Major engineering companies are looking at plans to slow the melting of a gigantic Greenland glacier, in what would be the first large-scale intervention to preserve ice anywhere in the world. If it goes ahead, and if it works, it could suggest a way to slow sea level rise from Antarctic melt, too.
狈辞谤飞补测鈥檚 and the , based in London, sent representatives to on 12 October in which proposals were discussed to construct a physical barrier to slow the ingress of warm seawater to the base of the glacier.
鈥淭he design concept, essentially, is you take a heavy premade set of concrete foundations that would be gently lowered onto the seafloor and they provide the anchor for a buoyant curtain,鈥� says , a glaciologist who has positions at the University of Lapland in Finland and Beijing Normal University in China.
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Recent research has found that melting on the underside of the Greenland ice sheet is progressing faster than anticipated. Moore鈥檚 idea is that the curtain will reduce the flow of warm water from the Atlantic Ocean to the base of the ice sheet.
Greenland鈥檚 ice sheet, the second largest in the world after the one covering most of Antarctica, holds nearly 2.9 million cubic kilometres of ice 鈥� enough to raise global sea level by 7.2 metres if it all melted. That would take many hundreds of years, but at least , attributable to Greenland alone.
The target for the proposed intervention is the Jakobshavn glacier, the major drainage point for Greenland鈥檚 ice melt. The speed of ice flow from Jakobshavn means .
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The mouth of Ilulissat fjord, where the glacier terminates, is some 5 kilometres across, and the project would require a curtain to be lowered across the gap. Moore estimates the cost at less than $500 million per kilometre, so the total bill would come in at around $2 billion.
鈥淭his is significant funding,鈥� said Moore, speaking to the New 杏吧原创 Weekly podcast. 鈥淏ut compare that with the costs of Greenland鈥檚 contribution to sea level rise and the expected damages. It鈥檚 far, far smaller. It鈥檚 of the order of 1 per cent.鈥�
The impacts of sea level rise of a metre and up would be catastrophic. Hundreds of millions of people are thought to be at risk of flooding due to sea level rise by 2100, with the financial cost estimated at many trillions of dollars.
Many unknowns remain. Prototypes will need to be built to test how, for example, icebergs pass through the curtain and to assess the impact on nutrient mixing in the fjord and on fish populations. The curtain does nothing to slow surface melting on the glacier, which is significant, and increasing. Time is also a factor, and Moore says the project would take 30 years to construct.
Local consultation
Any construction project of this scale would also require consultation and buy-in from local people. is an environmental social scientist at the University of Lapland who has been canvassing local attitudes to this kind of engineering intervention in Ilulissat, a town of some 4600 people near the Ilulissat fjord.
鈥淕reenlanders are concerned about climate change,鈥� she says. 鈥淭he proposal to intervene is a new scientific idea, but the views have been both positive and slightly concerned about possible impacts on livelihoods associated with tourism and fisheries. People have been expressing their interest towards doing climate action in Greenland 鈥� that鈥檚 a good starting point.鈥�
, an engineer at the University of Cambridge, says glacial curtains could slow down, and perhaps even reverse, the rate of melting of Arctic and Antarctic glaciers. 鈥淚f curtains can be made to work, then they might be a very cost-effective approach to protecting us all from significant sea level rise caused by the melting of polar glaciers.鈥�
However, , a glaciologist who is also at the University of Cambridge, says the idea wouldn鈥檛 change the melting caused by the warmer atmosphere, which is currently the biggest concern in Greenland. He also points out that Antarctica鈥檚 coastline is longer than Earth鈥檚 circumference, and the Greenland ice sheet covers 1.7 million square kilometres.
鈥淕eoengineering on this scale is unlikely to materialise any time soon,鈥� he says, nor on the timescale needed. 鈥淎 green revolution for the necessary reduction in fossil fuel use is under way and it is crucial that it continues.鈥�
The funding for the meeting in Iceland came from Frederik Paulsen, a Swedish billionaire. Moore says he is establishing an advisory committee focused on Greenland and Antarctica with the aim to encourage more investment from Paulsen and other billionaires.
Aker Solutions confirmed its interest in the project. 鈥淲e discussed in Reykjavik a possible sustainable engineering solution to reduce the inflow of warm, saline seawater that is contributing to the melting of the ice cap,鈥� says Marianne Hagen at the firm. 鈥淭his is a technically highly challenging project, but we鈥檝e achieved the impossible before and we cannot see one reason why we should not try, not least since our purpose is to solve global energy challenges for future generations.鈥�
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