A Crucial System of Ocean Currents Is Faltering, Research Suggests

By Heather Murphy

The water in the Atlantic is constantly circulating in a complex pattern that influences weather on several continents. And climate scientists have been asking a crucial question: Whether this vast system, which includes the Gulf Stream, is slowing down because of climate change.

[…]

Now, scientists have detected the early warning signs that this critical ocean system is at risk, according to a new analysis published Thursday in the scientific journal Nature Climate Change.

“I showed that this gradual slowing down of the circulation system is associated with a loss of stability,” said Niklas Boers, a researcher at the Potsdam Institute for Climate Impact Research in Germany, “and the approaching of a tipping point at which it would abruptly transition to a much slower state.”

[…]

[Susan Lozier] called Dr. Boers’ study “interesting,” but said she wasn’t convinced that the findings showed that circulation in that ocean system is slowing. “There are lots of things to worry about with the ocean,” she said, such as the more definitive concerns involving sea-level rise.

Read full article: https://www.nytimes.com/2021/08/05/us/gulf-stream-collapse.html

In the Atlantic Ocean, Subtle Shifts Hint at Dramatic Dangers

By MOISES VELASQUEZ-MANOFF and JEREMY WHITE

The warming atmosphere is causing an arm of the powerful Gulf Stream to weaken, some scientists fear.

[…]

It’s one of the mightiest rivers you will never see, carrying some 30 times more water than all the world’s freshwater rivers combined. In the North Atlantic, one arm of the Gulf Stream breaks toward Iceland, transporting vast amounts of warmth far northward, by one estimate supplying Scandinavia with heat equivalent to 78,000 times its current energy use. Without this current — a heat pump on a planetary scale — scientists believe that great swaths of the world might look quite different.

Now, a spate of studies, including one published last week, suggests this northern portion of the Gulf Stream and the deep ocean currents it’s connected to may be slowing. Pushing the bounds of oceanography, scientists have slung necklace-like sensor arrays across the Atlantic to better understand the complex network of currents that the Gulf Stream belongs to, not only at the surface, but hundreds of feet deep.

“We’re all wishing it’s not true,” Peter de Menocal, a paleoceanographer and president and director of the Woods Hole Oceanographic Institution, said of the changing ocean currents. “Because if that happens, it’s just a monstrous change.”

Read full article: https://www.nytimes.com/interactive/2021/03/02/climate/atlantic-ocean-climate-change.html