Thwaites Glacier in Antarctica is the size of Florida - “the widest glacier in the world” said Ted Scambos - senior research scientist at the Cooperative Institute for Research in Environmental Sciences (CIRES). It flows across a 120km stretch of frozen coastline.
Thwaites is a frozen river of ice and it already contributes to around 4 per cent of the global sea-level rise. Since 2000, the glacier lost more than 1,000 billion tons of ice and the speed of its flow has doubled since 1990. Thwaites is held by a floating platform of ice called an ice shelf which restrains the glacier and makes it flow less quickly. However, scientists confirmed that this is becoming destabilised and could collapse within 10 years according to Erin Pettit - glaciologist at Oregon State University.
The ‘doomsday glacier’ contains enough ice to raise global sea levels by 65cm if it were to completely collapse, and research now suggests that the long-term stability of the glacier is doubtful as it haemorrhages more ice. The research suggests that the glacier could completely collapse by the end of this decade if not sooner which could potentially trigger a catastrophic chain of events. The Glacier is retreating rapidly as a warming ocean erases its ice from below leading to faster facturing and a threat of collapse.
Predicting the breakup of ice sheets and the implications for future sea level rise is fraught with uncertainty. Depending on various emissions scenarios in the latest Intergovernmental Panel on Climate Change report, we could have as little as one foot of sea level rise by the end of the century, or nearly six feet of sea level rise.
“The difference between those [models] is a lot of lives and money,” says Richard Alley, a glaciologist at Penn State University, adding “The most likely place to generate [the worst scenario] is Thwaites.”
This could inundate many of the world’s cities: Shanghai, New York, Miami, Tokyo and Mumbai while it could also cover huge swathes of land in coastal regions and swallow up low-lying island nations such as Tuvalu and the Maldives.
“It’s doubled its outflow speed within the last 30 years, and the glacier in its entirety holds enough water to raise sea level by over two feet. And it could lead to even more sea-level rise, up to 10 feet, if it draws the surrounding glaciers with it.”
To contextualise what this means for the world: since 1900, there has been an approximately 20cm rise in sea-levels that already account for displacement in coastal communities, flooding, saltwater contamination and habitat loss. The Thwaites has been given the cheeky nickname ‘doomsday glacier’ due to its incremental role in the region. Its collapse could lead to what has been labelled as a catastrophic chain of events because it could trigger a regional chain reaction and drag other glaciers with it which could mean several meters of sea-level rise. This is due to the potential of Marine Ice Cliff Instability (MICI) where retreating ice exposes increasingly tall, unstable ice cliffs that collapse into the ocean.
Nevertheless, other works suggest that the destabilisation of the glacier’s ice shelf may not lead to the kind of catastrophic outcomes that some may fear. Sea ice and chunks of ice that break away from the collapsing ice shelf and glacier might have a similar restraining effect to the intact ice shelf, nipping the chain-reaction in the bud and preventing the sustained collapse of the West Antarctic ice sheet.