With global temperatures continuing to rise and Arctic sea ice extent shrinking, the consequences of climate change are becoming increasingly visible.
But one of the most significant threats posed by climate changes is the melting of permafrost.
Permafrost – ground that has been frozen for at least two years – covers 25 per cent of the Northern Hemisphere, keeping ancient bacteria, viruses and carbon preserved and locked away, much like a freezer does.
But a new report by the Arctic Council suggests that 20 per cent of permafrost near the surface near the surface could melt by 2040, releasing CO2 and other gases, resulting in range of other associated threats such as the release of ancient infections and the warping of roads and landscapes.
Permafrost, mostly found in high-latitude regions like the Arctic, stores large quantities of carbon dioxide and methane, which are released into the atmosphere if the soil melts and decomposes. Pictured is permafrost melting in Norway
Permafrost, mostly found in high-latitude regions like the Arctic, stores large quantities of carbon dioxide and methane, which are released into the atmosphere if the soil melts and decomposes.
A 2010 Russian study found that during the past 20 to 30 years, permafrost has been warming in a range between 0.5°C to 2°C.
And another study from 2010 found that the top layer of permafrost called the active layer, which normally thaws in the summer, is becoming deeper in the Arctic.
As permafrost melts and releases gases into the atmosphere which cause warming, permafrost melts even more, releasing more of these gases such as methane and CO2, leading a positive feedback loop that worsens climate change.
A study published in April in the journal Nature Climate Change, found that for every degree the world warms, four million sq km (1.5 million sq miles) of permafrost would be lost.
Dr Sarah Chadburn, lead author of the study, said: ‘The amount of permafrost that thaws under global warming is going to be very large, and this is the first time we’ve really put numbers on it.’
They looked at frozen waste areas in Siberia and Canada.
An increase in global warming by 2°C would thaw more than 40 per cent of the Earth’s permafrost, according to the study.
But what are some of the impacts that thawing permafrost could result in?
A study published in April in the journal Nature Climate Change, found that for every degree the world warms, four million sq km (1.5 million sq miles) of permafrost would be lost
Permafrost has acted like a freezer for tens of thousand of years, keeping 1,400 gigatons of ancient plant matter carbon trapped in the soil – more than double the 850 gigatons of carbon currently present in the atmosphere.
According to a 2014 study, melting permafrost could release 120 gigatons of carbon in the atmosphere by 2100, leading to a 0.29°C of extra warming – thus further exacerbating climate change.
But beyond this, the thawing of ancient permafrost could awaken ancient disease-causing microbes.
THREATS POSED BY THAWING PERMAFROST
Permafrost, mostly found in high-latitude regions like the Arctic, stores large quantities of carbon dioxide and methane, which are released into the atmosphere if the soil melts and decomposes.
As permafrost melts and releases gases into the atmosphere which cause warming, permafrost melts even more, releasing more of these gases such as methane and CO2, leading a positive feedback loop that worsens climate change.
But other threats posed by melting permafrost include:
- Release of ancient microbes: In late August, an anthrax outbreak in Siberia caused 72 people to become sick, and killed a 12-year-old boy. This was because an anthrax-infected reindeer had thawed, releasing the bacteria.
- Damaged landscapes and roads: When the ice in the permafrost thaws, the water runs off and the ground above can slump, deform, or fall apart. The Alaska Dispatch News has reported that thawing permafrost is warping roads in Bethel, Alaska.
- Loss of historical records: Thawing permaforst could also threaten natural historical records. For example, ‘Otzi’, a 5-300 year-old dead man found in the Alps, would not have been so well preserved if he had thawed.
As permafrost melts and releases gases into the atmosphere which cause warming, permafrost melts even more, releasing more of these gases such as methane and CO2, leading a positive feedback loop that worsens climate change
For example, in late August, an anthrax outbreak in Siberia caused 72 people to become sick, and killed a 12-year-old boy.
According to Wired, this was because an anthrax-infected reindeer had thawed, releasing the bacteria.
As permafrost continues to thaw, more ancient bacteria could be released.
Dr Jean-Michel Claverie, a genomics researchers who studies ancient viruses and bacteria, told Vox permafrost is able to preserve for hundreds of thousands of years – possibly even a million.
Permafrost – ground that has been frozen for at least two years – covers 25 per cent of the Northern Hemisphere, keeping ancient bacteria, viruses and carbon preserved and locked away, much like a freezer does. Pictured is a map of permafrost extent across Arctic regions
‘It is dark, it is cold, and it is also without oxygen. … There is no [ultraviolet] light,’ Dr Claverie said.
‘All the bacteria need is a thaw to wake back up.
‘If you take a yogurt and put it in permafrost [that remains frozen], I’m sure in 10,000 years from now it still will be good to eat,’ he said.
Not only could the thawing of permafrost unleash ancient infections, it could also encourage mining and other excavation projects – putting worked at risk of contracting ancient diseases.
As permafrost continues to thaw, more ancient bacteria could be released. Permafrost is able to preserve for hundreds of thousands of years – possibly even a million
Aside from health risks, melting permafrost can also have an impact on landscapes and roads.
When the ice in the permafrost thaws, the water runs off and the ground above can slump, deform, or fall apart.
‘You see buildings that are kind of slumping into the ground; you see that a lot in the Russian Arctic,’ Robert Max Holmes, an earth systems scientist with the Woods Hole Research Center, told Vox.
Aside from health risks, melting permafrost can also have an impact on landscapes and roads. When the ice in the permafrost thaws, the water runs off and the ground above can slump, deform, or fall apart. Pictured is a deformed railway line built on permafrost in Russia
And the Alaska Dispatch News has reported that thawing permafrost is warping roads in Bethel, Alaska.
Thawing permaforst could also threaten natural historical records.
For example, ‘Otzi’, a 5-300 year-old dead man found in the Alps, would not have been so well preserved if he had thawed.
The same is true of DNA from ancient mammals, such as the woolly mammoth, which could be revived in two years using DNA from frozen carcasses.
The 2015 Paris Agreement on climate change aims to limit warming, by using the cooperation of almost 200 countries to attempt to keep the global temperature increase ‘well below’ 2°C above pre-industrial levels.
But at the current level of warming, Dr Chadburn said, ‘you could lose almost all of the permafrost.’
An estimated 35 million people currently live in cities or towns on top of permafrost, and thawed soil could cause the ground to become unstable, researchers behind the 2017 Nature Climate Change study said.
Thawing permaforst could threaten natural historical records. For example, ‘Otzi’ , a 5-300 year-old dead man found in the Alps (pictured), would not have been so well preserved if he had thawed
The researchers said this would put buildings, roads and other infrastructure at risk of collapsing.
While there are some benefits to thawing permafrost, Dr Holmes told Vox that the negatives outweigh the negatives.
If permafrost thaws, natural historical records could be threatened, such as that of the woolly mammoth carcass (pictured) found frozen in Siberia, Russia. The ancient mammals could be revived in two years using DNA from frozen carcasses