Using an ice-sheet model, researchers found that the most substantial pre-industrial rates of ice loss from the Greenland sheet, up to 6,000 billion metric tons per century, took place in the early Holocene period, which began nearly 12,000 years before the present.
Simulations of future mass loss from the southwestern Greenland ice sheet predict that the mass lost in the 21st century will be between 8,800 and 35,900 billion metric tons, which is higher than the maximum loss rates over the past 12,000 years.
The researchers based their analysis on past records of the ice sheet’s movements and by analyzing the chemical composition of boulders that sit on former edges of glaciers or ice sheets, which are known as moraines. Through this analysis, the researchers were able to identify when ice retreated from the boulders.
The researchers thus concluded that the rate of mass loss from the Greenland ice sheet this century will exceed the Holocene rates.
Unless carbon pollution caused by burning fossil fuels is significantly reduced, these total sea level rises will become the “new normal,” lead author Jason Briner, a professor of geology at the State University of New York at Buffalo, told AFP. However, according to the researchers’ model, it’s too late to prevent the current century from taking its toll on the Greenland ice sheet.
"No matter what the future carbon emissions are going to be, the Greenland ice sheet will lose more ice this century than even during the warmest of times during the past 12,000 years," he added.
This is not the first study to show that Greenland is losing ice at a rapid rate. A study published last year in the Proceedings of the National Academy of Sciences shows that Greenland’s glaciers released around 286 billion tons of ice into the ocean between 2010 and 2018, compared to 51 billion tons between 1980 and 1990.
An August study also found that 28 trillion metric tons of ice disappeared from Earth’s surface between 1994 and 2017. The research, conducted by scientists from the University of Leeds, the University of Edinburgh and University College London, also found that sea-level rises could reach a meter by the end of the century.
Many experts have warned that the melting of ice can decrease the Earth’s ability to reflect solar radiation into space, which results in the additional absorption of heat by the sea and soil underneath the ice and increased warming of the planet.
