IPCC assessment reports indicate that climate change leads to a shifting baseline for ocean and cryosphere systems. However, there is high uncertainty for projected physical changes and thus their impacts. Physical changes include ocean warming and weakening of the AMOC (Atlantic Meridional Overturning Circulation), combined with progressive sea level rise. The impacts concern not only human infrastructure, societies and economies but also species and ecosystems in marine, coastal and neighboring terrestrial and freshwater realms. These challenges highlight a pressing need for closer monitoring of ocean health and a regular update mechanism to inform policy and develop solution options at global and regional scales. Particularly when it comes to AMOC, there is a need for several scientific communities to work together to comprehensively understand its changes and their potential impacts.

On 30 January 2024, experts and Joint Programming Initiative (JPI) country representatives gathered in Brussels to discuss the development of a new report advancing the scientific understanding of AMOC. The meeting in Brussels focused on shaping the scope of the report, defining the composition of the coordination team, and outlining the next steps for this initiative. ObsSea4Clim Project Coordinator Steffen M. Olsen, Gerard McCarthy and Simona Masina took active part in the meeting and will follow the initiative going forward.

“We highlighted the urgency for a consolidated assessment on this topic from society arguing that the report should deliver answers to key questions such as what currently is considered the very likely scenarios for the AMOC. Areas where ObsSea4Clim can contribute include indicators directly related to the AMOC as well as marine heat waves.” Steffen M. Olsen, ObsSea4Clim Project Coordinator

The planned report sets out to integrate contributions from international experts specializing in key ocean processes. It aims to provide a thorough assessment of uncertainties surrounding ongoing and projected oceanic changes and their impacts. The report will conclude with expert judgements on projected changes, associated risk levels, and critical thresholds that should not be exceeded—insights that will serve as a call to action for ambitious climate policies.

Another long-term ambition of this initiative is to develop and coordinate an update mechanism for ocean-related knowledge under climate change. This mechanism, potentially initiated through a start-up model, will progressively refine scientific understanding and reduce uncertainties over successive assessment cycles.

The assessment provided by the report is expected to contribute to the next IPCC main report within the 7th assessment cycle. Additionally, it will play a crucial role in informing European and national climate policies, as well as discussions at the G7 and G20 levels.

The Brussels meeting marked an important milestone in the project, bringing together leading scientists and policymakers to ensure a comprehensive and impactful assessment.

More information available through the Joint Programming Initiative: https://jpi-oceans.eu/en/weakening-tipping-or-going-strong-experts-convene-brussels-start-review-amoc