British scientists have received a double dose of funding to develop research and understanding into some of the more ocean-centric planetary tipping points – critical thresholds beyond which significant changes to the Earth’s systems will occur – including the receding Greenland Ice Sheet and the collapse of the Atlantic Subpolar Gyre – a key current within the global ocean’s circulation system.

Scientists at two of the UK’s key ocean research institutes – the National Oceanography Centre (NOC) and the British Antarctic Survey (BAS) – will receive their own shares of a five-year, £81 million research initiative launched by the UK’s Advanced Research and Invention Agency (ARIA) to advance our knowledge of the global network of system thresholds known as tipping points.

For their part, researchers at the NOC will use an £11 million funding package to develop an innovative mechanism for detecting the earliest warning signs of a collapse of the Atlantic Subpolar Gyre; a key component of the global ocean’s circulation system which – sitting just south of Greenland and Iceland – transports heats around the planet and helps to regulate temperatures in Europe and South America.

Identified as one of six of the planet’s major tipping points, collapse of the Atlantic Subpolar Gyre could have a major global impact on our weather, food, and security. While the critical need to observe the stability of the ocean current is well understood among the scientific community, existing climate models and ocean observations are currently too limited to accurately forecast a tipping point which could signal its collapse.

As part of its five-year Forecasting Tipping Points programme, ARIA has now awarded more than £11 million to the NOC to develop a means of detecting the earliest possible warning signs of a collapse.

NOC scientists are currently leading three of the eight projects being launched in total under ARIA’s £81 million initiative to further our knowledge of planetary tipping points. One of these projects is to explore the use of novel earth observation platforms – such as airships or high altitude pseudo-satellites – while a second will unlock the potential of existing international undersea communication cables to become a vast sensor network, starting in the North Atlantic.

The third project – which has been named the Subpolar gyre Observations, models and artificial intelligence to Resolve Tipping points and provide Early warning Detection, or SORTED for short – will use artificial intelligence and other models to push the limits of existing ocean observations and to transform our ability to detect the early warning signs of Subpolar Gyre collapse. This will include identifying gaps and uncertainty in data.

“This transformative funding from ARIA comes at a critical moment for ocean and climate science, helping to fulfil an urgent need to address gaps in our understanding of Subpolar North Atlantic tipping points,” said NOC Chief Scientist, Professor Penny Holliday.

“NOC will be at the forefront of this ambitious programme, developing pioneering innovative approaches – from AI-driven modelling to revolutionary ocean observation technologies – to bridge those knowledge gaps.”

It’s a firmly held belief among scientists that circulation in the Atlantic Subpolar Gyre is moving towards a collapse but that existing climate models and ocean observations are simply too limited to accurately forecast the point at which that threshold will be breached.

The project will, therefore, develop a means of combining AI and tipping point knowledge from current models – according to Dr Alejandra Sanchez-Franks – “to push the spatiotemporal limitations of existing observational records and underpin the robust early warning systems needed for a potential Subpolar Gyre collapse.”

The Atlantic Subpolar Gyre is a large circular ocean current in the North Atlantic which plays a crucial role in influencing the strength and dynamics of the Atlantic Meridional Overturning Circulation – or the AMOC – a large-scale, vertical movement of water in the Atlantic Ocean. 

The distribution of heat by the subpolar gyre has been shown to have a prominent effect on the downstream climate over Europe. However, the impact of human-driven climate change on the Gyre has been relatively unexplored until only very recently.

Climate tipping points – such as the collapse of the Atlantic Subpolar Gyre – have the potential to impact billions of people across the globe. If, for example, the Greenland Ice Sheet – another of the six identified tipping points – reaches a tipping point and collapses, it could significantly alter ocean currents and increase sea levels. This could lead to more frequent and severe flooding events.

As part of the wider programme from ARIA, further funding has been unlocked to develop research into this particular tipping point, to be led by scientists at the British Antarctic Survey. This initiative – called GRAIL (GReenland ice sheet to Atlantic tipping points from ice-sheets Loss), aims to understand how the melting of Greenland’s glaciers releases freshwater to the North Atlantic, affecting ocean circulation and the global climate.

“Greenland is the fastest melting place on Earth, but this ice loss has knock-on effects for both North Atlantic ocean currents and fisheries,” said Dr Kelly Hogan, a marine geophysicist at British Antarctic Survey.

“This crucial research will help us to understand how much freshwater the ice sheet is releasing, and what the subsequent effects will be on the ocean currents that bring warm waters and weather to the UK.

“This is now urgent work for us to do so policymakers can understand what will happen in the North Atlantic and set out appropriate adaptation and mitigation plans.

“Some computer models predict that large changes in the Atlantic Ocean could happen as soon as the 2040s, so this is a key moment for us to investigate this Greenland Ice Sheet tipping point.”

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