The Great Siberian Thaw

Permafrost occupies nine million square miles of the Earth’s surface, most of it in Russia.

Dubbed vechnaya merzlota, or “eternal frost” by Soviet scientist Mikhail Sumgin in the 1920s, permafrost captivates the imagination with its inscrutable grandeur. Spanning millions of square miles and with depths a mile deep in provinces such as Yakutia, it sits in the arctic regions in North America and occupies two-thirds of Russian territory, mostly in Siberia. It is an artifact of the glacial era three million years ago, freezing, thawing and refreezing as the planet cycled through ice ages. There is an estimated half a trillion tons of carbon locked in permafrost, twice as much as currently resides in the Earth’s atmosphere. For 150,000 years, it remained stable and inexorable. Now, with unprecedented warmth in the region, it is slowly melting.

Permafrost confounded explorers in the 17th and 18th centuries, as Russia expanded its empire eastward. Settlers in the city of Yakutsk, in Yakutia, encountered a “firm body of ice” that resisted all attempts at cultivation. “Shergin’s shaft,” dug in the 1820s, proved that permafrost was at ...