What happens when the permafrost thaws? | 91TV
Transcript
- DANIEL NILS ROBERTS: 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.
- DANIEL NILS ROBERTS: That brown dirt is permafrost.
- No-one is born, like, fascinated with permafrost.
- I do find it exciting,
- just thinking about different sediments and so on.
- DANIEL NILS ROBERTS: You don't have to pretend.
- MARJOLAINE VERRET: 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.
- DANIEL NILS ROBERTS: Around 11% of the Earth's landmass
- is covered by permafrost -
- half of Canada, two-thirds of Russia,
- even the Tibetan Plateau,
- and this place, the remote Norwegian archipelago of Svalbard.
- RADIO: ..Arctic and Antarctic regions
- composed of organic material...
- MARJOLAINE VERRET: In two words, it's frozen ground.
- - Where is it? - Here, 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.
- In areas in Antarctica, we find permafrost
- that's millions of years old.
- DANIEL NILS ROBERTS: But just because it's ancient
- doesn't mean all the permafrost is always frozen.
- MARJOLAINE VERRET: 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 will come here with a metal probe.
- We poke through the ground every week.
- We take a measure of how far the thaw has evolved
- through the summer, and then the maximum depth at each point
- will represent the active layer depth for that year.
- DANIEL NILS ROBERTS: This active layer allows for
- different ecosystems to sit on top of the permafrost,
- from huge forests to treeless 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.
- MARJOLAINE VERRET: The Arctic, it's warming at three to four times
- the rate of the rest of the planet.
- This kind of 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.
- DANIEL NILS ROBERTS: As temperatures rise,
- the permafrost is thawing.
- On average, the active layer has been deepening
- about 0.6cm per year for the last ten 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.
- DANIEL NILS ROBERTS: As the surface of the permafrost thaws downwards,
- many things that were frozen are uncovered.
- This could include as many as 10 million woolly 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.
- MARJOLAINE VERRET: Permafrost acts as a storage.
- GIDEON HENDERSON: It locks up the carbon from dead vegetation
- quite effectively,
- and it's accumulated over many thousands of years.
- MARJOLAINE VERRET: 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.
- DANIEL NILS ROBERTS: 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.
- MARJOLAINE VERRET: The more greenhouse gases
- that are in the atmosphere,
- the warmer the climate.
- The warmer the climate, the thicker the active layer,
- and the more greenhouse gases can escape from that portion
- of the permafrost that was locked away.
- There's sort of an underlying low 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.
- DANIEL NILS ROBERTS: People like Jessi,
- who lives here in the Inuvik 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 thermokarst megaslumps,
- which is a fantastic name for a band,
- where the ground kind of collapses in on itself
- and creates these huge craters.
- There's one in Arctic Russia
- which is called the Doorway to the Underworld,
- and it's getting bigger by the day.
- And you have large masses of land
- just flowing away because they're no longer solid.
- SIV LIMSTRAND: 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 out 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.
- CHARLOTTE WRIGLEY: Buildings start to crack,
- the roads will buckle, powerlines will tear.
- We just try to fix things for now
- and just take it, like, year by year.
- MARJOLAINE VERRET: People have lived in the Arctic
- for thousands of years now
- and they're seeing unprecedented changes to their environment.
- JESSI PASCAL: In Aklavik, 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 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.
- DANIEL NILS ROBERTS: Permafrost thaw 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 can do?
- MARJOLAINE VERRET: Um...
- I guess...
- Not really.
- I think what you can do
- is to stop climate from warming in the first place.
- There isn't, unfortunately, very much that we can do
- if we warm the planet to then stop the permafrost from melting.
- MARJOLAINE VERRET: One cold winter will not freeze back permafrost.
- What we can do is make more informed decisions 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.
- JESSI PASCAL: 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,
- you know, be a part of a solution.
Around 11% of the Earth's land mass is covered by permafrost. But its delicate balance is being threatened by climate change. Made in partnership with @bbcideas
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