Polar invasion: how plants and animals would colonise an ice-free Antarctica

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Tom Hart, Author provided

Peter Convey, British Antarctic Survey and Tom Hart, University of Oxford

Antarctica’s ice sheets could totally collapse if the world’s fossil fuels are burnt off, according to a recent climate change simulation. While we are unlikely to see such a dramatic event any time soon, we are already observing big changes and it’s worth considering what the worst case scenario might look like for the continent’s ecosystems. How long before Antarctica turns into grassy tundra?

For now, life thrives mostly at the very edge of the continent – it’s driven by the plankton-rich Southern Ocean and clustered around seasonally ice-free areas of coastal land. The interior might be sparsely inhabited, but the continent is not as barren as many think. There are around 110 native species of moss and two flowering plants, the Antarctic hairgrass and pearlwort. These plants have flourished along the relatively mild Antarctic Peninsula in recent decades. However they can’t go much further – they already occur at almost the most southern suitable ice-free ground.

With ice-caps and glaciers receding already in the Peninsula region, native land plants and animals are benefiting from more easily available liquid water. Already we are starting to see increased populations, greater areas occupied and faster growth rates, consequences only expected to increase – everything is currently limited by the extreme physical environment.

The world’s most southerly flower, the Antarctic hairgrass (Deschampsia Antarctica)
British Antarctic Survey, Author provided

It may eventually prove too warm for some native species, but the bigger issue in upcoming decades and centuries will be whether new and currently “non-native” species will arrive that are stronger competitors than the native organisms.

Antarctic invasions

Native polar species are inherently weak competitors, as they have evolved in an environment where surviving the cold, dry conditions is the overriding selective pressure rather than competition from other biological sources. If humans (or other wildlife expanding their range southwards) bring new competitors and diseases to Antarctica, that may pose a very grave risk to the existing biodiversity. Some native species would likely be pushed into the remaining more extreme regions where they can avoid competition and continue to rely on their inherent stress tolerance abilities.

Tom Hart with two million chinstrap penguins. Isolation has made Antarctic species vulnerable to introduced competition.
Richard White, Author provided

We usually split the process of natural colonisation – which applies even today in Antarctica – and that of movement of “alien” species by human agency. The best available data for the Antarctic region come from some sub-Antarctic islands, where it appears humans have been responsible for many more successful colonisations than nature. In fact, over the recent centuries of human contact with the region we have introduced 200-300 species compared to just two or three known natural colonisations.

Penguins, seals and flying seabirds move between islands and the Antarctic Peninsula, so there is potential for some natural colonisation. Vagrant birds are regularly observed across the sub-Antarctic and even along the Peninsula, some of which have colonised successfully (such as the starlings, redpolls and mallard ducks on Macquarie Island).

Migrants such as skuas and gulls, which spend time on land at both ends of their migration, could be important natural vectors of transfer for invertebrates, plant seeds and spores, and microbes into an ice-free Antarctica. Importantly, bird colonies also fertilise surrounding rock and soil with faeces, eggshells and carcasses. Plant and animal life flourishes near seabird colonies, encouraged by this enrichment.

What’s hitching a ride on this skua?
Tom Hart, Author provided

However it can be tough to predict what Antarctic melt would mean for individual species, never mind entire ecosystems. Take penguins, for instance – they have already survived previous inter-glacial retreats, but at reduced population sizes. This time round it is likely that Adélie and emperor penguins who are more dependent upon sea ice would decline, while less ice-dependent species such as gentoos and chinstraps might benefit. Indeed, there is already some evidence that emperors are struggling (although also that they may be adapting and learning to emigrate).

However the fact fish-eating gentoo penguins are increasing on the Peninsula while Adélies and chinstraps (both krill eaters) aren’t doing so well suggests prey availability can be more to blame than ice cover. Figuring out the impact of large-scale environmental change at ecosystem or food-web level is hard – it’s a complex process that will no doubt throw up some unexpected results.

This flightless midge comes from South Georgia but has been introduced further south.
British Antarctic Survey, Author provided

The sub-Antarctic islands are full of examples of such unexpected impacts. Pigs, dogs, cats, sheep, reindeer and rabbits have all been intentionally introduced in the past, with often devastating effects. Rats and mice were introduced to South Georgia and other islands accidentally by sealers and whalers, for instance, and have decimated seabird populations. A recent eradication campaign appears to have been successful and pipits, ducks and small seabirds are showing some immediate signs of recovery.

The removal of non-native cats from Macquarie and Marion Islands has similarly helped native burrowing seabirds, although responses in such ecosystems can be far more complex and unpredictable – the removal of cats from Macquarie also led to increase in the introduced rabbit population, and considerably increased damage to sensitive native vegetation.

Antarctic biodiversity is far more complex than widely assumed, with up to 15 distinct biogeographic regions that have been evolutionarily isolated for many millions of years. Humans present the greatest threat, not only of introducing new species, but also of moving “native” species between regions within Antarctica. This could be even more damaging, as these native species would already be pre-adapted to polar life.

Visitors to Antarctica are subject to increasingly strict biosecurity measures but accidental introductions continue to occur, often through food shipments for scientists. Changes in sea and land ice affect access to new areas, so we can only expect plant and invertebrate invasions to increase unless biosecurity becomes more effective.

The ConversationWhile cost issues may be raised, it is worth remembering that prevention will always be better – and cheaper – than subsequent control and eradication, even if such action is possible.

Peter Convey, Terrestrial Ecologist, British Antarctic Survey and Tom Hart, Penguinologist, University of Oxford

This article was originally published on The Conversation. Read the original article.


Antarctica has lost 3 trillion tonnes of ice in 25 years. Time is running out for the frozen continent

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As the world prevaricates over climate action, Antarctica’s future is shrouded in uncertainty.
Hamish Pritchard/British Antarctic Survey

Steve Rintoul, CSIRO and Steven Chown, Monash University

Antarctica lost 3 trillion tonnes of ice between 1992 and 2017, according to a new analysis of satellite observations. In vulnerable West Antarctica, the annual rate of ice loss has tripled during that period, reaching 159 billion tonnes a year. Overall, enough ice has been lost from Antarctica over the past quarter-century to raise global seas by 8 millimetres.

What will Antarctica look like in the year 2070, and how will changes in Antarctica impact the rest of the globe? The answer to these questions depends on choices we make in the next decade, as outlined in our accompanying paper, also published today in Nature.

Read more:
Ocean waves and lack of sea ice can trigger Antarctic ice shelves to disintegrate

Our research contrasts two potential narratives for Antarctica over the coming half-century – a story that will play out within the lifetimes of today’s children and young adults.

While the two scenarios are necessarily speculative, two things are certain. The first is that once significant changes occur in Antarctica, we are committed to centuries of further, irreversible change on global scales. The second is that we don’t have much time – the narrative that eventually plays out will depend on choices made in the coming decade.

Change in Antarctica has global impacts

Despite being the most remote region on Earth, changes in Antarctica and the Southern Ocean will have global consequences for the planet and humanity.

For example, the rate of sea-level rise depends on the response of the Antarctic ice sheet to warming of the atmosphere and ocean, while the speed of climate change depends on how much heat and carbon dioxide is taken up by the Southern Ocean. What’s more, marine ecosystems all over the world are sustained by the nutrients exported from the Southern Ocean to lower latitudes.

From a political perspective, Antarctica and the Southern Ocean are among the largest shared spaces on Earth, regulated by a unique governance regime known as the Antarctic Treaty System. So far this regime has been successful at managing the environment and avoiding discord.

However, just as the physical and biological systems of Antarctica face challenges from rapid environmental change driven by human activities, so too does the management of the continent.

Antarctica in 2070

We considered two narratives of the next 50 years for Antarctica, each describing a plausible future based on the latest science.

In the first scenario, global greenhouse gas emissions remain unchecked, the climate continues to warm, and little policy action is taken to respond to environmental factors and human activities that affect the Antarctic.

Under this scenario, Antarctica and the Southern Ocean undergo widespread and rapid change, with global consequences. Warming of the ocean and atmosphere result in dramatic loss of major ice shelves. This causes increased loss of ice from the Antarctic ice sheet and acceleration of sea-level rise to rates not seen since the end of the last glacial period more than 10,000 years ago.

Warming, sea-ice retreat and ocean acidification significantly change marine ecosystems. And unrestricted growth in human use of Antarctica degrades the environment and results in the establishment of invasive species.

Under the high-emissions scenario, widespread changes occur by 2070 in Antarctica and the Southern Ocean, with global impacts.
Rintoul et al. 2018. Click image to enlarge.

In the second scenario, ambitious action is taken to limit greenhouse gas emissions and to establish policies that reduce human pressure on Antarctica’s environment.

Under this scenario, Antarctica in 2070 looks much like it does today. The ice shelves remain largely intact, reducing loss of ice from the Antarctic ice sheet and therefore limiting sea-level rise.

An increasingly collaborative and effective governance regime helps to alleviate human pressures on Antarctica and the Southern Ocean. Marine ecosystems remain largely intact as warming and acidification are held in check. On land, biological invasions remain rare. Antarctica’s unique invertebrates and microbes continue to flourish.

Antarctica and the Southern Ocean in 2070, under the low-emissions (left) and high-emissions (right) scenarios. Each of these systems will continue to change after 2070, with the magnitude of the change to which we are committed being generally much larger than the change realised by 2070.
Rintoul et al. 2018. Click image to enlarge.

The choice is ours

We can choose which of these trajectories we follow over the coming half-century. But the window of opportunity is closing fast.

Global warming is determined by global greenhouse emissions, which continue to grow. This will commit us to further unavoidable climate impacts, some of which will take decades or centuries to play out. Greenhouse gas emissions must peak and start falling within the coming decade if our second narrative is to stand a chance of coming true.

If our more optimistic scenario for Antarctica plays out, there is a good chance that the continent’s buttressing ice shelves will survive and that Antarctica’s contribution to sea-level rise will remain below 1 metre. A rise of 1m or more would displace millions of people and cause substantial economic hardship.

Under the more damaging of our potential scenarios, many Antarctic ice shelves will likely be lost and the Antarctic ice sheet will contribute as much as 3m of sea level rise by 2300, with an irreversible commitment of 5-15m in the coming millennia.

The ConversationWhile challenging, we can take action now to prevent Antarctica and the world from suffering out-of-control climate consequences. Success will demonstrate the power of peaceful international collaboration and show that, when it comes to the crunch, we can use scientific evidence to take decisions that are in our long-term best interest.

The choice is ours.

Steve Rintoul, Research Team Leader, Marine & Atmospheric Research, CSIRO and Steven Chown, Professor of Biological Sciences, Monash University

This article was originally published on The Conversation. Read the original article.

Ocean waves and lack of sea ice can trigger Antarctic ice shelves to disintegrate

Luke Bennetts, University of Adelaide; Rob Massom, and Vernon Squire

Large waves after the loss of sea ice can trigger Antarctic ice shelf disintegration over a period of just days, according to our new research.

With other research also published today in Nature showing that the rate of annual ice loss from the vulnerable Antarctic Peninsula has quadrupled since 1992, our study of catastrophic ice shelf collapses during that time shows how the lack of a protective buffer of sea ice can leave ice shelves, already weakened by climate warming, wide open to attack by waves.

Read more:
Antarctica has lost 3 trillion tonnes of ice in 25 years. Time is running out for the frozen continent

Antarctica is covered by an ice sheet that is several kilometres thick in places. It covers an area of 14 million square kilometres – roughly twice the size of Australia. This ice sheet holds more than 90% of the world’s ice, which is enough to raise global mean sea level by 57 metres.

As snow falls and compacts on the ice sheet, the sheet thickens and flows out towards the coast, and then onto the ocean surface. The resulting “ice shelves” (and glacier tongues) buttress three-quarters of the Antarctic coastline. Ice shelves act as a crucial braking system for fast-flowing glaciers on the land, and thus moderate the ice sheet’s contribution to sea-level rise.

In the southern summer of 2002, scientists monitoring the Antarctic Peninsula (the northernmost part of mainland Antarctica) by satellite witnessed a dramatic ice shelf disintegration that was stunning in its abruptness and scale. In just 35 days, 3,250 square km of the Larsen B Ice Shelf (twice the size of Queensland’s Fraser Island) shattered, releasing an estimated 720 billion tonnes of icebergs into the Weddell Sea.

This wasn’t the first such recorded event. In January 1995, roughly 1,500 square km of the nearby Larsen A Ice Shelf suddenly disintegrated after several decades of warming and years of gradual retreat. To the southwest, the Wilkins Ice Shelf suffered a series of strikingly similar disintegration events in 1998, 2008 and 2009 — not only in summer but also in two of the Southern Hemisphere’s coldest months, May and July.

These sudden, large-scale fracturing events removed features that had been stable for centuries – up to 11,500 years in the case of Larsen B. While ice shelf disintegrations don’t directly raise sea level (because the ice shelves are already floating), the removal of shelf ice allows the glaciers behind them to accelerate their discharge of land-based ice into the ocean – and this does raise sea levels. Previous research has shown that the removal of Larsen B caused its tributary glaciers to flow eight times faster in the year following its disintegration.

Read more:
Cold and calculating: what the two different types of ice do to sea levels

The ocean around ice shelves is typically covered by a very different (but equally important) type of ice, called sea ice. This is formed from frozen seawater and is generally no more than a few metres thick. But it stretches far out into the ocean, doubling the area of the Antarctic ice cap when at its maximum extent in winter, and varying in extent throughout the year.

The response of Antarctic sea ice to climate change and variability is complex, and differs between regions. Around the Antarctic Peninsula, in the Bellingshausen and northwestern Weddell seas, it has clearly declined in extent and annual duration since satellite monitoring began in 1979, at a similar rate to the Arctic’s rapidly receding sea ice.

The Southern Ocean is also host to the largest waves on the planet, and these waves are becoming more extreme. Our new study focuses on “long-period” swell waves (with swells that last up to about 20 seconds). These are generated by distant storms and carry huge amounts of energy across the oceans, and can potentially flex the vulnerable outer margins of ice shelves.

The earliest whalers and polar pioneers knew that sea ice can damp these waves — Sir Ernest Shackleton reported it in his iconic book South!. Sea ice thus acts as a “buffer” that protects the Antarctic coastline, and its ice shelves, from destructive ocean swells.

Strikingly, all five of the sudden major ice shelf disintegrations listed above happened during periods when sea ice was abnormally low or even absent in these regions. This means that intense swell waves crashed directly onto the vulnerable ice shelf fronts.

The straw that broke the camel’s back

The Antarctic Peninsula has experienced particularly strong climate warming (roughly 0.5℃ per decade since the late 1940s), which has caused intense surface melting on its ice shelves and exacerbated their structural weaknesses such as fractures. These destabilising processes are the underlying drivers of ice shelf collapse. But they do not explain why the observed disintegrations were so abrupt.

Our new study suggests that the trigger mechanism was swell waves flexing and working weaknesses at the shelf fronts in the absence of sea ice, to the point where they calved away the shelf fronts in the form of long, thin “sliver-bergs”. The removal of these “keystone blocks” in turn led to the catastrophic breakup of the ice shelf interior, which was weakened by years of melt.

Our research thus underlines the complex and interdependent nature of the various types of Antarctic ice – particularly the important role of sea ice in forming a protective “buffer” for shelf ice. While much of the focus so far has been on the possibility of ice shelves melting from below as the sea beneath them warms, our research suggests an important role for sea ice and ocean swells too.

The edge of an ice shelf off the Antarctic Peninsula, with floating sea ice beyond (to the left in this image).
NASA/Maria Jose Vinas

In July 2017 an immense iceberg broke away from the Larsen C Ice Shelf, just south of Larsen B, prompting fears that it could disintegrate like its neighbours.

Our research suggests that four key factors will determine whether it does: extensive flooding and fracturing across the ice shelf; reduced sea ice coverage offshore; extensive fracturing of the ice shelf front; and calving of sliver-bergs.

Read more:
Don’t worry about the huge Antarctic iceberg – worry about the glaciers behind it

If temperatures continue to rise around the Antarctic, ice shelves will become weaker and sea ice less extensive, which would imply an increased likelihood of future disintegrations.

However, the picture is not that clear-cut, as not all remaining ice shelves are likely to respond in the same way to sea ice loss and swell wave impacts. Their response will also depend on their glaciological characteristics, physical setting, and the degree and nature of surface flooding. Some ice shelves may well be capable of surviving prolonged absences of sea ice.

The ConversationIrrespective of these differences, we need to include sea ice and ocean waves in our models of ice sheet behaviour. This will be a key step towards better forecasting the fate of Antarctica’s remaining ice shelves, and how much our seas will rise in response to projected climate change over coming decades. In parallel, our new findings underline the need to better understand and model the mechanisms responsible for recent sea ice trends around Antarctica, to enable prediction of likely future change in the exposure of ice shelves to ocean swells.

Luke Bennetts, Lecturer in applied mathematics, University of Adelaide; Rob Massom, Leader, Sea Ice Group, Antarctica & the Global System program, Australian Antarctic Division and Antarctic Climate and Ecosystems CRC, and Vernon Squire, Deputy Vice-Chancellor Academic, Professor of Applied Mathematics

This article was originally published on The Conversation. Read the original article.

Why remote Antarctica is so important in a warming world

Chris Fogwill, Keele University; Chris Turney, UNSW, and Zoe Robinson, Keele University

Ever since the ancient Greeks speculated a continent must exist in the south polar regions to balance those in the north, Antarctica has been popularly described as remote and extreme. Over the past two centuries, these factors have combined to create, in the human psyche, an almost mythical land – an idea reinforced by tales of heroism and adventure from the Edwardian golden age of “heroic exploration” and pioneers such as Robert Falcon Scott, Roald Amundsen and Ernest Shackleton.

Recent research, however, is casting new light on the importance of the southernmost continent, overturning centuries of misunderstanding and highlighting the role of Antarctica in how our planet works and the role it may play in a future, warmer world.

Heroic exploration, 1913.

What was once thought to be a largely unchanging mass of snow and ice is anything but. Antarctica holds a staggering amount of water. The three ice sheets that cover the continent contain around 70% of our planet’s fresh water, all of which we now know to be vulnerable to warming air and oceans. If all the ice sheets were to melt, Antarctica would raise global sea levels by at least 56m.

Where, when, and how quickly they might melt is a major focus of research. No one is suggesting all the ice sheets will melt over the next century but, given their size, even small losses could have global repercussions. Possible scenarios are deeply concerning: in addition to rising sea levels, meltwater would slow down the world’s ocean circulation, while shifting wind belts may affect the climate in the southern hemisphere.

In 2014, NASA reported that several major Antarctic ice streams, which hold enough water to trigger the equivalent of a one-and-a-half metre sea level rise, are now irreversibly in retreat. With more than 150m people exposed to the threat of sea level rise and sea levels now rising at a faster rate globally than any time in the past 3,000 years, these are sobering statistics for island nations and coastal cities worldwide.

An immediate and acute threat

Recent storm surges following hurricanes have demonstrated that rising sea levels are a future threat for densely populated regions such as Florida and New York. Meanwhile the threat for low-lying islands in areas such as the Pacific is immediate and acute.

Much of the continent’s ice is slowly sliding towards the sea.
R Bindschadler / wiki

Multiple factors mean that the vulnerability to global sea level rise is geographically variable and unequal, while there are also regional differences in the extremity of sea level rise itself. At present, the consensus of the IPPC 2013 report suggests a rise of between 40 and 80cm over the next century, with Antarctica only contributing around 5cm of this. Recent projections, however, suggest that Antarctic contributions may be up to ten times higher.

Studies also suggest that in a world 1.5-2°C warmer than today we will be locked into millennia of irreversible sea level rise, due to the slow response time of the Antarctic ice sheets to atmospheric and ocean warming.

We may already be living in such a world. Recent evidence shows global temperatures are close to 1.5°C warmer than pre-industrial times and, after the COP23 meeting in Bonn in November, it is apparent that keeping temperature rise within 2°C is unlikely.

So we now need to reconsider future sea level projections given the potential global impact from Antarctica. Given that 93% of the heat from anthropogenic global warming has gone into the ocean, and these warming ocean waters are now meeting the floating margins of the Antarctic ice sheet, the potential for rapid ice sheet melt in a 2°C world is high.

In polar regions, surface temperatures are projected to rise twice as fast as the global average, due to a phenomenon known as polar amplification. However, there is still hope to avoid this sword of Damocles, as studies suggest that a major reduction in greenhouse gases over the next decade would mean that irreversible sea level rise could be avoided. It is therefore crucial to reduce CO₂ levels now for the benefit of future generations, or adapt to a world in which more of our shorelines are significantly redrawn.

This is both a scientific and societal issue. We have choices: technological innovations are providing new ways to reduce CO₂ emissions, and offer the reality of a low-carbon future. This may help minimise sea level rise from Antarctica and make mitigation a viable possibility.

The ConversationGiven what rising sea levels could mean for human societies across the world, we must maintain our longstanding view of Antarctica as the most remote and isolated continent.

Chris Fogwill, Professor of Glaciology and Palaeoclimatology, Keele University; Chris Turney, Professor of Earth Sciences and Climate Change, UNSW, and Zoe Robinson, Reader in Physical Geography and Sustainability/Director of Education for Sustainability, Keele University

This article was originally published on The Conversation. Read the original article.

How a trip to Antarctica became a real-life experiment in decision-making

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The Homeward Bound initiative works with women in science to enhance their opportunity to take up leadership roles globally.
Oli Samson, Author provided

Sarah Hamylton, University of Wollongong and Rachelle Balez, University of Wollongong

This adventurous tale is part of our occasional long read series Zoom Out. Enjoy!

We were part of a group of 77 women travelling by ship to an Antarctic research station when our route was blocked by icebergs. We had to make a decision. Should we detour into rough open ocean to reach the target site, or abandon plans to visit Rothera Research Station and settle instead for a few days of exploring Antarctica’s calmer, protected waters?

This is the story of “Rothera-gate”, a leadership development experience on the largest all-female expedition to Antarctica. The 2018 expedition was the culmination of a year-long strategic leadership initiative for women scientists called Homeward Bound.

Men typically hold the leadership positions in STEMM (Science, Technology, Engineering, Mathematics and Medicine). In recognition of this, the Homeward Bound initiative works with women in science to enhance their opportunity to take up leadership roles globally, and contribute proactively to a sustainable world.

Headed for Rothera

Our experience took place while travelling down the Antarctic Peninsula to Rothera, a British research station at 67° south, just inside the Antarctic Circle. This was intended to be the southernmost point of our journey.

While our group was largely women, several men were on board, including the captain of the ship (in charge from a legal perspective), the expedition leader and members of the Homeward Bound “Faculty” (a group of ten experts coordinating, organising and delivering the formal scientific leadership program throughout the voyage).

Our presence in Rothera would be a special occasion, as not many Antarctic ships make it that far south – only two ship visits are permitted each year. Ours was to be a final visit before the base closed for a two-year refurbishment.

On day 13 of our voyage, within 75km of Rothera, we passed between Adelaide Island and the Antarctic Peninsula into a narrow passage known as The Gullet. Wind and waves had blown icebergs into the passage, blocking our way south. Our expedition leader announced that a difficult decision had to be made: should we or should we not continue to Rothera?

To go, we would need to double back and around the outside of Adelaide Island, a potentially difficult 24-hour return detour. This foray into rough open ocean would likely lead to seasickness for some. Alternatively, we could remain and explore the calm protected waters of Crystal Sound for a couple of days.

The options: re-route with risk of vomiting, or stay in calm waters?
Rachelle Balez, Author provided

Under other circumstances, such as a tourist passenger cruise, a unilateral decision would be taken by the captain and expedition leader. However, given the different and unique aims of our journey, this decision was handed over to the Homeward Bound organisational team (the “faculty”) who, in turn, consulted the participants.

An inclusive and supportive discussion among the 77 women assembled in the lounge of the ship followed, before a “closed eye” vote was taken. This allowed partipants to express their preference for either staying put, or pushing on to Rothera, without being influenced by the views of those around them – with the overall outcome noted by the observing faculty.

We voted overwhelmingly to venture outside Adelaide Island and push on south to Rothera.

Lots of hands up in the voting with closed eyes.
Oli Samson, Author provided

Plan B – and then Plan A again

To our surprise, a decision was subsequently taken by the faculty not to press on south. Some of us were surprised that our collective vote was not itself the deciding factor; others were surprised that the decision made was not in line with the majority vote.

Many of us were severely disappointed, despite being reassured that the well-being of individuals had been prioritised.

The following morning, we cruised across Crystal Sound in zodiac inflatable boats while pods of orcas criss-crossed the bay in searched of prey. Our disappointment at not reaching Rothera evaporated as we laughed and scrambled with our cameras among icebergs.

Upon returning to the ship, our captain and expedition leader let us know that the swell had died down. Conditions were good to head around the outside of Adelaide Island to Rothera after all, and the ship was leaving imminently. We whooped for joy and wound our way south.

The visit to Rothera was a success. As we left the station a nearby icebreaker reported that a change in wind direction meant The Gullet was clearing of icebergs. It was now possible to use the strengthened hull of our ship to cut a path back north for the return voyage, revisiting the moving sheets of sea ice that had prevented our passage from the other direction.

The next 12 hours were spent slowly zig-zagging forward across a mosaic of sea ice interspersed with slushy, fragmented “frazzle” ice crystals. These crystals were a telltale sign that the ice was on the verge of freezing solid.

With each small amount of headway made, we watched the ice close in quickly behind us, wondering for how much longer our captain’s nerve would hold. The tension on the bridge was palpable.

While our safety was never in question, we came dangerously close to becoming a stuck ship and the object of a recovery operation. Recognising the power of nature as we finally broke free the following afternoon, we stood on the deck enjoying metaphors about breaking glass ceilings. This was undoubtedly the most adventurous moment of our voyage.


Leadership lessons

Our journey offered many opportunities for reflection and learning. Over the three days that our story unfolded, we talked over the dinner table, in small groups, as a collective group and even workshopped the event, looking for meaning in the twists and turns of what happened.

Although the majority of women in the room had voted to continue south to Rothera, enough people expressed discomfort with the idea to trigger our organisational “faculty” team to change the plan.

Informed versus participatory decision making

Our first lesson highlights the difference between informed and participatory decision-making. While the former accounts for the views of a group of people, the latter is more like a typical democracy, and it depends on those views.

Some decision-making tools – for example, the Myers Briggs Z tool – weigh the needs of individuals against those of the collective group. Conventionally, if 35% of people are unsure about an action, their needs must be accounted for before moving forward.

A tangled psychological web

We used the Life Styles Inventory (LSI) chart to reflect on our individual thoughts and feelings in the moment we had voted, standing on the corresponding constructive, passive and aggressive behavioural styles on a Twister-like mat. This helped us to see how our thoughts guided us towards a desired outcome.

A complex picture of multiple responses in individuals emerged. Scaled up across the 77 women in the room, these played out as a tangled psychological web, aptly captured by the tangle of bodies on the chart.

Achievement versus empathy

Many of us reported a swing away from “competitive” or “achievement” styles – which would underpin thoughts such as “I want to achieve the visit to Rothera Station!” – toward the seemingly contrasting humanistic and passive styles.

These would underpin empathetic thoughts such as “If I don’t go, I will be disappointed, but if we go, she will be miserable, uncomfortable and seasick, which is worse than disappointment”.

Once voiced, anxiety can be an influential and persuasive force among groups of women, who typically show greater empathy for emotions such as fear.

Even though they were widely reported afterwards, the competitive-achievement sentiments found little voice in the room at the time of the vote. They were largely eclipsed by empathy for the well-being of others.

An opportunity taken

It is ironic that the dramatic push to 67° south, and the adventurous return journey through the ice on our “largest all-female expedition to Antarctica” were ultimately determined unilaterally by two of the highest-ranking people on the ship.

They were experienced, gracious, brave and modest men. Given that they had been directing our movements for the entirety of the voyage up until this point, this begs the question, why didn’t they just make the decision to push forward to Rothera in the first place?

While a unilateral approach would undoubtedly have been more efficient, with the benefit of hindsight, such a directive would have meant that the women of Homeward Bound would have missed out on a key opportunity to come together.

At times, this was a messy and angst-ridden experience. But it allowed us to build a sense of cohesion and strength through adversity, while enjoying the excitement of orcas and the catharsis of breaking the ice.

This raises an important question about leaders who habitually rely purely on expert opinion and authority as a basis for a decision, and regularly get acceptance. Do these leaders miss the opportunity for true ownership, engagement and perhaps even a better overall outcome that a longer, more unwieldy but ultimately more consultative approach may generate?

Given the lack of female representation in STEMM leadership roles, is this opportunity currently being missed in key decision-making forums on sustainability?

The value of diversity in decision-making

Perhaps the most important lesson from our story is the value of diversity in the decision-making process. Compared with their male counterparts, research suggests that women together are a little more collaborative and inclined towards participatory decision-making.

This was reflected in the purpose, consensus and empathy for the discomfort of others as 77 women consulted to make a collective decision. It was then followed up by a more directive decision based on the expertise and authority of our captain and expedition leader.

The two decisions together meant that we could have our cake and eat it: we empathised, we bonded over orcas, we reached Rothera Station, and we smashed the ice on the way home for good measure!

In a world of pressing scientific agendas, perhaps the best gains are made when different leadership styles come together.

The ConversationThe authors would like to acknowledge the contribution of Marshall Cowley, Senior Leadership Consultant at Dattner Grant, for his insight, expertise and help in preparing this article.

Sarah Hamylton, Senior Lecturer, School of Earth and Environmental Sciences, University of Wollongong and Rachelle Balez, PhD Candidate, University of Wollongong

This article was originally published on The Conversation. Read the original article.