Expert views diverge on how to decarbonize transport

Transport accounts for about one-quarter of global energy-related carbon-dioxide (CO2) emissions. However, decarbonization policies only show incremental progress as most jurisdictions lack an integrated approach. Siloed thinking between the energy and transport sectors holds back the development of more effective policies for transport decarbonization, although previous work has only reported this anecdotally. We systematically identify diverging perspectives between energy and transport experts globally at all levels of government. Using thematic and frequency analysis of expert elicitation survey responses combined with machine learning, we find that (1) both sectors tend to have a narrow focus that neglects broader issues and has led to policy failures; (2) views differ on which energy sources are sustainable with somewhat less variation on how to prioritize decarbonization measures; (3) both sectors support increased communication and coordination for better outcomes and efficiency; and (4) most experts anticipate that transport decarbonization will be insufficient to achieve net zero by 2050, with views varying more based on affiliation type and region. These results provide a starting point for governments to bridge the divide between the sectors and to formulate adequate policies enabling transport decarbonization in line with global climate and sustainability goals.