What Is Permafrost?

Permafrost is ground that remains completely frozen for at least 2 years in a row at a temperature of 0^oC or lower. Permafrost is common in regions in high altitudes, like mountains, and high latitudes, like the North and South Pole.

Permafrost covers vast areas of the Earth’s surface. Permafrost makes up almost a quarter of the land area of the Northern Hemisphere. Even though the ground is frozen, snow does not always cover permafrost. Permafrost even exists underwater. A part of the Arctic Ocean’s seafloor around the North Pole is frozen. This frozen ground underwater formed during the last Ice Age, 11,000 years ago, when regions on the surface got buried underwater at the end of the Ice Age.

Permafrost is a combination of rocks, sand, and soil held together by ice. Ice acts as a cement, binding the sediments together. The ice and soil in permafrost stay frozen throughout the year. Sometimes, there is a layer on top of the permafrost that does not stay frozen all year. We refer to this layer as the ‘active layer. The active layer freezes during the fall and winter months and thaws during the summer. It rarely ever thaws in colder regions. In cold regions, the active layer is very thin, only about 10-15 cm thick. The active layer in warmer regions can be several meters thick.

Permafrost and Climate Change

Near the surface, permafrost contains large quantities of organic carbon. The organic carbon comes from dead plants and other organic matter that couldn’t decompose because of the cold. This upper permafrost layer has acted as a carbon sink for thousands of years. Most of the permafrost we see today formed during the Earth’s glacial periods. The last glacial period was 10,000 years ago. That means for around 11,000 years, methane and carbon have accumulated in permafrost. Imagine the sheer quantity of those gases trapped in the frozen ground!

But global warming is changing that. Climate change could melt the permafrost. If it thaws, it can release enormous amounts of carbon, amplifying global warming. Some scientists believe that the quantity of carbon trapped in permafrost is almost double the amount in the atmosphere. This makes the melting of permafrost a serious threat to the fight against climate change.

The melting permafrost situation is much worse than researchers previously thought. An international team of scientists studied the melting permafrost in Siberia and Canada. They concluded that the permafrost would thaw 20% more than previous predictions.

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A 1^oC increase in global temperatures above pre-industrial levels will lead to a loss of permafrost roughly the size of India i.e., 4 million sq. km. We will lose 40% of the world’s permafrost if temperatures increase by 2^oC. We can save much of the planet’s permafrost by limiting warming to 1.5^oC, as outlined in the Paris Agreement.

Consequences of Melting Permafrost

Rising temperatures make the melting of permafrost a serious threat with disastrous consequences for life and the planet. They include:

1. The release of greenhouse gases

Permafrost contains gigatonnes of methane and carbon dioxide trapped in it. Rising temperatures slowly melt permafrost, releasing more of these greenhouse gases every year. These gases escaping the frozen ground will accelerate global warming, further melting even more permafrost and releasing more greenhouse gases. Scientists call this loop the ‘permafrost carbon feedback cycle’.

2. The emergence of viruses and bacteria

In August 2016, a 12-year boy died, and many others ended up in hospitals due to an anthrax outbreak in the Siberian tundra. Scientists believe that a reindeer carcass lying on a thawing layer of permafrost was the culprit behind the disease outbreak. Permafrost contains microbes that are over 40,000 years old. Scientists believe that many of the diseases that have plagued human history, like smallpox, are lying dormant in permafrost. The melting of the permafrost could release these diseases and plague humanity once again.

3. Ecosystems and biodiversity loss

Thawing permafrost will turn large parts of cold tundras into muddy landscapes. The local flora will disappear, and the wildlife that feeds on it will starve, causing disruptions throughout the food chain. When the permafrost beneath lakes melts, it adds sediments and soil to the water body. The water seeps into this newly formed ground and disappears, causing droughts.

4. Landslides and geological disasters

The ice in permafrost is a cement that binds together rocks, soil, and sediments. When this ice melts, landslides can occur. Houses and cities built on permafrost will collapse. Permafrost makes up 60% of the land in Russia. Yakutsk, the largest city built on permafrost, is already suffering from its thawing. The Batagaika Crater in Russia, formed as a result of the land giving way due to melting permafrost, best expresses the magnitude of the problem.

What Can We Do To Stop Permafrost From Melting?

A recent study explored how introducing wildlife like horses and bison to the cold tundra landscape can save permafrost. These animals can change woodlands to grasslands. In most parts of the world, woody forests are essential because they act as a carbon sink. But in the Arctic, grasslands actually save permafrost. Large mammals like horses remove woody vegetation and enhance grass growth. This increases albedo – the amount of incoming solar radiation that gets reflected back to space, thus delaying permafrost melt.

For most of us, permafrost seems like a minor problem because it’s millions of miles away. But no matter where we live, the consequences of melting permafrost will affect all of us. The everyday choices we make can contribute in small ways to climate change. Collectively, we make a big impact on the Earth. Now it is up to us to reverse that impact to ensure our children can enjoy a world just as we have. Reducing our carbon footprints, supporting earth-friendly businesses, legislation, and policies, and investing in energy-efficient technology and products can help reduce climate change. Together, we can preserve the Earth’s permafrost and end the upward trend of a warming planet.

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