ON THE ZYRYANKA RIVER, Russia — Andrey Danilov eased his motorboat onto the gravel riverbank, where the bones of a woolly mammoth lay scattered on the beach. A putrid odor filled the air — the stench of ancient plants and animals decomposing after millennia entombed in a frozen purgatory.
‘‘It smells like dead bodies,’’ Danilov said.
The skeletal remains were left behind by mammoth hunters hoping to strike it rich by pulling prehistoric ivory tusks from a vast underground layer of ice and frozen dirt called permafrost. It has been rapidly thawing as Siberia has warmed up faster than almost anywhere else on Earth. Scientists say the planet’s warming must not exceed 1.5 degrees Celsius — but Siberia’s temperatures have already spiked far beyond that.
A Washington Post analysis found that the region near the town of Zyryanka, in an enormous wedge of eastern Siberia called Yakutia, has warmed by more than 3 degrees Celsius since preindustrial times — roughly triple the global average.
The permafrost that once sustained farming — and upon which villages and cities are built — is in the midst of a great thaw, blanketing the region with swamps, lakes, and odd bubbles of earth that render the land virtually useless.
‘‘The warming got in the way of our good life,’’ said Alexander Fedorov, deputy director of the Melnikov Permafrost Institute in the regional capital of Yakutsk. ‘‘With every year, things are getting worse and worse.’’
For the 5.4 million people who live in Russia’s permafrost zone, the new climate has disrupted their homes and their livelihoods. Rivers are rising and running faster, and entire neighborhoods are falling into them. Arable land for farming has plummeted by more than half, to just 120,000 acres in 2017.
In Yakutia, an area one-third the size of the United States, cattle and reindeer herding have plunged 20 percent as the animals increasingly battle to survive the warming climate’s destruction of pastureland.
Siberians who grew up learning to read nature’s subtlest signals are being driven to migrate by a climate they no longer understand.
This migration from the countryside to cities and towns — also driven by factors such as low investment and spotty Internet — represents one of the most significant and little-noticed movements to date of climate refugees. The city of Yakutsk has seen its population surge 20 percent to more than 300,000 in the past decade.
And then there’s that rotting smell.
As the permafrost thaws, animals and plants frozen for thousands of years begin to decompose and send a steady flow of carbon dioxide and other gases into the atmosphere — accelerating climate change.
‘‘The permafrost is thawing so fast,’’ said Anna Liljedahl, an associate professor at the University of Alaska in Fairbanks. ‘‘We scientists can’t keep up anymore.’’
Against this backdrop, a booming cottage industry in mammoth hunting has taken hold. The long-frozen mammoth tusks — combined with Chinese demand for ivory — have imbued teetering local economies with a strike-it-rich ethos. Some people bask in instant money. But others watch in dismay as Siberia’s way of life is washed away.
The first sign of change was the birds.
Over the past several decades, never-before-seen species started to show up in the Upper Kolyma District, an area on the Arctic Circle in northeastern Siberia 1,000 miles west of Nome, Alaska.
The new arrivals included the mallard duck and barn swallow, whose normal range was previously well to the south. A study published last year by Yakutsk scientist Roman Desyatkin said ornithologists in the region have identified 48 new bird species in the past half century, an increase of almost 20 percent in the known diversity of bird life.
Then the land started to change.
Winters, though still brutal, turned milder — and shorter. Fed by the more rapidly thawing permafrost, rivers started flooding more, leaving some communities inaccessible for months and washing others away, along with the ground beneath them.
The village of Nelemnoye was cut off for three months in late 2017 when the lakes and rivers didn’t fully freeze, stranding residents who use the frozen waters for transport.
Claudia Shalugina, 63, used to teach at the three-story school in Zyryanka, a 90-minute motorboat ride downriver. Around 10 years ago, the Kolyma River washed away a section of Zyryanka, taking Shalugina’s school with it.
Smoking a cigarette on the porch of the village library, Shalugina offered her own analysis of the changing climate: ‘‘I think, ‘Lord, it’s probably going to be the end of the world.’ ‘‘
Just downstream from where the Zyryanka River flows into the mighty Kolyma, three huge tractor-trailers stand abandoned on the forested riverbank. Weeds and wildflowers rise up around them. The frozen river, used as a winter ice road, suddenly became too risky to drive on.