A life cycle assessment of fibre optic submarine cable systems
Twenty thousand leagues under the sea: A life cycle assessment of fibre optic submarine cable systems.
Degree Project at KTH, Department of Urban Planning and Environment, Division of Environmental Strategies Research (fms), Stockholm, 2009.
Submarine cables carry the vast majority of transcontinental voice and data traffic. The high capacity and bandwidth of these cables make it possible to transfer large amounts of data around the globe almost instantaneously. Yet, little is known about the potential environmental impacts of a submarine cable from a life cycle perspective. This study applies Life Cycle Assessment (LCA) methodology to collect and analyse the potential environmental impacts of a submarine cable system within a single consistent framework. The system boundary is drawn at the limits of the terminal station where the signal is transferred to, or from, the terrestrial network. All significant components and processes within the system boundary have been modelled to account for the flow of resources, energy, wastes and emissions. Data quality analysis is performed on certain variables to evaluate the effect of data uncertainties, data gaps and methodological choices. The results highlight those activities in the life cycle of a submarine cable that have the largest potential environmental impact; namely, electricity use at the terminal station and cable maintenance by purpose-built ship. For example, the results show that 7 grams of carbon dioxide equivalents (CO2 eq.) are potentially released for every ten thousand gigabit kilometres (10,000Gb/km), given current estimations of used capacity. The potential environmental impacts are directly linked to capacity and system usage, thus, increasing data traffic improves the environmental performance of the submarine cable system per unit of data. A focus area for further improvements is the emissions from ships, where the greatest gains in environmental performance are likely to be made through reduced emissions. This study is perhaps the first tentative step in linking together research into the environmental impact of terrestrial ICT networks.
The study was undertaken at Ericsson Research in Kista. Craig Donovan was suvervised by Åsa Moberg (Centre for Sustainable Communications) and Fredrik Jonsson (Ericsson).