Toward the 2-degree target: Evaluating co-benefits of road transportation in China

Background: Co-benefit assessments on health and economic impacts of climate change mitigation towards the 2-degree target are still largely insufficient in literature, especially from a sectoral perspective. Objectives: This study aims to (1) evaluate PM_2.5 pollution-related health impacts on China's road transport sector at both national and provincial levels towards the 2-degree target by 2050; (2) uncover the contribution from the road transport sector compared with that of all sectors; (3) distinguish the contribution from climate change mitigation actions compared with air pollution control oriented actions in road transport sector; and (4) identify the heterogeneous influences at the provincial level. Methods: Health and economic impacts are estimated using an integrated approach that combines the GAINS (Greenhouse Gas and Air Pollution Interactions and Synergies) model, the IMED/CGE (Integrated Model of Energy, Environment and Economy for Sustainable Development/computable general equilibrium) model and IMED/HEL (Health) model. Five scenarios are proposed based on climate change mitigation and stringency of air pollution control policy. Results: It is found that China's road transport sector could contribute to around 10.6% of total PM_2.5 concentration reduction resulting from all sectors' participation in achieving the 2-degree target, equivalent to 10.8% of the monetized health benefits obtained from achieving the 2-degree target by all sectors. Populous provinces dependent on secondary industries would benefit more under the 2-degree target. Meanwhile, compared with the potential maximum benefits from air pollution control oriented measures in the road transport sector, such climate actions could bring noticeable synergies as well. Approximately climate change mitigation action alone can lead to 70% reduction of health impacts by applying air pollution control measures. Conclusions: This research has implications for other emerging economies and those reluctant to engage in climate action and is deserving of further attention. The government should also realize the heterogeneity of road transport sector development in different provinces, and adopt a more flexible policy approach to take into account regional pollution levels and abatement options.