Will more ‘mouths to hell’ open up because of climate change? We asked a permafrost expert

You may have seen photos of a cavernous chunk of land in Siberia recently, accompanied by headlines on the growing ‘mouth of hell’.

The Batagaika crater in Yakutia, Russia, has recently entered the news again, though there’s no major update on its spread.

Resembling the rocky outline of a stingray from above, this giant hole first formed in the 1960s when nearby forest clearances caused the underground permafrost to thaw and collapse.

The Indigenous Yakut people who live in the area have reported hearing strange booming sounds for years, as more chunks of frozen wall fall in. While the recovery of a 42,000 year old extinct foal in 2019 - preserved with liquid blood inside - has added to the mysterious aura and scientific possibilities of this site where worlds seem to collide.

Scary as it sounds, the most alarming facts lie not with the dimensions of the biggest ‘abrupt thaw’, as they’re known. Instead it is the rate at which other permafrost-induced craters are forming in the Arctic, and the huge stores of greenhouse gases they unleash that are worrying.

Permafrost is any land that stays frozen all year (or, more precisely, for two years straight). The northern permafrost region spans 15 million square kilometres - roughly three times the entire area of the EU plus the UK.

Its compact soils contain more carbon because the plants that grow during the Arctic summer are frozen into the permafrost before they can decompose. This means the region’s frozen ground contains an estimated 1,500 billion tonnes of carbon.

It is a staggering amount that equates to three times the mass of all living vegetation on Earth, explains Gustaf Hugelius, a permafrost expert at Stockholm University.

As the landscape heats up, microbes start feeding on