Piers Sellers bei einem Außenbordeinsatz während der Space-Shuttle-Mission STS-121, bei dem er Reparaturtechniken für den Hitzeschutzschild der Raumfähre testet
Piers Sellers landed in Greenland on a frigid Monday morning in April, and as he stepped off the plane at Thule Air Base he regarded the surrounding snow-covered hills with delight. A former astronaut, six-time spacewalker, and presently the acting director of the Earth Sciences Division at NASA’s Goddard Space Flight Center, Sellers was visiting the country for the first time. “I didn’t even see this from space, since the farthest north the shuttle goes is fifty-one degrees latitude,” he said. “We’re at seventy-six degrees now, right? Fantastic.” Sellers’s plan was to rendezvous with NASA researchers at Thule (pronounced “TOO-lee”) and accompany them on Operation IceBridge, an annual mission to collect data on the diminishing ice in the Arctic Ocean and on the Greenland ice sheet. “These guys at IceBridge are always saying, ‘Oh, you should come along, see where the rubber meets the road,’ and I say that I’m too busy, with too much piled on my desk,” Sellers explained. “But, given my current situation, of all the things that we’re doing in the field, this one is probably the most critical right now.”
By Sellers’s “current situation,” he means the fact that he was recently diagnosed with Stage IV pancreatic cancer, a development that he wrote about earlier this year in the Times. After the diagnosis, he briefly considered living his final year or so—assuming his doctors’ expectations prove correct—as a rich man might, in a tropical, hedonistic splurge. “I thought of myself sitting for weeks on a beach,” he said. “What would I do? I’d be thinking about climate. And I know that I’d be thinking about the problem, and thinking about areas that needed to be investigated. All these things would just be going around in my head. I’d be sitting on my beach with my margarita—and it would be pointless.”
So Sellers went back to his desk job at Goddard, where he oversees the work of about sixteen hundred people, and considered how he could fit a few modest adventures between his office duties and chemotherapy sessions. Soon it occurred to him to go to the Arctic, which is warming faster than any other part of the world. “The global temperature has crept up one degree centigrade, but you can’t really feel that,” Sellers said. “But everyone can understand the ice melting. Everyone can see these graphs, and see the shrinkage of the pole, and see that the Greenland ice-sheet loss is just huge.” According to data from NASA satellites and airborne missions like IceBridge, Greenland is losing about two hundred and eighty-seven billion metric tons of ice each year. This spring, the ice sheet’s usual summertime melt began in mid-April, earlier than at any time in recorded history. That was worrisome to Sellers: if even a tenth of the Greenland ice sheet were to fall into the Atlantic, it would raise average global sea levels by about two feet.
The IceBridge plane, it turned out, was running late—delayed in Fairbanks, Alaska, for maintenance on one of its propellers. This meant that Sellers would be biding his time around Thule for the better part of a week. He seemed undaunted by the prospect; apart from some headaches due to his medications and some occasional spells of fatigue, he remarked that he felt well enough to do just about anything. Some colleagues from NASA quickly drew up a calendar of activities for the next few days. Mornings would begin at the mess hall with a large breakfast, and then he would visit local sites of geological and historical interest. “Most everything tastes like cardboard to me,” he complained. But one notable exception seemed to be a good latte. He discovered a coffee shop on the edge of the base, called Café Cool, where a young Danish barista had a deft touch with the espresso machine. “You know, I think I’ll get another after this,” Sellers said with surprise when he took a first sip. “It actually makes coming up to the Arctic worthwhile.”
At Thule, the mundane tends to intersect with a frozen, far-flung exoticism. When the U.S. government expanded the Thule base, in the early nineteen-fifties—mainly to keep a closer watch on the Soviet Union—it moved an entire village of native Inuit to a new location, about sixty miles away. A deserted village, known as Dundas, was left behind, and some of the homes remain standing a few miles from the base. As luck would have it, Sellers’s visit to Dundas coincided with the arrival of a bevy of dog-sled teams that had been on patrol for the Danish military. Two local Greenlandic hunters, Sofus Alataq and Gideon Kristiansen, had helped guide the Danes through some difficult inland terrain. The Greenlanders were dressed in hooded sweatshirts and faded Adidas warmup pants; their sled was laden with clothing, rifles, and polar-bear furs. (Licensed Greenlandic hunters are permitted to hunt polar bears, as part of longstanding Inuit tradition, and the bear’s hide is often worn as pants by hunters venturing out in extreme cold.) Alataq, who spoke passable English, said that most of their hunting this season had been for seal, and that recent changes to the climate had made sledding on the frozen bays and fjords—the primary mode of transport during the colder months—more difficult. “Less ice, warmer weather, spring is sooner,” he said. Sellers, a lanky figure dressed in faded jeans, Keen boots, and a bright-red winter jacket, was captivated by how the men’s tranquillity and modest gear contrasted with the demeanor and appearance of the Americans, who shivered in their parkas. “These guys were perfectly suited to their environment,” he said later. “They understand every aspect of it. Nothing here frightens them, even though they’re living in one of the most hostile places on Earth.” When he got back to base, he sent a photograph of the hunters to a NASA colleague who runs one of the agency’s planetary-science divisions. “These guys are ready for Europa!” he wrote, referring to a frozen moon of Jupiter.
The next day, a Danish Air Force team planned to make the five-hour round trip from Thule to the northeast coast of Greenland, where a science outpost called Station Nord is located. Their plane, a stout-bellied military C-130J, was hauling a load of diesel fuel to the station. Sellers, a licensed pilot, sat alongside the crew in the cockpit for most of the journey, taking in a broad view of the ice-locked northern coast of Greenland. Between cries of “Fabulous!” and “Fantastic!” and “I’ve got to get a picture of that!,” he snapped dozens of photos with his iPhone. The return trip took the C-130J over the ice sheet. This time Sellers shot photos from a window in the plane’s cargo bay, and there were similar outbursts of enthusiasm at the sight of the frosted, otherworldly contours of the world below. The sheet’s surface at this latitude didn’t yet show signs of the summer thaw—typically marked by pools and creeks of sapphire-blue meltwater—but it appeared to spread forever in all directions, not smooth but rippled, and veined with long, sinuous glacial lines. At times, the plane cruised over small, snow-encrusted peaks, which seemed knitted together in their adjoining valleys with jagged seams of ice that ran for miles, resembling an endless San Andreas of white.
Sellers spent much of his final day at Thule drinking lattes at Café Cool and planning a slide show on climate change for that evening. He held court in the center of the room and traded quips with whoever chose to pull up a chair. Earlier that morning, he took some time to consider the arc of his career. Born in southern England and raised in the U.K., Europe, and the Middle East, Sellers said he had wanted to be an astronaut from the moment he learned about Yuri Gagarin’s space launch, in 1961. From that point on, he followed every detail of NASA’s Mercury, Gemini, and Apollo programs. “I thought they were doing this just for me,” he recalled. At seventeen, Sellers began flying planes, but rather than pursue a career as a pilot he eventually chose to get a doctorate at the University of Leeds. He started as a biologist, then went to NASA as a postdoctoral researcher to put vegetation into climate models. He was a scientist before he was an astronaut, he remarked. “And now I’m a scientist again.”
Sellers allowed for the idea that he has never regarded Earth the way most humans do, as a place to walk, work, and inhabit. “I see it from above,” he said—with weather and climate patterns careering across the surface in a heady, complex swirl. Partly that’s a result of having seen the view from hundreds of miles above the planet during spacewalks on the International Space Station. “I remember one time I was looking between my boots at the Amazon and I could see the whole river snaking out to the sea ahead of me,” he recalled. “I could see all the way to the Atlantic, a thousand miles of river, the sun shining on it, the big forest, and I was realizing it was morning down there and the whole place was waking up.” Much of this world view, so to speak, also derives from a lifetime of reading climate and observational data collected from orbiting satellites. “But that’s why it’s great to be here, coming down from my usual perch, which is somewhat separated, where it’s all happening in my head, and actually wander around and use my eyes to see what’s on the ground.”
At the moment, Sellers is not sure how things will turn out for humanity. “I’ve been surprised lately at how quickly and visibly you can see the planet changing,” he said. “Half my lifetime—thirty years—I’ve been thinking of this, and I’m getting worried about the political response, particularly in this country, where it’s taken a long time to come around to a consensus.” Even if governments around the world manage to reduce their carbon emissions drastically and keep over-all warming to within two degrees Celsius above pre-industrial levels—the goal of last year’s climate accord in Paris—Sellers foresees some difficult circumstances for the planet. He pointed to the recent drought in North Africa and the eastern Mediterranean, which disproportionately affects the poor and drives the region’s conflicts. Still, the impacts on the developed world, Sellers said, might be manageable. “Now, what if you start creeping up to the hairy end of things—the three-degree world?” he asked. “Well, then we’ve got surprises.” Sellers rattled off the possibilities: intensified droughts, inexorable coastal flooding, severe food shortages. He wouldn’t be around to see these events happen, if indeed they came to pass, but his two children, both in their late twenties, might. The risk of political inaction worried him. “If you’re going to hang around until the Greenland ice sheet falls off into the Atlantic, or one of these big ice shelves becomes unzipped on Antarctica—if you wait for that, by the time that event has taken place, the series of follow-on events that leads you to really bad situations is unstoppable.”
The next morning, it was back to Washington, on an aging 757 that flies out of Thule one day a week. Sellers slept for most of the flight, but, in the customs line at B.W.I. airport, he sent an R.S.V.P. to India’s attaché in Washington, D.C., about a dinner date. “I’d love to come tonight,” he said over the phone. One of his main goals now, he explained after the call ended, is to reach out to foreign space agencies and move ahead on a number of coöperative (and expensive) international climate projects. “Maybe we can strike a deal tonight over the vindaloo,” he mused. Then he shrugged and checked his phone again. “I think I’ll stop by the office at Goddard today,” he added. “There’s still time, you know.”
Quelle: The New Yorker