What happens when the permafrost thaws? | BBC Ideas
BBC News- 266 views
- 20 Jul 2024
Around 11% of the Earth's land mass is covered by permafrost. But its delicate balance is being threatened by climate change.
When you think of the Arctic, maybe you picture this, or this, or this.
You're not going to imagine a piece of scrubby brown dirt.
That brown dirt is permafrost.
No one is born fascinated with permafrost.
I do find it exciting to think about different sediments and so on. You don't have to pretend.
But what permafrost does is of huge importance to the entire planet.
This is a map of Permafrost, and you see in purple here, the dark purple, especially the areas that are Permafrost.
Around 11% of the Earth's landmass is covered by Permafrost. Half of Canada, two-thirds of Russia, even the Tibettan plateau. And this place, the remote Norwegian archipelago of Svalberg. Both of the Arctic and Atlantic regions composed of organic material.
In two words, it's frozen ground.
Where is it?
Here, here, here, here. Permafrost is rock, sediment, or ice that remains at or below zero degrees celsius for two or more consecutive years. Most of it has been frozen for much, much longer than that. Arctic permafrost tends to be a few thousand years old. And areas in Antarctica, we find permafrost that's millions of years old.
But just because it's ancient doesn't mean all the permafrost is always frozen.
We have what we call the active layer. The active layer sits on top of the permafrost and thaws and freezes on an annual basis. We'll come here with a metal probe. We poke through the ground every week. We take a measure of how So as far as the thaw has evolved through the summer, and then the maximum depth at each point will represent the active layer depth for that year.
This active layer allows for different ecosystems to sit on top of the permafrost. From from huge forests to tree-less plains known as the Tundra. But this delicate balance is now being disrupted by climate change.
I've got pictures here that show the mean annual temperature, and you can see basically the blue areas that are on here. These are areas we'd expect to be permafrosted. This is gradually becoming redder and redder.
The Arctic, it's warming at three to four times the rate of the rest of the planet.
This weather, it's not supposed to be like this in October. It's supposed to be minus 15. Clear, dry climate, and it's not. It's a rainstorm.
As temperatures rise, the permafrost the permafrost is thawing.
On average, the active layer has been deepening about 0.6 cm per year for the last 10 years, which is about this much. But think about that through the whole landscape. We're seeing that the active layer is getting deeper and deeper in permafrost regions around the world. It creates immediate impacts.
As the surface of the permafrost thaws downwards, many things that were frozen are uncovered. This could include as many as 10 million wooly mammoths. And there are fears that ancient viruses could reawaken and infect humans. But there's something else which concerns scientists much more.
The scariest thing that is happening with permafrost is what it is doing to the climate itself.
Permafrost acts as a storage. It locks up the carbon from dead vegetation quite effectively, and it's accumulated over many thousands of years. We have this organic matter that's stored in the freezer, and as soon as you open the freezer door, then that becomes available to decay.
There's estimated to be four times more carbon trapped in Permafrost than all of the human-generated CO₂ emissions in modern history. The release into the atmosphere of even a fraction of this as carbon dioxide and methane will have a profound effect on the climate.
The more greenhouse gasses that are in the atmosphere, the warmer the climate, the warmer the climate, the thicker the active layer, and the more greenhouse gasses can escape from that portion of the permafrost that was locked away. There's an underlying flow level of change slowly creeping up on us.
People will frame Permafrost thaw as something that is a future catastrophe, when actually there is a catastrophe going on right now for people who live on top of Permafrost.
People like Jessie, who lives here in the Inyavik region of the Northwest Territories in Arctic Canada.
Just being out on the land, it really puts my soul at ease. This is the land that our ancestors have walked in. When I was younger, I didn't really know what Permafrost was. In recent years, it's been thawing fairly rapidly.
The most obvious way that the permafrost melting impacts on human society is that the ground that was once really solid and hard suddenly becomes squishy.
There are things called thermocast mega slumps, which is a fantastic name for a band, where the ground collapses in on itself and creates these huge craters. There's one in the Arctic Russia, which is called the doorway to the Underworld, and it's getting bigger by the day.
You have large masses of land just flowing away because they're no longer solid.
I see the wounds in the landscape from the landslides, and it reminds me that the whole Earth is crying out. It's a wounded Earth.
So this is the old hospital building.
We're going to go on on the back of it because that's where you can really see the damage.
We noticed that our home was starting to crack. So me and my dad, we always tried to just adapt to it to keep our house level.
Buildings start to crack, the roads will buckle, power lines will tear.
We just try to fix things for now and just take it year by year.
People have lived in the Arctic for thousands of years and they're seeing unprecedented changes to their environment.
In the Clavik, our motto is never say die. So when it floods or when our roads start to disappear, there are still people that live here and love it here, and they wouldn't want to move anywhere else. Knowing that all of this ice is going to melt underneath us makes me a little bit scared for the future.
Permafrost Thor could bring some new possibilities, from mining areas opening up to the potential to grow new crops. But both could exacerbate climate change and be of little consolation to the people losing their homes. In terms of slowing down or stopping this, is there anything we could do?
I guess not really.
The thing we can do is to stop climate from warming in the first place. There isn't, unfortunately, very much we can do if we warm the planet to then stop the permafrost from melting.
One cold winter will not freeze back permafrost. What we can do is make more informed decision and make sure that we build communities that are resilient to changes that are going to occur.
If they continue to listen to our people about all the stuff that's happening, then that gives me a little bit of hope.
I think this is the beginnings of us starting to think in a way that highlights the more entangled ways that humans exist with nature and their environments.
There's a lot of northern folks all around the globe. They all have their own traditions and values. I think my message would just be to help us out up here. Be a part of a solution.