Permafrost — ground that remains frozen for more than two years straight — underlies nearly one-quarter of the land in the northern hemisphere. The deepest parts extend a mile into the Earth, and the oldest parts are more than 600,000 years old.
But as the world warms, the permanence of the permafrost is being undermined in many places, including Canada, Alaska and Siberia.
Technically, permafrost doesn’t melt, it thaws. But you’re right to be concerned; scientists estimate that by 2100, as much as two-thirds of the Arctic’s near-surface permafrost could be lost. And yes, this could potentially unearth viruses and bacteria that have been sequestered for tens of thousands of years.
In 2016, a 12-year-old boy died and around 100 people became sick with anthrax poisoning in a region of Siberia that hadn’t seen an outbreak in over 70 years. Scientists think the outbreak was caused by anthrax spores released from a decades-old reindeer carcass that was newly exposed by thawing permafrost.
A single gram of permafrost can contain thousands of dormant microbe species. Scientists fear that a thaw could not only unearth diseases we thought we had conquered — including smallpox and bubonic plague — but also release ancient pathogens against which we currently have no natural immunity and no effective antibiotics or vaccinations.
The main mitigating factor will be the extent to which humans come into contact with these emerging threats. Today, fewer than five million people live in northern permafrost regions. But as the world warms, new shipping routes become viable, and resource extraction, commerce and tourism in the Arctic increase, we run the risk of people encountering ancient pathogens — and spreading them around the world.
Read more:
- How long has Antarctica been frozen?
- Could we live in Antarctica and Greenland if all the ice melted?
- Could the Black Death happen again?
- How do scientists develop vaccines for new viruses?
Asked by: Luke Russell, Wakefield
To submit your questions email us at questions@sciencefocus.com (don’t forget to include your name and location)