“Key Atlantic Ocean Current Weakening Faster Than Expected, Study Finds – What This Means for Climate Change”
A new study has revealed that the Atlantic Meridional Overturning Circulation (AMOC), a crucial ocean current that plays a significant role in regulating the planet’s climate, is weakening at a much faster rate than previously anticipated. The AMOC, which includes the Gulf Stream, is responsible for stabilizing climates in the Northern Hemisphere and beyond.
The study, published in the journal Nature Geoscience on November 18, incorporates data on freshwater melt from Greenland’s ice sheet into climate models. The findings suggest that if global carbon dioxide emissions continue at their current pace, the AMOC could weaken by up to one-third within the next 15 years.
The AMOC acts as a planetary conveyor belt, transporting nutrients, oxygen, and heat from tropical waters northward while circulating colder water southward. This delicate balance helps maintain temperatures on both sides of the Atlantic approximately 9 degrees Fahrenheit (5 degrees Celsius) warmer than they would be otherwise.
Historical climate data indicates that the AMOC has shut down in the past, and recent studies have indicated a slowdown in the current due to climate change. In a worst-case scenario, the current could collapse entirely, leading to widespread disruptions across the globe. These disruptions could include plummeting temperatures in Europe, increased storm activity at the equator, and unforeseen impacts on ecosystems like the Amazon rainforest.
While some climate models predict a gradual slowdown in the AMOC by the end of the century, the Intergovernmental Panel on Climate Change (IPCC) estimates that the likelihood of the current reaching a tipping point in this century is less than 10%. However, other models suggest a more imminent collapse of the current, sparking debate among scientists about the urgency of the situation.
One key factor contributing to the weakening of the AMOC is the influx of freshwater from melting glaciers in Greenland and the Canadian Arctic. This lighter freshwater disrupts the circulation of denser, saltier ocean water, slowing down the conveyor belt effect of the AMOC.
Researchers like Laurie Menviel and Gabriel Pontes from the University of New South Wales have developed new models that incorporate these meltwater outflows. Their research indicates that the AMOC has been slowing at a rate of 0.46 sverdrup per decade since 1950. If global warming exceeds 3.6 degrees Fahrenheit (2 degrees Celsius), the circulation could be 33% weaker by 2040.
Experts like Stefan Rahmstorf from the Potsdam Institute for Climate Impact Research emphasize the importance of these findings, suggesting that the decline of the AMOC may be faster than previously predicted by the IPCC. The implications of a weakened or collapsed AMOC could have far-reaching consequences for global climate patterns and ecosystems.