The Greenhouse Gas Footprint of LNG Pathways From Major Exporters

Liquefied natural gas (LNG) is often promoted as a cleaner alternative to coal, yet its climate advantage remains highly conditional. Existing literature frequently underestimates LNG’s short‐term climate impact by assuming uniformly low methane leakage and focusing on 100‐year global warming potential (GWP 100 ) metrics. This study addresses this gap by conducting a comparative cradle‐to‐grave life cycle assessment (LCA) of LNG‐to‐electricity pathways from five major exporters—the United States, Qatar, Algeria, Russia, and Australia—to European and Asian markets. The functional unit is 1 MWh of net electricity generated in modern combined‐cycle gas turbines (CCGTs), with results expressed in kg carbon dioxide (CO 2) e/MWh using the 20‐year GWP (GWP 20 , IPCC AR6). Emissions estimates are instantaneous per‐unit‐generation values, not time‐averaged. The analysis integrates country‐ and route‐specific methane leakage rates (0.2%–4.5%), liquefaction energy intensity, shipping distances, regasification configurations, and combustion performance. Results show significant variability: Qatar LNG has the lowest emissions (450–600 kg CO 2 e/MWh), followed by Algeria (530–570), Australia, and Russia (650–770), while U.S. LNG under high‐leakage conditions reaches 1050–1100 kg CO 2 e/MWh, comparable to or exceeding subcritical coal. The findings demonstrate that only low‐leakage LNG routes offer a meaningful emissions advantage over coal, underscoring the need for methane mitigation and route‐specific assessment in aligning LNG trade with near‐term decarbonization targets.