Extract from ABC News
Antarctica is set to change more in the next 80 years than perhaps any other time in human existence.
Key points:
- There's currently no cohesive plan to safeguard biodiversity in Antarctica in the face of climate change
- Researchers performed a cost-benefit analysis to decide which strategies offer the best value for money
- One strategy offers benefits far greater than all the others, but is hardest to achieve
Tens of thousands of square kilometres of land will become permanently ice-free, making more room for natives and ferals alike.
But according to researchers, who published a study in PLOS Biology today, while conservation efforts in Antarctica are relatively robust, current measures aren't really fit for future purpose.
So they identified 10 key areas that need be focused on to give the frozen continent's biodiversity the greatest chance of persevering into the future.
Importantly, they also did a cost-benefit analysis to identify which strategies yield the best bang for buck.
CSIRO research scientist Josie Carwardine said the study provides a roadmap to help governments achieve biodiversity targets, such as the pledge to conserve 30 per cent of the planet by 2030, agreed to at COP15 this week.
"Signing up to this '30 by 30' — we've got all these really good aspirations, and this study gives us a pathway of how we're going to get there [in Antarctica]," Dr Carwardine said.
Perhaps unsurprisingly, there's one target with a benefit that towers above the rest. But it's also the hardest to achieve.
Here are some of the stand-outs.
Protect threatened species
This step might sound like it goes without saying, but there are myriad and interconnected factors that may cause species to decline, or increase, as Antarctica changes.
And while we might think of increasing numbers of say, Gentoo penguins, as a good thing, this can also lead to more competition for another animal or habitat.
One that will almost certainly decline is the emperor penguin. Researchers predict that emperor penguins are the only Antarctic species seriously threatened with extinction by 2100.
That's because they rely on sea ice for breeding and food. As sea ice shrinks, so do their numbers.
Another that will almost certainly decline is the Adélie penguin, according to study lead author Jasmine Lee from the University of Queensland.
"The Adélie penguin we're already seeing decline in some areas."
But for others, it's less clear cut.
"The range of the two [vascular] plant species is already expanding — we're starting to see the early signals of change. [But] some species we definitely don't know enough about," said Dr Lee, who's now with the British Antarctic Survey.
In terms of cost efficiency, protecting threatened species is middle of the road — it can provide great benefit, but in some cases conservation is forecast to be costly.
Manage non-native species and disease
This one ranks seventh for cost-effectiveness out of the 10 strategies proposed. But that's not to say it shouldn't be a priority.
While it's expensive, managing and preventing pests from reaching Antarctica carries huge potential benefits, said Dr Carwardine, who conducted the cost-benefit analysis for the study.
"Even though we do rank the strategies, we want the focus to be on what you are trying to achieve," she said.
"[Managing non-natives and disease] is really difficult, but the benefits are really high."
When we think of invasive pests in Australia, animals that typically come to mind are the predators — cats, foxes, wild dogs — as well as cane toads and rabbits.
But in Antarctica, at least in the near-term, the likeliest threats are much harder to see.
Invasive invertebrates and even microbes have the potential to throw ecosystems out of whack, Dr Lee said.
"There's an invasive midge that has already changed turnover of soil on the peninsula islands.
"Another big one is Poa annua, the annual blue grass. It's already a prominent invader on the sub-Antarctic islands."
And while conditions are probably still too extreme for rats to establish in Antarctica, vigilance will be needed as the climate changes.
"Rats have devastated sub-Antarctic islands," Dr Lee said.
"If they did get into the [Antarctic] peninsula it would be really bad. They would nail the penguins [and] the breeding seabirds."
Minimise impacts of human activity
Human activity in Antarctica is already increasing and is set to continue rising over the coming decades.
In 2003-04, 19,385 tourists set foot on the continent, according to the International Association of Antarctic Tour Operators.
By 2019-20, that had risen to more than 55,000 tourists.
And there are around 70 permanent research stations in Antarctica.
Human traffic has already brought pest invasions to the continent, Dr Carwardine said.
The researchers identified minimising the impacts of human activity as a cost effective measure that can have significant ecological benefits.
"We need to try to do things in a way that actually doesn't impact negatively on nature," Dr Carwardine said.
"It's a bit of a transformation in the way we think."
Climate action
By far the biggest cause of the shifts unfolding in Antarctica is climate change.
While human activity — research and tourism — is expected to grow on the continent this century, those impacts will pale in comparison to the changing climate.
As well as permanently ice-free terrain expanding over Antarctica, food webs in the surrounding waters are expected to take a hit.
The breeding season of krill, which underpins the food web in the Southern Ocean, is expected to become less reliable.
Under high emissions scenarios, melting ice in Antarctica alone could contribute around 28 centimetres to sea level rise this century.
And there is still a lot of uncertainty around tipping points — thresholds that, when crossed, set off irreversible cascades.
It's no surprise then that the strategy identified as having the most potential benefit is what the researchers call "influencing external policy", or climate action.
The net benefits of achieving a strong emissions reduction pathway versus a weak one are substantial for maintaining intact habitat and biodiversity.
And the benefits extend far beyond Antarctica's borders. But so does the responsibility to achieve it.
It logically follows that it's also the most challenging to achieve, by far, of all objectives identified in the study.
"There are local actions that will have benefit, but at the end of the day the biggest ticket item is climate change," Dr Lee said.
"We've got to do something about climate change, otherwise everything else is just a band-aid."
'It's everybody's place'
The researchers compared the forecast effectiveness of their 10 strategies on Antarctic biodiversity under high and low emissions scenarios.
Almost all strategies achieved significantly greater outcomes under the low emissions pathway, but were positive under both.
"It's still really important to manage the threats we can manage," Dr Carwardine said.
"That will give biodiversity the best chance to adapt to climate change."
The researchers estimate that a total of $US23 million ($34 million) more investment is needed annually between now and 2100 to achieve their targets.
While that may sound like a lot, that would be shared between signatory countries to the Antarctic Treaty, and depending on national Antarctic programs.
"I think this is something we can do as a global society," Dr Carwardine said.
"It's everybody's place. The benefits are just so great."
Other target actions identified by the researchers were: expanding protected areas, transport management, protecting vegetation, managing new infrastructure, site remediation and managing existing infrastructure.
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