Utrecht University study finds warming speed impacts AMOC stability

Researchers at Utrecht University have discovered that the speed of global warming is as critical to the stability of the Atlantic Meridional Overturning Circulation (AMOC) as the total temperature increase reached. The study, published in Nature Climate Change, suggests that the rate of CO2 concentration growth significantly influences whether this vital ocean current system collapses.

Using climate models, scientists simulated different rates of warming. The results showed that the AMOC could withstand more than 4°C of warming if the temperature rise is slow. However, if the warming occurs rapidly, the circulation could collapse at a much lower threshold of approximately 2°C.

The AMOC acts as a heat engine, transporting warm water from the tropics to the North Atlantic, which helps maintain relatively mild climates in Western Europe. A collapse could shift the system from its current intense state to a much weaker one within decades, driven by factors such as rising temperatures and increased freshwater from polar ice melt.