Scientists are pushing for “radical” measures against climate change, proposing the construction of a dam across the Bering Strait that would link Alaska and Russia, said Science.
A study by University of Utrecht academics Jelle Soons and Henk Dijkstra suggests that this would be a decisive way to protect the Atlantic Meridional Overturning Circulation (AMOC), which is instrumental in regulating the planet’s sea temperature and climate.
Three separate dams would be needed across the strait, which is 51 miles (82km) wide at its narrowest, due to the two islands that lie in the middle, with the longest section spanning roughly 24 miles (38 km), said LiveScience. Similar structures already exist in the Netherlands and South Korea, although “not in remote locations with strong currents and sea ice, or with rival geopolitical powers on opposite sides”.
‘Grave’ dangers
Building a dam in the Bering Strait is just as “out there” an idea as “refreezing the Arctic” or “floating a giant parasol in outer space”, said The New York Times. The concern for the continuation of the AMOC is very real, however.
Acting as a “vast oceanic conveyor belt”, it carries tropical, salty currents from the Atlantic towards Europe. There, it releases the warmth into the air, which regulates the temperature across the continent. Once cooled, it circles back south, influencing rainfall patterns in Africa, South America, and beyond.
There is a “growing body of evidence” that human-caused global warming could cause it to “shut down or slow significantly”, which would have “grave effects” on weather patterns on multiple continents.
“At first glance”, the role of the Bering Strait “isn’t all that obvious” in this global cycle. However, it acts as the “gateway for large quantities of fresh water” to flow from the Pacific into the Arctic Ocean, then into the Atlantic. A dam in this region would alter the balance of fresh and salt water in all three oceans.
The University of Utrecht study was based on simulations indicating that the AMOC was “much stronger” in the Pliocene era – roughly 5.3 to 2.6 million years ago. During this era, sea levels in the strait were lower, exposing an intercontinental land bridge, leading Soons, the study’s lead researcher, to wonder “could we do this again?”, said New Scientist.
No ‘escape hatch’
It is an “audacious proposal”, and a project that would be on an unseen and “truly epic scale”. Researchers have been “mulling it over” at the European Geosciences Union general assembly in Vienna this month. But “because we don’t fully understand the AMOC, we can’t be sure of the consequences of such an intervention”. “These drastic things really do have big uncertainties attached”, Jonathan Rosser, a climate researcher at the London School of Economics, told the magazine.
“This is one of those climate ideas that sounds almost ridiculous when you first hear it”, said Earth.com. In fact, the “real takeaway” from the study, and its discussion at a conference level, is “how worried scientists have become about the AMOC”. “When researchers start seriously modelling something this extreme, it tells you that the level of concern is high.”
Even if this project were given the green light – following much more advanced and rigorous modelling – it would “raise huge environmental, political, legal and logistical questions”. The scale of the intervention, let alone the complex political relations between the US and Russia, would mean this project would not be anywhere as simple as “building a bridge or a seawall”. “It would be one of the boldest and strangest geoengineering projects ever seriously contemplated.”
Even then, it does not promise an “escape hatch”, or get-out-of-jail-free card. “Once you are debating mega-dams to prop up ocean currents”, it’s a clear sign that progress towards reducing emissions “has not gone nearly well enough”.