The heat wave that smashed records in Europe last week has now reached Greenland, where it is causing the world's second-largest ice sheet to endure one of its most exteme melting events ever documented, leading experts to express fresh concerns about what the global climate crisis will mean for future sea level rise.
Josh Willis, a NASA scientist who researches Greenland's melting glaciers, toldMashable on Thursday that "it's no surprise that Greenland keeps setting records for melt and high temperatures."
"The entire planet is getting warmer, but the Arctic is warming faster than every place else," said Willis. "We are watching these huge ice sheets shrink every year now, and there is no sign of that stopping any time soon."
Sharing updates on Greeland's temperature and ice melt records from this week that Xavier Fettweis--a polar scientist at the University of Liege in Belgium--posted to Twitter Thursday, meteorologist and science writer Eric Holthaus declared in a tweet, "We are in a climate emergency."
Holthaus also shared his latest piece for Rolling Stone, published ahead of the heat wave's peak on Thursday.
In the Rolling Stone article, Fettweis told Holthaus that "this melt event is a good alarm signal that we urgently need [to] change our way of living," and suggests that projections from the U.N.'s Intergovernmental Panel on Climate Change (IPCC) "are too optimistic in the Arctic."
Fettweis, in an interview with InsideClimate News, explained that "the current melt rate is equivalent to what the model projects for 2070, using the most pessimistic model," According to NASA, the global sea level will rise 17 to 23 feet if Greenland's ice sheet melts entirely.
Ruth Mottram, a climate scientist with the the Danish Meteorological Institute, drew a similar conclusion.
"By mid-to-end of the century is when we should be seeing these melt levels--not right now," she told InsideClimate News. "[The models] are clearly not able to capture some of these important processes."
"Somewhere between 1.5 and 2 degrees [Celsius] there's a tipping point after which it will no longer be possible to maintain the Greenland Ice Sheet," Mottram added. "What we don't have a handle on is how quickly the Greenland Ice Sheet will be lost."
That uncertainty has caused some observers, such as Holthaus, to express hope that humanity will act to address planet-warming emissions with the goal of preventing climate catastrophe. He wrote Wednesday for Rolling Stone:
As daunting as this is, the latest science on Greenland also points to a window of hope: Greenland's meltdown is not yet irreversible. That self-sustaining process of melt-begetting-more-melt would kick in at around 1.5 or 2 degrees Celsius of global warming. That means whether or not Greenland's ice sheet melts completely is almost entirely in human control: A full-scale mobilization--including rapidly transforming the basis of the global economy toward a future where fossil fuels are no longer used--would probably be enough to keep most of the remaining ice frozen, where it belongs.
But it's not just future sea level rise that has experts alarmed--it's also what is happening currently.
"The fate of Greenland's ice sheet is of critical importance to every coastal resident in the world, since Greenland is already the biggest contributor to modern-day sea level rise," The Washington Postreported Wednesday.
Marco Tedesco, a climate scientist at Columbia University, told the Post that because of surface melting and a lack of snow on the ice sheet this summer, "this is the year Greenland is contributing most to sea level rise."
Just this week, as Holthaus detailed in Rolling Stone, "Greenland will lose about 50 billion tons of ice, enough for a permanent rise in global sea levels by about 0.1mm. So far in July, the Greenland ice sheet has lost 160 billion tons of ice--enough to cover Florida in about six feet of water."
This week's historic heat wave in Greenland has drawn some comparisons to regional ice loss records from 2012. As Common Dreams reported Tuesday, experts have pointed out that this summer Greenland is experiencing consistent melting rather than bursts of melting observed seven years ago. However, there are also some similarities.
"Like 2012, this melt event reached the highest elevations of the ice sheet, which is highly unusual," Thomas Mote, a professor of geography at the University of Georgia, told the Post Thursday. "Both our satellite observations and the ground-based observations from summit indicated melt on Tuesday."
"The event itself was unusual that the warm air mass came from the east, and appears to be a part of the air mass that caused the record-breaking heat wave in Europe," Mote said. "Most of our extreme melt days on the Greenland Ice Sheet are associated with warm air masses moving from the west and south. I cannot recall an instance where we saw such extensive melt associated with an air mass coming from Northern Europe."