NASA
Gulf Stream – Atlantic Meridional Circulation
The plan involves building an 82-kilometer dam across the Bering Strait. However, there is a risk that the project will worsen the problem of weakening the Atlantic Meridional Overturning Circulation.
A controversial proposal to build a dam across the Bering Strait, with the aim of protect one of the most important ocean systems of Earth, may be theoretically feasible, but very risky.
According to new research in the journal Science Advances, the focus is on saving the Atlantic Meridional Overturning Circulation (AMOC), a vast network of ocean currents that plays a crucial role in regulating climate.
The system helps keep northern Europe relatively mild, limits sea level rise along parts of the east coast of North America, and contributes to the ocean’s ability to absorb carbon dioxide. However, growing evidence suggests that the AMOC is weakening and could collapse later this century, with potentially serious global consequences.
Researchers explored whether blocking water flow through the Bering Strait could help stabilize the system. Historically, the strait naturally closes during periods of lower sea levels, and past climate data indicates that AMOC was more stable at these times.
The idea is based on the role of fresh water. The water that flows from the Pacific to the Arctic through the Bering Strait is relatively fresh. This fresh water ends up reaching the North Atlantic, where it can stop the sinking of dense, salty water which drives the Atlantic Meridional Overturning Circulation (AMOC). By blocking the strait, scientists believe the Arctic and North Atlantic could become more saltypotentially strengthening circulation.
Using climate models, researchers found that such an intervention could indeed help, but only if implemented before AMOC weakens too much. If the system is still close to its historical strength, damming the strait could provide protection, allowing greater melting of Greenland’s ice without triggering a collapse, explains .
However, the study also highlights significant risks. If the AMOC is already very weak, blocking the strait could be counterproductive. The models suggest that this would increase Arctic sea icereducing evaporation and making ocean waters even less saline, which in turn would further destabilize the current. The researchers identified a critical point below which intervention would worsen the situation.
In addition to scientific uncertainty, the proposal raises major practical and political challenges. The strait extends for approximately 82 kilometers and lies between the United States and Russia, meaning any construction would require unprecedented international cooperation. Environmental concerns are also substantial, particularly for marine species that migrate through the region.
