The historical fingerprint and future impact of climate change on childhood malaria in Africa

Health-related risks from climate change are growing exponentially1, but direct attribution of health outcomes to human influence on the climate remains challenging 2,3. Here, we leverage a comprehensive dataset of 50,425 population surveys 4 to investigate whether human-caused climate change has increased the burden of childhood malaria across sub-Saharan Africa. In historical data, we find that prevalence shows a robust response to temperature and extreme precipitation, consistent with expectations from previous empirical and epidemiological work. Comparing historical climate reconstructions to counterfactual simulations without anthropogenic climate forcings, we find two-to-one odds that human-caused climate change has increased the overall prevalence of childhood malaria across sub-Saharan Africa since 1901. We estimate that by 2014, human-caused climate change was responsible for an average of 87 excess cases of malaria per 100,000 children ages 2 to 10 (95% confidence interval [CI]: -300, 507), with higher elevation and cooler regions in southern and east Africa experiencing greater increases. Under future climate change, we project that increasing temperatures could marginally accelerate the elimination of malaria in west and central Africa, where the present-day burden is highest, with an average overall reduction of 94 (low greenhouse gas emissions, SSP1-RCP2.6; 95% CI: -497, 160) to 1,890 (high emissions, SSP5-RCP8.5; 95% CI: -4846, 65) cases per 100,000 children in sub-Saharan Africa by the end of the century. However, we find that limiting future global warming to under 2{degrees}C (SSP1-RCP2.6) compared to 3{degrees}C (SSP2-RCP4.5) could prevent an average of 505 excess cases (95%: -199, 1209) per 100,000 children in southern Africa by 2100. Our study resolves a decades-old debate about one of the first suspected health impacts of climate change, and provides a template for future work measuring its true global burden.