Warming Climate Awakening Ancient Microbes from Frozen Sleep

November 28, 2022

On ancient microbes thawing from frozen sleep, there’s good news and bad news.

New Scientist:

Seven types of viruses that have lain frozen in the Siberian permafrost for thousands of years have been revived. The youngest were frozen for 27,000 years, while the oldest was on ice for 48,500 years – making it the most ancient virus resuscitated so far.

“48,500 years is a world record,” says Jean-Michel Claverie at Aix-Marseille University in France, who did the work with his colleagues. His team has previously revived two 30,000-year-old viruses from permafrost, the first of which was announced in 2014.

The team says the fact that all nine viruses remained capable of infecting cells shows that ancient viruses from melting permafrost are a threat to the health of plants and animals, including us.

While 48,500 years may be a record for a virus, several groups claim to have revived bacteria trapped in sedimentsice or salt crystals that are up to 250 million years old. However, it remains unclear whether the organisms are actually that old or are much younger ones that contaminated samples.

The nine viruses Claverie’s team has revived are distinct from all previously known ones, he says, so are very unlikely to be from contamination of the sample by modern entities. The team discounted several other apparently revived viruses because their genomes were too similar to known ones.

It could well be possible to resurrect viruses that are much more than 48,500 years old, says Claverie. The deepest permafrost is up to a million years old. However, it is difficult to establish the age of ancient permafrost because standard radiocarbon dating doesn’t work beyond 50,000 years.

The 48,500-year-old virus came from permafrost 16 metres below the bottom of a lake in Yukechi Alas in Yakutia, Russia. It is a type of pandoravirus – a giant virus that infects single-cell organisms known as amoebas.

In fact, all the nine viruses revived by the team so far are giant amoeba-infecting viruses because this is all the team looks for. The researchers add permafrost samples to cultures of amoebas and inspect them under a microscope for signs of infection, which shows the virus is “alive” and replicating.

If ancient giant viruses remain infectious after being frozen for such a long time, other kinds will too, says Claverie.

Eric Delwart of the University of California, San Francisco, who has recreated plant viruses from long-frozen caribou faeces, agrees.

“If the authors are indeed isolating live viruses from ancient permafrost, it is likely that the even smaller, simpler mammalian viruses would also survive frozen for eons,” says Delwart.


A team of researchers affiliated with multiple institutions across Europe, the U.K. and Canada has found that hundreds of thousands of tons of bacteria are currently being released annually into the environment by melting glaciers in the northern latitudes. In their paper published in the journal Communications Earth & Environment, the group describes sampling glacial runoff from multiple sites in Europe, North America and Greenland.

As climate change progresses, doomsday reports from around the world have proliferated. One alarming claim is that a virus or strain of bacteria will emerge from ancient ice that is impervious to the human immune system, killing off most, if not all, of humankind. In this new effort, the researchers have joined a growing effort to take samples of melting runoff from glaciers to learn more about their microbial ecosystems as a means to discover whether a threat exists, and if so, what sort.

The work involved collecting glacier runoff samples from eight glaciers in North America and Europe, and two from the Greenland ice cap. They studied the samples to learn more about the microbiota hosted in the runoff. They found tens of thousands of microbes in just millimeters of water and made estimates for the number of bacteria and algae that are currently being released from glaciers across the Northern Hemisphere—approximately 650,000 metric tons each year. They note that this is expected to continue for approximately 80 years, at which point, the glaciers will be gone.

The researchers did not study the bacteria individually, and thus did not spot any species that might pose a threat to human health. They did note that most of the bacteria were killed by the sun soon after exposure, suggesting that even if a human pathogen is among them, the chance of infection is slight. Bacteria in water samples, the researchers note, tend to have pigments that absorb sunlight, which further adds to warming in northern regions.


3 Responses to “Warming Climate Awakening Ancient Microbes from Frozen Sleep”

  1. It is a dangerous chapter that we have to deal with in the agony of the climate crisis. Thank you 🌍🙏

  2. rhymeswithgoalie Says:

    Nerd note: I’d learned that the mimivirus was the largest, but it appears that megavirus, discovered in 2010, was larger, and then the even larger pandoravirus was first described in the scientific literature in 2013.

  3. Brent Jensen-Schmidt Says:

    For those that expect Mother Nature to solve the problem of CC, you may be right.

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