The collapse of one of the world’s most important ocean currents, which could wreak havoc on Earth’s ecosystems, is generally considered highly unlikely. However, in a recent open letter, leading climate scientists warned that the threat has been underestimated and called for immediate action.
The Atlantic Meridional Overturning Circulation (AMOC) brings warm waters from the south to the North Atlantic. Along with these waters come carbon, nutrients, and other vital components necessary for sustaining the populations of fish and other aquatic animals. Data has consistently shown a slowdown in the flow of warm waters. In their letter addressed to the ministers of Northern European countries, over 40 prominent climate scientists from Europe, China, the United States, Israel, and Australia warned that the AMOC may now be just years away from complete collapse.
Climate scientists cited a report from the Intergovernmental Panel on Climate Change (IPCC) for 2023, stating that there is a “medium confidence” that the AMOC will not collapse suddenly by 2100. However, the report added that if such a low-probability event were to occur, it would likely result in sudden shifts in regional weather patterns and water circulation.
Global politics, especially in the Northern European region, can no longer ignore the threat of potential AMOC collapse. The risk of catastrophic outcomes is low but uncomfortably high. Risk = Impact x, making this a high-risk event. A turning point that must be taken very seriously.
– Johan Rockström (@jrockstrom) October 20, 2024
Recent research has revealed signs that the IPCC may have underestimated the risk. Concerns about the state of the AMOC have escalated in recent years. In 2023, an analysis of ocean current data published in Nature Communications concluded that the AMOC could collapse “around the mid-century under the current scenario of future emissions.” Another study from April 2024 offered faint glimmers of optimism, suggesting that even if atmospheric CO2 levels doubled pre-industrial levels, the AMOC could recover. Unfortunately, this recovery would take around 1000 years, which is the best-case scenario. If emissions continue to rise, it may take thousands of years for the AMOC to return to its natural state.
The scientists wrote in their letter, “Exceeding this tipping point is already a real possibility in the coming decades.” “Despite important research on the potential and mechanisms of collapse, the likelihood of such an event remains largely uncertain.”
While the collapse this century may not be guaranteed, the scientists emphasized that even this possibility must be taken incredibly seriously. They added that while the planet may potentially avoid the worst-case scenario in the first quarter of the 21st century, this does not mean humanity has averted a scenario that could happen in the next century.
What does an AMOC collapse mean? In short, it could be catastrophic. Researchers in their letter focused on the impacts in the Northern region. The area could face significant cooling and “unprecedented extreme weather.” The extent of the potential impacts of a collapse on the ecosystems, climate, and people in the region requires further study. However, it is likely to have a devastating impact on the ability of Northwest Europe to grow food.
The message was directed at the leaders of Northern European countries due to the significant role the North Pole plays in the AMOC. Climate change leads to changes in the ice sheet in Greenland, the ice in the Barents Sea, and other important natural systems that contribute to the functioning of the AMOC. However, if the AMOC were to collapse, the damage will not be contained to the five northern countries. In 2022, researchers projected all kinds of secondary impacts, including cooling in the Pacific Ocean, drier weather in the Northern Hemisphere, moist conditions in the Southern Hemisphere, and changes in trade winds.
Given the severity of the situation, scientists urged for necessary actions to be taken. They called on the ministers of Northern countries to assess what the collapse could mean for their nations and to “take steps to mitigate this risk as much as possible.”
These steps may include increasing pressure on other world leaders to fulfill their obligations under the 2016 Paris Agreement. The Trump administration withdrew the United States from the agreement, despite rejoining in 2021. With a potential return of Trump to office looming, stepping out and voting could be a great first step toward avoiding the collapse of one of the world’s most crucial environmental systems.
