Melting permafrost threatens to release microbes and carbon

The climate crisis is not only responsible for rising sea levels, but also for increasing carbon in L’atmosphere and maybe soon germs. In an article published on March 9, 2022, the Jet Propulsion Laboratory (JPL), antenna of the Nasa in charge of space exploration missions such as Perseverance or Curiosityexplains that the melting permafrost could release high doses of carbonaceous particles into the atmosphere and bacteria, viruses and microbes. This analysis is based on a study published in the journal Nature on January 11, 2022, looking at the emissions carbon in the polar Circle Arctic. During the XXI^and century, melting could really become a veritable climatic and biological time bomb.

Permafrost, a prison of ice

Permafrost is found on several continents and regions of the world. These expanses of frozen ground make up 90% of Greenland, 80% of Alaska, and 50% of Russia, with much of it concentrated in Siberia. The permafrost plays a key role in the development of certain ecosystems and for the biodiversity acclimatized to these austere environments. But for several years now, global warming has had a lasting impact on these frozen soils, particularly in theArctic.

As JPL points out, one of the direct impacts of this melting is the alterations suffered by human infrastructure, such as roads or the durability electrical systems. But, in the long term, more pernicious threats can arise from the sometimes thousand-year-old ice sheets that form the permafrost. In 2016, the newspaper Scientific American revealed that cases of contamination at theanthrax in Siberia were probably due to the release of anthrax, bacteria vectors of sometimes fatal infections. In 2014, scientists exposed in a study, already published by Naturehaving “resurrected” a virus trapped in the permafrost for 30,000 years.

Two years after the start of the Covid-19 pandemic having impacted all regions of the world, researchers are concerned to see old devastating diseases reappear, such as spanish flu or even the smallpoxdeclared eradicated since 1980 by the World Health Organization (WHO).

carbon bomb

The second main risk of melting permafrost is the release of methane and carbon dioxide. In the Arctic, it is estimated that the permafrost retains a colossal quantity: some 1,700 billion tonnes. the Jet Propulsion Laboratory illustrates this figure with an element of comparison, equivalent to 51 times the quantity of carbon emitted by the use of combustible fossil by mankind in 2019. The geologists fear too sudden an explosion of these gas in the atmosphere, which would probably come make the climate crisis worse.

For the time being, scientists cannot accurately predict the course of events concerning the melting of the permafrost. Numerous observation and surveillance missions, such as Copernicus headed by the European Space Agency, are however established to understand the phenomenon and try to anticipate its purposes.

Should we fear the release of pathogenic viruses with the melting of permafrost? Decryption

Article of Nathalie Mayerpublished on 03/11/2020

For several months now, the world has been fighting against pandemic murderer of the Covid-19. At the same time, global warming continues, inexorably. Two subjects that seem distant, but which could come closer together if, under the effect of rising temperatures, the thawing of the permafrost were to release long-dormant viruses and bacteria. Jean-Claude Manuguerra, virologist at the Institut Pasteur, reassures us… on this point.

On several occasions in the past, humanity has been confronted with epidemics, even to deadly pandemics. The ” spanish fluof 1918, due to a particularly virulent strain of the virus, caused between 50 and 100 million deaths worldwide. The plague caused by a bacterium called Yersinia pestis, or the Ebola virus disease are other well-known examples. And today, of course, the Covid-19 that the director general of the United Nations Environment Program consider as a “warning message for our civilization which plays with the fire ».

It plays with fire by destroying natural spaces and breaking down the barriers that previously existed between ecosystems. Leaving the carriesopen to close contact between humans and speciessavages carrying infectious pathogens . A determining cause of the development of future epidemics, according to scientists.

Bacteria released by thawing permafrost

But human activities are also at the origin of another phenomenon that could pose a problem. Anthropogenic global warming is now causing the melting of permafrost – permafrost, as the English call it – these pieces of basement that are in principle permanently frozen. A thaw that gradually releases what was held there, a prisoner for a long time. And in particular, alert some, viruses and bacteria.

“Some bacteria are both extremely resistant and pathogens , for both humans and animals. This is the case of Bacillus anthracis, the bacterium responsible for anthrax — a deadly disease if the drugs are not taken quickly antibiotics appropriate to eliminate it; it is also known as anthrax —which in the form of spores resists very well to difficult conditions of temperature and humidityexplains Jean-Claude Manuguerra, virologist and research director at the Institut Pasteur. Bacillus anthracis spores over a hundred years old and still viable have already been found. In the 19th^and century, the local populations spoke of “cursed fields” by this bacterium which remained in the soil for an extremely long time”.

In 2016, the media thus reported the story of this child who died of anthrax in Siberia. According to local authorities, an abnormally hot summer had melted the permafrost that held a reindeerinfected, releasing viable spores of the bacteria. “To my knowledge, this is the only example of infection of humans — or animals — with a pathogen from melting ice.”, notes Jean-Claude Manuguerra. But it shows that bacteria can indeed be released by the thawing of permafrost relatively superficial. “As for the melting of ice caps , the risks are low. Not to say non-existent. »

Can permafrost thaw release viruses?

Viruses capable of infecting humans or animals, for their part, remain relatively fragile. Including those that scientists commonly label as resistant. It is difficult for them to survive freezing or a slow increase in temperature. “I don’t imagine that ahuman virus pathogen can survive ice thawing under warming conditionsconfides to us the virologist of the Pasteur Institute. Not to mention the fact that to start an epidemic chain, it would be necessary that at the time of the thaw, the virus would have to infect a human being before the temperature becomes too high to guarantee its conservation. And that this human being then meets several other human beings whom he would infect. It is only in Hervé Bazin’s novel, “The Ninth Day” that this kind of catastrophic scenario can occur. »

Viruses of amoebas giants, mimivirus as scientists call them, have however been discovered in the Arctic. the Pithovirus and the Mollivirus, in particular, were buried in the ground 30 meters deep. It survived 30,000 years of freezing before being awakened by researchers. ” The H1N1 virus of the “Spanish flu” of 1918 was partly reconstructed thanks to sequences of his genome stored in permafrost. But no trace, this time, of a flu virus viable frozen”, further specifies Jean-Claude Manuguerra. More precisely, it was at the end of the 1990s, in the remains of an 18-year-old Inuit girl, baptized a posteriori “Lucie”, that fragments of the H1N1 virus were found and then amplified by Jeffery Taubenberger to determine the complete sequence of the ” spanish flu from 1918.

“Without having to go through cold storage, there are a lot of very virulent bacteria in the environment. And we probably have enough to worry about coronavirusresponsible for theCovid-19 pandemicso as not to worry about a danger toodiffusethan that of the potential release of pathogens by thawing permafrost. Zero risk does not exist, but we are not far from itpoints out Jean-Claude Manuguerra in conclusion. The dangers of melting ice are more to be found in the potential release of greenhouse gases or in rising sea levels than in that of a risk of a pandemic”.