Thwaites Glacier is rapidly shedding ice as the world warms from climate change, driven by the burning of fossil fuels. Thwaites is losing about 50 billion metric tons<\/a> of ice every year, contributing to about 4% of present-day sea-level rise worldwide. But if Thwaites were to melt down entirely, it could raise the average global sea level by more than 0.6 meters (2 feet) over the next few centuries. This would inundate coastal cities around the world and force hundreds of millions of people to migrate.<\/p>\n Some scientists think<\/a> it could be even worse. Thwaites may act as a natural dam for the rest of ice contained within West Antarctica. If it collapses, it could destabilize other glaciers, potentially pushing global sea level rise to as high as 3 m (10 ft).<\/p>\n In a 2024 briefing<\/a>, the International Thwaites Glacier Collaboration, a group of polar scientists closely studying the glacier\u2019s fate, said a worst-case meltdown scenario can\u2019t be ruled out, given that global greenhouse gas emissions are continuing to rise. Their findings suggest that Thwaites and much of the West Antarctic Ice Sheet could be lost by the 23rd century.<\/p>\n The risks would be catastrophically high for humanity.<\/p>\n That\u2019s why this January a group of scientists will travel to Thwaites to conduct field research on an idea once dismissed as outlandish: Building a giant sea curtain to shield Thwaites from the intrusion of warm water that threatens to be its undoing.<\/p>\n \u201cTo give people some potential solutions that might preserve the most vital parts of the [Earth] system, is proving real hope,\u201d says John Moore, a glaciologist with the University of Lapland in Finland, who first proposed the idea. \u201cAnd it\u2019s not empty hope. We know that some of these things work in nature \u2014 if you keep away the warm water, ice sheets are stable.\u201d<\/p>\n Warmer ocean water flowing underneath<\/a> Thwaites is thought to be the driver of its massive ice loss, vigorously speeding up melting. In 2018, Moore and Michael Wolovick, a glaciologist with the Alfred Wegener Institute in Germany, put forward<\/a> the idea of blocking the underwater pathways that deliver the warm water to the glacier. The mechanism they now propose would be a flexible, buoyant curtain anchored to the seabed.<\/p>\n With the world setting back-to-back warmest year records<\/a> in 2023 and 2024, and global climate diplomacy talks falling apart<\/a>, that idea has gained traction as Antarctica warms<\/a> at twice the rate of the global average.<\/p>\n On the upcoming visit to Thwaites, scientists will deploy two underwater robots in the Pine Island Trough, the possible location for a sea curtain, to gather data to help them understand whether a curtain could be installed \u2014 and if it could be done fast enough to make a difference for Thwaites and the world.<\/p>\n \u201cThe robots will travel up and down wires and they will check on the water speed, water temperature, water salt,\u201d says climate scientist David Holland with New York University, who is also working on the project.<\/p>\n The assignment will last two years, after which point, \u201cwe can then say to an engineer, this is the amount of force \u2014 this is how fast this thing is going,\u201d Holland says.<\/p>\n The Seabed Curtain Project<\/a> is supported by the University of the Arctic, a cooperative network of nearly 200 universities and research institutions. The project has obtained funding from the Tom Wilhelmsen Foundation, the charitable arm of Norwegian shipping giant Wilhelmsen, and Outlier Projects<\/a>, a philanthropic organization created by former Meta chief technology officer, Mike Schroepefer, which gives grants to research groups working on climate tech interventions.<\/p>\n The project is among a handful of proposals that scientists have put forward in a last-ditch effort to preserve the rapidly melting polar regions. These include drilling holes to the glacier bed to drain the water that lubricates the glacier\u2019s outward flow, and refreezing Arctic sea ice<\/a> by pumping up water from below onto the ice. One study<\/a> also found solar geoengineering<\/a>, known as stratospheric aerosol injection, might be able to save the West Antarctic Sheet.<\/p>\n However, these projects, which fall into the realm of geoengineering<\/a>, have received fierce pushback from some polar scientists. This month, 42 polar scientists \u2014 from institutions such as the British Antarctic Survey, Scripps Institution of Oceanography, and International Cryosphere Climate Initiative \u2014 published an assessment<\/a> of five polar geoengineering projects currently in development in the journal Frontiers in Science, titled \u201cSafeguarding the polar regions from dangerous geoengineering.\u201d<\/p>\n The scientists concluded that the proposed geoengineering projects would cost billions of dollars in setup and maintenance, and argued they would reduce pressure on policymakers and industries to slash greenhouse gas emissions. Additionally, the assessment looked at the ecological, legal and political obstacles in advancing these ideas.<\/p>\n Those in favor of considering such interventions argue that the world desperately needs a Plan B. Global carbon emissions from fossil fuels continue to hit<\/a> record highs, despite promises from world leaders to address climate change. Moreover, scientists say a certain amount of sea level rise from Thwaites is already locked in, even if the world were to stop all emissions tomorrow. And some<\/a> studies<\/a> suggest at least a partial loss is now unstoppable.<\/p>\n Holland, too, says his views have changed in recent years. He\u2019s made eight trips to Thwaites and once thought the seabed curtain was a crazy idea. \u201cCan you put in a curtain and save the coastline of the world? I would have said, \u2018No way,\u2019 two years ago.\u201d<\/p>\n But now, he says it\u2019s doable \u2014 at least from a scientific perspective.<\/p>\n \u201cAt some point, you just have to ask, \u2018Is it plausible?\u2019 Because if you\u2019re against it, then what are you against? Some unforeseen consequence that\u2019s going to destroy the Earth? Well, maybe that\u2019s what\u2019s happening right now.\u201d<\/p>\n One of the reasons scientists think an Antarctic curtain could work is because the warm, dense bottom waters melting Thwaites are first funneled through narrow channels in the continental shelf. That pathway, they theorize, could be plugged. Moore and Wolovick\u2019s initial design focused on installing an artificial sill up to 100 m (330 ft) high to block the warm water reaching Thwaites.<\/p>\n \u201cYou take advantage of nature\u2019s chokepoints to increase that with a barrier,\u201d Moore says.<\/p>\n Over the past seven years, their blueprint has evolved. \u201cOriginally, we had very naive concepts as scientists and not engineers that you would essentially build some kind of gravel dam to block this,\u201d Moore says.<\/p>\n In a 2023 paper<\/a> in the journal PNAS Nexus, the glaciologists instead proposed installing flexible curtains across 80 km (50 mi) at depths of 600 m (2,000 ft) on alluvial sediment. Curtains, they realized, would be cheaper, withstand iceberg collisions, and be easier to repair or remove in the face of unintended consequences, unlike a permanent fixture. Such an intervention, they calculated, would cost between $40 billion and $80 billion to install, and an additional $1 billion to $2 billion in annual maintenance.<\/p>\n While that might sound steep, it\u2019s nothing compared to the economic damages wrought by sea level rise, which scientists estimate could reach into the trillions of dollars<\/a> per year by the end of this century.<\/p>\n \u201cIt\u2019s a no-brainer to think, \u2018Do we spend $10 million finding out if this works? Or do we lose $10 trillion for doing nothing?\u2019\u201d Moore says.<\/p>\n In temperate waters, existing offshore and deep ocean construction techniques would make installing such a curtain possible. Polar waters, however, present a greater challenge, given the harsh environment and brief working seasons. But Moore and Wolovick say this could be overcome with present-day technology.<\/p>\n But other scientists disagree.<\/p>\n In the new paper published in Frontiers in Science, the authors closely examine the proposed seabed curtain.<\/p>\n \u201cWe were seeing some of these geoengineering ideas being presented at prominent meetings like the United Nations climate COP meetings or the World Economic Forum, and being done in such a way that minimizes the environmental challenges and maximizes the advantages,\u201d says lead author Martin Siegert, a glaciologist at the University of Exeter in the U.K.<\/p>\n That, he says, compelled other polar scientists to critically examine the projects being discussed.<\/p>\n \u201cIf there is a sense of a solution other than decarbonizing, for some people, that will be appealing,\u201d Siegert says. \u201cWe think that\u2019s a really dangerous message to be sending at this moment, when we absolutely need to nail down decarbonizing and do it really quickly.\u201d<\/p>\n First, their scientific assessment considers whether it would be feasible to install curtains that could withstand the force and hazards of the Antarctic region.<\/p>\n The proposed deployment site is considered \u201cone of the harshest environments on Earth, with a transit time of over one week from the nearest port and access likely to be possible only for a few months each year owing to polar darkness and extreme ice and climate conditions,\u201d the researchers write, adding the Inner Bay site has only been accessed once in the last 40 years.<\/p>\n The study also notes that even if successful, such an intervention could have unintended consequences of rerouting warm water to other ice shelf systems, as well as creating a barrier to marine life in the Amundsen Sea.<\/p>\n The politics are also tricky, as the approval and governance of a sea curtain would fall under the Antarctic Treaty System, a network of 57 nations that work to ensure Antarctica is only used for peaceful, scientific purposes and preserved as a global common.<\/p>\n \u201cObtaining international consensus to intervene in Antarctic processes at such a huge scale has never been attempted before, and those advocating sea curtains have given this necessary item scant consideration thus far,\u201d the study reads.<\/p>\n Scientists also took issue with the proposed costs, arguing $80 billion was a dramatic undercount of the money it would take to complete such an intervention, considering the costs of other engineering megaprojects, such as China\u2019s Three Gorges Dam.<\/p>\n \u201cIf we\u2019re going to spend hundreds of millions or maybe even billions of dollars on some of these ideas, it\u2019s better spent on decarbonizing,\u201d Siegert says.<\/p>\n So far, governments and industry have failed to make the deep cuts necessary to tamp down planet-warming emissions, giving scientists little choice but to explore alternative methods to preserve the world\u2019s polar regions, Moore says.<\/p>\n Looking at history, he says, he feels undeterred. \u201cIn the First World War, Britain built anti-submarine nets \u2014 curtains, if you like \u2014 around most of its coast, spanning thousands of kilometers,\u201d he says. \u201cThat was a massive investment at the time, but it was an existential threat, so it had to be done.\u201d<\/p>\n Moore and his colleagues say they hope to spend the next couple of years collecting data in the Amundsen Sea. This would serve as the scientific basis for the curtain\u2019s design and potential deployment.<\/p>\n In 2027, they say they hope to test a curtain at Ramfjorden near Troms\u00f8, Norway. But first they need to raise the funds \u2014 a key goal of the project at New York Climate Week this month, Moore says.<\/p>\n \u201cWe are very much in the research program,\u201d he says. \u201cOf course, we have the longer-term hope that eventually, if everything works out, we would be able to deploy this before it\u2019s too late in Antarctica.\u201d<\/p>\n That, he adds, is the big question. It\u2019s possible that a deployment in 20 years\u2019 time could already be past the point of no return for the glacier. But scientists won\u2019t know until they do the work.<\/p>\n Arguments for rapid decarbonization, Moore says, ignore the fact that the human race has so far chosen not to do the \u201cgood option\u201d of dramatically slashing carbon emissions.<\/p>\n \u201cSo what else is on the table? You\u2019ve got bad, and you\u2019ve got worse. We don\u2019t know which is bad and which is worse between geoengineering, and, in a way, sitting on our asses and doing nothing \u2014 which is what we have done for the last 30 years.\u201d<\/p>\n Banner image: Thwaites Glacier in Antarctica. Image by NASA<\/a> via Wikimedia Commons (public domain).<\/p>\n Citations:<\/p>\n Goddard, P. B., Kravitz, B., MacMartin, D. G., Visioni, D., Bednarz, E. M., & Lee, W. R. (2023). Stratospheric aerosol injection can reduce risks to Antarctic ice loss depending on injection location and amount. Journal of Geophysical Research: Atmospheres, 128, e2023JD039434. doi:10.1029\/2023JD039434<\/a><\/p>\n Jevrejeva, S., Jackson, L. P., Grinsted, A., Lincke, D., & Marzeion, B. (2018). Flood damage costs under sea\u2011level rise with warming of 1.5\u00b0C and 2\u00b0C. Environmental Research Letters, 13(7), 074014. doi:10.1088\/1748-9326\/aacc76<\/a><\/p>\n Keefer, B., Wolovick, M., & Moore, J. C. (2023). Feasibility of ice sheet conservation using seabed anchored curtains. PNAS Nexus, 2(3). doi:10.1093\/pnasnexus\/pgad053<\/a><\/p>\n Moore, J. C., Macias-Fauria, M., & Wolovick, M. (2025). A new paradigm from the Arctic. Frontiers in Science, 3, 1657323. doi:10.3389\/fsci.2025.1657323<\/a><\/p>\n Rignot, E., Cirac\u00ec, E., Scheuchl, B., & Dow, C. (2024). Widespread seawater intrusions beneath the grounded ice of Thwaites Glacier, West Antarctica. Proceedings of the National Academy of Sciences, 121(22), e2404766121. doi:10.1073\/pnas.2404766121<\/a><\/p>\n Rignot, E., Mouginot, J., Morlighem, M., Seroussi, H., & Scheuchl, B. (2014). Widespread, rapid grounding line retreat of Pine Island, Thwaites, Smith and Kohler glaciers, West Antarctica, from 1992 to\u202f2011. Geophysical Research Letters, 41(10), 3502-3509. doi:10.1002\/2014GL060140<\/a><\/p>\n Siegert, M., Sevestre, H., Bentley, M. J., Brigham-Grette, J., Burgess, H., Buzzard, S., \u2026 Truffer, M. (2025). Safeguarding the polar regions from dangerous geoengineering: A critical assessment of proposed concepts and future prospects. Frontiers in Science, 3, 1527393. doi:10.3389\/fsci.2025.1527393<\/a><\/p>\n Van den Akker, T., Lipscomb, W. H., Leguy, G. R., Bernales, J., Berends, C. J., Van de Berg, W. J., & Van de Wal, R. S. W. (2025). Present\u2011day mass loss rates are a precursor for West Antarctic Ice Sheet collapse. The Cryosphere, 19(1), 283-301. doi:10.5194\/tc-19-283-2025<\/a><\/p>\n Wolovick, M. J., & Moore, J. C. (2018). Stopping the flood: Could we use targeted geoengineering to mitigate sea level rise? The Cryosphere, 12(9), 2955-2967. doi:10.5194\/tc-12-2955-2018<\/a><\/p>\n ![\"The](\"https:\/\/www.newsbeep.com\/nz\/wp-content\/uploads\/2025\/09\/A_close_look_at_the_shelf_8093672443.jpg\")
The Thwaites Ice Shelf, photographed from the IceBridge DC-8 in 2012. Image by James Yungel for NASA ICE via Wikimedia Commons<\/a> (public domain).
\n\u2018Not empty hope\u2019<\/p>\n![\"Exchange](\"https:\/\/www.newsbeep.com\/nz\/wp-content\/uploads\/2025\/09\/the-seabed-curtain-project-illustration-with-labels.jpg\")
Exchange flow pattern of Subsea Anchored Curtain protecting tidewater glacier. Image by UArctic.
\nHow an Antarctic curtain could work<\/p>\n![\"Scientists](\"https:\/\/www.newsbeep.com\/nz\/wp-content\/uploads\/2025\/09\/2019Jan8-Thwaites-KBA-fuel-HR.jpg\")
Scientists on Thwaites Glacier in western Antarctica in 2019. Image by the United States Antarctic Program via Wikimedia Commons<\/a> (public domain).
\nDangerous territory<\/p>\n![\"The](\"https:\/\/www.newsbeep.com\/nz\/wp-content\/uploads\/2025\/09\/Thwaites_Ice_Tongue_from_Sentinel-2_pillars.jpg\")
The Thwaites Glacier, Ice Tongue and Eastern Ice Shelf, photographed in 2019 from the Sentinel-2 satellite. Image by the European Space Agency via Wikimedia Commons<\/a> (CC BY-SA 3.0)<\/a>.
\nNext steps<\/p>\n <\/p>\n