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Prof. Sharon Robinson - Australian Museum Eureka Prize Finalist 2021 - Homeward Bound Projects

The annual Eureka Prizes are Australia’s most comprehensive national science awards, honouring excellence across the areas of research and innovation, leadership, science engagement, and school science.

Homeward Bound science stream facilitator Professor Sharon Robinson from the Faculty of Science, Medicine and Health at the University of Wollongong (UOW) is a finalist this year. Sharon is a global leader and a renowned Antarctic environmental science researcher. She is the Executive Director of Global Challenges program, UOW’s strategic research initiative designed to harness the diverse expertise of researchers to address real-world problems.

Her research focuses on understanding the impacts of climate change on Antarctic ecosystems and informing better environmental protection through ground-breaking and interdisciplinary research methods.

Sharon has been working in Antarctica since 1996, and her research focus for almost two decades has been monitoring the terrestrial ecosystems, especially mosses and lichens, to see how they’re changing.

“We started doing this because every time we used to go down to Casey Station all the people on the station – trades people and others living there – all used to ask: ‘Is it changing? What’s happening to these ecosystems, are they are they changing due to climate change?’.

“We had no monitoring system. We actually couldn’t tell them because we didn’t know what it had been like 20 years before. So, in 2000 we set up a long-term monitoring system for the first time and marked places that we try to go back every five years to monitor.

“In 2018, we published a paper, which represented the first 15 years of that survey … and that was the first study to show that the terrestrial ecosystem in Antarctica has changed because of climate change.”

Sharon says the terrestrial ecosystem certainly isn’t the only Antarctic ecosystem that’s changed, but her work has put a process in place to monitor and observe how this system has changed and continues to change.

 

Time travel

“We know that [the mosses in Antarctica] they’re hundreds of years old, and we’ve been dating them using modern radiocarbon techniques.

“We use the radiocarbon that was released into the atmosphere because of atomic bomb testing in the 1950s and 1960s, which travelled all over the globe. The radioactive carbon from that ends up being taken up by everything that is photosynthesising – all the trees in the world have got a trace of this if they were growing in the 1950s and 60s. And we thought, well, maybe the mosses have that too.

“It’s always been really difficult to date Antarctic Moses, but this was a way of telling how old they are based on the fact that there was this pulse of radiocarbon associated with nuclear atomic nuclear testing. It’s a very, very sharp peak because we humans only did atmospheric nuclear testing for a short period of time. So, it goes up from the 50s, it peaks in 1965, and then drops off very rapidly.

“So, we’ve traced down the surface of these mosses … and they’re tiny by comparison to trees, but we can trace one or two centimetres down the stem to show that part of the plant that was growing in 1965.”

Mosses don’t have a vascular system; they don’t move their carbon around. They’re like tree rings, and that 1965 layer is one layer that tells a story of that time and space, with new layers growing on top. Other signatures in the moss “layers” tell Sharon’s team whether it was a wetter or drier environment than in the 1960s.

Her research has found that Antarctica is getting drier. When monitoring began the mosses were “quite green” but, in 2008 suddenly they were all red. In 2013 some were green again, but many areas had turned grey and were dying off.

“This is the first indication that the terrestrial ecosystem is changing on the continent. Up until then we thought that most of the change was happening on the Antarctic Peninsula, because that was the area of the planet that’s been warming the most rapidly.

“We actually have a term, if you look in IPCC reports, you’ll see there’s Arctic greening, and Arctic browning. We’re starting to see evidence in our moss beds in Antarctica, that that same thing is happening across the Antarctic.

“Some areas of the Antarctic have gotten warmer and wetter, that’s great for plant growth, but there’s other areas where they’ve actually been disconnected from their water supply and so they’re now turning grey and dying. And these are plants that we know have been growing for 500 years.”

In areas near Casey Station, “old growth” moss forests reach up to 14 centimetres tall and are more than 500 years old.

“We’re even seeing species change, where some species that used to not be able to grow in those areas … have actually started to move into those areas and are able to grow because it’s drier.

“One of the endemic species or species that are only found in Antarctica is being out competed by some other species that are moving in.  The are Antarctic native plants, not invasive species, but they’re moving into those areas and taking over the space because it’s getting drier.

Sharon says this is an indication that the things we’re doing across the planet are influencing everywhere, even places where there aren’t any humans, places that are really remote from any human settlements.

“It’s really one of those first indications that climate change is affecting that part of the continent that we really thought was like a great big block of ice and really wasn’t changing. But it’s changing in these subtle, subtle ways.”

 

Origins in ozone

Sharon’s interest in Antarctica came from her early work around the ozone hole.

“I did my PhD on carrot cells in culture in the UK. But when I came to Australia I started working on a range of different plants, including succulents and rain forest plants.

“I was interested in the ways in which high light affects plants. I was interested in what they were doing to protect themselves from high radiation, and I started working in Antarctica because that was the place where the ozone hole was having the biggest effect in terms of increasing ultraviolet radiation.”

Another example of humankind engineering the planet.

“That hole that appears each spring and it’s still appearing over Antarctica, which means that the plants in Antarctica have experienced this massive change in ultraviolet radiation from the reduction in ozone each spring.”

Her early research looked at how plants had been affected by extra UV.

“We found some of the plants actually did show low levels of DNA damage from the UVB, but most of the time they were able to put sunscreen pigments into their walls to protect themselves. We’ve actually discovered that the mosses, because they are mostly only one cell layer thick and don’t have a sort of protective cover – a waxy or a thick epidermis – put these special compounds in their cell walls.”

When the same species of moss in Antarctica is compared to one growing in Australia Sharon’s team found the Antarctic plants put more of those “sunscreen” compounds into their cell walls to protect themselves.

“These compounds, because they’re antioxidant protect the plants in many ways, and are really good for the plants when they’re going through desiccation and rehydration cycles. They’re coping with this massive number of different stresses, and on top of that, we’ve added additional UV.

“And now we’ve found that another effect of ozone depletion is that the winds around Antarctica are being pulled closer towards Antarctica. So, ozone depletion doesn’t just increase the UV, it also makes it windier in some parts of Antarctica, and that’s increasing the drying stress on the mosses.”

“We’re messing around with the whole globe’s climate by making these changes, whether it’s the ozone depletion or whether it’s greenhouse gases. They have far-reaching implications, as we’ve seen recently in terms of extreme weather events, like the fires, the heatwaves, changes to wind patterns, and changes to circulation patterns around the globe. These are probably some of the most profound effects. It’s not just the steady warming that we get with climate change.”

Sharon says ecological tipping points involve much more than just the warming planet, and once those systems change there will be profound changes for both humans, animals, and plants.

 

The driest place on earth

“The main thing that’s missing in Antarctica is water. The big question is, as the climate warms, what happens to the water supply?

People are aware that glaciers are retreating in many places, but you can’t automatically assume that means there’s more water. The problem is that often those melts will happen in a sudden surge in spring, and it will be so much that it causes floods, and it all drains off in one go.

In many parts of the globe communities are facing drought because snow melts too early in the spring, causing flooding and washing away topsoils – a vicious cycle of drought.

“In the same way in Antarctica, that snow can all melt away, and then the mosses have no snow. They’re relying on snowbanks to melt slowly through the summer and trickle water over them, but if it all melts in the early summer and floods them, then some of the plants will actually be washed away … so then they just have long periods of drought.

Sharon says the planet is already committed to a certain level of climate change because of the CO2 that’s already in the system.

“I think there’ll be there’ll be some plants and animals that are winners and there’ll be others that are losers. For example, emperor penguins need sea ice in order to lay their eggs and nest. If sea ice declines, those populations will be damaged, the penguins won’t be able to nest and won’t be able to find places to lay eggs. They’re one of the very vulnerable species to climate change.

“One of the things we’re very worried about with and within Antarctica is that, as it warms, it will become more hospitable for plants that currently can’t grow there. There’s a very real risk of invasive species, of plants and of animals. Some of those things will get there on their own – on the wind, or a seed might come on a bird – but as humans, we need to be really careful that we’re not introducing species that will be able to grow because the climate is better for them.”

 

Can we beat climate change?

“I think basically we have to! It’s our home we’re talking about, you know, we only have one planet. If we make it into a planet where we can’t survive, we have no home. And so, we have to do something about it. And I think absolutely, we can, but we have to have the political will to do it.”

“I think the most amazing thing about Homeward Bound is that it’s bringing together women from all over the world who are, who have a STEMM background working together as leaders for the greater good. And I think the thing that I’m most impressed by is that commonality we have in that space. You meet people from all over the world who sign up for Homeward Bound, and you realise that those same concerns that I might have about the future of the planet are shared by these women across the globe. It gives you hope that we will be able to work together to solve this.

“I think the other thing that is really important, probably now more than ever, is that we have people, not just women, but men and women who are who are scientifically trained to understand the scientific process, to help guide us through these difficult times that we’ve seen with COVID.

“People are listening to scientists. How do we manage this? How do we manage a pandemic? How do we keep ourselves safe? We’re listening to scientists because we perceive a threat to ourselves. But it’s equally important that we listen to science in terms of the climate. I think having more scientists, and especially more STEMM women, in leadership positions who have that expertise and understand that is just so important going forward. I find it really inspiring to actually meet women from all over the globe who have that background, but also have that shared view of what the future can bring.

 

Eureka Prize brings visibility for women in STEMM

Sharon says being a finalist for the Australian Museum’s Eureka Prize creates an opportunity to influence and inspire future leaders and encourage girls to pursue STEMM careers.

“I’m getting to that stage in my career, where it’s really important to me that it’s not just about what I do, it’s also about the recognition for the team that I’m working with. My role is to nurture and build that team and train and inspire and hopefully create a whole other group of scientists that are coming on behind.

“I think that’s one of the great things with Homeward Bound is that it’s about leading that next generation and bringing more people with you for the sake of science, but also for the sake of the planet.”

 

Resources

 

Words: Louise Johnson
Image: Homeward Bound Antarctic Voyage, January 2019 

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