Atmospheric health burden across the century and the accelerating impact of temperature compared to pollution

Anthropogenic emissions alter atmospheric composition and therefore the climate, with implications for air pollution- and climate-related human health. Mortality attributable to air pollution and non-optimal temperature is a major concern, expected to shift under future climate change and socioeconomic scenarios. In this work, results from numerical simulations are used to assess future changes in mortality attributable to long-term exposure to both non-optimal temperature and air pollution simultaneously. Here we show that under a realistic scenario, end-of-century mortality could quadruple from present-day values to around 30 (95% confidence interval:15-75 million people per year). While pollution-related mortality is predicted to increase five-fold, temperature-related mortality will experience a seven-fold, making it a more important health risk factor than pollution for at least 20% of the world's population. These findings highlight the urgent need to implement stronger climatic policies to prevent further losses of life, outweighing the benefits of air quality improvements alone.