It sounds like the plot of a disaster movie — but scientists say it could soon become real.
A new study warns that more than half of Antarctica’s ice shelves could collapse by the year 2300, triggering up to 32 feet of irreversible global sea-level rise. That means entire coastal cities — from London to Miami — could vanish beneath the waves.

Researchers from Sorbonne University in Paris found that 59% of Antarctica’s vast ice shelves could crumble if greenhouse gas emissions continue at today’s pace. “Our results show that current choices will decide whether we lose most Antarctic ice shelves forever,” the team wrote.
Under a low-emission future, only one shelf may fail. But if the planet warms by 12°C — a high-emission scenario — the world faces catastrophic flooding as early as 2085 to 2170. In that timeline, cities like Portsmouth, Venice, New Orleans, and Shanghai could all be underwater.
Ice shelves are like Earth’s safety belts — once they break, glaciers rush into the sea, accelerating disaster. And while 2300 sounds distant, the warning is clear: the world’s future shorelines are being decided right now.