Edinburgh Napier University

  Transport accounts for 40 % of global emissions, 72 % of which comes from road transport, and private cars are responsible for 60 % of road transport emissions. In cities, self-service bike sharing systems are quickly developing and are intended to offer an alternative and cleaner mode of transport than the car. However, the sustainability of such schemes is often taken as a given, rather than thoroughly evaluated. To address this gap, in this paper we undertake a life cycle assessment (LCA) of a public self-service bike sharing system in the city of Edinburgh, UK, modelling the production, operation and disposal elements of the system, but discounting additional food intake by users. Our results show that the bike sharing scheme is saving carbon dioxide equivalent emissions compared to the modes of transport by which its users previously travelled, but it is essential to optimize rebalancing operations and to manufacture bikes as near as possible to the point of use to further reduce carbon emissions; and that the overall emissions impacts of the scheme are critically dependent on how public transport providers respond to reductions in demand as users shift trips to bikeshare, since most trips transfer from walk and public transport, not private car. The policy implications for authorities seeking to use BSS as a GHG reduction intervention are not straightforward.