Thanks to the human-made global climate crisis, Greenland's mile-thick ice sheet is melting at the fastest rate recorded for centuries, according to new research published in Nature on Wednesday—and the implications for sea-level rise have scientists more than concerned.
"Climate change is not a thing of the future. It's here now. It's clear."
—Dr. Luke Trusel, lead author
"The melting of the Greenland ice sheet is off the charts today," declared Dr. Luke Trusel, a professor of geology at Rowan University and lead author of the report.
"What we found with our ice cores is that it's melting today more than at any time within at least the last three and a half centuries," he said, "and probably, melting more today than any time in the last seven to eight thousand years."
#Greenland's ice is melting more rapidly in recent decades than at any point in at least the last 350 years, and likely more than any time in the last 7,000-8,000 years. Runoff over the last 20 years is 50% greater than pre-industrial, and 33% greater than the 20th century alone. pic.twitter.com/WTmAEXNLk1
— Luke Trusel (@highlatitude) December 5, 2018
Given that melting ice is significantly fueling sea-level rise, Trusel concluded: "How much Greenland melts matters. It matters to everyone living near a coastline. Climate change is not a thing of the future. It's here now. It's clear."
Trusel's team of international researchers analyzed ice cores extracted from Greenland, a massive island wedged between the Arctic and Atlantic Oceans. A primary takeaway from the study, Trusel said in a statement, is the speed of melting, especially over the past 25 years.
"It's not just increasing, it's accelerating," he explained. "That's a key concern for the future."
These latest findings, as Nature pointed out, "bolster a study published in March that found that West Greenland is melting faster than it has in at least 450 years." Erich Osterberg of Dartmouth College, who co-authored the earlier study, said the new paper expands that record to the whole ice sheet.
The new analysis, the journal noted, also suggests that thawing and refreezing on the ice sheet's top layer has led to
a vicious cycle: bright snow is replaced by darker patches of ice that absorb more heat from the sun, further warming Greenland. The melting and freezing cycle also makes ice below the surface less permeable, so more runoff is shunted to the ocean rather than trickling down into the ice sheet.
Runoff from Greenland's ice sheet hit a 350-year high in 2012, when it dumped—according to Nature—240 million Olympic swimming pools worth of water into the ocean.
"It's one more nail in the coffin of climate denial."
—Josh Willis, NASA
Despite mounting research on anthropogenic global warming and alarm among scientists about the closing window to avert climate catastrophe, the Trump administration and Republicans in Congress continue to push for fossil-fuel friendly policies and roll back regulations meant to curb planet-warming emissions.
Federal scientists, meanwhile, are among those warning about the climate crisis. Responding to Trusel's research, NASA oceanographer and Greenland expert Josh Willis told Mashable, "It's one more nail in the coffin of climate denial." He added, "I don't know how many more nails we need."
The new findings—also published on a publicly-accessible website—and experts' subsequent warnings follow a record-setting warm winter in the Arctic earlier this year that left researchers "staggered" and culminated in the area's oldest and thickest sea ice, off the northern coast of Greenland, breaking up for the first time on record.