International Shipping

The International Maritime Organization (IMO) failed to adopt its Net Zero Framework (NZF) in October 2025 after a pressure campaign led by the United States and backed by Saudi Arabia. The IMO postponed its final decision to October 2026, despite governments approving a draft version of the NZF in April 2025. The NZF would have been a major mitigation milestone for international shipping: the framework would have introduced a global fuel emissions standard and a market-based measure for reducing the sector’s emissions. Following the NZF’s postponement, it is unclear whether the IMO will adopt, amend, or abolish the framework in 2026.

However, while a step in the right direction, the NZF would have also amounted to a highly watered-down compromise, falling far short of more ambitious proposals on emissions targets, carbon pricing, and revenue allocation. Despite these shortcomings, the NZF would have been a crucial tool to operationalise the transition to zero-emission fuels in shipping.

Due to the IMO’s failure to adopt the NZF, shipping sector emissions remain far from a 1.5°C aligned pathway. The CAT rates the sector as “Highly Insufficient,” indicating the sector’s targets and actions are consistent with warming over 3°C and up to 4°C.

If the NZF had been adopted at the IMO’s extraordinary session (ES2) in October 2025, the IMO would have introduced mid-term emission reductions measures, combining a goal-based marine fuel standard—to cut down the well-to-wake emissions intensity of onboard energy use—with a sector-wide pricing mechanism. The NZF was designed to operationalise the 2023 IMO GHG Reduction Strategy’s emissions reductions target for least 20–30% by 2030, 70–80% by 2040 below 2008 levels, and net zero “by or around” 2050. The framework would have covered roughly 85% of international shipping emissions.

In 2023, the IMO strengthened its long-term target to reach net zero "by or around" 2050. The strengthened net zero target is undermined by the vague deadline and the unclear residual emissions level in 2050, which mean the CAT cannot quantify the target. The IMO’s target to reduce shipping’s carbon intensity - by 40% in 2030 from 2008 levels - is expected to be largely ineffective, resulting in increased emissions by 2030. However, the ambition of the stronger GHG Reduction Strategy’s emissions reductions target for 2030 effectively overrides the carbon intensity target.

The draft NZF fell short of the expectations of the most climate-vulnerable nations. Small Island Developing States (SIDS) fought for a more ambitious flat levy carbon price, with revenues earmarked as climate finance for loss and damage and maritime decarbonisation in SIDS and Least Developed Countries (LDCs).

While the NZF would have allocated revenues to support maritime decarbonisation and zero-emission fuel projects to close the price gap between zero emission fuels and conventional fossil fuels, considerations for financing an equitable transition were limited. In this regard, shipping was heading in the right direction. However, without the NZF, it is unclear whether and how equitable transition measures will manifest. While governments walked away from the NZF in 2025, they did not walk away from the 2023 GHG Reduction Strategy which remains in force.

Emission projections following current policies will see shipping carbon emissions continue to rise by up to 4% from the baseline 2008 levels. Urgent action is required as the sector shows no signs of peaking emissions, let alone decarbonising entirely. Historical emissions data reveal that the COVID-19 pandemic had a temporary impact on shipping emissions, which began rising again in 2021. Without further action, emissions from international shipping are likely to continue to rising through 2050.

Action at the international level has kept to the IMO’s timelines, underscoring the IMO’s insufficient ambition over the past 29 years. To decarbonise the shipping sector, it is imperative that governments not only increase their ambition at the global level through the IMO, but also move forward with ambitious domestic action. The EU has demonstrated ambition in regulating and reducing emissions from the shipping sector.

Governments should include shipping’s emissions in their domestic emissions reductions targets, to provide a signal for the industry to adapt their strategies accordingly. This will help early adopters address the knowledge, administrative, and technological barriers for scaling zero-emission fuels and technologies.

Green shipping corridors can be used to facilitate shipping’s decarbonisation. Green shipping corridors are specific maritime routes where stakeholders collaborate to accelerate the deployment of zero-emission vessels and fuels by aligning policies, infrastructure, and investments along the entire route. Between 2023 and 2024, the number of green shipping corridors increased by 40%.

Methane emissions in shipping have been increasing. Between 2012 and 2018 methane increased by a factor 2.5, directly corresponding to the increased use of liquefied natural gas (LNG) as a shipping fuel (ICCT, 2020; IMO, 2020). As of 2023, it now makse up about 1% of shipping emissions (Xiaoli Mao et al., 2025)This trend is projected to continue, driven mostly by an increase in ships equipped with LNG-fuelled engines.

LNG is not an option to support the transition to zero-emission fuels, despite the industry's insistence that LNG is a bridging fuel. Instead of decreasing emissions, adopting LNG may increase international shipping’s climate impact when considering the full life cycle of all greenhouse gas emissions. Investments in LNG facilities are growing and could lead to stranded assets or perpetuate a carbon “lock-in” effect, as investments in LNG-powered ships and onshore LNG infrastructure would make it more difficult to transition to low-carbon fuels.