How Australia will be impacted by the ‘doomsday glacier' that could swallow cities

News.com.au

10 hours ago

It sounds like something out of a disaster movie, but it's a very real and concerning threat we are facing.
There's a glacier in Antarctica so big and unstable that scientists from The International Thwaites Glacier Collaboration call it the 'Doomsday Glacier'.
And if it collapses, it could raise sea levels enough to swallow parts of cities all over the world.
Thwaites Glacier is in West Antarctica and is roughly the size of Great Britain. It's more than 2 kilometres thick in places, which, when melted, is an astonishing amount of water.
Scientists warn that if it fully collapses, it could raise global sea levels by approximately 65 centimetres.
'If Thwaites Glacier collapses it would cause a rise of around 65cm (25 inches) in sea level,' said Dr Alastair Graham of the University of South Florida.
That might not sound like much … until you think about what it actually means.
A 65 centimetre rise is enough to flood huge areas of low-lying land. Cities like New York, London, and Bangkok would see chronic inundation.
Entire islands in the Pacific and Indian Oceans could become uninhabitable.
Even Australia isn't safe. Much of our population lives along the coast, and many suburbs in cities like Sydney, Melbourne, and the Gold Coast sit just metres above sea level, making them vulnerable to chronic flooding if the sea rises even half a metre.
What's worse is that Thwaites is already melting fast. Its ice flow into the ocean has surged, spilling ice at more than twice the rate seen in the 1990s.
The floating ice shelf in front of it, which acts like a doorstop slowing the glacier down, is cracking and weakening under pressure.
'This year is really different,' Ted Scambos, a glaciologist at the University of Colorado Boulder and leader of the Science Coordination Office for the International Thwaites Glacier Collaboration, told CNN.
'It's very difficult to recover from this in one season. The game has changed.'
Some scientists believe parts of that ice shelf could break apart within the next few years. If that happens, the glacier's flow could speed up dramatically, dumping even more ice into the ocean.
The truly terrifying part is that Thwaites is sometimes referred to as a 'keystone' glacier. If it falls, it could destabilise other nearby glaciers, eventually unlocking enough ice to raise sea levels by several metres over centuries.
And while those worst-case scenarios would take a long time, Thwaites is already adding to the current sea-level rise. How quickly it will deriorate depends heavily on future greenhouse gas emissions.
Climate scientists say this is yet another warning sign that our planet is heating in ways that will reshape coastlines, displace millions of people, and create massive economic and humanitarian challenges.
Fears as Antarctica melts at rapid pace
The story of Antarctica's ice isn't limited to this one glacier.
In fact, the entire continent is sending us alarm bells.
According to the National Snow and Ice Data Center, 'Antarctic sea ice has hit record-low levels for winter.'
Although sea ice isn't the same as land ice (it doesn't raise sea levels when it melts), it still plays a critical role in the climate system.
It acts like a giant mirror, reflecting sunlight back into space. Less sea ice means more dark ocean absorbs heat, warming the water even further.
That extra heat can creep under floating ice shelves all around Antarctica, making them melt from below. When those ice shelves weaken or collapse, they can no longer hold back the vast land-based glaciers behind them.
That's exactly the mechanism threatening Thwaites and other big glaciers in West Antarctica.
Scientists see the record-low sea ice as part of the same climate crisis threatening to reshape our world.
The frozen parts of Earth are changing faster than expected, and those changes are likely to come back to bite us all.