Giant dam to save the currents that keep Europe heated: crazy and dangerous plan

The ambitious geoengineering plan that proposes the construction of a giant dam to block the Bering Strait can destroy the ocean circulation it intends to protect, warns researchers.

Among the controversial “geoengineering” proposals to wage global warming we have recently been aware of, there are ideas like dispersing aerosols to darken the sun, lighten the clouds over the oceans or capture CO₂ and store it in underground deposits.

Now two researchers suggest a radical plan that would not apply to heaven, but to the sea: build a giant dam In the Bering Strait to save the currents that keep Europe heated.

The goal It is not to cool the planet, but avoid a consequence Paradoxical, and so far only hypothetical, of global warming, explains the.

To respond to the fear that “Charges Carrier ” from the Atlantic Ocean, Responsible for the mild climate of Western Europemay, the researchers propose the construction of a dam in the 80km passage that separates Siberia from Alaska.

Paleoclimatic evidence suggests that Southern circulation of the Atlantic (Amoc), which according to a 2024 study, it was stronger During a past glacial era, when the sea level was lower and there was one, which isolated the Arctic Ocean of the Pacific.

One Simple modeling experiencerecently in pre-publication in ARXIV, suggests that artificially recreate this barrier could reinforce the amoc.

“The risk of collapse It is not at all negligible. Given the potential vulnerability of Amoc, the idea deserves to be considered ”, considers the geophysical Jelle Soonsresearcher at the University of Utrecht, who led the study with the physical oceanographer Henk Dijkstra.

Other scientists ask, however, deeper analysis before considering the proposal seriously.

“Os chain effects and the consequences are huge And, in large part, unknown, ”warns Susan Lozieroceanógrafa no Georgia Institute of Technology.

One barrier of this scale between oceans It could affect other currents, marine ecosystems and even human societies. Even more worrying: climate modeling studies done over a decade shows that closing the Bering Strait could condemn Amoc instead of saving it.

There is no consensus on the dimension of the threat that global warming represents for the amoc and, so far, There are no clear signs of weakeningsays Lozier. “Climate models that predict break points have no validation.”

But science points two mechanisms through which global warming could collapse the amoc: the increased temperature of the North Atlantic, which would make it difficult to cool and sink the salty waters of the region, and the Fusion of ice layerswhich adds less dense freshwater to the mixture.

The study of Soons simulated this addition of freshwaterbut it emphasized the rapid warming of the waters. In this scenario, the entry of relatively fresh waters of the North Pacific through the Bering Strait would add pressure on the Amoc, eventually paralyzing it.

Closing the narrow with a dam would allow surviving circulation, support the authors of the study.

But one very detailed, conducted by Aixue HuOceanographer at the National Center for Atmospheric Research, and published in 2011 in the magazine PNAS, points in the opposite direction.

According to Hu, part of the freshwater of the North Atlantic flows to the Arctic and escapes then to the Pacific through the narrow, functioning as an exhaust valve that helps keep the amoc sufficiently salty.

Close the narrow would do this water accumulate in the Arctic until you return to the Atlantic, causing a sudden collapse of circulation.

Other studies have come to similar conclusions. “It’s an interesting idea,” Hu acknowledges about Soons’s proposal. “But, in practice, close the Bering Strait can generate exactly the problem that tries to avoid”.

As to technical viabilitySoons stresses that the work is less unrealistic than it seems. In the narrower point, Russia and Alaska are closer than Philadelphia and New York. THE maximum depth of the narrow is 59 meters And there are two islands in the center.

A largest existing comparable structurethe Saemangeum dike, in South Korea, has 33 kilometers long and up to 54 meters deep. It cost about $ 3 billion and was completed in 2010 – less than a meter extension in New York.

The difference is that the South Korean dike was built in calm coastal watersnot in remote and harsh seas, covered with marine ice for much of the year and between two geopolitical rivals.

A dam in the Bering Strait would still bring multiple collateral impacts. Marine mammals and various species of fish cross it seasonally, and the region serves as a refuge for expanding subars.

Change this ecosystem would inevitably affect indigenous communities that depend on it for food and commerce. In addition, it could make it difficult for maritime traffic, increasingly intense on that route, says Soons.

The researcher is testing the same scenarios in a more advanced climate model. For now, these results should be viewed with caution, warns Hu.

“This work, by itself, It is not enough to justify an intervention of these. ” If I could imagine a geoengineering plan to save the amoc, he adds, perhaps he would rather directly salting the North Atlantic to maintain your density.

Anyway, concludes Soons, the best solution It continues to wrap global warming by reducing the burning of fossil fuels.