As ships ordered today are expected to operate well beyond 2050, DNV highlights the need for decisions that balance near-term compliance requirements with the long-term flexibility needed to respond to changing regulations, fuel markets and technologies.   While global alignment at the International Maritime Organization (IMO) remains uncertain, regional regulation is already influencing decisions on fuel use, operations and investment. DNV’s report examines how different regulatory pathways could affect fuel demand, energy-efficiency uptake and fleet strategies.      Regulation is a key driver of maritime decarbonization, but uncertainty defines the current moment. According to DNV, the outcome of the IMO NZF negotiations will determine the pace of the energy transition, shaping future demand for low-GHG fuels and the scale of energy-efficiency uptake in the years ahead.      The report presents four regulatory scenarios ranging from NZF adoption to prolonged gridlock. These scenarios reflect the uncertainty surrounding future policy outcomes and illustrate how different regulatory pathways could influence fuel uptake and energy-efficiency deployment.      Energy efficiency can deliver fuel and emissions reductions across all scenarios while helping shipowners manage rising fuel costs. DNV says stronger global regulatory signals could accelerate the uptake of energy-efficiency measures, enabling the global fleet to consume up to 25% less energy by 2050 compared with a scenario where regulation is driven by regions.   This can be achieved through fleet renewal, operational improvements and retrofits. A case study of a hydrodynamic measures retrofit on a 5,000 TEU container vessel showed potential annual fuel savings of 16%, with a payback time of around one to four years depending on future fuel prices.      DNV highlights that the transition to low-GHG fuels will depend on stronger regulation-driven demand signals and continued investment in fuel production.   Depending on regulatory outcomes, shipping’s demand for low-GHG fuels could range from 4 to 22 Mtoe by 2030 and 33 to 185 Mtoe by 2050. As demand grows across shipping and other sectors, competition for fuels and feedstocks is expected to increase, placing pressure on fuel availability and costs.     Based on current project pipelines, a maximum of 270 Mtoe of low-GHG fuel supply could materialize by 2030. However, DNV notes that the actual volume is likely to be significantly lower due to project delays, cancellations and other uncertainties.     With regulatory pathways, fuel availability and technology development still evolving, DNV’s scenario-based approach is designed to help shipowners evaluate fleet strategies across multiple possible futures.      The report provides a framework for balancing cost, risk and flexibility, helping stakeholders assess how different combinations of fleet renewal, energy efficiency and fuel strategies could perform as the maritime energy transition develops.