A study warns that the Atlantic Ocean’s vital circulation patterns are nearing a catastrophic tipping point, with potentially severe consequences for global climate and human society. Researchers were taken aback by the projected rapidity of the system’s breakdown once the threshold is crossed, though the exact timing remains uncertain.
The Atlantic meridional overturning circulation (Amoc), which includes the Gulf Stream, plays a critical role in regulating the global climate by transporting tropical heat towards the Arctic. This marine conveyor belt’s function is threatened by the accelerated melting of Greenland’s ice and the influx of fresh water into the ocean, disrupting the natural flow.
Researchers utilizing computer simulations and historical data have discovered that Amoc is alarmingly close to a sudden shift, a phenomenon not seen in over 10 millennia. Such a shift could drastically affect regional climates worldwide.
Amoc has already seen a 15% decrease since 1950 and is exhibiting its weakest performance in over a thousand years. Predictions about the severity of its collapse vary, with some forecasting the tipping point could be between 2025 and 2095, while others, like the UK Met Office, deem it highly unlikely within this century.
The study, published in Science Advances, used salinity levels at the southern reaches of the Atlantic as an early warning indicator. The findings indicate that a gradual decline could lead to a rapid collapse within a century, with dire repercussions.
“This is bad news for the climate system and humanity as up till now one could think that Amoc tipping was only a theoretical concept and tipping would disappear as soon as the full climate system, with all its additional feedbacks, was considered,” the researchers stated.
The potential consequences of Amoc’s collapse are severe, with sea levels projected to rise by up to a meter in certain Atlantic regions, drastic changes to the Amazon’s seasons, increased temperature volatility globally, a cooler and drier Europe, and an overall acceleration of climate change impacts.
“What surprised us was the rate at which tipping occurs,” said René van Westen, the study’s lead author from Utrecht University. “It will be devastating.”
While the timeline for these events is still unknown, the study’s message is clear: The threat is real and demands a more serious approach to climate change.
