can accelerate their movement toward the ocean.

This process is already being observed in some parts of Antarctica.