Investments in LNG and methanol as transition fuels risk creating path dependencies that pull capital away from shipping’s long-term decarbonisation pathway, according to new research from University College London (UCL).

The study, titled “When is a stepping stone a dead-end? Insights into ‘stepping stone’ pathways from the maritime shipping transition,” examines whether near-term fuel options can genuinely help build a future zero-emissions shipping system.

According to the researchers, LNG and methanol may generate some useful knowledge spillovers and procedural regulatory learning relevant to green ammonia, but those advantages are likely to be outweighed by capital lock-in and the further entrenchment of fossil fuel infrastructure.

Dr Pinar Langer, Research Fellow at the UCL Energy Institute Shipping and Oceans Research Group, said: “There is a real danger in confusing short-term movement with long-term progress. Our findings based on interviews, documentary analysis, including patent data and econometric analysis, show that investments in LNG and methanol can easily become dead ends if they lock capital, infrastructure and expectations into pathways that do not lead to zero-emission shipping.”

The study is based on 25 semi-structured interviews with shipping professionals, documentary content analysis, patent data analysis and an econometric review of 7,355 vessels from the Clarksons World Fleet Register, used to assess the premium paid for dual-fuel newbuild capability.

Across four areas examined, material and financial resources, technological knowledge, regulatory institutions, and expectations and narratives, the researchers found a consistent pattern suggesting that any learning benefits from LNG and methanol are likely to be offset by lock-in effects.

For LNG, the paper says there may be some stepping-stone potential, but only if tougher policies lead to genuinely ammonia-ready ships, port infrastructure and bunkering systems that can later be repurposed cost-effectively. Without those safeguards, LNG investments risk becoming stranded assets that compete with, rather than support, green ammonia.

Methanol is assessed as having even weaker stepping-stone characteristics and, according to the study, may divert both capital and political attention away from ammonia without creating durable long-term system benefits.

Dr Will McDowall, at the UCL Energy Institute, said: “We know that we need deep decarbonisation of the global shipping fleet. Near-term investments need to build a pathway to a sustainable long-term solution, not risk locking in further reliance on unsustainable fossil fuels or insufficient bioenergy. Our analysis shows the risks inherent in today’s focus on methanol and LNG as routes to clean shipping – and we show that they risk becoming dead ends.”

The researchers call on policymakers to take two urgent steps: strengthen long-term credibility around emissions reduction goals so that investors place value on genuine ammonia readiness, and speed up ammonia deployment through dedicated research and development funding, demonstration projects and robust safety standards, with the aim of establishing ammonia in commercial niches during this decade.

The study also argues that its analytical framework could be applied more widely in other sectors assessing transition technologies, including hydrogen in gas networks and natural gas in power generation.

The full research paper is available here.