Mitigation of black carbon (BC) aerosol emissions can potentially contribute to both reducing air pollution and climate change, although mixed results have been reported regarding the latter. A detailed quantification of the synergy between global air quality and climate policy is still lacking. This study contributes with an integrated assessment model-based scenario analysis of BC-focused mitigation strategies aimed at maximizing air quality and climate benefits. The impacts of these policy strategies have been examined under different socio-economic conditions, climate ambitions, and BC mitigation strategies. The study finds that measures targeting BC emissions (including reduction of co-emitted organic carbon, sulfur dioxide, and nitrogen dioxides) result in significant decline in premature mortality due to ambient air pollution, in the order of 4 to 12 million avoided deaths between 2015 and 2030. Under certain circumstances, BC mitigation can also reduce climate change, i.e., mainly by lowering BC emissions in the residential sector and in high BC emission scenarios. Still, the effect of BC mitigation on global mean temperature is found to be modest at best (with a maximum short-term GMT decrease of 0.02 °C in 2030) and could even lead to warming (with a maximum increase of 0.05 °C in case of a health-focused strategy, where all aerosols are strongly reduced). At the same time, strong climate policy would improve air quality (the opposite relation) through reduced fossil fuel use, leading to an estimated 2 to 5 million avoided deaths in the period up to2030. By combining both air quality and climate goals, net health benefits can be maximized.

中文翻译：

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减缓黑碳对气候和空气质量的共同好处

减少黑碳 (BC) 气溶胶排放可能有助于减少空气污染和气候变化，尽管关于后者的报告结果喜忧参半。仍然缺乏对全球空气质量和气候政策之间协同作用的详细量化。这项研究有助于对以 BC 为重点的缓解策略进行基于综合评估模型的情景分析，旨在最大限度地提高空气质量和气候效益。这些政策战略的影响已经在不同的社会经济条件、气候目标和 BC 减缓战略下进行了审查。该研究发现，针对 BC 排放的措施（包括减少共同排放的有机碳、二氧化硫和二氧化氮）可显着降低因环境空气污染而导致的过早死亡率，在 2015 年至 2030 年期间避免了 4 到 1200 万人的死亡。在某些情况下，BC 缓解还可以减少气候变化，即主要通过降低住宅部门和高 BC 排放情景中的 BC 排放。尽管如此，人们发现 BC 减缓对全球平均温度的影响充其量只是适度的（2030 年 GMT 的短期最大降低 0.02 °C），甚至可能导致变暖（最大升高 0.05 °C 到 2030 年）以健康为重点的策略的情况下，所有气溶胶都大大减少）。与此同时，强有力的气候政策将通过减少化石燃料的使用来改善空气质量（相反的关系），预计到 2030 年将避免 2 至 500 万人死亡。通过结合空气质量和气候目标，可以最大限度地提高净健康效益。