A new study indicates Greenland’s ice sheet has been melting at a fast pace. The melting of the ice sheet began to increase during the 19th century, and now it has increased dramatically. Now new research published in the journal Nature indicates there’s no sign of it decreasing. Researchers also provided more firm evidence of how much the surface around the Arctic has been melting due to rapid climate change.
“Melting of the Greenland Ice Sheet has gone into overdrive. As a result, Greenland melt is adding to sea level more than any time during the last three and a half centuries, if not thousands of years,” lead author and Rowan University glaciologist Luke Trusel said in a statement. “And increasing melt began around the same time as we started altering the atmosphere in the mid-1800s.”
The melting of Greenland’s ice sheet is one of the main culprits behind the rising sea levels around the globe. Icebergs are separating from larger glaciers and ending up in the ocean.
“Rather than increasing steadily as climate warms, Greenland will melt increasingly more and more for every degree of warming. The melting and sea level rise we’ve observed already will be dwarfed by what may be expected in the future as climate continues to warm,” Trusel said.
To study the melting of Greenland’s ice sheet, the team used a large drill to collect ice cores from sites more than 6,000 feet above sea level on the ice sheet and a nearby ice cap. The team focused on these high elevations so they would be able to study records of the melting’s intensity of the melting dating all the way back to the 17th century.
They found that the surface of Greenland’s ice sheet melts on summer days. They also found higher intensities of melting at lower elevations. The team combined their results from different ice cores with satellite observations of the melting and modern climate change models. The team found that not only did their method show the thickness of the annual melt layer but also how much melting occurs at certain coring sites and across the whole of Greenland.
This approach helps researchers update their tracking record, which indicates that ice sheets are melting at a faster pace than previously thought. The satellites used to study ice sheet melting around the world haven’t been around long enough to capture a complete picture of the melting process. Ice core records provide critical historical context because the satellites have only been recording measurements since the late 1970s, according to study co-author and graduate student Matt Osman of the MIT-WHOI Joint Program.
“We have had a sense that there’s been a great deal of melting in recent decades, but we previously had no basis for comparison with melt rates going further back in time,” Osman said. “By sampling ice, we were able to extend the satellite data by a factor of 10 and get a clearer picture of just how extremely unusual melting has been in recent decades compared to the past.”
“To be able to answer what might happen to Greenland next, we need to understand how Greenland has already responded to climate change,” Trusel added. “What our ice cores show is that Greenland is now at a state where it’s much more sensitive to further increases in temperature than it was even 50 years ago.”
One way or another, scientists must figure out how to stop the rapid melting of Greenland’s ice sheet and other Arctic and Antarctic ice sheets before our planet is beyond saving.
