7. Is permafrost a climatic weather bomb due to global warming?
Permafrost is called to soil and subsoil frozen for long periods, lacking ice or snow often. Its thickness varies from a few meters to several hundred meters, depending on the climate of the place. A permafrost soil, due to the poverty of its nutrients, has a vegetation of very little diversity. These cold deserts, with very low humidity and rainfall, occupy huge territories such as the tundra, one of the coldest biomes on the planet, which has been described as a plain without trees. Permafrost is found mainly in Alaska, Canada and Russia, but also in the Nordic countries and the Himalayas.
Permafrost soils have a high organic carbon content. It is about 1700 million tons, as has been estimated, almost twice the total amount of carbon currently in the atmosphere. When the soil remains frozen, the carbon is inert, but when the permafrost is thawed, the decomposition of organic matter through microbial activity increases sharply, with the consequence that large amounts of carbon would eventually be emitted into the atmosphere as CO2 and to a lesser extent as methane. In other words: unlike warmer latitudes, where microorganisms in the soil constantly break down plant matter and send the carbon it contains to the atmosphere, arctic soils have been cold enough to preserve the frozen remains of life ancient vegetable. But as the planet heats up, soil microbes become capable of breaking down more and more carbon, sending it into the atmosphere, and worsening global warming in a turbulent feedback loop.