Accelerated attainment of global air quality standards with disproportional health co-benefits under the 1.5 °C target

Meeting the Paris Agreement targets and the World Health Organization 2021 Air Quality Guidelines is crucial for avoiding air pollution-related health damage. Failing these targets worsens climate change, intensifying environmental threats to public health. Here, we adopt an integrated assessment modeling framework to evaluate timelines for the AQGs attainment under different mitigation scenarios worldwide. We find that achieving 1.5 °C goal could expedite guidelines by decades, dropping PM_2.5 to 5 μg m^-3 and ozone to 30 parts per billion by volume by 2050, averting over a million mortalities and delivering major benefits in India, China, American, Europe, and Southeast Asia. Monetized health co-benefits would exceed mitigation costs, rising from 11 trillion to 22 trillion US dollars between 2050 and 2100. We show heightened climate ambition is both feasible and economical, offsetting global mitigation expenses via health benefits. Insufficient actions would exacerbate climate risks such as extreme weather, sea-level rise and economic loss.