Scientists warn of greater uncertainty in future of Atlantic Current

Scientists have found that a major ocean current system, the Atlantic Meridional Overturning Circulation, may weaken more than previously expected and sooner, with serious consequences for global climate.

Climate models are used to predict future conditions, helping governments plan for climate change. But these models don’t always agree. Predictions can vary depending on how the models are built, the emissions scenarios used, and natural climate variability.

For most climate projections, differences in future emissions are the biggest source of uncertainty. However, this new research shows that for the AMOC – the system of ocean currents regarded as one of the main temperature regulators on the planet – the main uncertainty comes from differences between the models themselves.

The AMOC is a system of ocean currents that moves warm water northwards in the Atlantic, where it cools, sinks, and flows back south at depth. This process helps regulate temperatures and weather patterns around the world. If the AMOC slows down, it can disrupt rainfall patterns, shift weather systems, and contribute to drying in vulnerable regions such as the Sahel in Africa.

Scientists already agree that the AMOC is likely to weaken this century. But how much it will weaken has remained unclear.

To improve predictions, researchers tested new methods that combine climate models with real-world observations, such as sea surface temperature and salinity. These factors influence how ocean water sinks and circulates.