Changing times in Antarctica – podcast
In the fifth episode of the Voice of the Sea Ice podcast series, RNZ science communicator Dr Claire Concannon discusses the implications of sea ice decline in Antarctica and the possible impacts on global warming and biodiversity in Antarctica.
Dr Inga Smith (University of Otago), Dr Natalie Robinson (NIWA), Dr Daniel Price (University of Canterbury), Dr Jacqui Stuart (Victoria University of Wellington) and Associate Professor Michelle LaRue talk about how their research impacts them on a personal level.
Questions for discussion
What are your thoughts about the implications of sea ice loss on the animals of Antarctica?
What actions could you take to support the scientists in their efforts to communicate the impacts of a changing climate on Antarctica and beyond?
The long-form version of this podcast is on the RNZ website here.
Transcript
Dr Natalie Robinson
Sea ice is a lovely bright white surface. So it reflects solar radiation back to space rather than allowing it to be further absorbed into the ocean. And you can see that that is sort of a self-perpetuating mechanism. If you warm the ocean, you form less sea ice and then that allows the ocean to warm more.
Dr Claire Concannon
Ah, the old feedback loop. Less than ideal. As for the other two, well, less sea ice being formed means ocean currents will change because there will be less of that cold, dense, briny water. And without a blanket of winter sea ice, more heat will move from the relatively warmer ocean to the atmosphere during the dark, freezing months, which will alter weather patterns. And this change in Antarctic weather patterns is likely the thing we’ll see in the short term as the amount of floating pack ice reduces.
What happens if we get less land-fast sea ice forming? Well, for that, we go back to episode 1 and Dr Daniel Price.
Dr Daniel Price
The sea ice can act as a sort of shield at the front of the ice shelves, protect them from things like swell that’s rolling in from the Southern Ocean and stop them from breaking out, essentially, stop them from calving.
Dr Claire Concannon
Now, this is a part of the normal process. Ice shelves are always flowing, the sea ice retreats in summer, big chunks fall off the ends, icebergs happen.
Dr Daniel Price
A lot of years here out the front of Scott Base, the sea ice will break out at the end of the summer and then that leaves the ice shelf behind it vulnerable. And then typically hours or days after, you’ll see icebergs calve off and float away because they’re no longer protected.
Dr Claire Concannon
But if you’ve got less sea ice doing the buttressing, what will happen then?
Dr Daniel Price
We’re looking at that by putting out stations on the sea ice and the ice shelf, and then at the end of the season when the sea ice naturally breaks out anyway, we can look at how the ice shelf responds and how it speeds up. I guess the hypothesis there is that if fast ice areas start to decrease because the climate is warming, what are the knock-on effects then to the ice shelves behind them?
Dr Claire Concannon
So far, so whatever, right? This is all ice that’s floating in the ocean, so it’s not going to contribute to sea-level rise. But remember, feeding the ice shelves are the ice sheets – those massive slabs of freshwater ice sitting on the Antarctic continent. And researchers have been studying the interaction of ice shelf and ice sheet, and when ice shelves lose ice faster at the edges or start to collapse, the flow of ice speeds up – meaning we then lose more of the ice sheet than can be replenished by new falling snow. And that definitely means sea-level rise.
That’s why Daniel was making his crazy journey across the ice shelf in the first place for a project that was looking back into the distant past to see what happened to the West Antarctic Ice Sheet, which feeds the Ross Ice Shelf, when the Earth was much hotter.
Dr Daniel Price
Looking to the past like this is – it’s the key tool to predict what’s going to happen in the future. So you can have this sort of paleoclimate effort, which is looking directly at what’s happened in the past, your contemporary scientific effort, which looks at observations in the real world now, and then you have the modelling, which looks to the future. And we use those three tools together to get the best understanding.
Dr Claire Concannon
All right, so we’ve got sea-level rise happening now and more coming for us. And what about the penguins, I hear you ask? They also need land-fast sea ice. Surely you were asking that? Everyone is concerned about the penguins.
Journalist
They are the iconic species of the Antarctic, but the question is for how much longer?
Dr Claire Concannon
They hit the headlines in 2022 when a satellite study linked the low summer sea ice extent to trouble for four penguin colonies.
Journalist
Emperor penguin colonies living in an area where there was total sea ice loss in 2022 have experienced almost total breeding failure.
Dr Claire Concannon
This is because if the land-fast sea ice breaks up before the penguin chicks have got their waterproof feathers, it’s really bad news.
This happened west of the Antarctic Peninsula. And look, while this does sound awful, it unfortunately sometimes does just happen.
With some colleagues, Dr Michelle LaRue analysed satellite images for where you find emperor penguins around the whole of Antarctica. The sites differ between time of ice formation and how much the ice forms and breaks up, though Michelle did find that bigger colonies tended to be in places with stable land-fast ice that only had small changes in its growth and retreat cycle. But what will the future look like?
Associate Professor Michelle LaRue
We don’t really know what’s going to happen. And the reason we don’t know that is because all of Antarctica, the different regions in Antarctica, the oceanography is really different. So in some places, the pack ice will actually hold the fast ice in place. And so perhaps in places like that, if the pack ice goes away, perhaps the fast ice would as well.
In other places, like here in the Ross Sea, if you look south of the Drygalski Ice Tongue, that holds the fast ice in place. And so it’s possible – though I don’t know this – it’s possible that, even if the pack ice in parts of the Ross Sea were to go away, that part of Antarctica may still have fast ice, simply because the Drygalski Ice Tongue is functioning as kind of an anchor for a lot of that fast ice.
So I think it’s really variable and it really depends where the emperor penguins are around Antarctica and what’s going to happen to their habitat.
Dr Claire Concannon
So if we’ve got a potential future with land-fast sea ice in some spots but maybe not others, will the penguins move?
Associate Professor Michelle LaRue
I think in places where emperor penguin colonies are in really good habitat – so they’ve got a lot of fast ice, the trend of the fast ice is increasing or it’s growing slightly – and if they’ve got a lot of food, why on Earth would you go anywhere else? You know, you’re kind of living it up, right? This is fantastic.
But there are other places around Antarctica where the colonies are quite small and they seem to be in that very good habitat. This is the kind of habitat where the fast ice might break away a little bit too early sometimes or doesn’t form at all. And the birds that had been there at that point or at some point in the past might show up and say, oh, this is no good, I’m going to try somewhere else, or I’m just not going to try this year at all. And so they both have the flexibility and also a little bit of what we would call philopatry, so that love of place, and to be able to come back to that spot.
So I think they can do both, and I think they’re very flexible.
Dr Claire Concannon
All right, so at least in the short term, some of our flexible penguin friends might be able to find the best patches of land-fast sea ice.
The modelling in the long term is not so good.
Journalist
Predictions that with current warming trends, over 90% of emperor penguin colonies will be all but extinct by the end of the century.
Dr Claire Concannon
Now it’s all very well talking data and uncertainty and observations and modelling with these scientists at what appears to be a time of unprecedented change for Antarctic sea ice, but I also wanted to know how they feel about it.
Dr Natalie Robinson
As a scientist, it’s sort of interesting because we’re racing to discover what’s going on and what it means, but as a human and part of the human race, I don’t know what is in the future for us. But certainly we like things the way they are, and they are already changing, so we’re not going to like what we have in store for us.
That appreciation that we are overheating the planet has developed in the time that I’ve been a scientist. So when I first came down here, people were starting to appreciate the role that Antarctica plays in our climate, but we hadn’t really got to the point of feeling alarmed. And so there was – it was the opportunity for lots of discovery, just fascinating science. But over my time here and working within this community, really, the time for being enchanted by the science is kind of gone for me. It’s much more about the obligation to understand what on Earth is going on, how fast it’s happening, what the implications are for society as a whole, and making sure that I’m doing everything I can to help get that message out and make sure that people understand what our future is really turning into.
Dr Claire Concannon
Working alongside Natalie are those like Dr Jacqui Stuart, who are just starting out in their career. At this time of extreme weather event headlines and increasingly urgent climate science reports, how does she feel?
Dr Jacqui Stuart
There are days where it is like way too much, but I’m really lucky in the sense that I am working in a job that I wake up, and I’m like, I’m doing work to try and help or to help understand. Like I’m not here solving the climate crisis, but I’m trying to understand how our world is going to react and what that might mean for nature and for us. And working in the space is a blessing and a curse in the sense that, you know, you’re working in the space and you’re working to try and help it, but you’re also exposed to it every single day. And thinking about that every day is sometimes not that healthy.
Dr Claire Concannon
And Dr Michelle LaRue?
Associate Professor Michelle LaRue
It’s really sad that we have done that and that we have known that we were doing that. We could have done something a long time ago and we decided not to. And so that makes me really sad, but I choose to have hope and I choose to have optimism.
And I want people to not give up. Honestly, like it’s – I think that sometimes people find that as like a platitude or just like a nice thing that scientists say, but I have never met a climate change scientist that says we’re done. Like I’ve never heard anyone say that. Like, and so this idea that, you know, it’s alarmism. It is absolutely not. And it’s not alarmism. And it’s also something that we still can have an impact on.
Dr Claire Concannon
Hmm. Scared, overwhelmed, sad, hopeful. Sounds about right. I feel these things too.
But time to put the practical hats back on. What is the world doing about it? What is New Zealand doing about it? And is there a different way for us to talk and think about it so that we don’t feel scared and overwhelmed?
Eloise Gibson
There’s lots of positive aspects to responding positively and boldly to climate disruption. Framing through those what we call better life aspects is a really helpful frame.
Dr Claire Concannon
That’s next on our last episode of Voice of the Sea Ice.
Thanks to Dr Inga Smith, Dr Natalie Robinson, Dr Daniel Price, Dr Michelle LaRue and Dr Jacqui Stuart. Reporting for this series was supported by Antarctica New Zealand’s Community Engagement Programme. Thanks to Megan Nicholl for her help on the ice.
Ellen Rykers and Liz Garton helped with production and editing, sound mixing and design was by William Saunders and there was additional sound design by Steve Burridge.
Tēnā koe i whakarongo mai. Thank you so much for listening. I’m Claire Concannon. Have a great week. Kia pai, te wiki.
Acknowledgements
This podcast is courtesy of RNZ. It is from the Voice of the Sea Ice series by Dr Claire Concannon. The series was made with travel support from the Antarctica New Zealand Community Engagement Programme.
Dr Inga Smith
Dr Natalie Robinson, NIWA
Dr Daniel Price, University of Canterbury and Kea Aerospace
Dr Jacqui Stuart, Victoria University of Wellington
Associate Professor Michelle LaRue, University of Canterbury
