Scientists have found that part of the Greenland ice sheet completely melted in the early Holocene – at temperatures comparable to forecasts for the end of the 21st century. The discovery heightens the risks of accelerated sea level rise in the future.
Today this dome exists again and reaches a thickness of about 500 meters. New research shows that with moderate warming, it has already melted to the ground once. The conclusions are based on core analysis, drilled to the underlying rocks under the dome. The researchers studied sediment beneath the ice and determined when it was last exposed to sunlight. The results showed that the surface was opened about 7 thousand years ago, which is only possible with the complete disappearance of ice.
According to scientists, during that period summer temperatures in Greenland were 3–6 degrees Celsius higher than today. Climate models predict similar warming by 2100. This means that modern climatic conditions are approaching those under which the ice dome could no longer survive. If it melts, the level of the world’s oceans could rise by more than 7 meters.
The authors emphasize that it is not yet known how long temperatures must remain high to cause complete melting of massive glaciated areas. But Greenland’s glaciers are sensitive to even moderate warming. Observations from the past provide important guidance for assessing future risks and highlight the importance of climate action in the coming decades.
Source: Live Science
Photo: Jason Briner
