The earliest occurrence occurred in 2025, and new research suggests that the Atlantic Ocean Current may collapse by the middle of this century
Contrary to the imagined impact of climate change on Europe, a colder future may be imminent. If current greenhouse gas emissions continue, the important ocean currents redistributing heat, cold, and precipitation in the northernmost tropical and Atlantic regions will cease around 2060. This is a conclusion based on new calculations by Danish scientists, which contradicts the latest report of the United Nations Intergovernmental Panel on Climate Change.
Contrary to the imagined impact of climate change on Europe, a colder future may be imminent. In a new study released on July 25th in Nature Communications, researchers from the Niels Bohr Institute and the Department of Mathematical Sciences at the University of Copenhagen in Denmark predict that if people continue to emit the same level of greenhouse gases as they do today, the current ocean current system that distributes heat and cold between the North Atlantic and tropical regions will come to a complete halt.
Using advanced statistical tools and ocean temperature data from the past 150 years, researchers have calculated that ocean currents known as thermohaline circulation or Atlantic meridional flipping circulation will collapse between 2025 and 2095, with a 95% chance of this conclusion. And all of this is likely to happen in 2057, 34 years from now, and may face significant challenges, especially tropical warming and an increase in storms in the North Atlantic region.
"The cessation of AMOC may have a very serious impact on the Earth's climate, such as altering the distribution of global heat and precipitation. Although the cooling in Europe may not seem as severe as global warming and heat waves increase, such a collapse will lead to intensified warming in tropical regions, with adverse effects on climate change," said Peter Ditlevsen, a professor at the Niels Bohr Institute.
"Our research findings emphasize the importance of reducing global greenhouse gas emissions as soon as possible," the researchers said.
However, these calculation results contradict the information in the latest IPCC report. The IPCC report is based on climate model simulations and suggests that a sudden change in the thermal salt circulation is unlikely to occur in this century.
The researchers' predictions are based on the observation of early warning signals exhibited when the ocean flow becomes unstable. The early warning signals of these hot salt circulation have been reported before, but it is only now that the development of advanced statistical methods has made it possible to predict when a collapse will occur.
Researchers analyzed the sea surface temperature in specific areas of the North Atlantic from 1870 to present. These sea surface temperatures are the "fingerprints" that prove the strength of AMOC, which were not directly measured until the past 15 years.
Professor Susanne Ditlevsen from the Department of Mathematical Sciences at the University of Copenhagen explained, "We used new and improved statistical tools to calculate and provide a more reliable estimate of the time when the thermohaline circulation is most likely to collapse, which we were unable to achieve before."
Since the last ice age, the thermohaline circulation has been operating in its current pattern, but it has indeed collapsed before. According to observations, there were 25 climate abrupt changes between the normal and collapsed states of AMOC during the glacial climate conditions, which is the famous Dansgard Echiger event that was first observed in the ice cores of the Greenland ice sheet. Among these events, climate change is extreme, changing by 10-15 degrees Celsius within 10 years, while the current climate change has warmed by 1.5 degrees Celsius within a century.
Related paper information:
https://doi.org/10.1038/s41467-023-39810-w
