Gulf Stream collapse could depend on rate of warming, scientists warn

A possible collapse of the Gulf Stream may depend more on how quickly the climate warms than on reaching a specific temperature threshold, according to Dutch climate scientists.

The findings suggest the Atlantic Meridional Overturning Circulation (AMOC), a major system of ocean currents, could reach a tipping point even without global temperatures reaching levels previously thought necessary to trigger such a collapse.

Scientists had previously estimated that an irreversible collapse could begin at around 2.5C of warming, potentially as early as 2060. The new study, however, suggests that the rate of warming may be more important than the temperature itself.

“The collapse occurs due to the rate of warming rather than reaching a specific temperature,” researcher Rene van Westen told public broadcaster NOS.

A shutdown could have major consequences. The Netherlands could become colder and drier, while sea levels and the risk of storm surges could rise. Rainfall patterns in the tropics could also shift, bringing drought to some areas and wetter conditions to others.

Van Westen said faster action was needed to prevent further weakening of the circulation.

Oceanographer Femke de Jong of NIOZ said the findings showed a need for greater caution.

“You cannot say that below a certain temperature there is no risk of the AMOC shutting down.”

She said the effects could last for hundreds of years, even if carbon dioxide levels returned to pre-industrial levels.

Scientists said more monitoring and research are needed, while policymakers should prepare for potentially severe climate changes. Preventing a collapse, they said, remains the best and least costly option.