Scientists suggest building walls to stop sea level rises

Scientists have floated the idea of building huge undersea walls around fast-melting parts of Antarctica.

It sounds like something right out of US President Donald Trump's playbook, but it's sea-level rise they're trying to stop, not Mexicans.

"Doing geo-engineering means often considering the unthinkable," says climate scientist John Moore of Beijing Normal University.

He's the co-author of a new paper, published in journal The Cryosphere, which proposes a radical solution to a problem that threatens low-lying communities across the world.

Scientists in Beijing and at Finland's University of Lapland Arctic Centre investigated whether Antarctic glacial melt could be slowed down or even stopped by building massive walls under the sea, holding them in. In particular, they concentrated on the icy continent's 100km-wide Thwaites Glacier.

"Thwaites could easily trigger a runaway [West Antarctic] ice sheet collapse that would ultimately raise global sea level by about three metres," says co-author Michael Wolovick.

A wall could block warm water from reaching the ice and melting it, or columns - a cheaper option - could at least hold the glacier in place, giving it a better chance of survival.

Computer modelling found erecting 300m-high mounds or columns would have a 30 percent chance of success, while going all-in and building a wall would more than double the odds.

Thwaites Glacier.
Thwaites Glacier. Photo credit: Reuters

They admit both options are "beyond the scale humanity has attempted so far", particularly the latter, and reining in greenhouse gas emissions is still the best option.

"There are dishonest elements of society that will try to use our research to argue against the necessity of emissions reductions," they say. "Our research does not in any way support that interpretation."

They don't estimate how much it would cost to build enough walls or mounds to make a worthwhile difference, or who will pay for it, but do note the US spends about 2160 times more on its military than its Antarctic programmes.

There's enough ice in Antarctica to raise sea levels by 200m. In this scenario, most of Auckland, Waikato, Northland, Wairarapa and Christchurch would go the way of Atlantis.

Newshub.

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