By definition, permafrost is any ground that remains completely frozen at a temperature of 0°C (32°F) or colder for at least two consecutive years. Commonly known as permanently frozen soil, permafrost covers about one fourth of the Northern Hemisphere.
While the name suggests that the particular soil is permanently frozen, the frozen beds of sediment, rock, and soil are actually thawing at an increasing rate. Permafrost degradation is a huge threat to the Arctic ecosystems and communities. It contributes to the positive feedback loop and climate change which threatens to push our planet into an environmental crisis. Read on to learn more.
Where is it Found?
Permafrost exists in a climate where the average yearly air temperature is 0°C (32°F) or colder. Such climate is normally characterized by cold, long winters with little snow and relatively dry, cool, and short summers. It is, therefore, widespread in the Arctic, Antarctica and sub-Arctic regions. According to a recent estimate, it covers about 20% of the land surface of the planet. On land, it is predominantly found in Northern Canada, Alaska, and Siberia.
Permafrost Zones
Depending on its lateral continuity, permafrost can be categorized into two broad zones: continuous and discontinuous. In the continuous zone, it forms and exists virtually everywhere in the far North. The only exception is soil under rivers and lakes, which do not freeze to the bottom.
The discontinuous zone includes many permafrost-free areas. They progressively increase in number and size from North to South. Only rare patches of permafrost have been found to exist near the Southern boundary.
Why is Permafrost So Important?
Now that you know the answers to ‘what is permafrost?’ and ‘where does it exist?’, you might be wondering what makes it so important. Well, for a start, it affects virtually everything in the Arctic ecosystem, from vegetation and soil to wildlife and water. It makes the soil wet by preventing water from soaking deep into the ground. In the ground, ice builds up and eventually melts, producing landslides, lakes, ponds, and pits.
Permafrost stores a large volume of the Earth’s soil organic carbon. When it thaws, this carbon is released form the soil as methane and carbon dioxide (greenhouse gases). This means that permafrost thawing increases soil erosion and creates landslides and ground slumps.
It also changes the local hydrology by changing nutrient cycling, soil wetness, siltation and sediment loads of lakes and streams, and can form and drain lakes. After wildfires, it is the second major cause of disturbance to boreal forests (aka Taiga).
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The Various Repercussions of Permafrost Thaw
As stated before, permafrost, despite what its name suggests, is not permanently frozen in some areas. It is thawing because the climate of the Earth has been increasingly warming up each year. When it thaws, the ice inside it melts, leaving behind soil and water. There are a number of dramatic impacts of this, both for our planet and the things that live on it. For instance:
- Many villages in the Northern regions are built on permafrost. It is harder than concrete when its frozen. However, when it thaws, it can destroy roads, houses, and other infrastructure. Gas and oil pipes are also affected where mining is prevalent.
- When permafrost thaws, so do ancient viruses and bacteria in the soil and ice. These newly-unfrozen microorganisms could make animals and humans very sick.
- Organic carbon – the plant material in the soil – cannot decompose or rot away when permafrost is frozen. However, as it thaws, microorganisms start decomposing this material. The whole process releases greenhouse gases (e.g. methane and carbon dioxide) to the atmosphere.
Impact on Climate Change
Permafrost thawing has a major impact on climate change but unfortunately, it is often overlooked. Thawing permafrost releases carbon. As a result, the Earth’s surface is starting to absorb solar rays at an increased rate.
Since the microbes that were previously frozen are back at producing carbon, greenhouse gas emissions are increasing significantly. This creates a continuous circle as it melts further with the warmer climate. This phenomenon is called the Permafrost Carbon Feedback (PCF).
The Arctic is warming twice as fast as the global average. The overall impact of permafrost thawing is not just changing this region but they also present the risk to spread across the boundaries and affect all life beyond it.
How Can We Stop Permafrost Thawing?
What happens in the Arctic impacts the world beyond it, and vice versa. So, urgent action must be taken to stop permafrost thawing and save the planet from the dangers it faces because of it. The solution is in our hands. We can drastically reduce the rate at which permafrost is thawing by the end of the century if we start ratcheting down our emissions now. We need to focus our efforts on conserving our planet in general.
Ultimately, addressing the impact of Arctic permafrost thawing will require global scientific collaboration as well as political will. Policies need to be redesigned or developed to find an optimal balance between carbon reducing solutions and continued world prosperity.
Tax incentives might have to be introduced to encourage companies around the world to have sustainable development strategies. Consuming and traveling less – and spreading the word to your friends, family, co-workers, and neighbours – are important steps you can take as an individual to steer our civilization in the right direction.
Animal Experiment
Apart from these, there may be another way to slow down permafrost thawing. Ongoing experiments in Siberia have shown that the presence of large herbivores, e.g. reindeer, bison, and horses, significantly decelerates this process. On this research, a study suggested that if we let groups of gazers roam throughout the Arctic, it could keep most of the planet’s permafrost intact until the next century.
The theory is that large grass-eating animals will stomp the soil, making it more compact and therefore more resilient to temperature rises. Early results have shown that it is having a positive impact on whole ecosystem. However, more data is needed.
Final Word
Nowhere on Earth is changing as quickly as the Arctic. It becomes easier to see year on year, and we are just beginning to learn the consequences. Permafrost is not a problem of the future. It is thawing now and has been for years. It has also never been more critical to take action and make sure that the situation does not spiral out of control.
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