An underwater curtain 150 meters tall and 80 kilometers wide, anchored to the Antarctic seabed, may be the most direct thing anyone can do about sea level rise this century. Marianne Hagen co-leads the Seabed Curtain Project after serving as Norway's deputy foreign minister and as an executive vice president at Aker Solutions, so she has spent a career inside the rooms where governments and industry actually decide about energy and risk. We talk about why warm, salty bottom water started creeping over a seabed sill a few decades ago and now flows down a Grand Canyon-sized channel to the soft underbelly of Thwaites Glacier, and why that glacier works like a cork in a champagne bottle holding back the West Antarctic Ice Sheet. Then we get into the fix itself: raising that sill, 200 kilometers from the glacier, back to the height that kept the warm water out. We also cover this year's expedition, which drilled through a thousand meters of ice and confirmed the warm water before losing its fiber optic cable at 700 meters, and why the next chance at that data is 2028 unless someone finds a ship.
Key topics
0:00 — Cold open: the warm water reaching Thwaites
2:58 — From Norwegian diplomacy and Aker Solutions to glacier intervention, and the moment the Ukraine invasion changed her math
18:39 — What sea level rise actually costs: coastlines, ports, agriculture, real estate, financial stability
26:18 — Why West Antarctica: the sill, the channel, and the soft underbelly of Thwaites
31:55 — The cork in the champagne bottle, and why Antarctica is a bowl of ice
34:44 — The curtain: fixing a leak in your basement, 150 meters tall and 80 kilometers wide
41:22 — The expedition: a borehole through 1,000 meters of ice, a cable stuck at 700, and no ship until 2028
47:37 — A permanent underwater observatory, the white paper, and what happens next
Links and resources
John Moore’s original 2018 proposal for seabed-anchored curtains (Nature comment, “Geoengineer polar glaciers to slow sea-level rise”)
New York Times coverage of this year’s Thwaites expedition
This episode is part of an ongoing series on the interventions that could hold Earth systems stable long enough for mitigation and carbon removal to finish the job, covering everything from stratospheric aerosols to the ice itself. Subscribing free at inevitableandobvious.com gets you every episode, the full show notes, and the essays that connect them.
