A model to estimate road transport emissions from the entire life cycle

摘要

Road transport is the most relevant source of Green House Gas (GHG) emissions in developed countries. To achieve global emission reductions in this sector it is necessary to take into account the life cycle of each technology. Therefore, policy makers need tools to compare policies and measures in terms of emissions in their life cycle. In this study, a methodology to account GHG emissions from life cycle for a vehicle fleet (e.g. from a country, a company, a city, etc.) was developed. Moreover, a software tool called GlobalTRANS was designed and built to compute emissions from the fleet. It improves a previous tool called EmiTRANS that estimated only exhaust emissions (Tank-to-Wheel) incorporating Well-to-Tank and vehicle manufacturing emissions. GlobalTRANS calculates and sums up emissions in terms of CO_2 equivalent. Default coefficients have been calculated for Spain but this tool allows users to change the coefficients and substitute them. Finally, the methodology has been successfully tested for the calculation of several fleets and pathways and results were compared with other Life Cycle Assessments (LCA). This paper presents an example from a diesel Euro 4 light duty vehicle showing that vehicle use means 79% of total emissions, while diesel production accounts for 13% and vehicle manufacture for 8%.