(Bloomberg) — Fossilized coral reefs formed the last time the Earth was warmer than today show sea levels could rise rapidly by the end of the century if global warming triggers a collapse of ice sheets in Greenland and Antarctica.

A

Ice caps like those that cover the Antarctic and Greenland are thought to be melting at a rate that could raise sea levels by about 12 meters over the next millennium, Blanchon said. His report, to be published in the April 16 issue of Nature, says global warming caused by burning fossil fuels could shorten that time frame to several hundred years.