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

The health burden of anthropogenic climate change is growing exponentially, but present-day impacts remain difficult to measure [1][1]–[3][2]. Here, we leverage a recently-published comprehensive dataset of 50,425 population surveys [4][3] 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 warming, 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 84 excess cases of malaria per 100,000 children ages 2 to 10, with higher elevation and cooler regions in southern and east Africa having greater increases. Under future climate change, we project increasing temperatures could plausibly accelerate the eradication of malaria in west and central Africa, where the present-day burden is highest, leading to continent-wide average reductions of 89 (low greenhouse gas emissions, SSP1-RCP2.6) to 1,750 (high emissions, SSP5-RCP8.5) cases per 100,000 children by the end of the century. However, we find that limiting future global warming to below 2°C (SSP1-RCP2.6) compared to ∼ 3°C (SSP2-RCP4.5) could prevent an average of 496 excess cases in southern Africa, and 40 excess cases in east Africa,per 100,000 children by 2100. Our study resolves a decades-old debate about one of the earliest health impacts of global warming, and provides a template for future work measuring the true global burden of climate change. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement CHT was supported by the University of Cape Town Future Leaders Programme and by the FLAIR Fellowship Programme: a partnership between the African Academy of Sciences and the Royal Society funded by the UK Government's Global Challenges Research Fund. RCO was supported by the Carnegie Corporation of New York through the Development of Emerging Academic Leaders (DEAL) in Africa and the German Academic Exchange Service (DAAD) ClimapAfrica programme. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data used in the study are available from other sources. All code are available on Github. [1]: #ref-1 [2]: #ref-3 [3]: #ref-4