Trade-Offs between Direct Emission Reduction and Intersectoral Additional Emissions: Evidence from the Electrification Transition in China's Transport Sector.

Electrifying the transport sector is crucial for reducing CO emissions and achieving Paris Agreement targets. This largely depends on rapid decarbonization in power plants; however, we often overlook the trade-offs between reduced transportation emissions and additional energy-supply sector emissions induced by electrification. Here, we developed a framework for China's transport sector, including analyzing driving factors of historical CO emissions, collecting energy-related parameters of numerous vehicles based on the field- investigation, and assessing the energy-environment impacts of electrification policies with national heterogeneity. We find holistic electrification in China's transport sector will cause substantial cumulative CO emission reduction (2025-2075), equivalent to 19.8-42% of global annual emissions, but with a 2.2-16.1 GtCO net increase considering the additional emissions in energy-supply sectors. It also leads to a 5.1- to 6.7-fold increase in electricity demand, and the resulting CO emissions far surpass the emission reduction achieved. Only under 2 and 1.5 °C scenarios, forcing further decarbonization in the energy supply sectors, will the holistic electrification of transportation have a robust mitigation effect, -2.5 to -7.0 Gt and -6.4 to -11.3 Gt net-negative emissions, respectively. Therefore, we conclude that electrifying the transport sector cannot be a one-size-fits-all policy, requiring synergistically decarbonization efforts in the energy-supply sectors.