A cool anomaly southeast of Greenland, dubbed the "cold blob," has been observed growing despite global ocean warming. scientists say the patch points to a weakening of the Atlantic Meridional Overturning Circulation (AMOC), a key heat‑transport system, and warn that a full collapse could arrie within decades.

Cold Blob Detected Southeast of Greenland

The region southeast of Greenland has remained unusually cold for years, standing out against the backdrop of a warming world. Researchers note that the anomaly persists at both the surface and at depths of around 1,000 meters, suggesting a deep‑water process rather than a fleeting surface event.

AMOC Weakening by 15% Since Mid‑20th Century

According to a study led by Professor Stefan Rahmstorf of Potsdam University, the AMOC has already lost roughly 15 percent of its strength since the 1950s. The decline is linked to fresh meltwater from Greenland’s glaciers, which dilutes salty Atlantic water and hampers the sinking that drives the circulation.

Study Rules Out Wind‑Driven Cooling Over Blob

The Rahmstorf team analyzed satellite, buoy and ship data and found that surface heat loss over the cold blob actually decreasd after 1995, contradicting theories that shifting jet‑stream winds are pulling heat away. This finding, reported in *Geophysical Research Letters*, strengthens the case that the cooling is ocean‑current driven.

Parliamentary Report Warns 2‑3°C Drop in UK

A recent UK parliamentary report warned that a collapse of the subpolar gyre—an outer loop that feeds salty water into the AMOC—could shave 2‑3 °C off winter temperatures in Britain and northern Europe, potentially outpacing the effects of a full AMOC shutdown.

What Will Trigger Full AMOC Collapse?

Scientists still debate the precise tipping point ; some argue that continued Greenland melt could push the system over the edge, while others point to complex feedbacks involving atmospheric patterns. as the source notes, direct AMOC measurements span only two decades ,leaving a gap in definitive proof.