Semiletov has handed me another hand grenade. On land, the state of the permafrost is clearer, and attempts to predict its future are more mainstream. The best person to provide a snapshot of what is happening is Vladimir Romanovsky, born in Siberia but now at the University of Alaska. I guess that his Siberian past led him to the permafrost. Romanovsky laughs and explains that he trained as a marine geophysicist in Moscow but he found that he “suffers very severely from sea sickness,” and so turned back to the solidity of frozen ground.
Romanovsky is currently running an international project to coordinate a network of permafrost observatories around the world. Each observatory is quite simple, he explains, just a one-inch-diameter borehole that typically drills a few dozen meters into the ground but in extreme cases can go a kilometer deep. Temperature sensors record what happens inside. With 400 boreholes in operation, a pretty consistent picture is emerging. “Most of the sites are showing increasing temperature over the last twenty to thirty years. Siberia is now a kind of hot spot, and Alaska was a hot spot during the 1990s when there was a major increase in permafrost temperatures. In West Siberia, we are starting to see thawing of the permafrost. And in places like the interior of Alaska, for example, ice is being lost inside the permafrost. At some point, of course, it will start to thaw.”
I wonder why the warming has moved to Siberia and quickly find that I have traveled in a circle and returned to where I began with the loss of the sea ice. “Most of the Siberian coast and inland is influenced by the Arctic Ocean,” says Romanovksy. “The dramatic decrease in sea ice really has this very big impact on climate.” I am back with those models of the spreading Arctic Ocean warmth and this time see their impact on the frozen ground rather than the vegetation. Perhaps not too surprisingly, NCAR’s David Lawrence, who made those models of the spreading Arctic warmth, is now working with Romanovsky to figure out how quickly the permafrost might change.18
It’s not easy, Lawrence explained to me. His first attempt, which concentrated only on the top layer (the first 11.5 feet) of frozen ground, created a major shock in 2005.19 That model showed that we could expect 90 percent of the top layer of permafrost to go this century. The current 3.9 million square miles of continuous permafrost that rims the Arctic (farther south there is a zone of patchy discontinuous permafrost) would shrink to a mere 390,000 square miles.
That model was quickly criticized by permafrost researchers, including Romanovksy, for having left out some key details. Now they are all working together and have come up with a more realistic picture.20 Still, it left no room for celebration: the new figure is that 80 percent of that top layer of permafrost will go by 2100.
There are many reasons to find this deeply troubling. Within the Arctic lands, the ecosystems and the plant and animal life that are adapted to frozen ground will be utterly transformed. The way water runs off the land and down the rivers of the Arctic will change in ways we cannot predict, while the rest of the world must fear the long-term impacts as feedback loops that we don’t really understand are set in motion. Warming permafrost will begin to turn its immense carbon stores into methane and carbon dioxide.
In 2006, Sergey Zimov, a Russian researcher who set up the Northeast Science Station in Cherskii, together with colleagues from the University of Alaska, published a paper in the journal Science estimating how much carbon might be frozen away in the Arctic and comparing it with the carbon found elsewhere.21 Up in the atmosphere there are 730 gigatons of carbon, most of it in the form of carbon dioxide. That amount has grown from the 560 gigatons of preindustrial times. We are adding 6.5 gigatons each year by burning fuels from the earth’s ancient fossil store. In the permafrost, Zimov estimated there was another 950 gigatons of carbon. If it were released, then greenhouse gas concentrations in the atmosphere would more than double, taking us back many millions of years to the era when temperatures were more than 7 degrees higher than they are now.22
Of course there is no way that the carbon will all be released at once. I suspect that the Arctic prefers a long, slow, sweet revenge. The permafrost will melt over hundreds and thousands of years. The very top layer will go quite quickly. Lakes that eat into the melting permafrost will bubble out methane ever faster throughout the century. The rotting ground will produce carbon dioxide. The slowly warming shelf seas will bubble methane and raise endless worries about the stability of those huge stores of methane hydrates at their bottom. There will be no sudden disaster but a long, slow, rising trickle of greenhouse gases and a progressive tightening of the noose. As greenhouse gas emissions rise from the Arctic, the only choice we’ll have to prevent still faster warming will be to reduce our own emissions. Year by year, the targets we’ll need to reach will grow tougher.
There is much more that could be said, for we have still hardly scratched the surface of all the ways that the changing Arctic will change the rest of the world. The melting ice and swelling rivers will send pulses of freshwater into the Atlantic and that will slow the warm ocean currents coming up from the south over this century. A huge store of freshwater floating on the saltier sea is now building up in the Arctic. Another large group of researchers are worrying about when it may go. Much less noticed is that a steady, extra trickle of fresher water out of the Arctic has begun to change the ecosystems of the North American Atlantic coast. Overfishing off the coast of Newfoundland destroyed the cod there, but the arrival of the Arctic freshwater is helping prevent their return.23
The sensible thing to do is to try to control human emissions of greenhouse gases as quickly as possible. But there are other things too. I take inspiration from something that is happening in Siberia. It may be quixotic, it may fail, but its vision is grand, and that should be enough to inspire us all to buckle down and get some global action to bring greenhouse gas emissions down. It is a project that tries to tackle the melting permafrost by undoing a change wrought by humans thousands of years ago.
The Siberian tundra is particularly rich in carbon because it contains a special soil, yedoma. When much of the northern world was covered in glaciers, the lands of eastern Siberia remained free from ice and accumulated wind-blown loess that supported a rich, savanna-like grassland. In that era, these vast grasslands were home to mammoth, bison, horses, musk oxen, Siberian antelope, rhinoceroses, and Siberian tigers. The closest thing left on the planet is the savannas of Africa and their herds of large mammals. The grasslands must have been a wonderful sight.
The large mammals of Siberia did not just live in this grassland ecosystem, they also created and maintained it. Trampling hooves stop mosses from growing and encourage grass instead. Grass uses up a lot of water and dries out the soil. Herbivores eat the grass, digest it, and recycle nutrients to the soil quickly. That keeps the grass growing and develops a thick soil which is a rich sink for carbon. Without herbivores, the ecosystem shifts to a soggy tundra where mosses trap moisture in the ground. With the right number of herbivores the ecosystem moves toward grassland and stays there.
Why did this ecosystem of mammoths and tigers vanish? Sergei Zimov believes that the arrival of human hunters was to blame.24 They wiped out the large mammals, just as they have done in so many other places. When that happened, the steppe stopped being a rich sink for carbon, where grass and bones were building up a thick soil. Instead, that store of carbon froze up—and now it is waiting to be released back into the atmosphere.
Zimov’s solution is to turn back the clock and make the tundra into grassland again. He is working to create what he calls “Pleistocene Park.” He has fenced off sixty square miles of Siberian tundra and has begun stocking it with reindeer, horse, and moose. If he can trigger the move toward grassland, he can later introduce bison, musk ox, and even fierce predators.
I’d long wanted to hear more about Sergei Zimov’s project so I was pleased to find him at the AGU meeting in San Francisco standing by a poster exhibit on the Siberian permafrost. I thought he looked astonishingly young for such a well-known scientist and I
said so. “I am Nikita,” was the reply. “You are thinking of my father.” The young man pointed to a large, bushy-haired, bearded gentleman standing nearby who was carrying on a rapid conversation with three people at once.
Sergei and Nikita work together on the project. Nikita explained to me that there would be many advantages to restoring the grassland. “You know the problem,” he said. “There are five hundred gigatons of carbon in the Siberian yedoma. It took thirty to forty thousand years to accumulate. We really don’t want to release it.” Returning the ecosystem to grassland would turn it back into a carbon sink again. Most important is that herds of animals will trample the snow. Fallen snow is a great warm blanket for the ground. “The air can be-40°C,” says Zimov, “but under the snow it is only-5°C to-10°C. When the snow is trampled that changes completely and the soil surface is at-30°C. That keeps the permafrost cold and keeps its carbon safe, he says.
The ultimate dream is to bring back the mammoth too. Mammoth bones are found easily in the tundra, and local indigenous people make a living by collecting and selling them. The Zimovs have brought Japanese scientists here who have recently found ways to resurrect DNA from dead, frozen mice. The return of the mammoth is not impossible.
I asked Katey Walter if the restoration of the Siberian grassland might really be practical. “I think it’s practical,” she replied. “Not many people are willing to take such risks and create a huge new ecosystem. That’s one of the wonderful things about being in the middle of nowhere in Siberia. You can do it.”
Could mammoths really save the tundra and help save the world? I am not convinced, but it is such a wonderful idea that it might call us all to action. And there is still one last thing that could be done.
Chapter Sixteen
BLACK AND WHITE
Traveling around the Arctic, there was one man I kept running into again and again. I came across him in Greenland, Svalbard, Norway, and Finland and his name recurred on old maps of Siberia, and even on the planet Mars. I can’t say that I met him in person, as he has been dead for more than a hundred years, but I do have a good idea of what he looked like—a firm gaze, jutting jaw, a thick head of hair swept back from his forehead, and a luxuriant mustache. A bust of him stands in Kaivopuisto Park in Helsinki from where he looks out across the gray Baltic Sea as the sailing boats go by. Alongside him are several stone panels depicting his own boat, the Vega, a 150-foot, three-masted whaler equipped with a powerful steam engine, and the route he took in it around the northern coast of Siberia.
He is the nineteenth-century scientist and explorer Baron Adolf Erik Nordenskiöld, the first man to travel the full length of the Northeast Passage.1 He left Tromsø in Norway in 1878 and sailed east, spent one winter locked in the ice not far from the Bering Strait, and arrived at Yokohama in Japan in 1880. Somewhere toward the end of his journey he must have crossed tracks with the U.S. ship Jeanette, sailing off in the other direction, toward the North Pole and the disaster that was to inspire Fridtjof Nansen. The recently opened Suez Canal gave Nordenskiöld a faster route back home to Sweden. Although Nordenskiöld was born here in Helsinki, he was banished by Finland’s Russian rulers for having made an excessively patriotic speech and lived most of his life in Stockholm. Both Finland and Sweden now claim him as a national hero.
Nordenskiöld is important to me not for his great voyage but because of one of his other journeys. I learned about that trip only by chance, but it led me to hear about one remarkable and little-considered way that we might yet slow the Arctic melt. It is not a solution to global warming, but it might help buy time for the planet and the ice while we find a way to cut greenhouse gas emissions. None of the scientists who helped me dissect the causes of the great ice loss mentioned it, so I am grateful that the long-departed baron’s adventures came echoing down the centuries to me. They carried me to another group of scientists and a handful of activists with an optimistic call for action in the Arctic.
The very first time I heard of Nordenskiöld was when I climbed the mountain named after him in Svalbard, in a bitter wind. A sheet of ice built up rapidly inside my high-tech windproof climbing jacket as we approached the summit. (“Useless for the Arctic,” my guide said contemptuously. “If you want to stay alive you should wear fur.” No doubt Nordenskiöld did.) A little later, I passed Nordenskiöld Land and then the Nordenskiöld Peninsula, all in Svalbard. On old maps of the Arctic I’d also found the Nordenskiöld Sea (now the Kara Sea) and the Nordenskiöld Archipelago. There is a nice medium-sized crater on Mars named in his honor, too.
Nordenskiöld made nine expeditions to the Arctic. As far as I know, the only place he ever failed to reach was the North Pole. He did try, but he made a mistake in choosing reindeer to haul his sleds rather than dogs. The reindeer ran away. Later in life he settled down and spent his time collecting maps. His vast collection is now in the University of Helsinki. It is the last of his expeditions—to Greenland in 1883—which led me to think again about the melting ice. I learned about it only after visiting an area just a few miles from where he had been 125 years earlier.
I had hiked up to the Greenland ice cap to look at moulins, those big holes where a churning stream of meltwater plunges deep down under the ice. Before I found the first of them I came across something odd. Here and there, puncturing the ice around my feet were scores of perfectly round holes. Many were an inch or so across and four or five inches deep. Some were smaller. Others were much larger and partly filled with water. Rising from the bottoms of these ponds were pointed islands of ice, resembling a chain of miniature volcanoes.
I had never seen these holes before, but it was not too hard to work out how they came about. At the bottom of any hole, small or large, there was always a thin layer of dust. Each hole begins when some black dust, often blown from the nearby moraine, lands on the pure white ice. The low-albedo dust soaks up the sunlight, warms, and begins to melt its way downward, leaving a smooth, round hole as it goes. Where many holes run close together, their walls partially melt into each other, leaving those little pointed islands of ice in the middle of a larger pond.
I discovered later that the holes are called “cryoconite” or “ice dust” holes. The man who had named them was, of course, none other than Baron Nordenskiöld. He had found the holes a great nuisance and grew quite angry with them. During the night a thin skin of ice would form on the surface of the bigger holes, making them hard to spot in the morning. “It was impossible not to stumble into them at every moment,” he complained in an account of his journey. “They are more dangerous than crevasses. They lie, with a diameter just large enough to hold the foot, as close to one another as the stumps of the trees in a felled forest.2”
He knew at once how the holes were created, but his curiosity and knowledge ran deeper than mine. Nordenskiöld had studied both chemistry and geology and at the age of twenty-six had become superintendent of the Mineralogical Department of the Swedish Royal Museum. He was excited by a layer of a fine dark substance at the bottom of the holes that seemed different from mere wind-blown sand and tested it as best he could. The substance could be “drawn to a magnet,” he found, and when it was ground in a crucible and heated with a blow pipe, it burnt with colors that suggested it contained zinc and iron. He recorded his results in the recently launched U.S. journal Science in 1883.
Nordenskiöld didn’t really know where this sediment came from, but we have a very good idea now. Timothy Garrett, a professor of meteorology at the University of Utah, reexamined the 1883 paper and thinks the dust was a by-product of smelting and coal burning during the late nineteenth-century industrial boom in Europe and North America. That early industrial pollution had been carried right up to the Arctic and dumped on the snow where it began to soak up heat and melt it away. Garrett published an article on early pollution in the Arctic which I came across as I searched for information about Nordenskiöld.3
It is possible to find evidence of that old pollution today by drilling deep into the w
est Greenland ice cap and pulling out frozen cores of ice several hundred meters long. Deep in the core is the compacted snow that fell hundreds of years ago. With skill and care, the layers of ice in the core can be read and dated. Joseph McConnell of the Desert Research Institute in Reno, along with Charles Zender of the University of California at Irvine and colleagues looked in these cores for a range of air pollutants. They published the work in the very same journal, Science.4 Sure enough the ice record showed that Nordenskiöld had been there just when the pollutants drifting to the Arctic from the burning of coal were coming to a peak.
Garrett isn’t a historian of science, and when I tracked him down at the University of Lille in France, he explained that he had looked back at old accounts of the Arctic because of his “contrarian nature.” Textbooks put the first eyewitness stories of Arctic air pollution in the 1950s, but Garrett was convinced that there must have been earlier accounts. He was right. “Our instinctive reaction is to believe the world was a cleaner place a hundred and thirty years ago. But industry was already darkening the snow and skies of the far North,” he says.
He has seen modern Arctic hazes for himself. His first experience was on a trip to the Arctic in 1998 on a University of Washington aircraft designed to study aerosols, the fine particles carried in the air, and clouds. “It was utterly new to me and completely surprising,” he says. “The plane would descend and the horizontal view would go from being absolutely crystal clear visibility, out to infinity, to looking like downtown Los Angeles.” The air pollution comes in distinct layers. “It is very stark,” says Garret.
I had been led to Timothy Garrett by his contrarian piece of historical research, but quickly progressed to a paper he had published in Nature.5 It showed that when air pollution reaches the Arctic and mixes with low clouds it quickly forms a Los Angeles-style smog that can trap heat, especially in winter and, like a thick blanket, keep the surface below much warmer than it would normally be. His work led me on again to many more papers showing that the air pollution carried to the Arctic could warm it in several ways, as a cloud blanket as he had described, as a heat-absorbing dark haze in the air above the ice, and by landing on the surface of the ice and darkening it so that it warmed and melted faster.
After the Ice Page 27