Slowing down climate change
Two men and a bunch of bison could help save our planet from climate change.
THE PERMAFROST IS DISAPPEARING. AS IT THAWS, BILLIONS OF TONNES OF LONG-BURIED CARBON COULD ESCAPE INTO OUR ATMOSPHERE WITH CATACLYSMIC CONSEQUENCES. BUT ONE MAN, HIS SON AND A BUNCH OF BISON HAVE A PLAN TO RESTORE THE ICE AGE ECOSYSTEM
“WE ARE RAPIDLY APPROACHING THE POINT WHERE THE ARCTIC PERMAFROST WILL START THAWING. THAT WILL BE CATASTROPHIC”
It sounds like the plot from a Hollywood blockbuster. Eight time zones east of Moscow, in a remote corner of Siberia accessible only by boat, two men are trying to save the world from calamitous global warming. One, Sergey Zimov, is a pony-tailed man with a ZZ Top beard and penchant for concocting grand theories and smoking roll-ups; the other is his long-suffering son, Nikita. Their plan is to create an Ice Age nature reserve full of Ice Age creatures that will act as climate change superheroes. Their only superpower is digestion. In a nod to the Stephen Spielberg classic, the Zimovs have decided to call their venture Pleistocene Park. Meanwhile, 9,000km away in a Harvard University laboratory, a bunch of scientists are working to bring back what could become the park’s star attraction – the ultimate Ice Age icon, the woolly mammoth. But time is running out and the odds are stacked against them. Can the intrepid scientists succeed before the frozen north melts?
ON THIN ICE
Scientists estimate that 1,400 billion tonnes of organic carbon lies locked up in the permafrost, the frozen subsurface layer of soil, ice and rock that covers around one-quarter of northern hemisphere land. That’s roughly twice as much carbon as exists in our atmosphere, and three times the amount found in all the world’s forests combined. Now, as our planet warms and the permafrost melts, microbes are starting to convert this organic carbon into methane and carbon dioxide. The concern is that as these greenhouse gases bleed into the atmosphere, they will accelerate the rate of global warming, leading to more melting and microbial activity. “We are rapidly approaching the point where the Arctic permafrost will start thawing everywhere,” says Nikita, who now manages Pleistocene Park. “That will be catastrophic but we hope that Pleistocene Park will make a difference.”
The Pleistocene is the moniker given to the last Ice Age, an interminable cold spell that began around 2.5 million years ago. It was a time when immense ice sheets waxed and waned over much of the northern hemisphere, locking up so much water they created cloudless blue skies. Beneath those skies were lush, open grasslands that covered much of Eurasia and North America; the so-called mammoth steppes. When Homo sapiens first set eyes on this vista, tens of thousands of years ago, it was a vibrant and biodiverse place. Immense herds of mammoth, bison, reindeer and horses roamed the plains, amidst watchful cave lions and wolves. “It was like an Arctic Serengeti,” says Nikita. “Modern humans didn’t need to worry about finding food; they needed to worry about being trampled.”
When the Pleistocene came to an end around 11,500 years ago, it all disappeared. Many of the biggest animals, including mammoths, woolly rhinos and cave lions went the way of the dodo, and the grasslands were replaced with an unkempt ragbag of scruffy tundra and scrawny saplings. Now the remains of that Ice Age ecosystem lie trapped in the permafrost.
Thirty years ago, most scientists thought this transition was driven by climate change. As the Ice Age drew to a close, warming caused the pastures and animals to die. Then Sergey put forward a new theory, which he outlined in a Soviet journal in 1988.
PARK LIFE
It’s well known that animals provide ecological services to the environment in which they live. According to
Sergey, during the Pleistocene, big herbivores would have kept weeds and forests at bay, and returned nutrients to the ground via their droppings. In summer, they helped send the Sun’s warming radiation away from the planet by maintaining grassland, which is more reflective than closed woodland. In winter, the herbivores broke up the snow and helped keep the ground frozen by exposing it to the bitter Arctic air. If the big grazers could be returned, he mused, they should be able to convert the mossy tundra back to productive grassland and help keep the permafrost frozen.
In 1996, he set up Pleistocene Park to test his ideas. The reserve, which lies close to the Kolyma River in the Sakha Republic, northeastern Siberia, incorporates 2,000 hectares of this barren tundra. With no funding, in the early days the project ran on fumes and enthusiasm. First, he acquired some stocky, semi-domesticated horses from Siberian natives who used them for meat. He fed the horses with porridge oats, but without any fences, the ungrateful animals just wandered off.
Fast-forward to the present day, and the father and son team have added more than 25km of fences, 30 sheep, 30 reindeer, 9 yak, a few musk ox, some bison
“IT WAS LIKE AN ARCTIC SERENGETI. MODERN HUMANS DIDN’T NEED TO WORRY ABOUT FOOD; THEY NEEDED TO WORRY ABOUT BEING TRAMPLED”
and a couple of dozen horses, all species that lived in Siberia during Pleistocene times. Shrubs that were once so tall they overshadowed people have now been grazed to waist height or less. Tussock, a common, slow-growing weed, is giving way to meadow grass. Slowly but surely, the mammoth steppe ecosystem is beginning to return. “It’s the start of a long process,” says Nikita, “but there are encouraging signs.”
The ability of animals to re-sculpt landscapes is well known. There are many examples where keystone