A recent study has raised concerns about the potential collapse of a crucial ocean current system responsible for transporting heat across the North Atlantic. Scientists warn that if this system, known as the Atlantic meridional overturning circulation, were to collapse by mid-century, it could lead to catastrophic sea-level rise and extreme weather events worldwide.
In the past, experts have both speculated and downplayed the possibility of such a collapse, leading to varying assessments of the situation. The United Nations Intergovernmental Panel on Climate Change previously deemed such a catastrophe unlikely in this century. However, the new study published in Nature Communications suggests that the situation may be more precarious than previously thought.
The Atlantic meridional overturning circulation plays a vital role in the circulation of water throughout the Atlantic Ocean, a process that typically takes about 1,000 years to complete. Nevertheless, in recent years, it has experienced a slowdown, raising concerns about its stability.
The consequences of a further slowdown or complete halt of this circulation could be severe, leading to extreme weather events in the Northern Hemisphere, rising sea levels along the East Coast of the United States, and widespread drought in southern Africa, as indicated by scientists from Germany and the US.
The timing of the potential collapse remains uncertain. The new study conducted by researchers Peter and Susanne Ditlevsen from Denmark utilized sea surface temperature data in the North Atlantic from 1870 to 2020 to assess the circulation’s state. Their findings indicate that the collapse could occur as early as 2025 or as late as 2095, depending on the trajectory of global greenhouse gas emissions.
This prediction diverges from the IPCC’s 2021 assessment, which deemed the collapse unlikely to happen this century. However, experts emphasize the presence of significant uncertainties in such studies and call for urgent and comprehensive action to address climate risks.
While some consider the tipping point for the Atlantic meridional overturning circulation’s collapse highly uncertain, others suggest that the IPCC estimate may be conservative. As the evidence grows, concerns mount about the potential risk being greater than initially thought, which could have worrying implications in the coming decades.
