The methane myth: Why US LNG still beats coal in the emissions race

The natural gas industry faces its most significant credibility test in decades. Recent scientific papers have challenged a fundamental assumption underpinning the global energy transition: that liquefied natural gas serves as a cleaner bridge fuel from coal to renewables.

The controversy centres on methane emissions throughout LNG's supply chain. Critics argue these losses, particularly from US unconventional gas production, potentially make LNG worse for the climate than coal when considering full lifecycle emissions. This narrative has gained traction among policymakers and environmental groups, threatening to undermine LNG's role in decarbonisation strategies.

However, new analysis using comprehensive industry data reveals a more nuanced reality. When comparing like-for-like power generation, US LNG consistently demonstrates lower emissions than coal across key markets, despite higher methane losses than LNG from other regions.

The geography of gas matters

The analysis reveals important nuances about US LNG supply sources that challenge common assumptions. While the methane-intensive Permian basin has drawn significant attention in emissions debates, it represents the exception rather than the rule in current US LNG supply chains, contributing only 10% of exports.

The majority of US LNG (two-thirds) actually originates from the Haynesville and Northeast basins, where operational characteristics create more favourable emissions profiles. These regions, characterised by drier gas production with lower associated liquids, experience methane intensities averaging below 1% compared to 1.7% in the Permian basin.

The Haynesville and Northeast basins benefit from production methods that naturally result in fewer methane losses during extraction and processing. Many projects in these regions have achieved certified methane intensities below 0.2%, indicating actual emissions may be even lower than basin averages suggest.

While the supply composition will evolve as new projects commence operations, potentially increasing Permian contribution to 19%, the current dominance of lower-emission basins in US LNG supply demonstrates that high-methane production represents a minority share rather than the industry standard.

Technology drives efficiency gains

US LNG projects benefit from technological advantages often overlooked in emissions comparisons. Modern liquefaction facilities utilise advanced turbine technologies, achieving average emissions intensities of 290 kgCO2e per tonne; over 20% below the global average of 370 kgCO2e per tonne.

Similarly, shipping emissions reflect fleet modernisation. While older steam turbine vessels produce 70% higher emissions than modern alternatives, they carried only 6% of US LNG volumes in 2024. The majority travels on efficient vessels with substantially lower emissions profiles, and this proportion will increase as older ships face retirement over the next five to ten years.

Coal's hidden methane burden

The comparison reveals coal's own significant methane challenge, particularly from underground mining operations. US bituminous coal exports to Northwest Europe, predominantly sourced from deep Appalachian mines, generate substantial fugitive methane emissions that constitute 96% of underground mining's upstream emissions footprint.

These mining emissions average 359 gCO2e per kWh of power produced for US coal exports to Northwest Europe, compared to only 83 gCO2e per kWh for Indonesian surface-mined coal to China. The depth and pressure of Appalachian coal seams create inherently higher methane release rates that remain largely unmitigated globally.

The numbers tell the story

When examined on a full lifecycle basis for electricity generation, US LNG demonstrates clear advantages. In Northwest Europe, US LNG produces approximately 540 gCO2e per kWh compared to 759 gCO2e per kWh for US bituminous coal, representing 48% of coal's emissions intensity.

The advantage persists in China, where US LNG generates 553 gCO2e per kWh against 792 gCO2e per kWh for Indonesian coal, equating to 63% of coal's emissions. Even comparing the highest-emitting US LNG with the lowest-emitting coal maintains a 23% advantage for gas across both markets.

These calculations assume modern, efficient power plants operating at 55% efficiency for gas and 42% for coal. In reality, LNG often displaces older, less efficient coal plants, making the emissions differential even more pronounced.

Building consensus for progress

The analysis highlights the need for evidence-based consensus on emissions data. Misconceptions about supply sources, technology deployment, and comparative emissions intensities risk undermining legitimate decarbonisation efforts and diverting attention from meaningful emission reduction opportunities.

The LNG industry must embrace transparency while working systematically to reduce value chain emissions. This includes expanding certified gas programmes, improving measurement and monitoring systems, and investing in emission reduction technologies across the supply chain.

The energy transition requires pragmatic solutions based on empirical evidence. While renewable energy remains the ultimate destination, the path forward demands honest assessment of available alternatives. The data suggests US LNG, despite its imperfections, continues to offer meaningful emissions reductions compared to coal in power generation.

The industry's credibility depends on acknowledging both its achievements and remaining challenges while working collaboratively toward a lower-carbon future.

Fraser Carson will be leading a presentation titled "Shining the Light on LNG and Coal Emissions" from 14:00 to 15:00 on 10 September 2025 at Gastech 2025.