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The headlines about scientists’ annual report card on the Arctic are alarming enough: warming temperatures, melting ice and rising seas. But the detail that The Washington Post’s Andrew Freedman highlighted is terrifying.

Permafrost — the frozen soil that makes up much of the Arctic, and that is filled with carbon — is thawing. As it does, it could release that carbon into the atmosphere, accelerating climate change. Freedman writes:

There has been concern throughout the scientific community that the approximately 1,460 billion to 1,600 billion metric tons of organic carbon stored in frozen Arctic soils, almost twice the amount of greenhouse gases as what is contained in the atmosphere, could be released as the permafrost melts. Warming temperatures allow microbes within the soil to convert permafrost carbon into the greenhouse gases — carbon dioxide and methane — which can be released into the air and accelerate warming.

Kendra Pierre-Louis of The Times put it this way:

Researchers say that if too much permafrost thaws it will create a self-reinforcing cycle wherein thawing permafrost will lead to still more thawing permafrost, which in turn will make climate change worse. Recent observations of carbon flows in Alaskan permafrost have found that more carbon is being released than stored.

Clara Jeffery, the editor of Mother Jones, wrote simply: “This is the tipping point I dread the most.”

I know that a lot happened yesterday — the unveiling of impeachment articles; President Trump’s continued flirtation with the Russians; the House Democrats’ dubious decision to hand Trump a political win on trade; and more. But the melting of the Arctic will have a more profound effect on our lives than any of these things.