NASA scientist Josh Willis flew over Greenland this week, and gazed at a sprawling polar world of melted ice and dark pools of water.
In mid-August, a potent heat wave melted large swathes of the Greenland ice sheet, which is three times the size of Texas. It's a vivid sign of changing times, and climes. In recent decades, Arctic scientists have observed record-breaking melt events in Greenland, which result in water pouring into the sea — and contribute to sea level rise. So far in 2021, the island's melted area (8.2 million square miles) is way above the 1981 to 2010 average-to-date, by some 1 million square miles.
"What’s important to know is that all the big melt years have happened in the last two decades or so," Willis, who researches ice sheets and oceans at NASA's Jet Propulsion Laboratory, told Mashable between Greenland flights. "That’s because the melt in Greenland is getting more extreme with every decade due to human interference with the climate."
Arctic scientists have found that, over the last couple decades, Greenland is melting faster than it has in at least 350 years. The ice sheet is shrinking.
As the climate warms, and heat waves become increasingly extreme, major melting events are even happening at the island's typically frigid summit. This summer, a couple of serious heat waves hit Greenland, noted Ted Scambos, an ice sheet expert at the University of Boulder Colorado who has no involvement with the NASA mission. It even rained atop Greenland, at 10,551 feet. Scientists had never observed rain there before.
Before 1995, centuries would go by between major melt events at the summit, explained Scambos, referencing evidence from cores of ancient Greenland ice. Now, it's occurred a handful of times in recent decades, he said.
The photos below were taken from a big DC-3 propellor plane (an "Indiana Jones plane") as it buzzed over southwestern Greenland. The dark blue areas show pools of meltwater. The lighter blue areas are "snow swamps" where the snow is saturated with water, and this melt is usually draining downhill in vast rivers towards the ocean. The elevations where melt events occur on Greenland's ice sheet have been slowly creeping uphill over the last three decades, explained Scambos.
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NASA's Willis and his team were not actually flying around to survey the melting on the mainland. As part of NASA's Oceans Melting Greenland mission, they're currently dropping sensors into the seas around the giant island's coast, to measure how the relentlessly warming ocean is eating away at some of the largest glaciers on Earth. (The melting along the coasts is significant, and expected to amplify as the seas continue warming.)
But while flying over Greenland en route to pick up more equipment, Willis and his team were "stunned" by Greenland's current melt. Their captain, Jim Haffey, said he'd never seen this scale of melting before.
"He’s been flying over the ice sheet for 25 years and he’s seen pretty much everything," said Willis. "As a scientist, I always want to look at the data before taking someone’s word on what they’ve seen. This time, the records told the same story as the pilot."
Other Arctic scientists recently spotted vast plains of meltwater over Greenland too, as the video taken by a scientist with Denmark's Monitoring of the Greenland Ice Sheet program shows:
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Both in late July and mid-August of this year, a melt event of over 800,000 square kilometers (309,000 square miles) in extent occurred on Greenland, according to the National Snow and Ice Data Center, an institution that researches polar and ice regions on Earth. In a single summer, multiple events of such extreme melting have only happened twice on record: In 2021 and 2012 (the current record melt year).
Climate change is about trends, and Greenland's continued pattern of more frequent large-scale melting is representative of extremes becoming more extreme as the planet continues warming. Greenland's accelerating ice loss is similar to more severe deluges, more intense droughts, and an increase in the frequency and extent of severe, inferno-like wildfires.
The melting of the planet's two largest ice sheets, in Greenland and Antarctica, has momentous global implications. In the past 30 years, ice loss in Greenland and Antarctica has already increased sixfold. These remote, ice-clad lands deeply concern earth scientists: This century alone, ice sheet and ocean researchers expect sea levels to rise by another 1.5 to 2.5 feet.
But even more sea level rise is already afoot for many future generations (though, crucially, fewer carbon emissions will mean less sea level rise). These sprawling masses of ice hold the potential for many feet of sea level rise in the coming centuries, and beyond.
