Life cycle assessment of car sharing models and the effect on GWP of urban transportation: A case study of Beijing.

Alongside a trend in lower private-vehicle ownership and the growing popularity of the shared use economy, car sharing is emerging as an alternative travel mode. The LCA model of car sharing is proposed, the global warming potential (GWP) of four car sharing models is determined, and the effect on GWP of urban transportation is explored. This study expanded the LCA of products to the LCA of services, by expanding the functional unit to service. In this study, the time dimension was considered during the functional unit setting. It was found that there are large GWP differences among different car sharing models. Electric vehicle car sharing models have less GWP than gasoline vehicle car sharing models. The dispatch distance and the numbers of passengers in one car are two key factors for GWP of car sharing models. When car sharing replaces ~10% and ~50% of private cars, the GWP reduction potentials of urban transportation are ~4% and ~20%, respectively. The overall distribution of car sharing should be set by considering the features of different models in different areas, to achieve the largest environment benefit by using car sharing in cities. Therefore, car sharing can be used as a measure for significant GWP reduction for city transportation.