An international group of scientists led by the European Space Agency has published a study in the journal Scientific Data. According to data from 27 satellites and 45 independent scientific studies, the ice sheets of Greenland and Antarctica have lost about 12,5 trillion tonnes of ice since the year 1979.
That amount is enough to cover the continental part of the United States with a layer of ice about 1,5 metre thick. The melted ice has turned into nearly 3 quadrillion gallons of water and has raised global sea level by roughly 3,1 cm.
The study covers the period from the year 1979 for Antarctica and from the year 1972 for Greenland. Previously, scientists relied only on European satellite data from the 1990s, but the addition of NASA data made it possible to extend the record.
Ice losses are accelerating with every decade, most noticeably in the 2010s. In Greenland, annual losses grew from about 60 billion tonnes in the 1980s to 264 billion tonnes in the 2010s.
About 83–84% of the losses are linked not to warming air, but to warmer ocean waters that undermine the ice from below and from the sides. This accelerates the flow of glaciers into the ocean.
The lead author of the study, Ines Otosaka of Northumbria University, notes a clear link to climate change. Co-author Eric Rignot of the University of California, Irvine, emphasises: the ice sheets are melting quickly, sea level is rising and increasing the vulnerability of coastal regions.
Every 0,85 cm of sea-level rise puts an additional 2–3 million people at risk of flooding each year. How will further acceleration of melting affect the millions of inhabitants of low-lying coasts?
In the years 2020–2023 there was a temporary slowdown, but scientists attribute this to short-term weather factors rather than to a long-term trend. The study shows that glacier dynamics respond to ocean warming, and the trend towards increasing losses persists.
