Dr Audrey Morley is a leading voice in Irish climate science. Her internationally leading research on reconstructing past ocean climates, for which she has developed robust innovative climate proxies, was published in Nature Communications in winter 2024. In this article, Cois Coiribe explores Dr Morley’s research and insights into the implications of ocean currents and temperatures. Her work on the Atlantic Meridional Overturning Circulation (AMOC) is a crucial part of the global effort to monitor and understand changes that could affect our climate in a major way.
What is AMOC?
In simple terms, the AMOC is a vast system of ocean currents, critical to Ireland’s temperate climate. The AMOC functions like a vast conveyor belt, moving warm water northwards from the tropics and returning colder water south at depth. This process moderates Ireland’s climate, making it considerably milder than other regions at similar latitudes. But as global temperatures rise, so too does concern that the AMOC could slow significantly or even reach a tipping point. ‘A tipping point means a threshold beyond which the system might undergo a dramatic and possibly irreversible change,’ explains Dr Morley. ‘We’re not saying this is imminent, but we are saying that the risk of an AMOC slowdown – or even a partial collapse – is real and must be taken seriously.’
By applying innovative climate proxies to her research, Dr Morley focuses on reconstructing the variability and stability of the AMOC. With mounting evidence that this system is weakening, Dr Morley and her colleagues are working to understand the risks this shift may bring.
Colder winters, bigger storms, extreme events – a weakened AMOC could negatively affect Irish weather
Even a gradual weakening of the AMOC could have far-reaching implications. These include colder winters, increased storminess, and changes to rainfall patterns across Ireland and northwestern Europe. Marine and coastal ecosystems could also face significant disruption. The Atlantic plays a key role in nutrient and carbon transport, and changes to its circulation could alter marine productivity and carbon drawdown in ways that are not yet fully understood.
To address these uncertainties, researchers in Ireland are focusing on several key areas, one of which is the development of a more robust and region-specific understanding of how AMOC changes could affect Ireland. While global models offer valuable insights, they often lack the detail needed to project local impacts.
Dr Morley explains how high-resolution modelling that can capture what a slowdown might actually look like here – how it could affect our weather, coasts, fisheries – would be critical to furthering our understanding of risks and impacts for Ireland specifically.
Extending the observational record
Another major focus is extending our observational record of the AMOC further back in time. The AMOC’s direct measurements only cover a few decades, which is a short window in the context of ocean systems that can shift over centuries. To extend that timeline, Dr Morley and her colleagues are combining marine climate archives – such as sediment cores from the seafloor – with contemporary observations. Dr Morley describes how longer records help us understand the natural variability and stability of the AMOC and how it responded to past climate changes. Longer records are crucial for building better models and identifying early warning signs.
One of the most promising frontiers in AMOC research is integrating paleo observations, modern data, and regional models. For example, recent work has shown that freshwater input from the Greenland Ice Sheet may be less critical to AMOC collapse than once thought, with heating and ocean stratification now viewed as major contributors. This has implications not only for Ireland’s climate but for how we design emissions pathways and adaptation strategies globally.
International collaboration
International collaboration is also essential. Programmes like OSNAP (Overturning in the Subpolar North Atlantic Program) and RAPID (Rapid Climate Change Programme) offer a shared infrastructure for measuring ocean currents and heat transport across the Atlantic. Irish researchers are active contributors to these efforts, which are helping to build a more complete picture of the AMOC’s current state and how it may evolve in the coming decades.
Realistic scenarios – moderate and extreme
It’s not only scientists who need to understand the stakes. The possibility of an AMOC slowdown has captured media attention in recent years, often with alarming headlines predicting everything from an ‘Ice Age in Europe’ to a sudden climate catastrophe. Dr Morley stresses the importance of clear, coordinated communication between scientists, policymakers, and the public:
‘There’s been a lot of anxiety caused by headlines that take model results out of context. Yes, some studies simulate a collapse of the AMOC by mid-century – but many of those rely on unrealistic assumptions, like a massive increase in freshwater from Greenland melt. We’re not saying those scenarios aren’t scientifically useful – they help us test and understand model responses – but they shouldn’t be interpreted as forecasts.’
In more realistic scenarios, current models and observations suggest a slowdown of around 2–3 Sverdrups – a unit of ocean flow – by 2050. That level of weakening, while far less dramatic than a collapse, could still have significant implications for Ireland’s climate, agriculture, and infrastructure. Dr Morley notes: ‘This isn’t just about extreme cases. A moderate slowdown can still disrupt our seasons, increase the frequency of extreme weather, and affect ecosystems that communities and economies depend on.’
Informing the public and working with policymakers
To support informed public discussion and avoid alarmist headlines, Dr Morley and her colleagues in Met Éireann and Maynooth University recommend the development of an online AMOC hub – a single, trusted platform where updates on AMOC research, events, and educational materials can be made available to the public, media, and policymakers. The idea is to not only present scientific findings but also to explain the methods behind them, and the confidence researchers place in different scenarios.
Workshops and expert roundtables are helping to bridge the gap between research and decision-making. Recent Irish AMOC meetings in 2024 and 2025 brought together oceanographers, climate modellers, and policymakers to align research priorities and identify collaborative opportunities. These meetings have helped shape recommendations for targeted investment in modelling, monitoring infrastructure, and communication strategies.
Ireland’s key role in AMOC research
Ireland has a key strategic role to play in AMOC research due to its geographical location. A network of marine data buoys already monitors ocean conditions around the Irish coast, and researchers are exploring how these can be enhanced to track deeper ocean variables most relevant to AMOC dynamics. By adding temperature and salinity sensors at depth, the buoys could act as an early warning system for AMOC-related changes in the subpolar North Atlantic.
Dr Morley’s message is clear: Ireland can and should take a leadership role in this field. With its marine observation capacity, strong academic institutions, and strategic location, the country is well placed to contribute to international efforts – and to protect its own climate future.
‘The AMOC is not just a distant oceanic process,’ says Dr Morley. ‘It’s part of what makes our environment liveable, our economy viable, and our ecosystems function. Understanding and monitoring it is in all of our interests.’
As climate change continues to alter the world’s oceans, the AMOC may well be one of the most important systems to watch. Thanks to Ryan Institute researchers like Dr Audrey Morley, Ireland is contributing to this effort with rigour, collaboration, and a growing sense of urgency.
