Widespread ice losses from Greenland have resulted in nearly a foot of global sea-level rise expected to occur in the near future — and new research suggests there’s no stopping it even if the world stopped releasing planet-warming emissions. today.
A study, published Monday in the journal Nature Climate Change, found that the overall loss of ice from the Greenland ice sheet will trigger at least 25.4 centimeters of sea level rise, regardless of climate warming scenarios. .
That’s generally the same amount that the global seas have already risen in the last century from Greenland, Antarctica, and thermal expansion (when ocean water expands as it warms) combined.
Researchers from the Geological Survey of Denmark and Greenland have observed changes in the volume of the ice sheet in and around Greenland and have seen that runoff from melt water has been the main factor.
Using “well-established theory,” scientists were able to determine that about 3.3% of Greenland’s ice sheet — equivalent to 110 trillion tons of ice — will inevitably melt as the ice sheet reacts to the changes that have already occurred. occurred.
Sea level rise from this melting ice will occur “regardless of any foreseeable future climate path this century,” according to lead author Jason Box, a scientist at the Geological Survey of Denmark and Greenland. “This water is technically already under the bridge.”
While the authors do not specify a timeline, they do predict that sea level change could occur between now and the end of the century.
The research was only to estimate a minimum, or “a very conservative lower bound”, of sea level rise due to melting in Greenland, “and in the virtually certain event that the climate continues to warm, the sea level commitment will only grows,” Box said.
Massive ice sheets can quickly melt when the air temperature is warm, but warmer ocean water is also eroding the layer around the edges.
The findings come on the heels of a 2022 sea level rise report released earlier this year by the National Oceanic and Atmospheric Administration, which found that US coasts can expect 25 to 30 inches of sea level rise over 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 contains enough ice that, if it all melted, it could raise sea levels around 7.62 meters around the world. Researchers point out that a sea level rise of 6 meters does not mean it will rise evenly across the world, leaving some places devastated while sea levels fall in others.
As places like Greenland lose ice, for example, they also lose the gravitational pull of ice on water, which means that Greenland’s sea level is falling as the level rises elsewhere, said William Colgan. , senior researcher at the Geological Survey of Denmark and Greenland.
The rate of this change is the problem, Colgan told CNN’s Bill Weir during a research trip in the summer of 2021.
“It will be very difficult to adapt to such rapid change,” said Colgan, standing on Greenland’s Jakobshavn Glacier, where the fjord is filled with ice that has broken off the glacier.
Before human-caused climate change, temperatures close to 0°C in Greenland were unknown. But since the 1980s, the region has warmed by about 1.5 degrees Celsius per decade — four times faster than the global rate — making it even more likely that temperatures will exceed the melting threshold.
Several days of unusually hot weather in northern Greenland have recently triggered rapid melting, with temperatures around 15°C — 10°C warmer than 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 a 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 said the trends in which climate change is accelerating are quite clear and that unless emissions are contained immediately, many other extreme melt events will continue to occur with greater intensity and frequency.
With information from René Marsh, CNN and Angela Fritz
Source: CNN Brasil
