The AMOC is driven, by differences in water temperatures and salinity, but climate change could disrupt that balance.

The Atlantic Meridional Overturning Circulation (AMOC) regulates the large-scale circulation of the Atlantic Ocean and influences the global climate, but a recent report from researchers at Utrecht University argues the current is more unstable than previously thought, and could begin collapsing in as little as 30 years.

This challenges the assumption made in a 2021 report by the Intergovernmental Panel on Climate Change (IPCC), which said the risk of an AMOC collapse this century is low.

The AMOC is part of the global conveyor belt, a complex system of global ocean currents that circulate cool subsurface water and warm surface water across the planet, the National Oceanic and Atmospheric Administration (NOAA) explains.

The AMOC is driven, by differences in water temperatures and salinity, but climate change could disrupt that balance.

"As rainfall increases and the Greenland ice sheet continues to melt, the water in the North Atlantic becomes less salty, and therefore less dense," reads a statement from Utrecht University.

"Under normal conditions, cold, salty water near Greenland sinks into the deep ocean, driving the AMOC. But as the water becomes lighter due to freshening, this sinking process weakens, disrupting the entire system. This weakening is being driven by climate change."