In order to fulfill the commitment of China to achieve carbon peak by 2030 and carbon neutrality by 2060, all industries have been taking their respective carbon reduction actions. The transportation industry accounts for 11% of CO₂ emission of the whole society, and its energy conservation and carbon reduction benefit is of great significance to the national carbon reduction process. New energy vehicles are undoubtedly one of the most important means of carbon emission reduction in the transportation sector. However, electric vehicles still have CO₂ emissions, as the fossil fuel use comes from upstream power. To systematically and comprehensively evaluate the CO₂ emissions of HEV, PHEV and BEV in the whole process, this study introduces the life-cycle method to research on the past and current situations, and predict future scenarios for ICEV and EV light-duty vehicles at the national and regional levels, by deeply analyzing the generation mix and generating efficiency from the WTT stage, and fuel economy from the TTW stage. The study shows that compared with ICEV, HEV and PHEV could reduce around 30% of CO₂ emissions. Currently, BEV could reduce 37% of CO₂ emission in the region where the proportion of coal-fired power is high, and 90% of CO₂ emission in the region where the proportion of hydro power is high. This study discusses the impact of the proportion of renewable energy application on the carbon emissions from electric vehicles, analyzes the environmental benefits of promoting electric vehicles in different regions, and lays a foundation for the promotion strategy of electric vehicles for different regions in the future.

With the booming freight industry in China in recent years, the freight volume has presented a growing trend, but the accompanied motor vehicle pollution emission becomes increasingly prominent. For the purpose of green development in freight industry, China is taking active measures to reduce emissions. Among them, the structural emission reduction enjoys the greatest potential in energy conservation and emission reduction in the transportation industry in the future. Its key is to adjust the current unreasonable transportation structure in China, and promote the transfer of freight transport from road to rail and water through the development of multimodal transport. Therefore, systematically finding out the structural characteristics of China’s freight industry and sorting out the problems existing in the freight structure can provide technical support for promoting the structural emission reduction of the freight industry and building an intensive, efficient and green cargo transportation system. This study systematically analyzed the overall development and structural characteristics of China’s freight transportation, calculated the current situation and characteristics of CO2 emissions in China’s freight transportation sector, summarized and analyzed the main problems facing energy conservation and emission reduction in China’s freight transportation sector, and put forward countermeasures and suggestions.

Controlling air pollution from sea-going vessels is crucial to the sustainable development of maritime transportation. However, emissions of intermediate volatility organic compounds (IVOCs), an emerging aerosol precursor, remain poorly understood. This study developed a ship-type-, fuel-, and operating-mode-specific IVOC emission factor dataset based on existing real-world vessel measurements, and a ship-call-based IVOC inventory methodology tailored for regulatory applications. We quantified IVOC emissions from sea-going ships (excluding fishing and military vessels) entering or departing from the ports in the Economic Zone on the West Coast of the Taiwan Straits in 2014. The total IVOC emissions were 481.4 ± 220.0 t, with Xiamen Port contributing the highest share. Cargo and passenger ships accounted for 65% and 21% of emissions, respectively. While switching to low-sulfur and ultra-low-sulfur fuels increased IVOC emissions by 87% and 49% compared to high-sulfur fuels, the greater reductions in particulate matter and SO₂ emissions still yielded net environmental benefits. The ship IVOC emissions might have become more important in recent years due to enhanced port activity and fuel switching. Uncertainty analysis emphasizes the urgent need for IVOC emission testing on more vessel types. By providing a high-resolution profile of IVOC emissions from selected ports, this study underscores the urgency of adopting shore power and zero-emission vessels to mitigate organic aerosol pollution and offers a foundation for refining environmental impact assessments and efficient emission control policies to achieve sustainability in maritime transportation.

Rail subsidies are widely recognized as an effective policy instrument for promoting modal shift from road to rail. However, existing studies rarely consider shippers’ mode choice and origin-destination (OD) matching behavior jointly in subsidy scheme design. This study fills this gap by developing a bi-level multi-objective programming model to determine differentiated subsidy rates for each OD pair. The upper level optimizes economic and environmental objectives, while the lower level predicts shippers’ behavior using a combined spatial interaction and logit model. A genetic algorithm with a membership function approach is designed to solve the model. Using Beijing’s sand and gravel aggregate freight network as a case study, results show that the subsidy policy reduces carbon emissions by 46% and shifts 60.04 million tons of freight from road to rail, with the share of rail freight rising from less than 1% to about 62%. The optimal subsidy rates exhibit significant spatial heterogeneity. Compared with a uniform subsidy scheme, the OD-differentiated scheme performs better in both economic and environmental terms. Sensitivity analyses show that the total subsidy cap affects the results the model can achieve, and that a trade-off exists between the economic and environmental objectives.