An Atlantic Ocean current known as the “conveyor belt of the ocean,” and credited for helping regulate our planet’s climate, is now moving at its slowest pace in 1,000 years. This has raised concern among scientists, who believe that the trend could lead to climate extremes at some point in the future, meaning fiercer storms and even colder winters.
In a new study published in the journal Nature, researchers explained that the Atlantic meridional overturning circulation (AMOC), which is a system of North Atlantic Ocean currents, has weakened by about 15 percent since the middle of the 20th century. The current, according to the Washington Post, functions like a conveyor belt, as it distributes warm water from the equator to the North Pole. Once the warm water’s temperature decreases, it is sent back to the south, via the deep ocean.
In recent years, however, man-made climate change has led to ice melt in Greenland and the rest of the Arctic, as freshwater drains into the ocean, with its density causing Atlantic Ocean currents to slow down. According to NBC News, this could make climate conditions more volatile in different parts of the globe, including Europe, which could be besieged by extreme storms and winters, and the U.S. East Coast, where sea levels could keep rising, potentially disrupting the fishery business as waters continue to warm.
The AMOC’s slowing could be “bad news,” according to study author Stefan Rahmstorf of Germany’s Potsdam Institute for Climate Impact Research, as it fulfills a number of climate model predictions from previous years.
In a separate study also published in Nature, researchers noted that Atlantic Ocean currents are at their weakest in more than 1,000 years, with the AMOC having slowed considerably since the early years of the industrial era, which is a significantly earlier starting point than what the first study suggested. According to study co-author and University of Reading researcher Jon Robson, the AMOC’s movement has been especially slow in the last 100 years or so.
“These two new papers do point strongly to the fact that the overturning has probably weakened over the last 150 years,” Robson commented.
“There’s uncertainty about when, but the analogy between what happened 150 years ago and today is quite strong.”
It’s still unsure when the climate extremes scientists have warned about will take place, if Atlantic Ocean currents continue to weaken. But in an interview with NBC News, Yale University climate scientist Alexey Fedorov said that the two studies suggest the AMOC’s collapse might happen sooner than expected, and that existing climate models, which predicted the collapse taking place sometime in the 22nd century, might have been too conservative.
“There is a growing concern that the models may be underestimating the risk of the AMOC collapse, and it can happen much sooner than anticipated,” said Fedorov, who was not involved in either study, but had co-authored a paper in 2017 detailing the association between the AMOC’s slowdown and Arctic ice loss.
Despite Fedorov’s grim warning, other experts believe that it’s too early to push the panic button when it comes to the slowdown of Atlantic Ocean currents. Purdue University Climate Change Research Center director Jeffrey Dukes told NBC News that it’s hardly likely that cataclysmic weather events will take place in the immediate foreseeable future, though he added that two new studies are a “big deal” and should not be taken lightly.