Scientists have long been worried about what many call “the methane bomb” — the potentially catastrophic release of methane from thawing wetlands in Siberia’s permafrost.

But now a study by three geologists says that a heat wave in 2020 has revealed a surge in methane emissions “potentially in much higher amounts” from a different source: thawing rock formations in the Arctic permafrost.

The difference is that thawing wetlands releases “microbial” methane from the decay of soil and organic matter, while thawing limestone — or carbonate rock — releases hydrocarbons and gas hydrates from reservoirs both below and within the permafrost, making it “much more dangerous” than past studies have suggested.

Nikolaus Froitzheim, who teaches at the Institute of Geosciences at the University of Bonn, said that he and two colleagues used satellite maps that measured intense methane concentrations over two “conspicuous elongated areas” of limestone — stripes that were several miles wide and up to 375 miles long — in the Taymyr Peninsula and […]