Researchers from the Geological Survey of Denmark and Greenland observed changes in ice sheet volume in and around Greenland and saw that meltwater runoff was the main driver. Using “well-established theory,” scientists were able to determine that about 3.3 percent of the Greenland ice sheet — equivalent to 110 trillion tons of ice — will inevitably melt as the ice sheet reacts to changes that have already occurred .
Sea-level rise from this melting ice will occur “regardless of any predictable future climate path this century,” according to lead author Jason Box, a scientist at 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 the change in sea level could occur between now and the end of the century.
The research was aimed solely at estimating a minimum or “very conservative lower bound” of sea-level rise from melting in Greenland, “and in the almost certain case that the climate continues to warm, sea-level sequestration only increases,” Box said. .
Huge ice sheets can melt quickly when the air temperature is warm, but warmer ocean water also erodes the sheet around the edges.
The findings follow a 2022 sea level rise report released earlier this year by the National Oceanic and Atmospheric Administration, which found that US coasts could expect sea level rise of 10 to 12 inches the next 30 years. This will cause high-tide flooding to occur more than 10 times more often and allow storms to spread further inland, according to the report.
Greenland has enough ice that if it all melted, it could raise sea levels by about 25 feet worldwide. The researchers point out that a 20-foot sea level rise doesn’t mean it will rise evenly around the world, leaving some places in ruins as sea levels fall in others.
As places like Greenland lose ice, for example, they also lose the ice’s gravitational pull on water, meaning Greenland’s sea level falls as it rises elsewhere, said William Colgan, a senior researcher at the Geological Survey of Denmark and of Greenland. The pace of that change is the problem, Colgan told CNN’s Bill Weir during a research trip in the summer of 2021.
“It’s going to be very difficult to adapt to change so quickly,” Colgan said, standing on Greenland’s Jakobshavn Glacier, where the fjord is filled with ice that has broken off from the glacier.
Before human-induced climate change began, temperatures near 32 degrees Fahrenheit in Greenland were unheard of. But since the 1980s, the region has warmed by about 1.5 degrees per decade — four times faster than the global rate — making it increasingly likely that temperatures will cross the melting threshold.
Several days of unusually warm weather in northern Greenland recently caused rapid melting, with temperatures nearing 60 degrees — 10 degrees above normal for this time of year, scientists told CNN.
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-sized swimming pools, according to data from the US National Snow and Ice Data Center.
Global scientists have said that the trends in which climate change is accelerating are quite clear, and that unless emissions are curbed immediately, many more extreme melting events will continue to occur more intensely and frequently.
CNN’s René Marsh and Angela Fritz contributed to this report.
