In the increasingly unfrozen north, dangerous creatures are stirring back to life
For the first time in centuries, which covers a quarter of the Northern Hemisphere to depths as great as 1,000 feet — is softening, like a stick of butter left out on the counter. Embedded within it are flash-frozen plants, carcasses of extinct mammals, and microbes — including smallpox and other worrisome bugs. The noninfectious bacteria pose a threat, too:
They could convert all that dead matter into more CO2 than humans have released since the Industrial Revolution.