The Atlantic Meridional Overturning Circulation (AMOC) system of currents is unlikely to collapse this century, according to a new study.
The study published in the journal Nature suggests that warm water rising from the Southern Ocean could help to keep it stable.
The AMOC is a system which circulates water around the Atlantic Ocean, and part of it is the North Atlantic current which helps to keep Ireland’s climate warm in spite of its latitude.
The study in Nature led by Dr Jonathan Baker at Britain’s Met Office suggests that the AMOC is very likely to weaken under global warming, but not likely to collapse this century.
However, its weakening will still result in major climate challenges across the globe, with more floods and droughts and faster sea level rise, Dr Baker has said.
Dr Baker and fellow authors used 34 state-of-the-art climate models to assess the Amoc, including applying extreme conditions – a quadrupling of carbon dioxide levels or a huge influx of meltwater into the North Atlantic.
They noted that upwelling in the Southern Ocean, driven by persistent Southern Ocean winds, sustains a weakened AMOC in all cases, preventing its complete collapse.
“ As Southern Ocean upwelling must be balanced by downwelling in the Atlantic or Pacific, the AMOC can only collapse if a compensating Pacific Meridional Overturning Circulation (PMOC) develops,”their paper states.
“Remarkably, a PMOC does emerge in almost all models, but it is too weak to balance all of the Southern Ocean upwelling, suggesting that an AMOC collapse is unlikely this century,”they state.
The scientists say that better understanding and estimates of the Southern Ocean and Indo-Pacific circulations are “urgently needed” to accurately predict future AMOC change.
Read more in Nature here
