ACTION: Reducing global sea level rise by ice sheet conservation using seabed anchored curtains
Sea level rise is probably the single biggest impact of global warming, with effects on the majority of the world’s nations and their inhabitants. The warming climate causes ice sheets and glaciers in Greenland and Antarctica to lose billions of tons of mass, adding significant amounts of water to the ocean.
The consequences will be severe: increased flooding, coastline erosion, damage to key infrastructure, lost habitat for plants and animals. Within the next eighty years, the World Economic Forum estimates around 400 million people to be at risk because of sea level rise.
Sea level rise by the Antarctic and Greenland ice sheet collapse could be reduced if the ice sheets could be conserved. The largest concern for rapid sea level rise is the collapse of parts of the West Antarctic ice sheet where ocean melting has already destabilized ice so much that, when released, it will raise the ocean up a meter or more globally. The Thwaites Glacier (a.k.a. the “Doomsday Glacier”) is likely already in an unstable regime as its protecting ice shelf is thinned by deep intruding currents of relatively warm seawater.
To counteract the melting, our group of internationally renowned glaciologists, oceanographers and engineers propose a system of flexible barriers – curtains – to limit access of warm deep ocean currents that would allow the vulnerable ice shelves to thicken, reground and buttress the inland ice. Modelling indicates that this idea is not only implementable, but also immensely less costly than the alternative – to wait and face the sea level rise. While we know this is doable, there are still needs for testing, modelling, finding optional solutions, and, importantly, ensuring political support for a functional solution. Interventions like these can only be tested and implemented in partnership with the country itself (see our principles and guidelines for reference).
Reducing greenhouse gas (GHG) emissions as agreed in the Paris agreement is the only sustainable pathway to a liveable future. However, it is looking extremely likely that global warming will exceed the 1.5 degree threshold (IPCC special report 2018), and IEA states that we are on a path to 2.4 degrees C. This risks several tipping point thresholds - especially in the Greenland and West Antarctic ice sheets, the summer Arctic sea ice, and Arctic permafrost. This means that the world, in parallel with reducing GHG, must develop science based interventions that can be deployed if necessary when global governance and regulations are in place.