PNNL

Abstract

Currently responsible for over one fifth of carbon emissions worldwide, the transportation sector will need to undergo a substantial technological transition to ensure compatibility with global climate goals. Few studies have modeled aggressive strategies to achieve zero emissions across all transportation modes, including aviation and shipping, alongside an integrated analysis of feedbacks on other sectors and environmental systems. We use a global integrated assessment model to evaluate deep decarbonization scenarios for the transportation sector consistent with maintaining end-of-century warming below 1.5°C, considering varied timelines for the phase-out of fossil fuels and the implementation of advanced alternative technologies. Our most ambitious scenario eliminates transportation emissions by mid-century. We highlight the leading low-carbon technologies for each transportation mode, finding that electrification contributes most to decarbonization across the sector. Biofuels and hydrogen are particularly important for aviation and shipping, respectively. While increased emissions mitigation in the transportation sector reduces the pressure on other sectors to decarbonize, the rapid technological shifts have implications for resource demands and fuel availability.