Scientists from the University of Bordeaux have published research indicating that the AMOC could weaken by 50% by the end of this century, double the 32% projected in previous studies, according to the study. The new findings, reported by major media outlets, correct biases in salinity and temperature data, leading to a higher projected weakening rate. The study suggests that the AMOC may be closer to a tipping point than previously thought.
If the AMOC weakens significantly, the researchers warn of 'extensive drying' in Africa's Sahel region and a potential drop in temperatures across the Northern Hemisphere. These impacts could have far-reaching consequences for agriculture, water resources, and ecosystems.
The Intergovernmental Panel on Climate Change (IPCC), in its latest report, stated with 'high confidence' that continued global warming will lead to a weakening of the AMOC, but with 'medium confidence' that it will not cause an abrupt and complete collapse before 2100. However, new research cited in a report by the Swedish Meteorological and Hydrological Institute (SMHI) suggests a real possibility of passing a tipping point for the AMOC before 2100, with a near-complete collapse possible during the 2200s.
Even though AMOC's future is uncertain, the potential for a rapid weakening or collapse is a risk we must take seriously, especially in the Nordic region where the consequences could have major societal impacts.
The SMHI report, titled 'A Nordic Perspective on AMOC Tipping', was produced following a workshop called 'Nordic Tipping Week' held under Finland's presidency of the Nordic Council. It assesses certain effects as robust: general cooling of the North Atlantic and surrounding areas, sea level rise in northern Europe, and changes in tropical precipitation patterns. If the AMOC collapses, the main signal would be cooling compared to the warming level at the time of collapse. However, other effects, such as the extent of winter and summer cooling, remain more uncertain.
The report identifies knowledge gaps regarding sector-specific impacts on food production, energy systems, and other climate-sensitive sectors in Nordic countries. It calls for strong emission reductions, long-term funding for observation networks, and an early warning system for AMOC. René Navarro-Labastida, a climate researcher at SMHI and one of the report's authors, said: 'Even though AMOC's future is uncertain, the potential for a rapid weakening or collapse is a risk we must take seriously, especially in the Nordic region where the consequences could have major societal impacts.'
Uncertainties remain about the exact probability of an AMOC collapse before 2100 and how it would specifically affect Nordic food production and energy systems. The timeline for implementing an early warning system for AMOC is also unclear. The new salinity and temperature corrections may affect other climate models, but further research is needed to determine the specific regional impacts of AMOC weakening on Northern Hemisphere temperatures.