Research conducted at the University of Exeter has warned that changes to the circulation of the Atlantic Ocean could cause droughts and large changes in sea levels and other serious implications for the global climate system.
The study, which was published today by the journal Nature Communications, analyses the Atlantic Meridional Overturning Circulation (AMOC) by using a simulation derived from a complex model. The research concludes that warning signs that the AMOC was in danger of collapse could be detected up to 250 years in advance.
The AMOC transports heat from the Southern Hemisphere to the North Atlantic, and is powered by the salinity and temperature of the water. If the AMOC were to collapse as a result of freshwater entering the North Atlantic region, it is predicted that the air temperature could cool by up to 8°C in the worst affected regions.
Any collapse of the AMOC would encourage droughts in the Sahel, an area south of the Sahara, and changes of up to 80 metres in sea levels across Europe and North America.
Lead author Chris Boulton said, “We found that natural fluctuations in the circulation were getting longer-lived as the collapse was approached, a phenomenon known as critical slowing down,”
It is not known how far away a collapse of the circulation is. However, co-author Professor Tim Lenton was enthusiastic about the findings, “The best early warning signals in the model world are in places where major efforts are going into monitoring the circulation in the real world” he said.
The simulation of this type of early warning signals is thought to be the most realistic to date.
James Beeson, Sport Editor.