“A full AMOC collapse would be a massive, planetary-scale disaster” is how Stefan Rahmstorf, an oceanographer at the University of Potsdam, in Germany, recently put it. “We really want to prevent this from happening.”
Greenland, the world’s largest island, is a Danish territory. Though eighty per cent of the island is covered in ice, there are slender ice-free strips along the coast, and people have inhabited these areas, on and off, for nearly five thousand years. Today, most Greenlanders are of Inuit descent and speak both Danish and Greenlandic. About a third of the island’s fifty-six thousand residents live in the capital, Nuuk; the rest live in towns and villages that hug the fjords.
Kangerlussuaq, which has a population of about five hundred, sits at the end of a particularly long fjord on Greenland’s west coast. The town exists largely because of its runway, which was built by the U.S. Air Force during the Second World War and is now used by Air Greenland as well as by the New York Air National Guard. It has a grocery store, a restaurant overlooking the runway, and a recreation center open only to Guard members and their invited guests. After my stay at Summit, Kangerlussuaq struck me as positively cosmopolitan.
In Kanger, as it is often called, I had arranged to meet Marco Tedesco, a climate scientist at Columbia who studies ice dynamics. When I caught up with him, he was fuming over a rental car. He’d been under the impression that he’d reserved an S.U.V. with off-road clearance; instead, he’d been handed the keys to an ancient Honda. Would the car get stuck in glacial silt, which sometimes acts like quicksand? From Tedesco, I learned a new word in Greenlandic: immaqa, meaning “maybe.”
Tedesco, who grew up near Naples, is tall and lanky, with a shaved head and a collection of tattoos that he has acquired in various places for various reasons. On his right arm is a shower of snowflakes; one is twelve-pointed, which, he told me, is a design very rarely found in nature and which he chose in memory of his mother. On his left arm, the assortment includes a water droplet that he got in Hawaii during a low period—“I felt like a drop in the ocean”—and on his chest are Chinese characters that he translated as “big truth.” Tedesco had brought along a former graduate student of his, Paolo Colosio, who’s now a postdoc at the University of Brescia. When I told them that my husband taught Dante, they both began reciting the opening canto of the Inferno: Nel mezzo del cammin di nostra vita / mi ritrovai per una selva oscura / ché la diritta via era smarrita.
We went to have dinner at the restaurant by the runway. The weather along the coast had been bad, and the place was crowded with people whose flights had been cancelled. (I later heard that Air Greenland is sometimes referred to as Immaqa Airline.)
Tedesco told me that he had become interested in the Greenland ice sheet about twenty years ago. At the time, he was working for NASA, thinking about how to improve the detection of snowmelt via satellite. After a while, he decided that he needed to see the place for himself. “I wanted to look at things more completely,” he said. Since 2010, he has visited Greenland fourteen times. On one visit, he launched a radio-controlled boat into a meltwater lake and, from a safe distance, watched the lake drain. On another, he installed sensors on the bottom of an empty meltwater lake and, from a not so safe distance, waited for it to fill.
On a trip last year, Tedesco brought along a drone to measure albedo at the edge of the ice sheet. Melt along the edge is exposing more rock and soil; since these are darker than ice, they absorb more sunlight, fostering more melt. But even where plenty of ice remains the reflectivity of the surface is dropping.
“The surface is darkening from an energy point of view,” Tedesco said. “It’s basically like exposing a wound and then putting some salt in it.”
Beyond its runway, Kangerlussuaq has one main attraction: a twenty-mile dirt road that leads away from the coast, toward the ice sheet. The road, improbably enough, was laid for Volkswagen, in the late nineties. As the story goes, the carmaker had a cold-weather test facility erected on the ice which included a track and a dorm for workers. But, after a few years, the whole scheme was abandoned. The road is now maintained by the municipality of Qeqqata, which encompasses Kangerlussuaq and is the size of Ohio.
“I’m always very emotional when I drive this road,” Tedesco said the next morning, as we headed out. “It’s my adopted land.” As he drove, he described to me a scheme of his own—never realized—to establish a museum of Arctic smells. Archived fragrances might include the herbal scent of the tundra and the perfectly blank smell of the ice. It was Colosio’s first visit to Greenland, and Tedesco warned him that the place had a mystical draw.
“You’re going to want to keep coming back,” he said. “You’re going to be under the spell.”
The old VW road runs almost due east, through a flat, sandy valley flanked by glacially smoothed hills. The area’s native trees are all low and shrubby, but a few miles out of Kanger we came to a grove of introduced pines. The pines seemed to be thriving in the warming climate, and people had decorated some of them with Christmas ornaments. We passed an Arctic hare—very white and surprisingly large—and then a family of reindeer.
After about an hour, we reached a spot where, across the valley, a tongue of ice spilled over a ridge. Tedesco identified the tongue as belonging to the Russell Glacier. (In addition to the ice sheet, which is essentially one enormous glacier, Greenland also has thousands of smaller, peripheral glaciers.) We stopped to take a better look.
When Tedesco first travelled the VW road, Russell ended in a dramatic wall of ice. Now the wall is gone, and the glacier looks deflated—more like an ice doormat. Tedesco compared visiting Russell to calling on a friend with a terminal illness. “You have to have the strength to say goodbye,” he said. “You see this and you say, ‘Oh, man, it’s happening really fast.’ ”
The VW road originally ran from Kangerlussuaq all the way to the ice sheet. Thanks to melt, it no longer gets there. Instead, it gives out a half mile short, at a huge pile of dirt and jumbled rock—a moraine in the making. We parked near an old bulldozer that seemed to be rusting into the ground. Tedesco and Colosio strapped on backpacks filled with equipment, and we began hiking over the rubble.
Cartoon by E. S. Glenn
It was cloudy and a relatively balmy forty degrees. (The average annual temperature in Kangerlussuaq is around twenty-four degrees Fahrenheit, compared with about minus twenty degrees at Summit.) “Speriamo che non piova,” Colosio remarked. (Let’s hope it doesn’t rain.) We reached the edge of the ice sheet, which was so thin that we could walk right onto it, as you would step onto a curb. There was meltwater everywhere, collecting in puddles and running in rivulets. In some places, the rivulets had merged to form streams that had to be jumped across.
“If we come back in a few days, we’ll have to bring bathing suits,” Tedesco joked, laying down his backpack.
Tedesco’s goal for the expedition was to repeat the albedo measurements that he had made last year, to see how conditions had changed. Once again, he’d brought along his drone. It was equipped with two sets of sensors—one to measure incoming radiation, from the sun, the other to measure outgoing radiation, reflected off the ice. To calibrate the sensors, he laid out a plastic sheet checkered in black and white, like a signal flag. It was apparently a lot more high-tech than it looked. “That little square cost me two thousand bucks,” he said.
While Tedesco and Colosio tinkered with the drone, I wandered around. At Summit, it’s always very white because there’s always—or nearly always—fresh snow, and everyone wears goggles or sunglasses to prevent snow blindness. At the ice sheet’s ragged edge, whatever snow had fallen during the winter had, by mid-July, long melted away, and there was only ice, which came in many shades, all of them gray. The ice was speckled with bits of dust, which glaciologists call cryoconite, and pocked with cryoconite holes, which form because dust absorbs sunlight more efficiently than ice does. The surface was changing so quickly that I could watch as neighboring holes merged to form pools. I also came upon a much larger hole, maybe twenty feet across and perfectly round, that went straight down. It had, I figured, once been a moulin, which is a shaft tunnelled out by a river of meltwater. When they’re full, moulins are spectacularly beautiful and equally dangerous. This one was empty and dingy, with blackened edges. It looked like some kind of side entrance to the underworld.
Source link : http://www.bing.com/news/apiclick.aspx?ref=FexRss&aid=&tid=6703b7c2adba4b3cb8403920ade6a7ce&url=https%3A%2F%2Fwww.newyorker.com%2Fmagazine%2F2024%2F10%2F14%2Fwhen-the-arctic-melts&c=16056497105187840109&mkt=en-us
Author :
Publish date : 2024-10-06 23:00:00
Copyright for syndicated content belongs to the linked Source.