This extreme melting came during the hottest month ever recorded
, as an intense heat wave washed over Europe
then wafted over to Greenland.
Low-elevation ice began to melt and form pools across the ice sheet, and those pools' dark colors absorbed more sunlight, which further melted the glacier around them and exposed more ice to hot air.
Ice melts during a heatwave in Kangerlussuaq, Greenland on August 1, 2019.Caspar Haarloev from "Into the Ice" documentary via Reuters
Similarly above-average melting was observed in Switzerland — glaciers there lost 800 million tons of ice
during the heat waves of June and July. Alaska also saw record sea-ice melt
All that melting exposes more permafrost
: frozen soil that releases powerful greenhouse gases when it thaws. That's happening faster than scientists predicted
. The release of those gases leads the planet to warm even more, which accelerates more ice melt.
Last month was an anomaly for Greenland, but it could be the new normal by 2070 if humans don't curb greenhouse-gas emissions, according to climate models simulated by Xavier Fettweis
, a climate researcher at the University of Liège in Belgium.
"By mid to end of the century is when we should be seeing these melt levels — not right now," Ruth Mottram, a climate scientist at the Danish Meteorological Institute, told Inside Climate News
. "[The models] are clearly not able to capture some of these important processes."
Melting ice in Greenland raises sea levels
Greenland's ice melt has already raised sea levels more than 0.5 inches since 1972. Half of that occurred just in the last eight years, according to a study
published in April.
Ice melt forms gushing white water in Kangerlussuaq, Greenland on August 1, 2019.tk
At this rate, the entire Greenland ice sheet could melt
within 1,000 years, causing up to 23 feet of sea level rise.
But Mottram isn't so sure about that projected timeline.
"Somewhere between 1.5 and 2 degrees, there's a tipping point after which it will no longer be possible to maintain the Greenland Ice Sheet," she told Inside Climate News
. "What we don't have a handle on is how quickly the Greenland Ice Sheet will be lost."
Greenland's ice is already approaching that tipping point, according to a study
published in May. Whereas melting during warm cycles used to get balanced out by new ice forming during cool cycles, warm periods now cause significant meltdown and cool periods simply pause it.
That makes it difficult for the ice sheet to regenerate what it's losing.