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. Last Updated: 07/27/2016

When Ancient Dung Thaws

ReutersScientist Sergei Zimov examining a handful dirt from the layer of permafrost thawing due to climate changes. The result? The release of methane gas.
DUVANNY YAR, Sakha -- Sergei Zimov bends down, picks up a handful of mud and holds it up to his nose. It smells like a cow patty, but he knows better.

"It smells like mammoth dung," he says.

This is more than just another symptom of global warming.

For millennia, layers of animal waste and other organic matter left behind by the creatures that used to roam the Arctic tundra have been sealed inside the frozen permafrost. Now, climate change is thawing the permafrost and lifting this prehistoric ooze from suspended animation.

But Zimov, chief scientist at the Russian Academy of Sciences' North Eastern Scientific station, three plane rides and eight times zones away from Moscow, believes that as this organic matter becomes exposed to the air, it will accelerate global warming faster than even some of the most pessimistic forecasts.

"This will lead to a type of global warming that will be impossible to stop," he said.

When the organic matter left behind by mammoths and other wildlife is exposed to the air by the thawing permafrost, his theory goes, microbes that have been dormant for thousands of years spring back into action.

They emit carbon dioxide as a byproduct and -- even more damaging in terms of its impact on the climate -- methane gas.

Zimov, who has studied climate change in Russia's Arctic for almost 30 years, says the microbes are going to start emitting these gases in enormous quantities.

Here in Sakha, a republic in the northeastern corner of Siberia, the belt of permafrost containing the mammoth-era soil covers an area roughly the size of France and Germany combined. There is even more of it elsewhere in Siberia.

"The deposits of organic matter in these soils are so gigantic that they dwarf global oil reserves," Zimov said.

U.S. government statistics show mankind emits about 7 billion tons of carbon per year.

"Permafrost areas hold 500 billion tons of carbon, which can quickly turn into greenhouse gases," Zimov said.

Dmitry Solovyov / Reuters
Lakes bubbling with methane in Sakha, the northeastern corner of Siberia.
"If you don't stop emissions of greenhouse gases into the atmosphere ... the Kyoto Protocol will seem like childish prattle," he said, referring to an international pact aimed at reducing greenhouse emissions.

It might be easy to dismiss the 52-year-old, with his beard and shock of wavy hair, as an alarmist crank, but his theory is grabbing attention in the scientific community.

"There's quite a bit of truth in it," said Julian Murton, member of the International Permafrost Association. "The methane and carbon dioxide levels will increase as a result of permafrost degradation."

A United Nations report in June said there was yet no sign of widespread melting of permafrost that could stoke global warming but noted the potential threat. "Permafrost stores a lot of carbon, with upper permafrost layers estimated to contain more organic carbon than is currently contained in the atmosphere," the report said. "Permafrost thawing results in the release of this carbon in the form of greenhouse gases, which will have a positive feedback effect to global warming."

At Duvanny Yar on the shores of the Kolyma River, the phenomenon that Zimov describes in speeches at scientific conferences can be seen first hand.

The steep-sided riverbank, until now held up by permafrost, is collapsing as the ice melts. Every few minutes, a thud can be heard as another wedge of soil and permafrost comes tumbling down, or a splash as a chunk falls into the river.

Nearby, Zimov points to an area unaffected by the melting so far -- a forest of larch trees with berries and mushrooms and covered with a soft cushion of moss and lichen.

Farther down the slope though, the landscape is covered with trees toppled over as the soil disintegrates. Brooks murmur down the slope carrying melted ice.

Elsewhere, places that five or 10 years ago were empty tundra are now dotted with lakes -- a result of thawing permafrost. These "thermokarst" lakes bubble with methane, over 20 times more potent as a greenhouse gas than carbon dioxide.

The permafrost thaw affects those rare outposts where humans have settled. In Chersky, a town of 3,000 people, apartment blocks have cracks running through their walls as the earth beneath them subsides. Many have been demolished because they were no longer safe.

So few people live in or visit this wilderness that the changing landscape on its own is unlikely to worry people on the other side of the world. But Zimov warned that people everywhere should take notice, because within a few years, the effect of the permafrost melting in Siberia will have a direct impact on their lives.

"Siberia's landscape is changing," he said. "But in the end, local problems of the north will inevitably turn into the problems of Russia's south, the Amazon region or Holland."