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The huge reserves of greenhouse gases, frozen deep beneath the seabed, are starting to disintegrate at an alarming rate. This is according to an international team of scientists whose preliminary results were recently reported The Guardian.
These deposits, technically called methane “gas hydrates”, are often described as “burning ice” because of the parlor trick of burning what appears to be ice on top of a Bunsen burner.
The research has not yet been peer-reviewed and has been controversial, according to some climate scientists The Guardian the article makes unsupported claims. We agree that the findings should be peer reviewed before being reported.
But as experts in these exact methane hydrates, we are more sympathetic than climate scientists to the idea that this is a serious possibility that we need to start worrying about.
So, while controversial, let’s assume for a moment that these latest findings are real and that methane frozen under the seabed is indeed being released. What does this mean?
Methane is not as common as carbon dioxide, but it also contains carbon and is a powerful greenhouse gas. Many people have heard of methane stored in Arctic permafrost, but few realize that there are also massive and much larger deposits of gas stuck under the sea floor.
Although thawing of seabed greenhouse gases has long been predicted – and feared – it was suspected that it would only become a serious problem by the middle of this century. If it now appears to be melting much earlier, it is a sign that human indifference to the environment and the release of carbon from fossil fuels is now effectively amplified by the disintegration of our planet’s geological balance.
To put this into perspective, there is perhaps 20 times more carbon stored in these underground nature reserves than in the entire biomass of the Earth combined, i.e. all plants, animals and microbes. Clearly, there is at least the potential for the release of greenhouse gases from these deposits on a significant scale.
The methane trapped in their freezing underground hydrate cells is expected to remain there for millions of years, accumulating over the eons. If these deposits are now thawing rapidly, we might think that basic physical parameters such as temperature and pressure are the only things that control their formation and destabilization.
If so, the problem could be easily understood and perhaps even mitigated through human intervention. However, it increasingly appears that other, less predictable factors are also relevant.
One unexpected influence is the Earth’s fluctuating magnetic field which, as we found in a study published last year, can potentially destabilize methane deposits.
There is also the possibility that this same effect could eventually lead to mass extinction: the global destruction of gas hydrates could have caused the great extinction event of the late Permian, which wiped out 90% of species on Earth. about 250 million years ago.
Estimated presence of methane hydrate in the world. (World Ocean Review / Wallmann et al.)
Microbes could stabilize these methane deposits
Another overlooked factor is the role of microbial life. Microbes have been with us for more than 3 billion years and are found virtually everywhere on our planet, including the depths of the sea floor, in places that we might otherwise think living things couldn’t survive, let alone thrive.
It therefore seems perfectly natural for these same microbes to interact with stored hydrate reserves, perhaps even using high-energy methane to thrive.
What if these microbes also stabilized their “food source”? Our research groups have recently shown that marine bacteria that use methane can easily produce simple proteins or “biomolecules” that do just that.
Furthermore, in laboratory experiments and computer simulations, we have demonstrated the accelerated formation of gas hydrates by such biomolecules so that we can now conclude that microbes will actually coordinate these reserves under the real world conditions found beneath our seas. and oceans.
The story becomes even more intriguing. We then studied the effect of both magnetic field changes and biomolecules on methane hydrate formation rates.
These two factors seem to complement each other, so that microbes growing on hydrates in the presence of the Earth’s relatively weak, but changing magnetic field, may have adapted and evolved – no doubt on geological time scales – to skillfully control massive hydrate deposits of methane. found beneath the seabed and in the permafrost.
In other words: yes, microbes could indeed be the keepers of this aspect of the Earth’s climatic stability. If, and clearly it’s still a big “if”, we’ve upset this delicate geo-microbial balancing act through global warming, then we’re not just playing with fiery ice, we may eventually see a world with temperature rises not seen before dinosaurs roamed the planet. 
Chris Allen, Professor of Interdisciplinary Microbiology, Queen’s University Belfast and Niall English, Professor, School of Chemical and Bioprocess Engineering, University College Dublin.
This article was republished by The Conversation under a Creative Commons license. Read the original article.
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