NEWS Born to rewild A father and son’s quixotic quest to bring back a lost —and save the world

By Eli Kintisch, in Chersky, Photography by Chris Linder on December 3, 2015 www.sciencemag.org Downloaded from

n April 2011, Nikita Zimov climbed into that covered the truck’s roof to keep the , ment’s success. A decade ago, Sergey and col- a heavy duty truck with six elk in the also uninjured, from bolting. “I was miser- leagues estimated that encircling back and set out from Novosibirsk, a able,” he says. “Almost literally insane.” the upper Northern Hemisphere contains major city in southern , on a Sergey swooped in to rescue Nikita and a whopping 1 trillion tons of —twice 4000-kilometer trek to the edge of the the elk, and the animals finally reached earlier estimates—and that this vast pool world. Time was not on his side. He their destination: Park, a 14,000- may be on the brink of leaking into the had to reach the town of Cher- reserve near Chersky founded by the atmosphere. The finding was a clarion call sky, where he and his father, Sergey, elder Zimov 19 years ago. It’s a grand experi- to climate scientists to take the arctic carbon run a hardscrabble research outpost ment to test whether large —elk, threat seriously. “This is the most dangerous called the Northeast Science Station (NESS), , , , and —can, territory in the world in terms of climate Ibefore the spring thaw melted the frozen simply by , bring back a grass- change,” Zimov declares. rivers that serve as winter roads in northern dominated ecosystem called the Zimov’s calculations and field measure- Siberia. White wooden crosses marked spots . That dominated the north- ments soon persuaded his colleagues. along the winding road where unlucky driv- ern reaches of and “Sergey comes up with these wild ideas. ers had perished. Two weeks into his jour- for 2 million years, until the end of the last They seem implausible, but they turn out to ney, just 40 kilometers from home, Zimov glacial period some 13,000 years ago, when be right,” says longtime collaborator Terry hit a snowbank—his brakes were shot—and the landscape turned to mossy and Chapin, an ecologist at the University of the truck tipped over. Unscathed, he phoned sparsely forested . Alaska, Fairbanks. Now, Zimov is straining his father and spent the next 4 hours, cold If the Zimovs are right, a brighter future credibility again with his proposal for con- and exhausted, leaning against a flimsy tarp for the entire globe may hinge on the experi- taining the threat. He has called for rewild-

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Ecologist believes restoring the Pleistocene will protect permafrost and provide habitat for millions of herbivores.

vostok. Instead they capitalized on the Soviet collapse, gathering up speedboats and trucks at steep discounts and stockpiling food and fuel in shipping containers. “We were feast- ing off the dead carcass of the Soviet Union,” says Nikita, who as a teenager spent a sum- mer cleaning a 33-meter-long shipping barge that his dad would convert into a floating re- search station. The son of a Soviet naval officer, Sergey Zimov had a maverick’s temperament from the start, and it flourished in Chersky’s post- Soviet isolation. He questioned the prevail- ing theory for why , bison, and other arctic died out at the end of the Pleistocene. Most scientists believed the warming climate disrupted northern ecosys- tems, changing the steppe to tun- dra and starving the beasts. Zimov thought proponents of that idea had cause and effect reversed. He knew that in northern Siberia, taiga and tundra turned grassy wherever it was disturbed, whether by wild horses or by one of Stalin’s gulags. In 1988, Zimov penned up 25 Yakutian horses, a breed adapted to the cold, and watched how they quickly trans- formed mossy wet tundra into grassy pasture by gnawing on shrubs and fertilizing the soil. He theorized that herbivores had maintained the expansive mammoth steppe, and the land only turned to taiga and tundra after their numbers fell for another reason—pre- sumably . Intrigued by Zimov’s ideas, Chapin and James Reynolds, an ecologist at Duke Uni- versity in Durham, North Carolina, visited NESS in the summer of 1993. “Zimov is like a spinning tornado of chaos, confusion, and creativity,” Reynolds penned in his di- ary. They weren’t immediately sold on his ing the Arctic: repopulating vast swaths of Zimov, however, appears unfazed by the gulf big idea. Zimov “takes a few data points the permafrost zone of Eurasia and North between the reality so far and his monumen- and if his hypothesis works, he’s convinced,” America with large herbivores. By restoring tal vision. “It’s probably the biggest project Chapin says. But the discussions were in- the mammoth steppe, he says, those mega- ever,” he says, nonchalantly. vigorating, he says, and Reynolds came fauna would help to keep the permafrost in- up with a model that reproduced Zimov’s tact even as the atmosphere warms. SERGEY, with three colleagues, in 1980 conclusion. In 1995, the trio and Russian “Sergey is a visionary, a challenger of par- established NESS in a wooden hut along colleagues published a paper in American adigms,” says ecologist Heather Alexander of a small river near Chersky as an Arctic Naturalist declaring that “human hunting University of Texas, Brownville. But this par- research redoubt of the Pacific Institute could have played as great a role as climate” ticular vision may be a fantasy. Recreating of Geo graphy in Vladivostok. Soviet-era in extirpating Arctic megafauna. the mammoth steppe’s estimated Chersky was a bustling hub for gold miners Zimov saw implications for the future as density—20 large animals per square kilo- and for scientists in transit to research bases well. Pleistocene in northern Rus- meter—would mean sustaining millions of near the North Pole. When the Soviet Union sia and northwest Alaska accumulated or- beasts in Siberia. Yet the Zimovs have strug- unraveled in 1991, “people were fleeing ganic material over hundreds of thousands gled to keep a handful of herbivores alive in [Chersky], but Sergey said we should stay,” of years. The soil distilled from —a speck in the vastness says ornithologist Eugene Potapov, a long- all that plant material is some of the most of Siberia. As a testament to the challenge, time visiting scientist at NESS who works at carbon-rich on the planet, and the soil runs the elk that Nikita risked his life to bring to Bryn Athyn College in Pennsylvania. deep, with an average thickness of 25 meters. Chersky had all died or hopped a fence and As Chersky emptied, NESS scientists ig- It is now preserved under the tundra, deep- escaped within a year of their arrival. Sergey nored an official request to return to Vladi- frozen in permafrost.

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Averting an Arctic apocalypse Zimov and colleagues have warned that thawing Arctic permafrost will release prodigious quantities of greenhouse gases. Introducing horses, deer, bison, and other large herbivores, they argue, would restore arctic grasslands. By insulating the permafrost, pastures would keep the soil and ice wedges from melting into a swampy morass—and keep much of the carbon safely bottled up.

Current landscape 15 years after 3oC climate warming

Without herbivores With CO2 herbivores Soil pillars

Ice wedges

Zimov and Chapin saw yedoma as a time Yakutian horses whose grazing helped the ing it: Dozens of Yakutian horses have fallen bomb. A decade ago in Science, they con- grasses gain ground. The park, Sergey says, prey to bears and other predators or died cluded that estimates of carbon content in is “a war zone between two .” after eating cowbane, a poisonous member Arctic soils were grossly underestimated, It’s also a war between Zimov’s vision of the hemlock family. Four bison from rela- and that under “extreme” but plausible and some mundane challenges. Key among tively balmy Moscow died of exposure dur- conditions some 500 billion tons of carbon them, he says, is raising an army of herbi- ing the harsh Chersky winter. These days would be liberated from yedoma within a vores without government support. The Zi- about 70 animals roam the park, a fraction century (16 June 2006, p. 1612). (Since then, movs have ranged hundreds of kilometers to of the 1000 Sergey hoped to have amassed the consensus Arctic carbon estimate has stalk moose, driving them into rivers where by now. risen by another 50%; one recent study es- they can haul the calves into boats and Even so, the browsers are helping to timated that at the current atmospheric make off with them. In 2010, the Zimovs spare the permafrost from climate warming. warming rate, (CO2) and ventured 1000 kilometers north across the Grasses are better than mosses, shrubs, and released from permafrost would , steering clear of polar bears, trees at reflecting sunshine, so they are more warm the planet by an additional 0.3°C by to purchase six musk oxen from a wildlife effective insulators in the summer, when for 2100.) Zimov had “basically discovered and reserve on . Maintaining the weeks the Arctic sun doesn’t set. During the explored a pool of vulnerable carbon approx- menagerie has proven as difficult as acquir- rest of the year, when northern Siberia is imately equal to the entire pool in plants and blanketed in snow, herbivores keep the per- unfrozen soils,” says ecologist Chris Field of mafrost frozen by ensuring it is exposed to the Carnegie Institution for Science in Palo the frigid Arctic air. By trampling down the Alto, California. snow, they compact it and make it a poorer By then, Zimov was seeing, on a small insulator; in some cases they sweep away scale, the devastating effects of warming the snow altogether to graze. In Pleistocene temperatures in the Arctic. At a 3-hectare Park, two temperature loggers in boreholes plot near Chersky, Zimov 11 years ago used a show average permafrost temperatures 2°C bulldozer to strip away the moss and soil that colder in the grazed area. That temperature insulate yedoma in the summer. Ice wedges difference is “enough to protect the perma- in the exposed permafrost rapidly melted, frost,” Nikita says. laying bare the pitted, thawing soil. Soil bac- Others aren’t so sure. If winters become teria set to work freeing CO2 and methane. warm enough, says Michelle Mack, a soil Today, the site is pocked with 3-meter-deep ecologist at Northern Arizona University in melt pools and bizarre pillars of gray dirt. Flagstaff, trampling or sweeping away snow “This is the future we are facing if we cannot could have the opposite effect, allowing stabilize the permafrost,” Zimov says. warmth to penetrate the soil more quickly. “It may well be that Sergey is right,” she says, TO AVERT THAT FATE, Zimov has pro- but the Zimovs haven’t made their case rigor- posed geoengineering permafrost on a ously with models or data. global scale. He started small, with Pleis- Chapin points out that other than cutting tocene Park, a 45-kilometer boat ride up global emissions, no solu- SCIENCE the River from Chersky. Its mod- tions, apart from Zimov’s, have emerged to est entrance features a disgruntled cat and address the “dire” prospect of permafrost a metal fence in a patch of mud. Inside, carbon release. Zimov himself says it’s too 50 of grasses have replaced scrag- Nastya Zimova cares for a moose calf purchased from early to draw firm conclusions. “Pleistocene

gly larch and moss. Idling by a lakeshore are a hunter for Pleistocene Park. Park is an experiment that must be contin- ALTOUNIAN/ V. GRAPHIC:

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Published by AAAS In a fenced-in section of Pleistocene Park, bison and other herbivores have transformed taiga into pasture. Scaling up is a daunting challenge. ued for tens of years,” he says over moose ers that collect atmospheric data. “There’s room featuring Siberian vodka and beer stew one evening in NESS’s dining room, a nowhere comparable to Sergey’s station chilling in an ice-filled bathtub. The many soaring round room crowned with a mas- in the Russian Arctic,” says marine ecolo- Arctic scientists who flock to Chersky bring sive Soviet-era satellite dish. gist Robert Max Holmes of the Woods Hole dollars and euros that could help sustain the But on his 60th birthday last summer, Research Center in Falmouth, Massachu- station and Pleistocene Park. Sergey and a few dozen friends and col- setts. Nikita wants to maintain that infra- But running NESS is more rollercoaster leagues celebrated his semiofficial retire- structure in a remote hot spot for Arctic ride than party. One day in early July, ment with salmon caviar and vodka toasts field studies. With tensions high between Nikita took a dozen visiting graduate stu- at NESS. Now, the fate of Sergey’s living ex- Russia and the West, that’s a daunting chal- dents waterskiing on the Kolyma River in a periment rests with his son. lenge. Two major U.S. research grants—one dilapidated motorboat, with techno music supporting NESS as a teaching lab for un- blasting from a portable stereo. The next IN THE EARLY 2000s, Nikita attended one dergraduate and graduate students and the day came a cluster bomb of lows. The per- of Russia’s top science high schools, in No- other paying for the remote sensing—ended son who maintains an atmospheric sensing vosibirsk, and then stayed there at the state this year, with no promises for renewal. The tower told Nikita he intended to quit; plant university for undergraduate and master’s Russian government, meanwhile, provides samples that visiting German botanists degrees in math and computer modeling. only measly salaries. wanted to bring home were 160 kilograms Life in Novosibirsk offered more opportuni- Yet fully testing Zimov’s ideas will take too heavy, and sure to create a hassle at the ties than moribund Chersky, where many more money, land, and animals. To lay the airport; and a moose calf for which Nikita buildings are abandoned and sinking into groundwork, Nikita plans to expand Pleisto- had paid $500 escaped after jumping a the thawing permafrost. “I didn’t think I cene Park’s fenced area. And to raise aware- makeshift pen that Sergey had built. “I told would want to return,” he says. ness inside Russia, the station recently cre- him that he should hire a carpenter, but no, “Getting Nikita to come [back] was ated a 300-hectare preserve eight time zones he insisted he would do it himself,” Nikita the hardest scientific problem of my life,” to the west, near Moscow. Called Wild Field, says. He watches his father, wearing a mos- Sergey says. Nikita worried whether he the pasture filled with horses, sheep, deer, quito head net with a hole at mouth level could build on his father’s legacy. “I know antelope, and cows is meant to simulate the for an ever-present cigarette, head off on an I can’t compete with my dad as a scientist. mammoth steppe, minus mammoths and all-terrain vehicle in search of the stray calf. [But] I’m interested in managing the sta- other lost megafauna. “He is stubborn,” Nikita says with a shrug. tion, growing the park.” On the prowl for major funding, Nikita “And I am stubborn.” ■ Over the years, NESS has grown into a showed his father’s touch for schmoozing at sprawling compound that serves dozens of the American Geophysical Union meeting Reporting for this article was supported visiting scientists with soil and biological in San Francisco, California, last December, by a grant from the Pulitzer Center on labs, state-of-the-art instruments, and tow- treating colleagues to a party in his hotel Crisis Reporting.

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