The Institute of Marine Engineering, Science and Technology (IMarEST) has called on International Maritime Organization (IMO) member states to consider its latest analysis as negotiations continue on a Net-Zero Framework (NZF) for international shipping.

Ahead of the 22nd Intersessional Working Group on Greenhouse Gas Emissions from Ships (ISWG-GHG 22), scheduled for September 1-4, 2026, IMarEST has submitted a series of papers aimed at supporting discussions and helping delegates evaluate proposed measures against the IMO’s 2023 GHG Strategy.

One of the submissions examines four proposed NZF amendment options to the MARPOL Convention currently under consideration at the IMO. The analysis assesses how each option could contribute to meeting emissions reduction targets while supporting a fair and equitable transition toward cleaner fuels and technologies in the maritime sector.

IMarEST said the work is intended to provide technical insight for member states as they seek to align future regulatory measures with the industry’s long-term decarbonization goals.

It also examines trade-offs between environmental performance, cost impacts and revenue generation. The key finding is that the ‘levy-based’ framework is most likely to deliver the IMO’s 2030 and 2040 emissions reduction checkpoints.

As highlighted, this option proposes using fixed financial penalties for vessels not complying with emissions standards, and only subsidising operators using zero, or near zero, fuels and technologies.

However, the analysis also highlights that another of the options, which proposes keeping the Net-Zero framework in its current form, could offer the lowest average carbon abatement cost among the pricing-based options, provided significant increases in biofuel prices are avoided before 2038.

The analysis uses the most up-to-date modelling undertaken by University College London (UCL)’s Energy Institute Shipping and Oceans Research Group and the Rocky Mountain Institute.

Commenting on the new study, Dr Tristan Smith, Professor of Energy and Transport at UCL’s Energy Institute and head of the IMarEST IMO GHG delegation, said: “This is the first study to model the specifics of all four proposals side-by-side, building on the assumptions and methods used in the IMO’s own Comprehensive Impact Assessment of mid-term measures.”

As negotiations intensify ahead of MEPC 85 at the end of the year, we are hopeful our analysis will help guide IMO member states to a workable solution for the Net-Zero Framework.

…Dr Tristan Smith noted. 

As discussions progress, the IMarEST is also launching an industry consultation to gather professional views on the effectiveness of current IMO GHG measures and the potential practical implications of developing net-zero policies for the maritime sector.

As negotiations move into a crucial phase, we also want to hear from the wider maritime community. By bringing together the views of engineers, scientists and technologists, we can help ensure the Institute’s contributions at the IMO continue to reflect our sector’s expertise and experience.

…highlighted Alasdair Wishart, Director of Technical and Policy at the IMarEST. 

The consultation is available on the IMarEST website and will remain open until 16 September 2026. Responses are invited from individuals and organisations with a stake in maritime decarbonisation.