What is Permafrost and how is it formed?
Water that is trapped in the cracks and pores of rocks and under the soil turns into ice when the ground temperature drops below 32°F (0°C). When the frozen state continues for at least two consecutive years, it’s called permafrost.
Closer to the surface, permafrost soils contain large quantities of carbon because the optimum temperature for microbial decomposition of dead plants is between an 60-85°F (15-30°C) and the decomposition is is stalled as the temperature drops.
The lower permafrost soil is mainly made up of minerals. The layer of soil above permafrost does not stay frozen all year. This layer, called the active layer, can be several meters thick.
Where are such regions found?
Permafrost covers approximately 22.8 million square kilometres of the Earth's Northern Hemisphere and is often found in Arctic regions such as Greenland, the US state Alaska, Russia, China, and Eastern Europe. Permafrost is found in and under as well as on and under the ocean floor.
What happens when permafrost thaws?
Now, when permafrost remains frozen, it is good news. But that is not the case. So we have reasons to worry. Why? When temperature rises and the ice in these regions, marked in the figures above, melts causing microbial decomposition. On decomposing, the carbon from the permafrost enters the atmosphere as carbon dioxide and methane, contributing to global warming. These are the harmful greenhouse gases (GHGs) I have discussed at length in my earlier pieces, too. Further, to make matters worse, ancient bacteria and viruses present in the ice and soil thaw along with the permafrost and the newly-unfrozen microbes could prove lethal to humans and animals. Scientists have discovered microbes more than 400,000 years old in the thawed permafrost.
Permafrost is one of planet Earth’s greatest storehouses of GHGs, estimated to hold nearly twice as much carbon as there exists in the atmosphere, today. It also consists of a sizeable amount of methane, a powerful GHG that traps more than eighty times more heat on the planet than carbon does. This results in melting even more carbon- and methane-emitting permafrost triggering a vicious cycle.
We are yet to hear of the most ruinous effects of permafrost thawing. If you thought this pandemic is the worst humanity has suffered, I am sorry to be the harbinger of bad news — Our scientists are painfully aware of plenty more troubles ahead, and despite their repeated warnings we continue to remain unaffected.
Carbon and methane aren’t the only pollutants contained in permafrost. A recent study has found that Arctic permafrost is a massive source of natural mercury, a neurotoxin. It is estimated that around 15 million gallons of mercury (i.e., nearly twice the amount of mercury found in the ocean, atmosphere, and all other soils combined) are locked in permafrost soils. Once released, this can spread through water or air into ecosystems and potentially even into the food chain.
Another major issue of thawing permafrost is that when water turns into ice underground, it expands causing the ground to swell. This makes the earth crack or cave in. This can result in destruction of townships and cities, along with claiming the lives of many, while leaving behind many hurt and disabled. About 35 million people live in a permafrost zone. As that solid ground softens, the infrastructure these communities rely on grows increasingly unstable.
What is vital to understand is that whether the thawing is in areas where we live or thousands of miles away, every being will still be affected and the responsibility is shared. If we do not adopt sustainable practices, this very minute, we are all equally responsible for climate change and its aftermath, no matter where we live. Our everyday choices contribute to climate change collectively. It is also utterly consequential to remember and remind ourselves that we cannot resort to blaming the richer or poorer countries for climate change. Yet, acknowledging the tendency of the first world countries to outsource blame, too, to the third world countries, along with the many polluting industries, is loud and clear. The questions are: How does that help? Why are the developed countries reluctant to share clean technologies and innovations with the developing and under-developing countries of the world?
Now, a quick look at what can we do to prevent thawing of permafrost?
1. By reducing our carbon footprint
2. Investing in energy-efficient products
3. Supporting climate-friendly businesses, technology-sharing, knowledge-sharing, legislation and policies