The Antarctic ice sheet is less stable than previously thought, and Greenland is comparatively safer, according to research from the US.

In the last interglacial period, sea levels were up to 6.5 metres higher than current levels, but research from the Unviersity of Wisconsin-Madison suggests the West Antarctic was partially to blame.

“The implication of our results is that West Antarctica likely was much smaller than it is today,” researcher Anders Carlson said. “If West Antarctica collapsed, that means it’s more unstable than we expected, which is quite scary.”