Greenland. Progressive loss of ice shelves. Without them, we will face a disaster

In October, a report by the British Antarctic Survey was published online, which showed that The melting of Antarctica cannot be completely stopped – the process has simply gone too far. As a study published in Nature Communications shows, ice loss has also taken on alarming dimensions in the northern hemisphere.

Scientists from France, Denmark and the United States analyzed the state of ice shelves – parts of the ice sheet that float on water – in northern Greenland. Using satellite data and climate models, they tracked changes in ice extent and thickness over recent decades, as well as their impact on neighboring glaciers.

The results showed that since 1978, the northern Greenland shelves have lost about 35 percent of their volume. Of the eight giant masses of ice, five have survived to this day, and they are also becoming smaller, weaker and cracked. The disintegration processes are driven by increasingly warmer waters, washing away the ice structures and melting them from below.

“These are the last shelves of the Greenland ice sheet,” said Romain Millan of Universite Grenoble Alpes, the study’s lead author.

As the authors explained, although the melting of shelves themselves does not raise sea levels and oceans, it can cause a chain reaction – they act as natural barriers stopping water from escaping from glaciers into the ocean.

This is particularly concerning because ice loss from Greenland is responsible for about 17 percent of global sea level rise between 2006 and 2018. Once one of the largest shelves, Zachariae Isstrom collapsed between 2003 and 2012, causing meltwater to flow from the neighboring glacier into the ocean. It loses 18 billion tons of ice every year – for comparison, it takes about 360 billion tons of ice to raise sea levels by a millimeter.

“What will happen to the poles and sea levels in the future depends on the decisions politicians make to reduce greenhouse gas emissions,” Millan added.