The melting of the Antarctic ice sheet can still be stopped



by LORENZO CIOTTI

The melting of the Antarctic ice sheet can still be stopped

According to a recent study published in Nature Communications, it would still be possible to stop the melting of the Antarctic ice sheet. The study investigated the climatic dynamics affecting the rate at which West Antarctica's glaciers are retreating, revealing that decisive action to reduce global emissions in all likelihood can still prevent their final collapse in decades, and centuries, to come.

The West Antarctic ice cap, unlike the eastern one, does not in fact rest on the emerged lands of the continent, but is instead supported by the bedrock that lies below sea level. It is therefore susceptible to what scientists describe as marine ice sheet instability.

A phenomenon caused by the influx of hot water into the areas bordering the margins of the glacier, and which indicates the presence of a point of no return, beyond which the melting of the ice caused by climate change is destined to inexorably cause its collapse, independent, at that point, of climatic conditions.

Analyzing satellite data, the new study found significant differences in how the West Antarctic ice sheet has evolved since 2003, observing both a slowing in the pace of retreat in the Amundsen Marine Sector, an area of West Antarctica overlooking the Pacific Ocean, and an acceleration in the nearby marine sector of Bellingshausen, closer to the Antarctic peninsula.

The team, which involved researchers from the University of Cambridge, the University of Edinburgh and the University of Washington, explained: “Doubts remain about the extent to which ongoing climate change still drives ice losses along the entire coast of West Antarctica.

When the prevailing westerly winds are stronger, more of the deeper, warmer ocean water reaches the surface and increases the rate of ice melt. But between 2003 and 2015, off the Amundsen marine sector, the intensity of the prevailing westerly winds decreased, limiting the intrusion of deeper and warmer water, with a notable change in the corresponding behavior of glaciers across the region: a sharp reduction in the rate of melting and loss of ice mass.

This system is the key pattern of atmospheric circulation in the region and its location in the low-pressure center, near which the changes in the intensity of the winds are greater, it is typically found off the coast of the same name for most of the year.

Oceanic and atmospheric still really matter in West Antarctica. This means that the collapse of the ice sheet is not inevitable. Everything will depend on how the climate changes in the coming decades, on which we can have a positive influence by reducing greenhouse gas emissions."