The Greenland ice sheet is melting faster today than at any point in the last 350 years, according to a new study published in the journal Nature. The research is the first continuous, multi-century analysis of melting and runoff on the ice sheet, one of the largest drivers of sea level rise globally.
Lead by glaciologist and climate scientist Luke Trusel of Rowan University, a team of U.S. and European researchers analyzed more than three centuries of melt patterns in ice cores from western Greenland. They then linked this historical data to modern observations of melting and runoff across the entire ice sheet, creating a timeline dating back to 1650.
"From a historical perspective, today's melt rates are off the charts," Sarah Das, a glaciologist at Woods Hole Oceanographic Institution and co-author of the new study, said in a statement. "We found a 50 percent increase in total ice sheet meltwater runoff versus the start of the industrial era, and a 30 percent increase since the 20th century alone."
According to the analysis, melting on the Greenland ice sheet sped up in the mid-1800s, shortly after the onset of industrial-era warming in the Arctic. Over the last 20 years, melt intensity has increased 250 to 575 percent compared to pre-industrial melt rates. Across the ice sheet, melting was more rapid in 2012 than any other year and the most recent decade included in the ice core-analysis, 2004-2013, experienced "a more sustained and greater magnitude of melt than any other 10-year period" in the 350-year record, the scientists wrote.
"The melting is not just increasing — it's accelerating," Trusel told Nature. "And that's a key concern for the future."
The Greenland ice sheet is the largest single contributor to global sea level rise today, adding 72 cubic miles of meltwater to the world's oceans every year. The ice sheet has the potential to raise global sea levels by 23 feet if it melts in its entirety.