When, where and how can the electrification of passenger cars reduce greenhouse gas emissions?

Reducing the climate impacts of passenger cars has a high priority on the political agenda, especially in the EU. However, there is disagreement on how this can best be achieved – with battery or fuel cell electric vehicles, or rather with combustion engine vehicles using electricity-based synthetic liquid fuels. To answer this question and to quantify potential environmental co-benefits and trade-offs, this paper introduces carculator, a Python library to conduct environmental life cycle assessments of current and future passenger vehicles. Because carculator is open-source and equipped with an easy-to-use online graphical user interface, it produces context-specific results, deemed more relevant than results otherwise published in more static formats. carculator supports for several powertrains, vehicle size categories and fuel types, for any year between 2000 and 2050, as well as error propagation from input parameters. We demonstrate carculator with an analysis of the expected evolution of life cycle greenhouse gas emissions of hybrid vehicles powered by fossil or synthetic gasoline and battery electric vehicles between 2020 and 2050, for all European countries and Brazil, China, India, Japan and the United States. Results show that current battery electric vehicles perform better than gasoline-powered vehicles in 26 out of the 35 countries considered. In the future, electricity-based synthetic fuels show the potential to reduce climate impacts due to the expected massive decarbonization of electricity supply. However, due to their comparatively inefficient supply and use, limited renewable resources represent a challenge and should better be used for other purposes.