Why an ocean current is on the brink of collapse

An important Atlantic Ocean current system is on the brink of collapse, according to a study published in the journal Nature Communications.

Known as the Atlantic Meridional Overturning Circulation (AMOC), the current is "part of a 'global conveyor belt' that moves water around the world" and "helps to regulate everything from the rate of sea level rise on the East Coast to Europe's average temperatures," Axios reported. The AMOC also serves as a crucial "tipping element," meaning it "could undergo an abrupt and irreversible change, with dramatic consequences for the rest of the globe," per The Washington Post.

The AMOC plays an important role in the overall climate system; however, climate change "has thrown a wrench in the system," the Post wrote. Climate change has caused ice to melt, moving cold freshwater into the Atlantic Ocean. "When the increased meltwater from Greenland enters the North Atlantic, it's freshwater, which is lighter than the salty seawater around it," study co-authors Peter and Susanne Ditlevsen told USA Today. "This excess freshwater can disrupt the normal sinking of the salty water, weakening or even shutting down the AMOC." 

The study found that the AMOC could collapse sometime between 2025 and 2095, with somewhere between 2039 and 2070 being the most likely, Peter Ditlevsen told CNN. "The scientific evidence now is that we can't even rule out crossing a tipping point already in the next decade or two," Stefan Rahmstorf, an oceanographer at the Potsdam Institute, told the Post.

"Our result underscores the importance of reducing global greenhouse gas emissions as soon as possible," said Peter Ditlevsen, per USA Today. A collapse "would affect every person on the planet — it's that big and important," added Peter de Menocal, the president of the Woods Hole Oceanographic Institution, while speaking with CNN.