Scientists trying to piece together data on the stability of one of the largest carbon sinks on Earth may see their work hampered by Vladimir Putin’s invasion of Ukraine.
Permafrost, the permafrost that covers about 60 percent of Russia’s territory, is estimated to contain twice as much greenhouse gases as the atmosphere.
Its stability is key to limiting global warming to 1.5C, and if carbon is released, the UN’s global targets will fall far behind.
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A team from Northumbria University and Russian colleagues recently received a grant from the educational foundation Leverhulme Trust to continue their decades-long research on collecting rock formations from Siberian caves.
These rocks store the history of the global climate, and by studying them, scientists can estimate when permafrost was last transformed into a thawed state, as well as temperatures reached during previous warm periods.
There are fears that a massive thaw would create a positive feedback loop, releasing greenhouse gases that would accelerate global warming, hasten the disappearance of remaining permafrost and release more carbon.
Reliable data on this tipping point is an important clue that is largely missing from current climate models.
Dr Stuart Umbo from Northumbria University said: “Permafrost thaw is not only controlled by temperature – precipitation, seasonality and atmospheric patterns also play a role.
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“With these changes, no one really knows what effect it will have on permafrost thawing on a regional scale. But we know there’s a lot of carbon in there.
“When the permafrost starts to thaw, this carbon will be released into the atmosphere, but what the controls are, and when the thaw will actually start, is really uncertain.”
Rock samples include cave deposits such as stalagmites, stalactites, and spherical cave pearls known as “cave rocks.”
They are all formed from carbonates formed by dripping water.
“If you form a cave in Siberia, you have to thaw the permafrost above the cave because you need dripping water,” Dr Umbo told PA news agency.
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“We take these formations, and we can date them the same way we use carbon dating, but instead of carbon, we use uranium, thorium and lead, which are longer-lived elements.
“If we know that the stalagmites formed at a particular time, we can say we know that the permafrost above the cave has thawed — which is the basis of our entire study.”
Over the past 2 million years, Earth has cycled in and out of ice ages and warm periods called interglacials, just as it does in modern times.
The last interglacial occurred about 130,000 years ago, and there is already plenty of evidence for the climate during this time.
