New Research Sparks Concerns That Ocean Circulation Will Collapse


It is being hailed as a sea change in scientific understanding of the global ocean circulation system and how it will respond as the world heats up. A doomsday scenario involving the collapse of the circulation — previously portrayed in both peer-reviewed research and the climate disaster movie The Day After Tomorrow — came a lot closer in the last month. But rather than playing out in the far North Atlantic, as previously assumed, it now seems much more likely at the opposite end of the planet.

new analysis by Australian and American researchers, using new and more detailed modeling of the oceans, predicts that the long-feared turn-off of the circulation will likely occur in the Southern Ocean, as billions of tons of ice melt on the land mass of Antarctica. And rather than being more than a century away, as models predict for the North Atlantic, it could happen within the next three decades.

Leading ocean and climate researchers not involved in the study who were contacted for comment praised the findings. “This is a really important paper,” says Stefan Rahmstorf, an oceanographer and head of earth system analysis at the Potsdam Institute for Climate Impact Research in Germany. “I think the method and model are convincing.”

“It is the most original research I have seen for some time,” says British polar researcher Andrew Shepherd of Northumbria University, Newcastle. “I was genuinely surprised by this work, but they have convinced me. It is agenda-setting. All the attention has been on the North Atlantic; but I expect there will now be a shift in attention to the Southern Ocean.”