Marshes could save the world: this is the conclusion reached in an article published in Horizon Magazine according to which peat bogs, swamps with a large abundance of slow-moving water at low temperatures, can represent an “excellent” deposit for carbon dioxide.
Carbon dioxide is one of the most powerful and most capable of changing the earth’s climate and it is important to “sequester” it or store it so that it is not lost to the environment. There are many methods that scientists are devising to achieve this goal but more and more often we resort to the same nature that has already shown that it can perform this task perhaps even more efficiently than any method developed in the laboratory. Among the many types of natural environments that can “sequester” carbon dioxide there are also marshes: peat bogs, made mostly of decaying dead plant material, can cause carbon dioxide to deposit under this layer.
The plant material is usually broken down by the enzymes that are in turn present in the microorganisms. In peat bogs, however, there are also other compounds called phenols that stop the functioning of some of these sets and lead to a “spectacular failure of decomposition,” as Chris Freeman, biogeochemist of Bangor University, UK, explains, who is studying the swamps and their ability to store carbon dioxide. This is a somewhat precarious equilibrium: it would suffice for only one of these enzymes, called phenol oxidase, to come into action because the decomposition process starts again and the peat bogs begin to release their carbon into the environment. It is, as defined in the press release, a “delicate standstill that holds the door to climate disaster.”
Now scientists fear that this can happen with global warming and with the ever more pressing drought and for this very reason Freeman himself, together with researcher Juanita Mora-Gomez, now at the Earth Sciences Institute of Orléans, have started a new project called microPEAT to study the bogs of Wales, the Arctic and Colombia with much more detail. They took samples from these swamps and brought them to the laboratory to subject them to pressing drought conditions and to understand the resulting effects.
In fact, what was feared happened with the champions of Wales and the Arctic: with drought, the microbes in the peat changed their metabolism and began to emit carbon. However, with the Colombian champions, the same state of drought went instead to further suppress the phenoloxidase enzymes. Researchers want to understand the reason for this differentiation but already believe that there are some particular points in the peat bogs that may be more resistant to climate change than others.
Answering these questions could be very important to prevent the release of carbon into the environment and therefore the acceleration of global warming. This is a “very important possibility,” as Freeman himself explains, a sort of “plan B for the planet.”