Updated: Nov 17, 2020
As the Earth warms, permafrost is thawing, turning the once solid ground into watery mush. There are many impacts from the thawing of the ground: massive carbon emissions, toxic mercury and deadly diseases.
Permafrost is ground that is completely frozen at 0 degrees Celsius or below and remains that way for at least 2 consecutive years. Permafrost is found near the Earth’s poles. Most permafrost is found in the Northern hemisphere, in countries such as Russia (Siberia), Canada, Greenland and Alaska. Under the Sea in the Arctic, parts of the ocean floor are frozen in what is called a Subsea permafrost. In total, permafrost covers 9 million square miles in the northern hemisphere. In the southern hemisphere, permafrost is less prevalent but still present in the Andes and Southern Alps mountain ranges, as well as in Antarctica.
As the planet is warming, permafrost is thawing, especially in the Arctic, where temperatures are rising faster than anywhere else on Earth.
The top layer of permafrost is the active layer, and it thaws every summer and refreezes every winter. Depending on the location of the permafrost, the active layer can be a few centimeters thick to a few meters thick. Recently, it has been observed that some areas of permafrost have active layers that thaw for longer, while some have layers that never fully refreezes. When the active layer does not fully refreeze, this allows the warmer surface waters to spread deeper into the frozen ground, which speeds up the thawing of the permafrost.
It is estimated that about 2.5 million square miles of permafrost could thaw by 2100. This is bad news for the environment, as trapped in the Arctic permafrost is up to 1,600 gigatons of carbon, which is getting released into the atmosphere as the ground thaws. This amount is almost double the 870 gigatons of carbon in our atmosphere today.
How does permafrost thaw lead to carbon emissions?
Organic carbon, which is the dead matter of plants and animals is buried in permafrost layers. As the permafrost warms and thaws, microorganisms are able to start decomposing the dead matter, releasing the carbon stored inside them back into the atmosphere. Greenhouse gases carbon dioxide and methane (which is 80 times more effective at trapping heat than carbon dioxide), end up escaping from the permafrost and entering the atmosphere. As greenhouse gases escape from the permafrost, a feedback loop could be started, where the escaping gas causes more warming, which leads to more thawing, which in turns leads to even more gases escaping into the atmosphere. Although this has not yet happened, it could effectively speed up warming and cause climate change to be even more catastrophic if it does.
Other than the massive amount of carbon, Arctic permafrost also holds toxic mercury, which could be a health threat. Researchers have found around 15 million gallons of mercury trapped in the Arctic permafrost, and it is possible that the mercury will be released as frozen ground starts to thaw. It could be absorbed by plants that grow on the thawed ground or enter water sources. Although researchers are still not sure how big of an issue this mercury will be, it most likely will have an impact on humans all around the world.
Other than the impact from the carbon and mercury stored in permafrost, deadly diseases could be released from the frozen ground.
Trapped in the permafrost are pathogens like bacteria and viruses, most never seen before by scientists. While newly discovered permafrost pathogens do not infect humans, there could be ones that have infected humans in the past, and have the potential to do so again, still buried in the ground, waiting to be discovered. The organic carbon in permafrost also contains bodies of humans and animals that died from diseases in the past, and as the ground thaws, there is concern that the pathogens in the bodies survived and could still be infectious. In 2018, an outbreak of Anthrax in Siberia killed a child and caused 72 people to fall ill. The source of the outbreak was linked back to infected reindeer corpses buried in the permafrost, and as the ground thawed, the bacteria was awakened and could have spread into the drinking water. There is concern that this outbreak could happen again, in other regions and with other viruses and bacteria as more of the ground thaws.
While there is still a lot that scientists do not know about the impacts of the thawing permafrost, research so far has concluded that permafrost thaw will negatively impact the planet, the environment and human health. The root cause of the thaw is the warming of the planet, and climate change. We all know that climate change is largely caused by human activities emitting carbon, and if emissions are not reduced, the consequences will be borne by future generations. We need law makers and companies to do their part, but we can also take steps to save the planet. We all want a better future for the children of today, so let’s start today, and save tomorrow.