Integrated monitoring and lifecycle assessment of green hydrogen, ammonia, and synthetic fuels: Advancing environmental sustainability and carbon traceability in the clean energy transition

Abstract Decarbonizing the global energy system requires clean fuel pathways that are low carbon at the point of use and sustainable throughout their lifecycles. This review compares green hydrogen (H 2 ), green ammonia (NH 3 ), and synthetic electrofuels (e‐fuels). It focuses on integrating advanced monitoring technologies and standardized life‐cycle assessment (LCA) frameworks. We critically examine contemporary monitoring techniques, including Raman spectroscopy, tunable diode laser absorption spectroscopy (TDLAS), gas chromatography–mass spectrometry (GC–MS), fiber‐optic sensing, and AI‐enabled digital twins with SCADA systems. Their effectiveness is assessed for leak detection, fuel quality, emissions quantification, and operational safety across production, storage, transport, and end‐use phases. A synthesized cradle‐to‐grave and well‐to‐wheel LCA, consistent with International Organization for Standardization (ISO) 14040 and ISO 14044 standards, quantifies environmental performance and shows key sources of variability among the three energy carriers. The literature shows greenhouse gas (GHG) emission reduction potentials from about 70% to 98%, depending on electricity carbon intensity, production pathways, carbon dioxide (CO 2 ) sourcing, and system boundary definitions. H 2 offers the greatest decarbonization potential for industrial and grid‐scale applications. NH 3 is useful for long‐distance transport and seasonal energy storage. E‐fuels, though less energy‐efficient, help facilitate near‐term adoption in hard‐to‐electrify sectors like aviation and maritime transport. Combining operational monitoring data with life‐cycle carbon accounting enables transparent, certification‐ready sustainability governance that aligns with United Nations Sustainable Development Goals 7, 9, and 13.