Aerosol pollution events pose serious threats to humans and ecosystems. Natural aerosols are much less studied than fossil fuel-sourced aerosols for their air quality impacts, even though ‘natural’ aerosols such as dust and wildfires are likely to have substantially changed because of anthropogenic activities. Using the Community Earth System Model version 2 and the Community Atmospheric Model version 6 atmospheric model, we simulated dust and open-fire PM2.5 concentrations over Africa for preindustrial (PI), present-day, and future scenarios. Health impacts were assessed using the integrated exposure–response model applied to gridded population and disease-specific mortality data. Currently, we estimate that desert dust causes 30 000 (95% confidence interval (CI) 29 700–303 000) excess deaths annually in Africa (36% of the total excess premature mortality), while open fires result in 20 000 (95% CI: 19 500–22 500) excess deaths (24% of the mortality). All mortality estimates reported in this study represent annual excess deaths, calculated based on annual average PM2.5 concentrations. Concentrations of dust dominate aerosol concentration at the continental scale, and paleo records suggest dust loading has increased by 55% since PI times. Because of the lower population in dust-dominated regions, these do not affect health as much as combustion but are still important. In PI times, we estimate deaths due to dust as 6400 (95% CI: 6050–6750) (or 7000 if we keep the population at current levels), showing a large growth to the present day (over 400% increase). Excess deaths due to open fires have increased from 6900 (95% CI: 5800–7400) in the PI to 20 000 today (approximately 190% increase). For future scenarios in 2100, there is significant uncertainty; therefore, we present a high and low scenario, indicating that in the future, between 53 000 (95% CI: 49 000–55 000) and 67 000 (95% CI: 63 000–70 000) deaths will result from dust. Similarly, for future open fire excess deaths, we estimate a range of 19 000–40 000 (95% CI: 33 000–44 000) deaths, including population changes (−1% to +100% changes relative to today). In the current climate, as well as in the past and future, the amount and proportion of deaths attributed to ‘natural’ aerosols exceeds 50% of the total PM2.5 attributable mortality in Africa, showing that addressing possible changes in ‘natural’ aerosols is extremely important for improving air quality.

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