Climate scientists are monitoring a blob of cold water in the North Atlantic, which they fear could be a troubling signal for ocean currents.
The area in question has cooled by about 1.8 degrees since 1900. Scientists have debated the cause, especially since ocean temperatures overall have risen.
A new study analyzed by CNN suggests that the cold-water blob could be a sign of disruption in the Atlantic Meridional Overturning Circulation (AMOC). The AMOC transports heat through ocean currents, and a potential disruption of that current could impact sea level rise and temperatures.
The study, published in Advancing Earth and Space Sciences, notes that the data suggest the cold blob effectively is a result of changes to the AMOC. "This is of concern because a further weakening of Atlantic heat transport in future climate change could lead to serious impacts on climate and weather conditions in Europe and other parts of the world," it stated.
The study noted that the "subpolar Atlantic is the only region of the world ocean which has been cooling significantly." It also found that the salinity within the cold blob area was at its lowest level in 120 years of data, suggesting that saltwater is not being carried into the area and that melting ice is lessening the salinity.
The AMOC is considered a vital ocean current. If it were to collapse, the result could be a cooling climate in places like Greenland, Iceland, and northern Europe.
CNN noted that a collapse of the AMOC would be a "global catastrophe," accelerating sea level rise on the east coast and causing a "deep freeze" for Europe.
However, scientists also said that the study is just one piece of a scientific puzzle and that the issue of whether the AMOC is causing the blob or is on the brink of collapse is far from settled.
"I would view this study as adding evidence for an AMOC contribution to the cold blob, rather than definitively settling the question," Jonathan Baker, a senior climate scientist at the UK Met Office told CNN.
