In a study published on Tuesday in Nature Communications, a group of American and Danish scientists described the precipitous drop in their volume.
What they found is that since 1978, roughly 400 billion tons of floating ice around Greenland has disappeared, accounting for 35% of the total floating sea ice around the massive island.
“The implications of these findings are profound, as they reveal a direct connection between ice shelf changes and the dynamics of Greenland’s glaciers,” Stef Lhermitte, a scientist specializing in satellite observations of glaciers at the Delft University of Technology in the Netherlands who was not involved in the study, told US media.
“The retreat of grounding lines and increased ice discharge are clear signs of a weakening ice shelf system,” Lhermitte added.
The massive ice shelves are by themselves capable of triggering a rise in ocean levels of roughly 3.6 feet if they totally melted, which would put in danger hundreds of millions of people who live in coastal cities and regions.
However, the ice shelves play a highly important role in protecting the vast Greenland Ice Cap from ocean waters, which could cause that ice cap to begin melting a lot quicker. The ice cap is nearly a mile thick and covers the whole interior of the island, and if it melted, it could raise sea levels by an astonishing 23 feet.
Scientists say the planet must be limited to a global increase of less than 1.5 degrees Celsius by the end of the century to avoid such a catastrophe. However, that could come a lot sooner than expected: a recent study found the average temperature on Earth over the last decade was about 1.1 degrees Celsius higher than pre-industrial temperatures.