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3rd September 2025
Independent research and energy intelligence firm Rystad Energy have published the results of a landmark study on the greenhouse gas (GHG) emissions from the LNG bunker supply chain, commissioned by SEA-LNG. This is the most accurate and up-to-date certified data on LNG as a marine fuel designed to help guide IMO’s Net-Zero Framework and future fuel policy.
The study’s implications for policy makers developing regulations to decarbonise shipping are:
The study analyses emissions originating from the five key fuel lifecycle stages of LNG: upstream, transportation & processing, liquefaction, shipping, and distribution & bunkering operations. It aligns with the International Maritime Organization’s (IMO) WtT lifecycle analysis guidelines, the Intergovernmental Panel on Climate Change’s (IPCC) AR5 GHG definitions, and is based on asset-specific 2024 data.
The study finds that 2024 global WtT emissions intensity for LNG bunkering fuel is 13.9g CO2e/MJ (LHV). Carbon dioxide dominates global WtT emissions, responsible for 84% of emissions.
Carbon dioxide emissions were most prevalent in the liquefaction stage, responsible for 99% of the stage’s 5.9 g CO2e/MJ.
Methane emissions were responsible for 16% of total WtT emissions, equivalent to 2.2 g CO2e/MJ. They were most prevalent in upstream gas production lifecycle stage, responsible for 38% of total emissions from that stage.
On a global basis, upstream gas production and liquefaction were responsible for the majority of bunker supply chain emissions at 30% and 43% respectively. Consequently, these two stages should be the focus for most future decarbonisation efforts.
The industry should continue with its methane mitigation efforts in the upstream sector, where significant improvements have been seen over the past few years through initiatives such as the Oil and Gas Climate Initiative (OGCI) and the Oil and Gas Methane Partnership (OGMP 2.0). Improvements in liquefaction emissions have also been observed over recent years, tied to greater utilisation of more efficient technologies. This trend is likely to continue when coupled with key electrification projects using renewable energy, such as hydro and solar power.
With the transition from fossil fuels in its early stages across most industry sectors, including maritime, around 95% of vessels are still powered by oil-based marine fuels. LNG is the only viable option available at scale at a commercially competitive price. Consequently, it represents the leading alternative and already accounts for nearly 20% of the vessel orderbook. As the industry transitions toward net-zero and prepares for a rapidly expanding fleet of LNG-fuelled vessels, understanding the real-world lifecycle emissions of LNG is critical to shaping effective regulation and guiding future investment decisions.
Results also show wide variation between regions and cargoes, reflecting differences in gas sources, liquefaction technologies, and shipping distances. In some cases, emissions intensities differed by as much as 6.6 g CO2e/MJ, highlighting that a single global average does not capture the full picture and risks leading to poorly informed regulatory choices.
Patrick King, Vice President Emissions Research, Rystad Energy commented: “Our analysis is based on asset-level data that ties specific gas fields to liquefaction facilities. This approach, supported by satellite-detected methane plume data and reported asset information, gives a more accurate picture of the LNG actually used for bunkering, rather than relying on outdated, hypothetical or overly broad averages.”
Peter Keller, Chairman of SEA-LNG, concluded: “This landmark report sets the high standards the IMO should demand on such a key topic as alternative fuel emissions and performance within the Net-Zero Framework. Decisions must be based on real and recent data or risk undermining the significant progress already made along the practical and realistic LNG pathway to decarbonisation.”
The Key Findings Document can be found here, and the full Rystad Energy LNG well-to-tank emissions analysis here
“Policymakers must create regulations that reflect the true carbon intensity of marine fuels, rewarding reductions across the supply chain. Marine regulators should incentivise participants in the LNG bunker supply chain to continue to reduce GHG emissions.”
Steve Esau, Chief Operating Officer of SEA-LNG
About Rystad Energy
Rystad Energy is a leading global independent research and energy intelligence company dedicated to helping clients navigate the future of energy. By providing high-quality data and thought leadership, our international team empowers businesses, governments and organizations to make well-informed decisions.
Our extensive portfolio of products and solutions covers all aspects of global energy fundamentals, spanning every corner of the oil and gas industry, renewables, clean technologies, supply chain and power markets. Headquartered in Oslo, Norway, with an expansive global network, our data, analysis, advisory and education services provide clients a competitive edge in the market.
For more information, visit www.rystadenergy.com.