'Doomsday glacier' rapid melt could lead to higher sea level rise than thought: study (2024)

The world’s so-called “doomsday glacier” may be breaking up faster than previously thought, which could have catastrophic implications for B.C.’s major coastal cities in the next couple of decades, according to a new international study involving Canadian research.

Christine Dow, a glaciologist and associate professor at the University of Waterloo, is part of an international team of scientists studying the Thwaites Glacier in western Antarctica.

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She said Thwaites Glacier, which is about the same size as Florida, is very unstable, and this study concerns scientists because it’s the first time they’ve had a visual on just how far warm water rushing below the surface is moving inland.

“What we saw was the ocean water is penetrating about 12 kilometres inland from where we thought it was before,” she said Friday. Dow is also the Canadian research chair in glacier hydrology and ice dynamics.

“Any time you have ocean water interacting with ice you get a lot of melt because the ocean’s quite warm. And so that means it’s getting very, very close to a position where it’s going to have catastrophic retreat.”

The team’s study, led by the University of California, Irvine, was published last week in Proceedings of the National Academy of Sciences.

Using high-resolution satellite radar data, the researchers discovered that Thwaites is being flooded with warm sea water, which means scientists may need to reassess global sea level rise projections.

If it collapses, it would contribute to about 60 centimetres of sea level rise, say the researchers, but it would also trigger other glacier melt, potentially raising the sea by another 3½ metres.

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“The worry is that we are underestimating the speed that the glacier is changing, which would be devastating for coastal communities around the world,” said Dow.

B.C.’s coast would be hit particularly hard if nothing is done to stop emissions and slow global warming, she added.

“Vancouver is probably going to suffer the worst in Canada from sea level rise, especially places like Richmond which is close to the sea,” said Dow.

“It is just going to take half a metre of sea level rise for a lot of flooding to occur, and at a metre of sea level rise most of that highly populated area at sea level will be unliveable unless there is infrastructure built to hold back the ocean or some other adaptation process.”

One of the most important reasons for doing this study, said Dow, is to continue to improve modelling to make better projections on just how much the sea will rise.

Dow said scientists believe the glacier has as little as 10 years until it reaches the point of no return, where the melt will speed up.

“We still have time to act … but because the climate system can react quite slowly to change because we have put so much carbon into the atmosphere, we really have to stop emissions now to prevent catastrophic destruction,” she said.

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“If we’re going to be able to stop multiple metres of sea level rise, it has to be right now.”

Dow said sea level rise is now inevitable. But if nothing is done and the glaciers all melt, the world is facing an estimated 12-metre sea level rise, which would wipe out coastal cities and force a mass migration inland.

“You’d have to rebuild all your infrastructure, and you’ve got to worry about the fact that the saltwater might intrude into your fresh groundwater making that undrinkable. You’re going to change agriculture, you’re going to change everything really. The world would be a completely different place.”

People don’t tend to think about the Antarctic because it’s so far away, but it absolutely will affect us,” she said.

Eric Rignot, a professor of Earth system science at the University of California, Irvine , said in the past researchers had some sporadically available data and it was hard to figure out what was happening. But with the satellite data from ICEYE in Finland along with subglacial water modelling, they now have a much better view of what is happening.

“When we have a continuous time series and compare that with the tidal cycle, we see the sea water coming in at high tide and receding and sometimes going farther up underneath the glacier and getting trapped,” Rignot said in a statement release by UC Irvine.

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Next, the team will be analyzing data from glaciers around the Antarctic, which will allow them to do more accurate sea level rise projections before the end of the year.

ticrawford@postmedia.com

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