The words “zombie virus found in Russian ice” sounds like something straight out of a horror movie – even after the pandemic, it’s hard to shock anyone.
But scientists this week published research showing a virus frozen for tens of thousands of years in Siberian permafrost is coming back to life.
Researchers from France, Germany and Russia revived 13 new types of viruses that have been frozen in the Siberian soil for 27,000 to 48,500 years.
They say the work poses an unacceptable risk to people – unlike other scientists looking for ancient viruses in the frozen remains of mammoths, woolly rhinos or prehistoric horses.
But the results can, he writes, “be extrapolated to many other DNA viruses that can infect humans or animals”.
“Thus, the ancient permafrost … would have released this unknown virus when it thawed,” he said on bioRxiv, an online research portal.
“How long this virus can remain infectious once it has been exposed to outdoor conditions and the probability that it will encounter and infect a suitable host in that interval cannot yet be estimated.
“But the risk will increase in the context of global warming, when the thawing of permafrost will continue to accelerate, and more people will live in the Arctic after industrial efforts.”
The so-called zombie virus does not pose a threat to people, as it is the type that only infects microorganisms, but other pathogens that will be released in the future due to the melting of permafrost could, scientists say, pose a risk to humans.
A report from Greenpeace, an environmental organization, even questioned whether these “back-from-the-dead” pathogens could cause a new pandemic.
The findings are echoes of the 1993 film Jurassic Parkwhere scientists cloned dinosaurs using DNA taken from insects preserved in amber – only for the creatures to wreak havoc on humans.
Permafrost, or permanently frozen ground, is mostly found in Alaska, Canada and Siberia, and covers about a quarter of the Northern Hemisphere, but the area is thawing when the climate warms.
Many other research groups are looking at pathogens, including bacteria, and larger organisms that are released.
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Viruses dating back 15,000 years have been found in the ice caps of Tibet, research published last year.
Even more remarkably, a 2018 report showed that tiny nematode worms have been revived from frozen Siberian soil samples up to 42,000 years old.
The researchers behind the study are confident that the creature, which began to move and eat after being kept at 20°C in a Petri dish containing a nutrient medium, was not due to contamination of the sample.
Among those interested in the disease threat from permafrost microorganisms is Prof. Birgitta Evengard, from the Department of Clinical Microbiology at Umea University in Sweden.
Prof Evengard helped organize the 2019 conference, Understanding and Responding to Global Health Security Risks from Microbial Threats in the Arctic.
He said it is not possible to say that some pathogens found in thawing permafrost definitely pose a threat to people, but there is the same chance.
“There is a Pandora’s box – it has the potential to become a human pathogen,” he said, adding that there would be spillover into the environment.
“In Siberia you have three rivers that carry debris from the permafrost into the Bering Sea, a pretty busy ocean current.
“They will go around the world in a few weeks. People don’t know. The world is very, very connected with all ecosystems – sea, land and air.”
The risk is heightened by research released a few months ago showing that the Arctic, since 1979, has warmed almost four times faster than the rest of the world, a finding that Prof Evengard described as alarming.
“This means that what happens in the Arctic is a driver for what will happen around the world,” he said.
It is important, he added, that scientists have access to regions such as Siberia to analyze what is happening.
Aside from the potential to release pathogens into the environment and cause land areas to collapse, thawing permafrost risks accelerating climate change.
When the soil thaws these microbes cause the release of carbon dioxide and methane, two greenhouse gases, because they consume organic matter in the soil.
Updated: 06 December 2022, 04:04