What happens when the permafrost thaws?
What happens when the permafrost thaws?
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.