Nature: Ocean Circulation Is Changing

Rising temperatures and melting polar ice influence the system of ocean currents that shift cold water from Greenland. “Since the 1950s, geologists and oceanographers have been gathering convincing evidence that alterations in ocean circulation are a key determinant of climate change,” notes an editorial from Nature, warning that abrupt shifts in the past have resulted in dramatic temperature fluctuations. The journal has published research that the system known as the Atlantic meridional overturning circulation – the flow of warm waters northward and cold waters southward – has immense variability but is weakening. Ocean research is limited and costly, the editors warn, and the science is complex with many unknowns and questions: “Can the effects of climate change and natural variability on the AMOC be disentangled? And if the ocean circulation is sensitive to climate change, as is highly likely, will the currents respond abruptly and perhaps violently at some point, or will the transition be smooth?” Abrupt changes in the systems that regulate climate could make the planet uninhabitable. – YaleGlobal