It sounds like something from a sci-fi thriller, but it’s very real: Climate change is melting glaciers and thawing permafrost, potentially releasing ancient viruses and bacteria that have been frozen for hundreds or even thousands of years.
Earlier this year, researchers analyzing ice cores from the Guliya ice cap in Tibet found 28 never-before-seen virus genera, some of which had been frozen for up to 15,000 years.
While the discovery undoubtedly provides a fascinating snapshot of Earth's microbial and climate history, more alarmingly, it's possible that as glaciers melt, such viruses could be released into the environment and cause harm.
Such concerns of "reanimated" viruses and bacteria are not unfounded. In 2016, for example, a child died and dozens of people were hospitalized after exposure to anthrax in remote Siberia. The outbreak was indirectly caused by a heat wave, which exposed the corpse of a reindeer that had died of anthrax 75 years earlier and was covered over by permafrost. Once thawed, bacteria from the reindeer remains were released onto the tundra, infecting modern-day reindeer and then humans.
Frozen fears:
- Viruses and bacteria are thought to be able to remain viable in permafrost (frozen soil) for extremely long periods of time, possibly even millions of years.
- Temperatures in the Arctic Circle are rising quickly -- at least twice as fast as the global average.
- Scientists have to take particular care when extracting ancient microbes from glaciers, as it's easy to accidentally contaminate ice core samples with modern pathogens.