The Thwaites 'Doomsday' glacier's ice shelf is about to break away

0:00And now a word from our sponsor, South by Southwest London. Imagine a future where things just make sense. In the 1700s, we had canals. In the 1800s, the railways. Then telecom, fibre optic. And now? In a world that's more unsure than ever before, we need the answers. South by Southwest London presents over 900 speakers, 200 music artists and 100 films in one location in June. To find out how they merge together and shape the future in person, visit southbysouthwestlondon.com. That's s-x-s-w-london.com. We talked about sea level rise recently on the podcast, and today we're here to discuss some very worrying news about the world's widest glacier.

0:40That's the Thwaites Glacier in Antarctica, sometimes called the Doomsday Glacier, and with good reason. Yeah, so Thwaites is this massive glacier, size of Florida or Britain, mind-bogglingly big, isn't it? On the end of it, there's this big tongue of ice hanging off into the ocean. And the news is that that ice shelf is about to detach from the main part of the glacier. And that has basically desperate implications for sea level rise. From New Scientist, this is The World, The Universe and Us. I'm Dr Rowan Hooper. And I'm Dr Penny Sarche. And joining us today is Alison George, former British Antarctic Survey scientist and long-time New Scientist journalist.

1:20Hi, Ali. Hello. Hello. Let's talk first about maybe some context about Antarctica, the ice there and the role sort of Thwaites plays in all of that. OK, so if you look at Antarctica on a map, it's white, it's covered in ice, a massive ice sheet that's about two kilometres thick. And we really want that ice to stay stable because if it slides off into the sea, it'll ultimately raise sea levels such that the whole coastline on Earth will be underwater. water so scientists have been looking closely at what's going on in the ice there by satellites and they noticed one particular region Thwaites Glacier was a real hot spot for ice loss it's really dramatic when you look at these maps of ice loss it's hugely worrying what's going on there by the way this is not somewhere I've been it's a really really remote place I have been to Antarctica but much further north it's possibly one of the hardest places to reach in the world I was recently talking to a researcher called Wong Sang Lee who is at the Korean Polar Research Institute and he led the latest expedition to the glacier in January December January and despite spending 55 days at sea this only allowed them two weeks actually at the glacier and then bad weather actually meant that they only had a couple of days to carry out the main part of their project which was drilling through the ice so it's a really really difficult place to work Even though it was summer, there was probably so much sea ice, the boat, their ship, couldn't get close enough to where it needed to be.

2:54I think in this case there wasn't that much sea ice, but it's still really difficult. And you get terrible storms and all sorts of other things. So we've been worried about the stability of the Thwaites Glacier for a long time, haven't we? And there's its neighbour, the Pine Island Glacier as well. They're together described as the weak underbelly of Antarctica because a lot of water can get underneath them and that causes the instability. Yeah, that's right. Yeah, because they're based on rock, which is actually under sea level. So they're particularly vulnerable. This glacier is essentially a slow moving river of ice.

3:28And under stable conditions, the ice flowing off into the sea will be balanced out by new ice forming upstream from snowfall. but this glacier is not in a balanced state at all. It's been losing ice on an epic scale. It's collapsing. So that's climate change. We're not getting as much ice and snow forming to replace the ice that's being lost. That is, I mean, it's very hard to attribute anything to climate change especially one of these slow-moving systems but I think that is the conclusion that we've altered the climate so much that it's having these effects. So the real worry is that But if this glacier collapses, it will trigger a sort of domino effect in the whole ice in the West Antarctic region.

4:13And if this all came off into the sea, it would raise sea levels by about 3.3 metres. And that will threaten many coastal cities, New York, London, Shanghai. So finding out if this collapse is going to happen and how fast it's going to happen is absolutely crucial. And so that's why it's got this sort of name, the Doomsday Glacier, which was coined apparently in Rolling Stone back in 2017. Yeah, and we've used it a lot. Everyone uses it. All journalists use it now a lot. But, you know, I do know that some glaciologists don't like it being characterised as that. And I understand why, actually, because it suggests we are doomed already.

4:49It's a doomer outlook and we're not quite we are not quite doomed yet. Yes. But Ali, what's the latest on this, you know, very dramatic situation? In a nutshell, this key part of the glacier is going to break away, the ice shelf. And this is the, as you said, it's the floating layer of ice that forms when the glacier ice moves away from the land and floats out over onto the ocean. And this helps protect and buttress the glacier under normal circumstances. And as you might expect, the Thwaites ice shelf is absolutely massive. it's about the size of Greater London about 1500 square kilometres and around 350 metres thick and it looks like it's going to sort of detach and break away any day now.

5:33That sounds very dramatic and rather nightmarish. What do we think is going on? Well in the past the shelf was sort of anchored to the sea floor right out far at sea by what's called a pinning point which is like a raised ridge in the sea floor and it was held in place by that. So the ice itself went down to the sea floor? No, no, there's a bump in the sea floor that sort of poked up and pinned the ice in place. Like a doorstop? Yeah, like a doorstop. So it's come adrift from this, this doorstop. And the ice has also been thinning and weakening thanks to changes in the ocean circulation, which I think you talked about recently on the podcast, which means that warm ocean water is now reaching the ice when it didn't in the past and melting it.

6:17and this means ultimately the ice shelf is being torn apart and huge rifts are forming all over it. And when I've spoken to some researchers about this recently, they were quite shocked at the speed at which this is happening. When you're a glaciologist, you don't really expect things to happen that fast. One said it was like watching a windscreen shattering. Another, Karen Alley from the University of Manitoba, said she visited the glacier six years ago and when she looks at the satellite images now, she doesn't recognize it because of the rifts that are formed all over the places that she visited.

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7:57This message was sponsored by the Alzheimer's Society. So one thing I always have to sort of wrap my head around when we're talking about places like Antarctica is there's this warm water that's melting the glass here but warm is a relative term here right it's cold it's cold by anybody's standard it's about one plus one degrees celsius so it's not something you'd want to take a bath in you swam in it when you were there i have swam in it yes yeah refreshing or was it a dip rather than a swim i haven't actually had a swim actually it's very refreshing you don't feel your extremities very very i did i did one in the arctic but um i did a dip a very quick dip and then a swim that was i'd say 15 seconds and then And they made us get out because, yeah, it's pretty dangerous.

8:38It's very cold. Yeah, you lose the usual feeling in your limbs very quickly. Yeah, so not a good place to go swimming unless you want a cold shock. But this one degree Celsius is still a massive reservoir of heat because it's actually three degrees above the freezing point of seawater and it has a lot of power to melt a lot of ice, even though it's not actually that warm. So, you know, I mentioned that there has been this fear of the Thwaites collapsing for a long time. is there anything recently now that we are now even more worried that it is actually imminent? Well the ice shelf itself is going to break away any day now.

9:17Yes but that's distinct from the whole glacier. Yeah the whole glacier is going to be an unfurling calamity which happens over hundreds of years. Yeah it's not going to slide off like food off a trail. No that would be very very worrying. No it's not going to be like that. So what we're talking about here is the floating ice shelf breaking away. so that could happen any day now. Apparently the satellite that you can view the glacier from, you can only get an image from it every 6 to 12 days, so the scientists are sort of logging on and they're wondering what's going to have happened. If it's going to literally have broken away in the last time the satellite went over, wow.

9:53Yeah, so what would happen is there are already massive crevasses at the point where the glacier goes afloat, and at some point they're all going to join up, and apparently that can be quite sudden, and in that point the ice shelf is effectively severed and apparently the British Antarctic survey have already prepared an obituary in advance so that they won't be caught on the hop but equally these things are not that predictable the ice shelf could still be there in a year's time and apparently it's a bit like predicting an earthquake you know it's going to happen but you're just not really sure quite when but it looks like it's going to go any minute and it could be quite sudden And so when it does go, do we get an iceberg the size of London or does it break into loads of pieces?

10:40What will happen, do we think? Well, some icebergs in Antarctica and the Arctic do break off into these huge icebergs that sort of hog the headlines. But in this case, I think we're going to be a bit disappointed if that's the kind of thing you're after, because the geography of the region means that any ice that breaks off is probably going to be stuck there. and this size shelf is already quite fractured so it's going to break off into I say smaller icebergs they're still going to be absolutely massive but they're not going to be probably the size of London. And you know we mentioned this thing about it being called the doomsday glacier when and if well when this thing does break off the the shelf part of it does that mean we're doomed or is there anything feasibly we could do?

11:21Well in a sense ice flowing off Antarctica and breaking off into icebergs is like business as usual that's totally normal um but what happens when you get more ice breaking off than is formed on the continent that's when you start being a calamity really um so in itself this ice shelf breaking off uh isn't necessarily a bad thing it could be business as usual but new research which is out very soon actually shows that um this break off is actually stopping the buttressing of the flow upstream so the ice uh on the continent is flowing a lot faster apparently it's sped up by about 33 percent in the last six years which is um shockingly fast for sort of glaciology so this ice shelf um despite the speeding up of the flow of the glacier which which is quite shocking and alarming this ice shelf is helping to hold some of that back at the moment it was it was and it is no longer doing that because it's now coming off itself yeah it's already sort Essentially, the break-up is already a very slow process and it's already underway in the fact that it's lost this buttressing power.

12:27So all of this has implications for sea level rise then? Well, the ice pouring off the continent is going to have implications for sea level rise. And what's worse is this isn't the only glacier this is happening to. It looks like a similar thing is happening to the neighbouring massive glacier called Pinine and Glacier. Yeah, it's just so mind-boggling because we think of glaciers and we think of them as something you can picture. but something the size of Florida is something we just cannot, it's an ice sheet but it's also, it's an actual glacier. It's moving, yeah. It's absolutely mind-boggling.

13:00Yeah, and then what's going to happen ultimately is more ice is just going to pour off the continent, be dumped into the ocean and will raise sea level rise. But this isn't going to happen, it's not going to hit home tomorrow, we don't need to suddenly run up hills tomorrow but this is going to unfurl over decades and by the turn of the century all the predictions are that this glacier is going to be sort of running away collapse it's going to be moving inland and ice is going to be pouring off it and that's going to be very problematic and really the doomsday glacier does deserve its name. I assume the answer is no but is there anything that can be done you know there's always a question of is there any kind of clever geoengineering we could we could be having a go at but when we're talking about something this massive is that feasible in any way well there's a couple of scientists who have got some outrageous plans to geoengineer the region and the leading one is a massive sort of 100 kilometer wide undersea curtain which would in theory stop this warm water reaching the ice of the glacier but i mean thinking about it if research can only sort of be there for a couple of weeks and how you're going to erect a sort of 100 meter 100 kilometer long sea curtain there's no guarantee it would even work and you'd only prove you're protecting a very short uh part of the coastline so really the answer is obvious we all know it we've got to stop pouring carbon dioxide into the atmosphere as soon as possible and slow down climate warming yeah like i used to be quite keen if that's the right word in in some of these ideas of um putting curtains up and stuff until I went to the Arctic and saw some glaciers myself.

14:45And these are little puny Arctic glaciers. But the size of them blew my mind, just the Arctic ones. And the idea, even those ones that you could put an undersea curtain across them. And they've been thinking about this in Greenland. Even that is like, no, it's not going to work. So for something the size of Florida, the size of Greater London, it's been called the largest civil engineering project that humanity has ever attempted but i i think it's i do think it's infeasible but one thing i do that does strike me about these ideas is the pricing and people say oh it costs tens of billions of dollars to to do this and and as you say it might not work but that's still less than the price we're going to pay when the sea level rises yeah you know so we do have to do these things well we have to look at these things certainly we have to look at mitigation and and as you say as we always say we have to cut emissions because that's the only way to to really solve these problems yeah yeah that's all for this episode thanks to our guest alison george and thanks to you for listening do follow and subscribe wherever you get your podcasts bye for now