El permafrost It is a crucial term when talking about the coldest areas of the planet and the impacts of climate change in the Arctic, Siberia or even in high mountain regions. Also known as permafrost, this frozen ground has been a cause of growing concern among scientists and engineers due to the accelerated thawing it is currently experiencing. In fact, it is estimated that permafrost covers around 24% of the earth's surface in the northern hemisphere, with much of this soil frozen since the last ice age.
This article aims to explain in detail what permafrost is and what its effects are. characteristics, formation, location and dangers associated with its defrostingPermafrost plays a central role in regulating the global climate by storing large amounts of carbon and methane, two of the most dangerous greenhouse gases. However, its thawing is releasing these gases, which could significantly increase global warming.
What is permafrost?
El permafrost is a layer of soil, rock, sand, or sediment that remains frozen for at least two years at a time, although in many areas it has remained frozen for thousands of years. This type of soil covers a vast area of the Earth's surface, especially in the Northern Hemisphere, encompassing approximately 23 million square kilometersIt is found mainly in areas such as the Siberian Arctic, Alaska, Canada, Greenland and the Tibetan Plateau.
This frozen soil has a peculiar characteristic: its upper layer, known as active layer, thaws during the warmer months of the year and refreezes in winter. It is often 0,3 to 4 meters thick and is composed primarily of organic materials, such as remains of dead plants and animals. When the active layer thaws, microorganisms in the soil begin to break down the organic matter, causing the release of carbon dioxide (CO2) y methane (CH4), which are two potent greenhouse gases.
Because of its ability to store large amounts of organic carbon, permafrost plays a essential role in climate stability of the planet. However, it also represents a potential risk, since its thawing is not only releasing more greenhouse gases but may also release Ancestral viruses and bacteria, some of which have been dormant for thousands of years.
Formation and characteristics of permafrost
Permafrost forms in areas where temperatures remain constantly falling for long periods of time, usually in areas where the average annual temperature is below 0 °CThese conditions allow water present in the soil and rock to freeze, resulting in soil that remains solid and stable ice.
One of the most worrying features of permafrost is its ability to store large amounts of carbon. It is currently estimated that this soil contains up to twice the carbon present in the atmosphere, making it a key factor in controlling climate change. Methane, a byproduct of thawing, has a greenhouse effect 25 times more powerful than carbon dioxide, making permafrost one of the greatest risks to global climate stability.
In addition, permafrost also represents a geological risk important. As the ground thaws, it loses its stability, which can lead to subsidence, erosion and the collapse of infrastructure that has been built on it, such as buildings, roads and pipelines. This problem is mainly affecting areas of the Arctic, where entire communities are seeing their infrastructure sink.
Another important classification of permafrost lies in its continuity or discontinuity. continuous permafrost covers more than 90% of the land in a given region, while the discontinuous permafrost covers between 50% and 90% of the surface. There is also the sporadic permafrost, which is visible in warmer or high mountain areas.
Consequences of permafrost thawing
The consequences of permafrost thawing are multiple and affect both locally and globally. At the local level, thawing causes the ground instability, which has devastating effects on infrastructure built in Alaska, Siberia and Canada. Buildings and roads begin to fracture or even collapse due to the loss of ground stability.
On the other hand, the global repercussions are much more worrying due to the release of greenhouse gases. For thousands of years, permafrost has been acting as a natural carbon sink, but when defrosted, it becomes a carbon emission source, releasing a considerable amount into the environment. This aggravates the effects of climate change and jeopardizes international efforts to reduce emissions.
In addition to carbon, permafrost can also release trapped contaminants as heavy metals, mainly mercury. Even more worrying is the possibility that ancient Virus and bacteria pathogens, which have been dormant for millennia, re-emerge and affect both humans and local fauna. In 2016, there was an outbreak of anthrax affecting several people and hundreds of reindeer, highlighting the seriousness of these risks.
Impact on local ecosystems
Thawing permafrost is disrupting local ecosystems, particularly in Arctic regions. The tundra, which covers much of Siberia and the Arctic, is being replaced by swamps and mud areas, which affects the biodiversity of these areas. Animals such as reindeer, whose seasonal migrations depend on the stability of the frozen ground, are seeing their habitats destroyed. This ecological imbalance also has repercussions for indigenous communities that have lived in harmony with these ecosystems for generations.
Such ecosystem changes can trigger a cascade of effects. For example, microbial activity that accelerates with the thawing of the active layer of permafrost could further contribute to the release of greenhouse gases, creating a climate feedback loop difficult to control.
Importance of permafrost conservation
Conserving permafrost is of vital importance to delay the advance of climate changeKeeping it frozen not only helps reduce the amount of greenhouse gases released into the atmosphere, but also preserves the stability of Arctic ecosystems. Arctic areas reflect more solar radiation due to their ice and snow cover, directly contributing to the planet's thermal regulation.
Among the main benefits derived from permafrost conservation are:
- Carbon storage: It is crucial to prevent the release of carbon stored in permafrost. If it thaws, global CO2 emissions could double what is currently in the atmosphere.
- Soil stability: The stability of infrastructure in the Arctic depends on the permafrost remaining frozen. Thawing it puts millions of people and their homes at risk.
- Local ecosystems: Permafrost is home and a source of sustenance for many species, including humans in these cold regions. Its conservation is key to prevent the collapse of these ecosystems.
- Preventing disease outbreaks: In addition to dangerous gases, permafrost could release ancient pathogens that could wreak havoc on global public health.
That is why the fight against climate change must include efforts to mitigate the thawing of permafrost. Among other strategies, reducing greenhouse gas emissions at global and local levels, as well as conserving sensitive areas, can help slow down this process.
Climate science is making important strides in understanding how different forms of ice melting affect the global climate. Recent studies have shown that the abrupt and localized thaw, known as thermokarst, is particularly worrying. This phenomenon occurs in about 20% of the permafrost regions in the northern hemisphere where the ground collapses due to accelerated thawing. This process can release large quantities of CO2 that further intensify climate change. In a study published in Nature Geoscience, it was concluded that areas where thermokarst has occurred show a release of CO2 up to five times higher than areas where the phenomenon has not occurred.
While much remains to be learned about the global impact of thawing permafrost, it is estimated that it could contribute up to 40% more CO2 emissions than previously anticipated by the end of the century.
Global warming must be addressed urgently if we are to safeguard Earth’s climatic future. The decisions we make today on how to mitigate climate change will directly influence how quickly the permafrost thaws and, therefore, how extreme weather events will develop in the years to come.
Although the outlook is worrying, not all is lost. There are pilot projects such as the Pleistocene Park In Russia, where scientists like Sergey Zimov are trying to restore Arctic ecosystems by reintroducing large mammals like bison, which could help keep permafrost intact. These kinds of initiatives, while small, are an example of what could be done on a larger scale to mitigate permafrost thawing.
Ultimately, the fate of permafrost is closely linked to our actions to curb climate change. Every degree of increase in global temperature accelerates its thawing and turns the Arctic into a climate bomb that, if left unchecked, could unleash irreversible damage to the planet's climate system.