Post-mortem on IMO’s Net Zero Framework discussions: UCL readout

UCL provides a detailed analysis of what happened and the implications on future adoption of the policy on mid-term measures for reducing GHG emissions.

London 24^th October 2025. Two weeks of negotiations at the IMO give two confusingly different signals, as well as plenty of information on detail to digest, according to UCL (University College London) in their informative readout. In the first week the IMO’s efforts to adopt binding GHG measures in the form of the Net Zero Framework, agreed in principle in April, went backwards. Countries voted to defer the meeting and therefore the decision to adopt. There is now certainty that this regulation’s entry into effect will be delayed by 12 months to 1^st January 2029, but there is also increased uncertainty that it will be adopted at all.

Although US and Saudi Arabian pressure was central, the full explanation for the significant shift in positions from April to October is difficult to decompose. Interventions by countries during negotiations offer some narrative and potential explanations, but all the underlying reasons are likely complex and may involve multiple interacting causes.

Dr Tristan Smith, Professor of Energy and Transport at UCL Shipping and Oceans Research Group said: “Instead of clarification, shipping and the global trade and energy systems now face significantly increased uncertainty and therefore risk. Understanding what happened at the IMO in October and why is now central not just for any chance of future adoption, but for just and equitable climate action generally. This lost momentum can be recovered, but we have taken a step closer to the abyss that is dangerous climate change."

However, the second week of negotiations, the ISWG-GHG 20, made steady progress on the discussion of the detail for the regulation’s implementation. Many of the countries which had been negative towards adoption in the previous week were back to negotiating their preferences on all the key implementation details – how the regulation should incentivise energy transition, how the fund should be setup, how the lifecycle and sustainability of different fuels should be evaluated and certified.

Dr Annika Frosch, Research Fellow at UCL Shipping and Oceans Research Group said: “After last week’s challenges, this week’s intersessional negotiations were promising. We observed constructive participation from all parties — including those with prior concerns — which led to real progress on key technical guidelines. Even previously contentious topics, such as the Net Zero Fund, experienced broad and active involvement from many delegations, helping to clarify priorities like establishing the Governing Board and fundamental principles to guide the Fund’s future work.”

Beyond the overall outcome on adoption, the detailed discussions in ISWG-GHG 20 reveal some positive emerging perspectives that will form the basis of the guidelines. No decisions were taken to rule on detail either way, and so the ideas all move forwards to greater clarification.

Dr Pinar Langer, Research Fellow at UCL Shipping and Oceans Research Group said: “The past two weeks at the IMO sent mixed signals — while the adoption of the Net Zero Framework was delayed, detailed negotiations showed that most countries still see it as the right foundation for maritime decarbonisation, keeping the door open for meaningful progress in 2026.”

• Zero Near Zero (ZNZ) definition - looks unlikely to go beyond the detail in the MARPOL amendment (e.g. the limit on GHG fuel intensity).

• Reward mechanism - will remain fluid, although saw good support for differentiating rewards to different fuels. It was clear that member states see these guidelines as a priority and will likely work to clarify significantly during 2026.

• Net Zero Fund - mixed signals from the member state interventions. Some were keen to move forwards with urgency and develop some initial governing provisions that would provide a minimum further clarity, but there was also opposition to this.

• Lifecycle analysis (LCA) and certification - The question of sustainability criteria (an important issue for biofuel evaluation) was widely discussed, and is likely to see further attention alongside questions of environmental integrity and GHG emission accountancy.

Dr Marie Fricaudet, Research Fellow at UCL Shipping and Oceans Research Group said: “The industry now faces increased investment uncertainty: regulatory uncertainty from the IMO (timing and stringency of the NZF); from the concrete implementation of the guidelines which will have a large impact on fuels and technologies’ competitiveness and prices; but also from the space it opens for more disparate regional and private initiatives to fill the gap left by the IMO in the meantime.”