Greenland Ice Sheet Caught in Feedback Loop, Melting Fast

JAKOBSHAVN, GREENLAND — A new study published in the Proceedings of the National Academy of Sciences of the U.S. claims that the massive Greenland ice sheet is on the brink of a major tipping point.

The study's authors say enough ice to raise the global sea level by more than a meter is probably already doomed to melt from Greenland in the next few decades. Here are the details:

The Guardian reports that a new study of the ice-sheet heights and melting rates in Greenland's Jakobshavn basin shows that the Greenland ice sheet is on the brink of a major tipping point.

Rising temperatures caused by the climate crisis have already seen trillions of tons of Greenland's ice pour into the ocean.

Melting its ice sheet completely would eventually raise the global sea level by seven meters.

The prime suspect for this surge in melting in Greenland is a vicious circle in which melting lowers the height of the ice sheet, exposing it to the warmer air found at lower altitudes, which causes further melting.

Study co-author Niklas Boers says the findings show destabilisation of this ice sheet is under way, and might already have passed the tipping point.

Boers said the findings suggest there will be substantially increased melting in the near future.

Ice equivalent to one to two metres of sea level rise was probably already doomed to melt, though this would take centuries, and melting the whole ice sheet would take a millennium.

Scientists say any large-scale melting of the Greenland ice sheet would have long-term global consequences, beyond rising sea levels.

It could halt the Gulf Stream ocean current, with potential knock-on effects on the Amazon rainforest and tropical monsoons.