Measurement-based insights into methane emissions from LNG export terminals in Australia

Global liquefied natural gas (LNG) exports were around 400 Mt in 2023, with 20% of this production from Australia. The industry-wide extent of methane (CH₄) emissions from LNG export terminals are not well characterized in the literature through measurement-based methods, leading to a range of values being used in life cycle analyses.  As part of UNEP’s International Methane Emissions Observatory Methane Science Studies, a series of scientific flights were conducted around eight LNG liquefaction terminals in Australia between 2021 and 2024, covering 95% of Australian LNG nameplate capacity. In-situ mole fractions of CH₄ and carbon dioxide (CO₂) were measured on the research aircraft, in addition to meteorological data, GPS data and measurements of ultrafine particles. The measurements resulted in over 100 CH₄ mass balance quantifications and an extensive dataset to explore tracer correlations between CH₄ and CO₂ which aid emissions quantification and understanding. Here, we present the most extensive measurement-based analysis of site-level emissions to date from LNG export terminals, enabling us to examine industry-wide methane emissions and emission intensities. We explore factors that impact derived emission intensities from different LNG sites and the implications for methane emissions from the wider LNG supply chain.