In a brand new development in the tussle for column inches among the scientific community, it would appear that the Atlantic Meridional Overturning Circulation – an ocean current vital for transporting heat across the planet known as the AMOC – is unlikely to collapse this century. 

This is according to the latest scientific report – published in Nature this week – and led by a team of scientists from the Met Office and the University of Exeter.

It’s a headline assessment of the AMOC – a system of ocean currents that circulate water throughout the Atlantic Ocean, and part of the global ocean conveyor belt that moves heat and nutrients around the world – that suggests that while it is indeed weakening, its collapse within the next 75 years is actually rather unlikely.

It concludes that, for now at least, the current – which has been the subject of numerous ‘push-me pull-you’ headline-making studies in recent months, seems to be more stable than others believe.

It’s a finding that flies in opposition of recent studies carried out by scientists at the University of Potsdam, suggesting the AMOC could be on the brink of collapse, sooner, and with greater impacts than has been previously estimated.

A letter signed by more than 40 of the world’s leading ocean and climate scientists towards the end of last year, warned that this network of ocean currents could pass a crucial tipping point, thus heading towards a total collapse within the next few decades.

Passing this point of no return would trigger a series of devastating and irreversible climate impacts for countries around the world, and particularly those within the Nordic region.

However, according to new modelling from the Met Office and the University of Exeter, it’s unlikely that this will occur within the next 75 years.

Dr Jonathan Baker, a scientist at the Met Office and the paper’s lead author, said: “The AMOC has a crucial role in regulating our climate; without it, northwest Europe’s temperatures would be much cooler.

“Our modelling study suggests the AMOC will resist pressures from rising global temperatures and inputs of freshwater into the North Atlantic, with the weakened system being largely driven by winds over the Southern Ocean.

“Crucially, Baker has added that while a collapse this century is unlikely, what is more certain is that the AMOC will weaken, which itself will present “climate challenges for Europe and beyond.”

“This study brings important new insights into the future of the AMOC,” said Professor Rowan Sutton, director of the Met Office Hadley Centre. “It shows that aspects of the AMOC may be more robust to a changing climate than some previous research has suggested.

“However, it doesn’t change our expectation that the AMOC will weaken over the 21st Century, and that this weakening will have important impacts on climate.”

This is a nuance that many in the ocean and climate science community are now calling to be acknowledged, suggesting that results from this study ought not be a reason to put the brakes on carbon emission reduction ambitions, and to certainly not avoid the real issue of climate change faced by the planet right now.

Professor Geoff Vallis of the University of Exeter, said: “Our theoretical understanding, coupled with the use of state-of-the-art models, indicate that an imminent collapse of the AMOC is unlikely. However, this does not in any way mean that global warming is not a severe problem for society, and our planet.

“I think it very unlikely that my house will burn down in the coming years; however, I still buy insurance to guard against that risk.”

Under some of the most extreme climate change scenarios, the authors discovered the emergence of a Pacific Meridional Overturning Circulation (PMOC), which sinks in the Pacific Ocean, in most simulations. 

“However, this is not strong enough to balance all of the Southern Ocean wind-driven upwelling,” said Dr Baker. “Therefore, some level of sinking in the North Atlantic must be maintained, preventing a complete collapse of the AMOC.” 

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