The climate threat
New report on the "doomsday glacier" - that's how close the collapse is
Jonathan Jeppsson
Digging manager and climate columnist
This is a commenting text. Analysis and positions are the writer's.
Updated 23.23 | Published 23.16
The so-called "doomsday glacier" Thwaites is close to a tipping point and may break up within the next few years.
The results of a six-year research project show that this is only the beginning of a melting that will last for centuries.
The grim fact is that this seems to happen regardless of how much we limit our emissions.
A six-year effort to understand Thwaites, also called the "doomsday glacier", is now over.
It has involved hundreds of researchers from a number of countries, who have tried to map the glacier's vulnerability with the help of robotic submarines, satellites and drilling.
The glacier has been retreating for 80 years, a process that has accelerated over the past 30 years and will accelerate even more in the future, the researchers note.
"Towards the end of this century, or into the next, it is very likely that we will see a rapid increase in the amount of ice coming off Antarctica," said Ted Scambos, a glaciologist at the University of Colorado who was involved in the study. ”Thwaites is basically doomed.”
Three meter rise
Thwaites is about the same size as Florida in surface area, and if the entire glacier were to collapse, it would raise sea level by about 65 centimeters.
But because it sits as a plug for large parts of the other glaciers in West Antarctica, the sea level rise could be significantly greater. The total increase, according to Scambos, will be closer to three metres.
But there is still a glimmer of light: The conclusion is that a complete collapse of the Thwaites Glacier this century may be somewhat less likely than previously thought. However, the models predict that the loss of ice will accelerate in the 21st and 22nd centuries, which could lead to a "general collapse of the West Antarctic ice sheet in the 24th century."
Can't be ruled out
However, a worst-case meltdown scenario still cannot be ruled out, as greenhouse gas emissions have continued to reach new record levels year after year.
Together with meltwater from other parts of Antarctica and Greenland, as well as from mountain glaciers around the world and the expansion that occurs because the oceans are warming, a melting of the Thwaites Glacier could lead to a rise in sea levels of two meters by 2100, according to the researchers.
Sooner or later this will lead to enormous problems for the hundreds of millions who live in low-lying areas near the coasts. Last October, a report was published in Nature Climate Change which stated that the Thwaites and Pine Island glaciers will continue to melt, regardless of how much we limit emissions.
"It is really worrying that the latest models all point to an irreversible decline that may already have been triggered," said James Kirkham, head of the International Cryosphere Climate Initiative scientific council.
Within five years
Things will also unfold in the near future.
The researchers believe that the outermost part of the glacier, the ice shelf that floats on the sea, is likely to break up into several large icebergs within the next two to three years – exposing the front of the glacier to the sea. What this means is shrouded in obscurity – it won't necessarily lead to an acceleration of melting, but will still change how the ocean interacts with the ice.
New findings have shown how tidal waves moving under the Thwaites Glacier have created a large zone where warm water repeatedly flows under the ice, speeding up melting. This tidal pulse has increased the instability of the glacier.
Anna Wåhlin, professor of oceanography at Gothenburg University. Photo: Johan Wingborg/Gu
Swedish professor Anna Wåhlin, who researched Thwaites for many years and herself operated one of the underwater robots, believes that the glacier has passed a tipping point where stability is gone.
- The changes happen very quickly. The glacier is very unstable right now. It will not be around within five years, maybe even within three years, she told Svenska Dagbladet this spring.
But she emphasizes that it is not entirely certain that there will be a sea level rise, and if it does happen, we will have time to prepare, because it will be some time before the rises become significant.
Absolutely crucial
Humanity in general has a very difficult time relating to challenges that lie far into the future. We are short-sighted creatures – MRI research of our brains has shown that when we think of ourselves in the future, we begin to see our future selves as completely different people.
Still, emissions reductions can buy us – or indeed future generations – more time in terms of how quickly the water will rise.
But in order to be able to make the right decisions and take the right measures, for both adaptations and limitations, it is crucial that we know how big the stakes are.
We simply have to be aware of the risks.
There, reports like the one about Thwaites are absolutely decisive.
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