The fate of the planet’s coastlines depends on how fast Antarctica’s ice sheets melt. We don’t know what’s coming

Researchers on the Totten glacier retrieve data and reset field monitoring equipment. Dr Ben Galton-Fenzi (on far right) stands next to Madi Gamble Rosevear. Photograph: Madi Gamble Rosevear

On one side of Dr Ben Galton-Fenzi’s view across the vast Totten ice shelf, the sun sat low on the Antarctic horizon. On the other, a full moon.

The ice shelf is “flat and white”, says Galton-Fenzi. “If there’s cloud around, you lose the horizon.”