Greenhouse gas emissions of subsea telecommunications cables: A comparative study of trans-Atlantic and trans-Pacific systems

Abstract

Subsea cables are critical for international data exchange. Yet lifecycle assessments (LCA) remain scarce, leaving a critical gap in understanding both the climate impacts of these systems and wider global telecommunications networks. Drawing on a unique model of industry collaboration, this study conducts a comprehensive LCA of both trans-Atlantic and trans-Pacific subsea cables, assessing cradle-to-grave greenhouse gas (GHG) emissions across manufacturing, installation, operations, and end-of-life management. Our results show that the GHG emissions for transmitting data are 0.182–0.364 gCO 2 e/(Pb⋅km) in the Atlantic and 0.236–0.472 gCO 2 e/(Pb⋅km) in the Pacific. Approximately 50% of these emissions are associated with marine fuels. Installation contributes roughly half of lifecycle emissions, while the operational phase presents high variability due to different capacities and grid locations. Our findings show substantial improvements in operational efficiency over recent decades, while underscoring the opportunities for more comprehensive climate strategies for both industry and policy actors.