Urban greenhouse gas emission peaking paths and embedded health co-benefits: A multicases comparison study in China

Cities play an important role in global greenhouse gas management. To identify and develop effective mitigation strategies for urban carbon emission management and energy system transitions, a bottom-up energy-emissionhealth model framework was developed. Using ten typical cities in China as cases, this study grouped the cities based on their development characteristics and then explored the potential carbon peaking paths and related health co-benefits for cities in different industrialization stages. Results showed the great health benefits for cities to reach their carbon mitigation goal and demonstrated the significant roles of energy substitution for cities to achieve their carbon peaking commitment. In 2030, the carbon peaking strategies could not only save 30 - 50% energy consumption but can also avoid over 100% disability-adjusted life years compared with 2015.In addition, our results show that tradeoffs existed among the carbon reduction potential, total health cobenefits, and marginal health co-benefits. A strategy that can bring the most carbon reduction and total health co-benefits would not perform the best in marginal health co-benefits, leading to relatively low costeffectiveness of additional carbon reductions. And such optimum choices can also dynamically change with time. Furthermore, although transportation, construction, and residential sectors contributed relatively lower total carbon reduction, they can bring great marginal health co-benefits.Our analysis highlighted cities should dynamically adjust their low carbon development trajectories according to their socioeconomic levels and specific policy objectives and shed light on the importance of promoting carbon peaking to improve air quality and public health at the city level.