A massive ocean current that keeps the Earth’s climate stable didn't just slow down; it 'stepped' off a cliff in 2009.
April 14, 2026
Original Paper
A Regime Shift in Atlantic Surface Currents Reveals a Step-like Decline of the Meridional Overturning Circulation
arXiv · 2604.11605
AI-generated illustration
The Takeaway
The Atlantic Meridional Overturning Circulation (AMOC) underwent an abrupt, non-linear decline rather than a gradual weakening. This means the risk of sudden, catastrophic climate tipping points is much higher and more immediate than previous 'slow-slide' models suggested.
From the abstract
The Atlantic surface currents associated with the Atlantic Meridional Overturning Circulation (AMOC) play a central role in regulating Earth's climate, yet their large scale dynamical response to climate variability remains poorly understood. Here we identify a previously unrecognized basin scale phase of Atlantic surface circulation, termed the Atlantic Convergence Divergence Mode (ACDM), characterized by a convergence divergence pattern in the North Atlantic and coherent meridional flows in th