Breaking the Ice
A video series of ‘TED-type’ talks, featuring stories and ideas from amazing people at the Australian Antarctic Division.
Breaking Barriers
Video transcript
My name is Associate Professor Meredith Nash, and I’m a Senior Advisor for Inclusion, Diversity and Equity at the Australian Antarctic Division.
My story begins in 2016. I’m on a ship to Antarctica as a sociologist to study a group of 77 women who are about to embark on a 3-week leadership program for women in STEMM.
These women worked in all different scientific fields – there were mathematicians, evolutionary biologists, geologists, pharmacologists, forest rangers, astronomers, and engineers.
Up until this point, as a sociologist, I had basically never thought about Antarctica, women in STEMM, or just how seasick you can get from a 4-metre swell.
But this voyage was important… because it was the largest non-scientific expedition of women to Antarctica in history.
Women have been heading south to Antarctica in a range of capacities for decades, but the thing is – the icy continent has historically been a place for men to do research and exploration.
During my three weeks in Antarctica, I pondered this question… how had our expedition had come to be such a big deal?
And it was… there was even a film made about it.
How had Antarctica come to be so dominated by men? Where were all the women?
And the answer to my question had been there all along, on a map on the wall of the ship where I looked every morning to see where we were headed
On one of these mornings, I spotted Marguerite Bay, on the Western Antarctic peninsula.
Aha, I thought, so there were women here, at least symbolically, ages ago.
Antarctica has been mapped geographically since ancient times, but its human history is relatively new.
And for the most part, when we talk about Antarctica’s human history, we are talking about heroic white men who explored the continent.
But who was Marguerite…?
Her name reached the Antarctic because her husband, Dr Jean-Baptiste Charcot, leader of the French Antarctic Expedition, discovered a bay and named it for her in 1909.
So there she was, symbolically, as were many of the other women to Antarctica — names on maps.
More than 200 places in Antarctica are named after women.
In 1931 two Norwegians, Ingrid Christensen and Mathilde Wegger were the first women to visit Antarctica, and they stayed on the ship.
They arrived on the Thorhaven. Ingrid’s husband was a shipping magnate and he owned the Thorhaven.
A coast was named in Ingrid Christensen’s honour.
Australian explorer Douglas Mawson, also landed in Antarctica in 1931, and he got quite a shock when he saw Christensen and Wegger on a ship and reported his ‘astonishment’ to the Sydney Morning Herald.
It’s entirely possible that women visited Antarctica earlier, but their stories were never recorded.We do know, when Ernest Shackleton advertised his 1914 Antarctic expedition, “three sporty girls” begged to join. He replied: “regrets there are no vacancies for the opposite sex on the expedition.”
Caroline Mikkelson was the first woman to set foot on Antarctica in 1935.
She arrived a century after men. A few women over-wintered in Antarctica in the 1940s but it really wasn’t until 1956 that things started to change when it came to women’s involvement in science.
Russian geologist Maria Klenova landed in Antarctica to make the first Soviet Antarctic Atlas.
Now not only were women on maps of Antarctica, but they were also literally in Antarctica making maps.
Nel Law was the first Australian woman to set foot on the continent, at Mawson in 1960-61.
Nel accompanied her husband Phil Law on the Magga Dan.
Phil was the Director of the Antarctic Division and leader of the Australian National Antarctic Research Expeditions (ANARE)
Nel was an artist and some of her paintings from the voyage can be seen here at the Australian Antarctic Division.
When Phil Law decided he wanted to take Nel to Antarctica, he had to smuggle her on to the ship in Perth.
When Nel was discovered by the crew, it caused quite a stir and she could stay because they thought it would cause too much negative publicity for the voyage.
In the end, it was a great boon for ANARE and led to increased support for the wives of expeditioners.
In fact, the Danish-built icebreaker MV Nella Dan was later named in Nel’s honour
Then in 1969 an American group of all-women scientists led by Lois Jones landed in Antarctica. They wanted to collect their own samples from the McMurdo Dry Valleys but had been prevented from doing so up until this point.
The significance of this expedition was noted by Walter Sullivan in the New York Times, when he described the 1969 expedition of US scientists as “an incursion of females” into “the largest male sanctuary remaining on this planet.”
Following these developments, The Australian Antarctic Division and the British Antarctic Survey allowed women to stay on research stations and conduct land-based Antarctic fieldwork, starting in the 1980s.
Now, today, women are more fully integrated into National Antarctic Programs and women often lead field teams.
Nearly 60% of early career researchers in polar science internationally are women.
Yet there is still work to be done which is why I’m here at the Australian Antarctic Program as Senior Advisor – Inclusion, Diversity, and Equity.
For example, while women’s participation in the Australian Antarctic Program is increasing, women still comprise only 24% of expeditioners… the US Antarctic Program and British Antarctic Program, report 33% and 30%, respectively.
Antarctica is a diverse workplace and as such, we need to continually reassess our processes and procedures to ensure that a polar career is safe and accessible for all people.
Considering changing social norms and recent movements like #MeToo and Black Lives Matter, the AAD has acknowledged, there is a need to rethink equity and inclusion in the context of polar research, and to address the structural inequality that underpins science more broadly.
A key question for us is whether we are going to interrupt or disrupt gender inequality in the AAP.
Interrupting is recognising that inequality exists, but we aren’t holding ourselves accountable.
Disrupting inequality is about ending inequality – we commit to holding systems and people accountable.
Disruption requires a mindset of vulnerability – it is a recognition of the fact that change is hard – and long – there are no shortcuts. We might make mistakes along the way but that’s okay.
So my aim is to use insights from social science to spark a conversation about what disrupting inequality looks like in the Australian Antarctic Program and how we can bring about systematic change within Antarctic research.
For example, this year I’m focusing on how we can update the image of an Antarctic scientist so that it is more inclusive of under-represented groups like women, people of colour, and LGBTIQ+ folks.
I’m also working to ensure that here at the AAD we are regularly engaging our community in issues of diversity and equity – like celebrating international days of recognition like NAIDOC week and recognising Polar Pride.
This will enrich the diversity of the scientific community and have flow on effects for the quality of Australia’s Antarctic science.
[end transcript]
Traversing: how to get a mobile research station deep into Antarctica
Video transcript
Hello everyone, my name's Anthony Hull and I'm part of the Traverse project team. So what I thought I'd do today would be to give you a walk and talk through our Lego model of our planned Traverse.
One of the main purposes of the Traverse capability is to deliver a mobile inland station to a site approximately 1200 kilometres inland from Casey station.
At the front we have kind of where we feed and prepare meals, which has been designed to cater for 16 people. Obviously being at such a remote site 1200 kilometres from the coast of Antarctica, we need to look after our expeditioners from a medical perspective, so part of the inland station will be a containerised medical facility and that will be staffed by a doctor.
Overall we've had to manage the weight of the Traverse so some of the structures we will use at the mobile inland station will be tents. So there's a series of tents that are going to be used to support the Million Year Ice Core component, which is the reason why we're putting the mobile inland station on site. But also some of the tents will be used as a mechanical workshop because they're bigger structures we can erect on site which give us more space, but also save us weight for the overall Traverse we have to transport.
The most exciting thing about the new Traverse capability and the mobile inland station is the endeavour to drill for a Million Year Ice Core, which is kind of the scientific holy grail in glaciology at the moment. So this will be the primary focus for the next five or six years of the Antarctic Program.
So what we need to transport inland is all the drilling equipment and infrastructure to enable us to drill for this Million Year Ice Core. So behind this tractor we have the Ice Core drill and winch. So this drill is going to drill approximately 3 kilometres through the ice cap. So we need to put all of the supporting power generation, scientific instrumentation to support that drilling process.
Once the Ice Cores are drilled they'll be brought to the surface, they'll undergo some scientific processing and analysis. For us to be able to return the Ice Cores to Australia we've had to put a system in so they don't thaw out on the way back to Australia. They'll be temperature controlled so we can make sure we don't lose those Ice Cores.
The procedures at the end of the day, this snow groomer here, his job during the day has been to groom the Traverse route out the front. To knock down the lumps and bumps so this Traverse train can travel smoothly. The first job when parking up for the night will be to move through this area and turn this into a car park for the other pieces of plant, or the tractors and the groomers. The reason we need to do this is overnight we need to plug all of these vehicles, the tractors and the groomers, into power, because this allows us the next day to wake up and move away from our overnight camp with warm machinery.
The whole Traverse capability will have actually five of these tractor and Traverse trains behind them. On the table we could, we've got three here for you. So the overall capability needs to be able to tow about 400 tonnes inland, so we need to distribute that load across five tractors, because roughly we can put 80 tonnes behind a single tractor. When we're actually on the Traverse route there's one road being prepared out the front by the groomers. So that's the function of these guys, they knock those lumps and bumps off the Traverse route.
The temperature range that we can expect from sea level, right up to 3200 meters, there could be a difference of -30 and -40 temperatures. So that's the reason when we've designed the Traverse and the living infrastructure we've had to build them to withstand those temperatures. Noting that that happens during the summer period and will be active from December through to February on a given year. But we can't bring all of this equipment and gear back home during the winter because the Traverse will be too heavy for the following season when the Traverse has to go back up the hill. So the plan will be to leave some of the infrastructure at the mobile inland station site. From a temperature perspective there some of these living vans may need to withstand temperatures as cold as -60 or -70, so there's been a lot of thought and planning put into not only the design of the living vans themselves, but also the tractors and the groomers have been heavily modified to suit those Antarctic conditions.
In terms of delivering the whole capability to Antarctica, the plan for this season is to deliver the remaining tractors and groomers into Casey by air. On station, once it's delivered we'll spend the remainder of the summer building the Traverse capability. The reason we're doing that, so in the season of 2022-23, we can look to stage our first Traverse out of Casey station.
[end transcript]
Top Tips for a science career: a journey from viruses to whales
Video transcript
If I said to you that viruses, bacteria, seahorses and whales are very similar, I wouldn’t blame you for thinking that I am completely and utterly crazy… but bear with me…
Biologically speaking, viruses, bacteria, seahorses and whales are all quite different and, naturally, whales are much, much bigger than microbes.
But from my perspective, what links them all is my career in science so far.
Let me explain…
I went from studying tiny viruses and bacteria for my PhD, to a postdoctoral position researching seahorses, to now studying whales in the Southern Ocean.
I want to tell you a bit about what I’ve learned along the way, and give you my top tips about following a career in science.
Don’t be afraid to take chances
When I was an undergrad studying environmental biology in the UK, I dreamed of working in the Daintree studying some of the largest plants on the planet, trees, by day, star-gazing by night and snorkelling on coral reefs in my spare time.
I also vividly remember enjoying a course on Polar Ecology but watching episodes of the BBC’s Life in the Freezer as part of that course and thinking to myself that I could never, ever work in Antarctica!
But would you believe it? That’s exactly where I ended up. Almost immediately after graduating I found myself in Antarctica, just 22 years old, starting a PhD studying some of the smallest plants on the planet, algae, plus those bacteria and viruses mentioned earlier.
26 years on, I’m still working in Antarctica, but have since managed to work in the tropics and on coral reefs too!
So did I go wrong? Did I lose my way?
No, I didn’t, I took a chance and seized an opportunity that challenged all my preconceived ideas about what I thought I wanted to do, and I went for it.
And that’s a key lesson: don’t be afraid to take chances, as you may never get those opportunities again.
Skills are transferable
It is also important to view every opportunity, however different, however mundane, however challenging, as a chance to learn new skills that can be used to steer your career in directions you do ultimately want it to go.
My Antarctic opportunity allowed me to develop skills that are transferrable to practically any setting: fieldwork, laboratory work, data handling and analysis, writing scientific papers, communicating with people from different walks of life, how to run my own projects and manage my own budgets.
Plus the fact that anyone who works in Antarctica will tell you about the “A-factor” – if anything is going to break, it will break, just when you need it and likely in the middle of a blizzard! Having to trouble shoot and fix gear in extremely cold, windy conditions taught me more than I could ever have imagined and has helped me overcome equally challenging, albeit not so cold, situations since.
Let your passion take you anywhere
It’s also important to let your passion take you anywhere… and I mean anywhere.
Some of my most successful colleagues are those that took a particular skill, technique or method, for example statistics or genetic techniques or stable isotope analyses, and applied it to lots of different scientific questions literally from Antarctic microbes to hippos in Africa.
In that sense my career has been no different, by letting my passions and skills be my guide, I was able to comfortably move from a PhD working on microbes in the Antarctic to working on seahorses in the tropics, and more recently into working with whales in the Antarctic again.
Walk away when you need to
Of course some of the chances you take may not turn out well.
If you’re truly not happy or inspired by what you are doing never feel the need to get locked in.
Don’t be afraid to change tack completely. Know when to walk away. And then learn from that experience.
Knowing what you don’t want to do is as valuable as learning what you do!
Find a mentor
To help with making big career decisions like taking a chance or walking away, it is really useful to find a mentor.
Everyone needs someone they can talk to about their work and their career choices.
You may in fact end up with several mentors whom you approach about different things at different stages of your career.
Later on you may even be able to return the favour and mentor someone else as they embark upon their own scientific career.
Collaborate!
The importance of other people does not stop at mentors.
I can’t stress strongly enough how important team work and a willingness to collaborate with other scientists is… and how much fun too!
One of the best aspects of my current job is that I work closely with scientists from all over the world in a huge collaborative network.
We achieve far more working collaboratively than we would so alone, pooling our collective brain power to tackle big problems and sharing resources that are not necessarily available to a particular individual or institution.
Those collaborators will also be your inspiration and your support network.
Believe that you can make a difference!
I have also learned it is really important to keep believing in yourself and believing that you can make a difference. The human race is facing a number of huge challenges that need the input of scientists: climate change, finding a vaccine for coronavirus to name only two.
I’m not saying that everyone is going to win a Nobel Prize for their scientific endeavours to tackle these problems.
But I am saying that every piece of science that we do fits another tiny piece into a huge and often complex, jigsaw puzzle.
And your tiny piece of that puzzle is absolutely critical to the whole picture finally being revealed.
What’s more, your tiny piece is likely to make it possible for other people to slot their pieces into the puzzle too!
You will get there in the end…
Finally, whichever seemingly unrelated opportunities that you seize along the way, know that you will get there in the end… or somewhere equally as interesting.
When I was younger, never in my wildest dreams did I think I’d be working on whales in the Antarctic, but I did know that I loved the oceans and that I cared deeply about conservation and about finding ways to help threatened species.
In that sense I am right where I want to be. That might not be the Daintree studying trees but I am researching magnificent whales, in an extraordinary place, the Antarctic, with amazing people from all over the world, and using my research to influence the choices that governments around the world make about the management and conservation of these creatures.
And along the way I got to play with viruses, bacteria and seahorses as well, and had a lot of fun!
[end transcript]
Frozen Ocean: how a freezing Southern Ocean affects the world
Video transcript
Hi I'm Dr Dirk Welsford. I'm currently the Chief Scientist at the Australian Antarctic Division. So every year in the darkness of the southern hemisphere winter something truly incredible happens. It's the world's largest natural phenomenon. The Southern Ocean freezes.
At first you can barely notice it, the ocean starts to look sort of greasy, oily. Slush starts to form, but then slowly that starts to solidify into larger and larger pieces and as they jostle in the tide and in the wind, eventually they form a massive continuous sheet right around Antarctica.
The Antarctic is really, really big so continental Antarctica itself is already twice the size of Australia. But if you then add this massive sheet of sea ice, that entire area is four times the size of Australia.
Now such a big phenomenon has big consequences. It has consequences for the animals and things that live in the Southern Ocean, but it also has big consequences for us. For the organisms that live in the sea, so things like whales, penguins and seals, the way that they do their life has to change.
They've been down there in summer, swimming around in the ocean that's mostly ice free, eating krill. But with the formation of the continuous hard sheet they have to change. The whales actually leave. A lot of the whales move north in to the tropics to breed. For the seals and penguins the ice actually becomes a convenient place for them to haul out, so they actually sit on the ice and have a bit of rest between bouts of foraging.
For organisms that live in the sea, particularly near the surface, it is so cold that they could freeze solid, and some of the fishes that live in the Southern Ocean actually have anti-freeze chemicals in their bloodstream to prevent that happening.
The ice itself can form up to a 2 metre deep layer, and that's a habitat in itself. It's full of small cracks and small bubbles and there is a whole suite of microbes that live inside those cracks and bubbles. Some of them are photosynthetic so they are like plants and they'll sit there and they will basically go to sleep over winter and wait for spring to come, and for the sunlight to come. But others actually become hunters and they will be working their way through the holes in the ice, hunting other microbes and eating them.
At some places, the wind that is blowing of the top of Antarctica is so fast and so hard that it actually blows the top of the ice away, and it forms a hole in the ice, and these holes are called polynyas. These polynyas are really important as well. They are a place where ice continues to form because the ice keeps getting blown away. There's new sea surface that gets exposed and then that freezes, but also as the ice freezes it sheds salt, and the ocean underneath the polynya gets very, very cold, becomes very, very dense and it actually sinks. And so much of this water is formed in these polynyas and it actually flows down off the continental shelf of Antarctica, out in to the deep ocean and then all the way up in to the northern hemisphere and you can actually find chemical signals from this water, all the way up in to the North Pacific and in to the North Atlantic.
So this enormous process, this massive natural phenomenon, which happens every year around Antarctica every winter, has massive consequences for us. We need to keep an eye on this process. It is changing with climate change. It's been going on for 20 million years, for as long as Antarctica has been where it is. But without it, life on earth will be very different.
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Ocean Giants: meet the only person in the world to attach a satellite tag to an Antarctic blue whale
Video transcript
Hi, I'm Virginia Andrews-Goff, I'm a marine mammal research scientist. Welcome to 'Breaking the Ice'.
On Valentine’s Day in 2013 I found myself bouncing up and down alongside the largest animal that has ever lived on this earth. I was in the bowsprit of a six metre boat in Antarctica beside a 30 metre Antarctic blue whale, and I was attempting to build up the courage to place a satellite tag on its flank. It wasn't much of a romantic day but it sure was an amazing day.
There's a reason no one had ever done this before. Antarctic blue whales are known for their speed and their agility. Even some of the whales alive today evaded capture during commercial whaling.
There had literally been hours upon hours of preparation and training involved for both myself and the coxswain to get us ready for this moment. There was massive cost involved in launching a voyage and sending a ship into the Southern Ocean and then there was the huge technological advances required to actually find the Antarctic blue whale in the first place, not to mention the fact that the satellite tags I was attempting to deploy were worth thousands of dollars and could sink.
So why bother? To answer that question I need to take you along the Antarctic blue whale's timeline to near-extinction.
With the advent of factory ships onto the commercial whaling scene came the ability to target whales far from shore. So Antarctic whaling began in 1904, and it peaked in 1930 with the production of three million barrels of whale oil, equivalent to more than 40,000 individual whales. In 1931, 75 percent of the world's whale oil production was from Antarctic blue whales. Soon after, the whale oil price crashed and there was a lot of concern around the depletion of whale stocks. It was time to regulate the industry.
A couple of attempts at regulation in the 1930s failed, but then in 1945 the international convention for the regulation of whaling was established. However there was no scientific procedure around the calculation of catch limits, and the unsustainable whaling in 1963 led to the near extinction of Antarctic blue whales.
In 1964 Antarctic blue whales were formally protected. By that stage 340,000 Antarctic blue whales had been killed taking the population down to less than one percent of its pre-exploitation size, leaving just 360 individuals. Over four decades of protection later the population remains critically endangered as classified by the IUCN. I guess to say that Antarctic blue whales are scarce is an understatement. Some 30 years worth of surveys from the late 1960s found on average one Antarctic blue whale per 2,500 kilometres of survey, and that was during the Antarctic summer when Antarctic blue whales are at their most concentrated.
For the largest animal that has ever lived on this earth, surprisingly little is known about their distribution and their movements. So, what don't we know that satellite tags can tell us? And how does this help the Antarctic blue whale along its road to recovery? We don't know the simplest information about Antarctic blue whales. We don't know where these animals migrate to during winter, or whether some of the animals remain in Antarctica for the winter.
By gaining some understanding around the movements of Antarctic blue whales, we can gain some understanding about the threats that they may encounter along the way. So for example, what if Antarctic blue whales migrate north and what if they cross a major shipping lane as they do so? Do we need to make some management decisions around vessel speed in order to avoid lethal collision?
But from my perspective some of the most interesting information we can gain from satellite tags comes from looking at the animals behaviour on the feeding grounds.
For example, we've tagged West Australian humpback whales and we know that they tend to target productive predictable and persistent feeding grounds in Antarctica. What if Antarctic blue whales were to do the same? What if they prefer a certain region and they return to that spot every year?
We've also tagged East Australian humpbacks and we've learnt from that dataset that some of the animals like to stop and have a little snack on their way down south. What if Antarctic blue whales were to do the same thing? What if they would support their huge energetic demands during winter by having a little winter snack? What if Antarctic blue whales prefer krill in a certain form. We know from our work currently that Antarctic blue whales are often associated with krill swarms that are dense shallow and skinny. All this information is really important for the regulation of the krill fishery.
What if Antarctic blue whales are associated with features that concentrate prey? We know from our satellite tagging data that Antarctic blue whales are associated with polar fronts and the productive Antarctic ice edge. These are both features that concentrate prey, and these are both features that are going to be impacted by climate change. So in short, satellite tag-derived movement data is essential for the conservation and management of the recovering Antarctic blue whale population.
But here's a concept we should probably get our heads around. Conservation and management isn't about Antarctic blue whales. These whales are completely successful at what they do. They swim around, they consume huge amounts of krill, they sing to one another, they inspire awe in everyone who gets close to them. Conservation and management is about people. It's about managing the threats that we pose and these threats for Antarctic blue whales are things like fishery management, vessel traffic, ocean noise, ocean pollution, and of course climate change.
Antarctic blue whales were almost wiped out by commercial whaling. It took over 30 years for managers to step in and make that last minute decision to ban the take of Antarctic blue whales. We now know better. In the face of these emerging threats, we can do better.
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Antarctic Climate Science: the ice tells us that things are going to be different in the future than they were in the past
Video transcript
I'm Dr Tas van Ommen of the Australian Antarctic Division, and I lead the Antarctic Climate program. It was one of those unfortunate ends to a day that had otherwise been quite successful in the field, that made me step back and ask myself, why was I there doing what I was doing?
The day had gone quite well, we'd travelled a little over 100 kilometres in 12 hours, driving tractors across the East Antarctic plateau, and the plan at the end of the day was for me to drill a shallow ice core, get a short snapshot of recent climate from the three kilometre time machine in the layers of ice beneath my feet.
The weather was coming up, a little inclement though, it was minus 30 degrees and the wind picking up, blowing shards of ice against any exposed skin, so we were keen to get the job done. And as I lifted the drill for the final run of the day, I looked in despair as the business end of the drill disappeared down a hole three stories beneath my feet. I'd forgotten to secure a locking pin. Well, with some ingenuity from my colleagues we got the drill back, we fished it out, and next day we continued on our journey, but that's another story. What I really want to talk about here is why we were doing what we were doing. That's an interesting question. I mean, Antarctica is a fantastic place, privileged to work there, it's stunningly beautiful, harsh and captivating. But that's not the reason why we're there.
You see, Antarctica matters in very direct ways to all of us. The early explorers, Mawson and colleagues, understood some of this. They knew that Antarctica was important for the weather of Australia and other Southern Hemisphere continents. In 100 years or so since, we've learned a great deal more and we know now that Antarctica and the Southern Ocean are engine rooms of the global climate system.
I'm a glaciologist and a climate scientist and I work in a team of scientists here who are studying how Antarctica fits into the global climate system. We look back at the climate past from ice cores and other sources of evidence, we look at how things are now and how they're changing, all so that we can better predict where we're headed in the future.
What I want to do now is just take you through some of the areas of study and give you a feel for what that work involves. When we think of Antarctica of course, we think of ice. It has more than 90 percent of the planet's ice, and in fact if it was all to melt it would raise sea levels by 60 odd metres. That's not going to happen. Antarctica has had ice sheets for tens of millions of years, but we do know from the past that the waxing and waning of the Antarctic ice sheet influences sea level. Last time temperatures were two to three degrees above pre-industrial, roughly where we're heading if we overshoot the Paris targets, sea levels were six to nine metres above present.
How that plays out in our warming world, what's the timing, what are the rates of change, where are the vulnerabilities, are key questions for Antarctic glaciologists. The best we can say at present is that sea level rise by the end of this century 2100 will be between about 29 centimetres if we mitigate really hard, and 1.1 metres. That's a distressingly large range and it overlooks the fact that that's only the likely range, the actual sea level rise could even be higher still. And of course we care what happens beyond the year 2100.
Ice is also a feature on the oceans around Antarctica. Every winter we see a growth of the sea ice around Antarctica, the frozen skin of ocean, on average around a metre or so thick, more in some places and less in others. Sea ice plays a critical role in the climate system by reflecting light back to space and actually regulating the flow of heat and moisture between the ocean and the atmosphere. Sea ice is also really important for the Antarctic ecosystem, but that's a separate story. When we look at how sea ice has changed over recent decades, we see that in the Antarctic if anything it's increased very slightly, unlike the Arctic where sea ice has gone down precipitously. Although in the last few years in the Antarctic we've also seen a reversal and a starting of a decline in sea ice. We understand parts of what we're seeing here, we understand the importance of ocean currents and winds and the input of fresh water from the ice sheet and from precipitation. All of these jigsaw pieces are important but we don't have the overall picture of where sea ice is heading, how fast is it going to change and what does that mean?
The ocean around Antarctica is also important. It connects Antarctica to the rest of the planet through deep ocean currents that travel around the globe. The largest of these currents is the Antarctic Circumpolar Current, which as the name suggests, travels all the way around Antarctica connecting all of the ocean basins. It also actually regulates the mixing of deep ocean water and surface waters and along with the oceans as a whole plays a really important role buffering our climate system. In total the oceans of the planet have soaked up something like 30 percent of the CO2 we've ever emitted and more than 90 percent of the heat. What happens to this buffering as we go forward is a really critical question if we're going to predict the future, and we're part of international efforts to monitor the Southern Ocean to measure the currents and the properties and look for signs of change and ensure that we understand what's going on.
So the final part of the climate machinery that we look at is the atmosphere over Antarctica and the Southern Ocean. The atmosphere like the ocean is a fluid component moving heat and water around the planet, connecting the tropics to Antarctica and connecting Antarctica back to mid-latitudes in Australia in particular, and the Antarctic atmosphere has changed as a result of human activity. Mostly ozone depletion, the ozone hole, but also CO2. These things have changed the temperature structure of the atmosphere above Antarctica, cooling the stratosphere and above, and actually strengthening the winds that circulate around Antarctica.
These westerly winds that circulate around the Southern Ocean have not only strengthened but they've shrunk towards the pole southward, taking with them some of the rain-bearing fronts that actually intersect southern Australia and the other continents.
We're also concerned when we talk of the atmosphere about the clouds in the Southern Ocean which play a really important role reflecting light back to space and controlling the amount of heat which actually reaches the ocean below. That reflectivity is critically dependent on the mix between ice and supercooled water in the clouds, and scientists are carefully modelling and understanding that mix so that we can do a better job of predicting weather and climate into the future.
As we look to the future we think also of the deeper time in the past, and so if we look at that three kilometre time machine I referred to earlier, we can drill ice cores that go all the way to the bottom of the ice sheet. Presently the longest of these is a core that goes back 800,000 years.
This eight hundred thousand year ice core shows us in detail how the climate's waxed and waned over that period. We've seen warm periods like the present interspersed with cold periods where there were ice sheets over North America and northern Europe. This pulsing we see in the chemical signatures from the ice core shows the climate over that time period, but we also see from the ice core something else. Trapped between the snowflakes as it gets buried, we get bubbles of past atmosphere and when we crack open those bubbles we can see CO2 levels, and what we see is the CO2 over those 800,000 years looks remarkably like the temperature. Amazingly so. This shows us that temperature and CO2 on the planet are tightly coupled in the natural system.
That is until we come to the recent period, if you look on the far right you can see how the CO2 has increased since industrialisation to levels well above anything seen in the 800,000 year record. Even before we turn to our well-understood physics of greenhouse gases and our climate models, the ice is telling us that things are going to be different in the future than they were in the past. You will have heard in what I've been saying a recurring theme, that while we understand Antarctica and the Southern Ocean much better than we did, and we know a lot more about the climate system, there are still really important gaps in our understanding. Gaps that matter to our ability to project what's going to happen in the future. And as we look to the future I'm reminded of the words of former White House advisor on climate John Holdren, who said all we have is adaptation, mitigation and suffering.
As a scientist, my hope is that we can use our understanding to chart a pathway to a resilient future. Knowledge is power. Knowledge will tell us what we absolutely need to avoid. Knowledge will guide our adaptation, and knowledge will help reduce suffering. And thinking back to that cold night on the Antarctic plateau, there's the answer to my question. That's why I do what I do.
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Krill on Acid: as the Southern Ocean becomes more acidic, what will this mean for Antarctic krill?
Video transcript
Hi, I'm Rob King, I'm a krill biologist at the Australian Antarctic Division. I'm standing in front of the biggest pile of Antarctic krill food north of about 60 degrees south. This is Antarctic phytoplankton, microscopic plants that drift around in the Southern Ocean and take up carbon dioxide and turn it into organic matter, joining the carbon atoms together using the energy from sunlight. And this is important for us here because we hold one of the world's only captive populations of Antarctic krill for research, here in this laboratory in Hobart.
The krill are in the lab next door, the phytoplankton here are grown in these cultures to mass produce, to feed krill some of the food they'd be eating in the wild. This is just two species, a red one and a green one, both with a photosynthetic pigment for trapping sunlight to take that energy and put it into the chemicals that they're making to pass up the food chain.
Now what's important about the Southern Ocean is that food chain starts with Antarctic krill as the next customer eating this phytoplankton, and then the great whales, the seals, the penguins and the squid, all rely on krill being there in vast numbers, up to 500 million tonnes of krill swimming around the Southern Ocean.
So this is a very important food chain, a food chain that supports some of the most charismatic marine life we know of on the planet, the great blue whale, and also an important fishery for humans, around 300 000 tonnes of krill each year taken from the Southern Ocean and at the moment that's a very well managed fishery, that is a tiny proportion of the biomass.
But our interest here in this lab is to understand what is going to happen to krill in the future, and the reason we need to know that is because the planet is literally changing so fast around the krill and what the fundamental change is this increasing carbon dioxide. We've all heard about climate change, the trapping of carbon dioxide in the atmosphere, heating the planet, but there's another carbon dioxide problem, and that's called ocean acidification, and that comes about because this extra carbon dioxide that we're putting in the atmosphere is dissolving in the world's oceans.
Each year, about nine billion tonnes of carbon dioxide dissolve in the ocean, and that's good for us here up on land because it decreases the amount of warming on land, but it comes at a cost to the marine environment, because when it dissolves in water it reacts to form carbonic acid and carbonic acid is a weak acid but there's enough of it that it is changing the acidity of the water, more hydrogen ions, the pH is changing and this change is different depending what organism you happen to be.
Some organisms are good at coping with pH change and some aren't, and the other problem is that the rate it dissolves into the oceans is different across the planet. Carbon dioxide dissolves very well in cold water, and that means that the polar oceans of the earth are going to be more strongly affected by ocean acidification sooner.
So what does that mean for krill? Krill are mainly up in the surface where they're eating this stuff, the phytoplankton, they have to be there that's where the light is. And for krill there are big problems as well, but it's not the adult krill it seems to be the embryos. Let's go and have a look at the krill and we'll take them some phytoplankton on the way
This is a little piece of the Southern Ocean, there's about a thousand litres of sea water in here and about a thousand Antarctic krill as well. They were brought back to Australia on the Aurora Australis and we're keeping them here to produce eggs, eggs for research on ocean acidification, but what these krill are after at the moment is some phytoplankton. Krill are the combine harvesters of the Southern Ocean eating everything that they can catch in those front legs.
So these krill will filter this phytoplankton out of the water and trap it in their front legs. They'll pass it up into their stomach, which has a set of teeth inside the stomach that grind it up, and that will break the cells apart, which are microscopic, and release the nutrients to the krill which you can see being digested in that dark blob behind the eyes, which is the digestive gland.
And that's great because krill feed well here in the lab and we try and feed them a natural food source because we're producing eggs to use in the research next door. And what we've found in the research is that if you apply ocean acidification to Antarctic krill, you really don't see a great effect. The krill as adults aren't really that bothered by the sort of levels of ocean acidification we expect to see over the next hundred years, if we were to do nothing about our emissions of carbon dioxide.
However it's no good being an adult krill, even though you might live for five or seven years as an adult, unless you can produce viable offspring to replace you when you've been taken by a whale or a seal or a penguin. You've got to reproduce or you'll be gone, and it turns out that the eggs of krill are vulnerable to ocean acidification. Now why does this matter? Because ocean acidification is coming fast in the Antarctic.
There are in fact krill all over the planet, all the world's oceans. But it's the krill in the polar oceans, and particularly this very important, Antarctic krill, that really could be a key tipping point for the Southern Ocean ecosystem. When krill are spawned, they spawn at the surface. The eggs sink a kilometre deep over the next five days where they hatch, and then they go through a developmental ascent, swimming back to the surface and then associated tightly with the sea ice for six months going through another 12 larval stages. So sea ice is very important to krill.
But the journey is even more important, because what happens is those krill are sinking through layers of the ocean that have different concentrations of effective carbon dioxide gas in them. It's dissolved, but the problem is that acidity is there, the hydrogen ions are released from that dissolution.
The problem coming though, is that if we continue to emit carbon dioxide at high levels they'll be sailing down, sinking, as completely vulnerable eggs totally out of any control of their own. They will sink through layers that are exceeding a thousand parts per million, and what we've been able to show in the lab here by taking eggs from these animals when they spawn, and exposing them to various concentrations of carbon dioxide to simulate what we expect them to be sinking through in the future, is that by the end of the century if we do nothing to slow down our emission rates, half the krill eggs in the Southern Ocean won't hatch. They simply stop developing as embryos, and don't break out of the eggs, pausing their growth and not making it to become the viable embryo that has to swim a kilometre to the surface, so they don't really have much of a chance. But if we go to the year 2300 with no control on emissions, the hatch rate falls to 2 percent of the current hatch rate.
Now that sounds diabolical, and I really, really am confident we're not going to take the planet to that extreme, but that is what would happen based on the modelling we've done on the experimental results from this aquarium.
The good news story is that, that's the normal business-as-usual emissions. If we drop from business-as-usual emissions to high or medium level emissions, the hatch rate is only depressed to about 85 percent of what it is now. So a much smaller reduction by the end of this century, and by the year 2300 you drop to 50 percent of the hatch rate of krill.
So you can see by doing just a little bit now you can make a tremendous difference for generations of krill, and generations of humans, whales, seals and penguins down the track.
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