Researchers from the Geological Survey of Denmark and Greenland observed changes in the volume of the ice sheet in and around Greenland and found that meltwater runoff was the main driver. Using a “well-established theory”, scientists were able to determine that around 3.3% of the Greenland ice sheet – the equivalent of 110 trillion tonnes of ice – will inevitably melt as the ice sheet reacts to the changes that have already happened.
Sea level rise from this melted ice will occur “regardless of any foreseeable future climate trajectory in this century”, according to lead author Jason Box, a scientist with the Geological Survey of Denmark and Greenland. “That water is technically already under the bridge.”
Although the authors did not specify a timeline, they predict that sea level change may occur by the end of the century.
The research was only intended to estimate a minimum, or “a very conservative lower bound”, of sea level rise from melting Greenland, “and in the virtually certain event that the climate continues to warm, l sea level engagement is only increasing,” Box said. .
Massive ice caps can melt quickly when the air temperature is warm, but warmer ocean water also erodes the ice cap at the edges.
Greenland contains enough ice that, if it all melted, it could raise sea levels around the world by about 25 feet. The researchers point out that a sea level rise of 20 feet does not mean it will rise evenly around the globe, leaving some places devastated while sea levels drop in others.
When places like Greenland lose ice, for example, they also lose the gravitational pull of ice on water, which means sea levels in Greenland drop as levels rise elsewhere, a said William Colgan, senior researcher at the Geological Survey of Denmark and Greenland. The pace of this change is the problem, Colgan told CNN’s Bill Weir during a research trip in the summer of 2021.
“It will be really difficult to adapt to such rapid changes,” said Colgan, standing at Greenland’s Jakobshavn glacier, where the fjord is full of ice that has broken off from the glacier.
Before human-caused climate change occurred, temperatures near 32 degrees Fahrenheit in Greenland were unheard of. But since the 1980s, the region has warmed at around 1.5 degrees per decade – four times faster than the global rate – making it all the more likely that temperatures will cross the melting threshold.
The amount of ice that melted in Greenland between July 15 and 17 alone – 6 billion tons of water per day – would be enough to fill 7.2 million Olympic swimming pools, according to data from the US National Snow and Ice Data. Center. .
CNN’s René Marsh and Angela Fritz contributed to this report.