A collapse of the large-scale ocean circulation in the Atlantic would bring about severe global climate repercussions, according to simulations by researchers from Utrecht University.
Publishing their findings in the scientific journal, Science Adventures, the researchers warned of “alarming trends” indicating a gradual decline in the strength of the Atlantic meridional overturning circulation (AMOC) over recent decades. This raises concerns over just how it could be suddenly weakened due to future climate conditions.
Designing a model through which they were able to introduce a freshwater force into the Atlantic Ocean, the researchers were able to measure this sudden weakening, finding circulation strength gradually decreased until reaching a critical tipping point before collapsing. This led to the European climate dropping 1°C per decade, with some regions seeing cooling of as much as 3°C per decade.
While, on the face of it, the idea of cooler temperatures in light of global warming appears appealing, the researchers stressed that the repercussions would be “far-reaching”. Other regions would experience accelerated warming and altered precipitation patterns. A 100cm rise in European sea levels was also projected to occur because of an abrupt ocean circulation collapse.
Moving forwards, the research team stressed the need for there to be a physics-based and measurable early warning indicator, ensuring how close that tipping point is can be seen. Henk Dijkstra, part of the team, explained: “Current observational records are too short to make a reliable estimation, but the early warning indicator shows that we are moving in the direction of the tipping point.”
Another member, René van Westen, stressed the importance of avoiding this tipping point, warning it is “imperative” to avoid devastating consequences on the climate, society and the environment. Van Westen continued: “Once the Atlantic Ocean circulation collapses, the resulting climate impacts are nearly irreversible on human timescales, as our earlier research has shown.”
