Over the next few days, Greenland is expected to roast as the weather system that fueled Europe’s second record-smashing heatwave of the summer marches north and west. Scientists are warning of what could be a near-record melt-out across the northern ice sheet’s surface, one that may also impact sea ice surrounding the island.
It’s just the latest manifestation of the high fever gripping the Arctic in a year where sea ice is running near record-low levels and Greenland has already sweated through one major melt event in June. And whether or not 2019 goes down as an all-time record year for Arctic ice losses on land or at sea—both of which experts say are possible—years of extreme ice demise like this one are consistent with a pattern of rapid transformation taking place up north due to human-caused climate change.
“This fits in exactly with our expectations of long-term climate change,” Zack Labe, a climate scientist and PhD candidate at the University of California Irvine, told Motherboard, speaking of this year’s ice conditions.
The heat wave currently bearing down on Greenland comes courtesy of the same weather pattern that caused Western Europe to experience its hottest day on record on Thursday—a strong, high pressure air mass associated with mild temperatures. That weather system migrated over Scandinavia this weekend, shattering heat records in southern Finland and causing many places in Norway to experience what the national meteorological service described as “tropical nights” on Sunday.
Now the hot weather is making a run to the west. Weather models predict temperatures across Greenland could rise as much as 10 degrees Celsius (18 degrees Fahrenheit) above normal on Tuesday and Wednesday, with extreme heat engulfing a vast swath of the ice sheet. Twila Moon, a glaciologist at the National Snow and Ice Data Center, told Motherboard current forecasts suggest this is likely to be Greenland’s second-largest melt event in terms of aerial extent since record-keeping began in the 1950s.
It has already been a sad year for ice in the Arctic. Ruth Mottram, a glaciologist with the Danish Meteorological Institute, told Motherboard that Greenland saw an unusually dry winter, meaning less new snowfall accumulated than usual. When the summer melt season got going, the snow that had accumulated started to vanish, exposing bare glacier ice. Bare ice is darker than snow, meaning its reflectivity, or albedo, is lower and it absorbs more heat, which hastens the melt along.
“So that’s a feedback,” Mottram said.
In mid-June, a spate of exceptionally warm weather triggered a melt event that encompassed nearly half of Greenland’s ice at its peak, something that’s very unusual so early in the year. According to the National Snow and Ice Data Center, some 80 billion tons of ice were lost over the course of the entire event from June 11-20.
The ice losses have continued apace throughout July as albedo along the ice sheet’s margins, where the melting is highest, veered into record-low territory. Mottram said that as of Sunday, Greenland had lost 177 billion tons of ice this month—far above what scientists would typically expect even in the peak of summer. And she was “sure there would be elevated melting” across Greenland again this week. Mottram cautioned, however, that the incoming weather system is also bringing a lot of moisture, and snowfall at higher elevations could counterbalance some of the losses.
2012 currently holds the record both for largest individual melt event and largest ice losses in a single year across Greenland. While it’s too early to say for sure, Moon said that “if we see the full extent of the melt event that we expect, we’ll be on course to have an amount of ice loss that might rival or even set a new record” this year.
The warm weather may also have some impact on the sea ice still hanging around Greenland’s northeastern coast. Then again, there isn’t much there. In fact, sea ice across the Arctic Ocean is running at or near record low levels right now, and as with Greenland, there’s a chance of eclipsing an all-time low set in September 2012.
Mark Serreze of the National Snow and Ice Data Center told Motherboard that will very much depend on the weather patterns over the rest of the summer. But, he added, “every day that goes by that we continue at a record low increases the probability that we’re gonna set a new record low.”
Record-setter or no, Arctic sea ice losses have been dramatic this year, particularly in the Laptev Sea north of Russia and in the Beaufort and Chukchi Seas north of Alaska, where the ice is currently in a state of “collapse” as state climatologist Rick Thoman put it on Twitter. Labe worried about what the diminished state of Alaska’s sea ice would mean for the freeze-up that occurs every fall.
“I have to wonder how much it’s going to affect and delay freeze up this fall,” he said. “There’s so much open water.”
Of course, the melting that’s occurring this year, and that which took place in 2012, can’t just be seen as one-off events. As Labe noted, these spikes are part of a longer-term pattern of rapid change taking place across the Arctic, where temperatures are rising at about twice the globally-averaged rate. And that has consequences for the entire planet.
Ice losses from Greenland have already caused global sea levels to rise about half an inch, and the rate of rise is accelerating as the ice melts faster. A study published in June found that if emissions continue to climb at their present rate, Greenland’s melting could raise sea levels by up to a foot by the end of the century. If all of Greenland were to melt, global sea levels would rise by about 23 feet.
Arctic sea ice loss doesn’t contribute to sea level rise. But its dramatic decline over the past 30 years is having a host of other impacts, from hastening coastal erosion to disrupting indigenous hunting and fishing activities that rely on the ice to alterning the the Arctic food chain from its base. What’s more, as shiny, reflective surfaces gives way to darker ocean water, the Arctic is absorbing more of the Sun’s energy, amplifying warming and hastening melt. There may even be connections between this Arctic amplification and the jet stream that can influence weather patterns further south.
What happens to the Arctic’s ice—this week, this year, and over the decades to come—will be felt far beyond its melting, receding edges.
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