Societal risks increase as Earth warms, and increase further for emissions trajectories accepting relatively high levels of near-term emissions while assuming future negative emissions will compensate, even if they lead to identical warming as trajectories with reduced near-term emissions¹. Accelerating carbon dioxide (CO₂) emissions reductions, including as a substitute for negative emissions, hence reduces long-term risks but requires dramatic near-term societal transformations². A major barrier to emissions reductions is the difficulty of reconciling immediate, localized costs with global, long-term benefits^3,4. However, 2 °C trajectories not relying on negative emissions or 1.5 °C trajectories require elimination of most fossil-fuel-related emissions. This generally reduces co-emissions that cause ambient air pollution, resulting in near-term, localized health benefits. We therefore examine the human health benefits of increasing 21st-century CO₂ reductions by 180 GtC, an amount that would shift a ‘standard’ 2 °C scenario to 1.5 °C or could achieve 2 °C without negative emissions. The decreased air pollution leads to 153 ± 43 million fewer premature deaths worldwide, with ~40% occurring during the next 40 years, and minimal climate disbenefits. More than a million premature deaths would be prevented in many metropolitan areas in Asia and Africa, and >200,000 in individual urban areas on every inhabited continent except Australia.

随着地球变暖，社会风险会增加，接受相对较高水平的近期排放的排放轨迹会进一步增加，同时假设未来的负排放将得到补偿，即使它们导致与近期排放量减少的轨迹相同的变暖¹。加速减少二氧化碳（CO ₂）的排放，包括替代负排放，因此降低了长期风险，但需要近期的社会转型²。减少排放量的主要障碍是难以将即时的，本地化的成本与全球性的长期利益相协调^3,4。但是，2°C的轨迹不依赖负排放或1.5°C的轨迹需要消除大多数与化石燃料有关的排放。通常，这会减少导致环境空气污染的共同排放，从而带来近期的局部健康益处。因此，我们研究了增加21世纪CO ₂对人类健康的益处减少了180 GtC的排放量，这会将“标准” 2°C情景转变为1.5°C或达到2°C而不会产生负排放。减少的空气污染使全世界的过早死亡人数减少了153±4300万，在接下来的40年中，约40％的人发生，而对气候的不利影响则最小。在亚洲和非洲的许多大都市地区，将防止超过100万人过早死亡，而在除澳大利亚以外的每个有人居住的大陆上，超过200,000个单独的城市地区都将得到预防。