A new study suggests that the circulation of the entire Atlantic ocean will collapse soon due to increasing carbon dioxide levels in the Earth's atmosphere.
This circulation known as the Atlantic Meridional Overturning Current (AMOC) has been stable and intact ever since record keeping began. Past climate models predict that the AMOC will remain this way for centuries even after carbon dioxide levels doubled from the 1990s.
In this new study, scientists from the University of California, San Diego and the University of Wisconsin-Madison suggest that the AMOC is much more sensitive and its collapse is predicted to happen after 300 years of doubling atmospheric carbon dioxide levels.
In this new model, the team was able to take into account fresh water circulation by the AMOC that flows throughout the Atlantic and the Arctic oceans and then compared and corrected biases with existing climate models.
The team discovered that fresh water is most likely to accumulate in the North Atlantic region and can further trigger the collapse of the AMOC.
What happens when this circulation collapses? The team revealed that there would be a prominent cooling around the North Atlantic and surrounding regions where sea ice will increase over Greenland, Iceland, and Norway and finally, rainfall will increase over the southern Atlantic tropical regions.
However, if the entire AMOC shuts down permanently, there will be profound consequences on global climate. AMOC generally carries heat towards the Arctic region and it can dramatically change weather patterns in Europe.
According to the author of the study, Wei Liu from the University of California, San Diego, when the AMOC disappears there will be colder winters in the Atlantic rim nations.
Liu added that the AMOC is responsible for carrying massive heat from the ocean northward up to the Arctic region and also causes moderate climate in the United Kingdom and northwestern Europe. When this circulation is disrupted or ends permanently, heat will not be distributed upwards and can bring about great cooling and colder winters in those regions.
This new study was published in the journal Science Advances.