May 19-20, 2026
London, UK
The US-UK Scientific Forum on Shifts and Tipping Points in Ocean Systems convened leading scientists to examine the frontier of knowledge on critical thresholds in ocean systems. Incremental pressures such as warming, acidification, and fishing can trigger abrupt, likely irreversible nonlinear shifts in circulation, biogeochemistry, and ecosystem structure and functioning. The forum explored examples of such shifts from the recent and geological past, as well as those projected for the future. It examined the drivers and mechanisms for shifts, indicators and early-warning signals of approaching thresholds, implications for ecosystem services and human systems, and strategies for anticipating, avoiding, or adapting to abrupt changes in marine environments. The Forum has been supported by the National Academy of Sciences George and Cynthia Mitchell Endowment for Sustainability Science.
Please note that some presentations featured at the conference contained unpublished results and therefore are not publicly available. They are marked with an asterisk (*).
Keynote Session: Shifts, Tipping Points, and Systems Dynamics
Session chair: Corinne Le Quéré CBE FRS, University of East Anglia, UK
Session speakers:
- Tim Lenton OBE, University of Exeter, UK
- Lisa A. Levin, Scripps Institution of Oceanography, University of California San Diego, US
Session 2: Shifts and Tipping Points in Ocean Circulation
Session chair: Michael Meredith, British Antarctic Survey, UK
Session speakers:
- Stefan Rahmstorf, Potsdam Institute for Climate Impact Research, Germany
- Sophie Nowicki, University at Buffalo, US (*)
- Alejandra Sanchez-Franks, National Oceanography Centre, UK
- Alberto Naveira Garabato, University of Southampton, UK
Session 3: Shifts and Tipping Points in Ocean Biogeochemical Cycles
Session chair: Anastasia Romanou, NASA Goddard Institute for Space Studies, US
Session speakers:
- Jaime B. Palter, The University of Rhode Island, US
- Ros Rickaby, University of Oxford, UK
- James Rae, University of St Andrews, UK
- Nicole Lovenduski, University of Colorado Boulder, US
Session 4: Shifts and Tipping Points in Marine Ecosystems
Session chair: Malin Pinsky, University of California, Santa Cruz, US
Session speakers:
- Samantha Siedlecki, University of Connecticut, US
- Stephanie Henson, National Oceanography Centre, UK
- Lisa C. McManus, Hawaiʻi Institute of Marine Biology, University of Hawaiʻi at Mānoa, US
- Michael T. Burrows, Scottish Association for Marine Science, UK
Session 5: Tipping Points in Ecosystem Services
Session chair: Ida Kubiszewski, University College London, UK
Session speakers:
- Emma Cavan, Imperial College London, UK (*)
- Adrian Stier, UC Santa Barbara, US
- Will White, Oregon State University, US
- Dan Smale, Marine Biological Association, UK
Session 6: Human Dimensions of Ocean Tipping Points
Session chair: Corinne Le Quéré CBE FRS, University of East Anglia, UK
Session speakers:
- ‘Aulani Wilhelm, Nia Tero, US
- Laurie Laybourn, Strategic Climate Risks Initiative (SCRI), UK
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