Last updated March 23, 2020 at 11:02 am
The Antarctic Ice Sheet is shrinking faster and faster, affecting the surrounding ocean currents and ice loss, say international researchers.
Why This Matters: The ice sheet might be far away, but the impacts will be felt right here by our coastlines.
Antarctica contains most of the Earth’s fresh water in two large ice sheets – the East and West Antarctic Ice Sheets.
And while a huge block of ice might seem too far away and irrelevant to Aussies, researchers are urging us to take heed, as the ice loss has major implications, both in Australia and abroad.
The Special Section released in the journal Science describes a kind of snowball effect where ice loss is accelerating at unprecedented rates as they are increasingly exposed to warming oceans and changing currents caused by the ice loss.
Sea level rise will continue to accelerate as Antarctic ice sheet
Ian Simmonds from the School of Earth Sciences at the University of Melbourne, who was not an author on the paper, told the AusSMC that the papers make use of the latest data and satellite information to show that Antarctica is losing ice, and this has important implications for sea level rise.
Also: Ancient West Antarctic ice sheet melt increased sea levels by 3+ metres – and it could happen again
According to the review, Antarctic ice loss has contributed to a sea level rise of around 8mm since 1992, but this will continue to accelerate as oceans warm and the ice melts further.
“If global temperatures rise by another 2°C, melting will increase and a sea level rise of a metre or more is likely,” says Stephen Lincoln from the School of Physical Sciences at the University of Adelaide.
This is of great concern to communities in low-lying regions such as the Pacific Islands near Australia, he says, but as two major greenhouse gas emitters, coastal areas of China and the US should also be concerned.
But there are implications for Australia too.
Australian coats will feel the effects
“Even small rates of sea level rise can have a big impact on coastal flooding,” he says. “As a rule of thumb, every 10cm of sea level rise increases the frequency of a given coastal flood by a factor of three.”
“This means that a 0.6m rise in sea level – predicted for Australia in the next few decades – will turn a flood event that is expected to occur on average only once every century to one that occurs every 5 to 6 years.”
Mortlock says coastal managers are currently planning for a sea level rise of one metre by the end of the century, taking coastal airports and other infrastructure into consideration.
But now with all these unknowns surrounding the accelerated melting of the ice sheets, he says a rise of two to three metres could be plausible.
Australia needs to step up efforts in Antarctica
Matt King, a Polar Geodesy researcher at the University of Tasmania, told the AusSMC that Australia now needs to step up in our work in and around Antarctica, especially since we claim around 42 per cent of the space.
“That one of the most prestigious scientific journals globally – urgently publishing the greatest medical and scientific breakthroughs – would devote an issue to Antarctica says that humanity needs to understand Antarctica quickly,” he says.
“All of Australia’s claim is in East Antarctica and the work summarises that it likely collapsed in past warm periods – warm periods we are heading toward with just 1.5 or 2 degrees of warming.”
“We need government urgency and financial support to enable the researchers to quickly shift us from deep uncertainty to giving clear guidance on the consequences of our choices in mitigating climate change.”
Read the full reaction here.