Deep ocean circulation patterns are slowing down

Two primary, deep ocean circulation patterns are being impacted by climate change. The Atlantic and Southern Ocean Meridional Overturning circulations are slowing down, which could have devastating impacts over the next 100 to 300 years, according to a new study from the University of California at Irvine.

If this weakening trend of these two deep ocean circulations continues, then it will cause the oceans to be less effective at removing excess carbon dioxide from the atmosphere, which will further accelerate climate change.

Utilizing data from three dozen climate models, the scientists estimate that the Atlantic and Southern Ocean Meridional Overturning circulations will slow by an average of 42 percent by the end of this century and may cease completely by 2300.

“A disruption in circulation would reduce ocean uptake of carbon dioxide from the atmosphere, intensifying and extending the hot climate conditions,” said co-author J. Keith Moore, UCI professor of Earth system science. “Over time, the nutrients that support marine ecosystems would increasingly become trapped in the deep ocean, leading to declining global-ocean biological productivity.”

A significant reduction of man-made greenhouse gas emissions may be able to prevent this scenario, but action needs to begin now, according to the researchers.