Permafrost soils are melting after thousands of years due to climate change, and they are releasing ancient viruses and bacteria. Frozen permafrost soil is perfect for preserving bacteria and viruses because it is cold, dark, and lacks oxygen. The risk from permafrost pathogens is still unknowable, but does not mean they should be ignored.

Read more about how dormant bacteria and viruses are being revived as Earth’s climate warms.