Malaria is the deadliest climate-sensitive infectious disease. Yet, researchers and public health officials have long argued over how climate change has shaped its spread. The Climate Impact Lab’s Tamma Carleton and her co-authors resolve this debate in a new study. They find that climate change has slightly increased childhood malaria risk over time across Africa, with larger increases in high-elevation East Africa and southern Africa. Looking forward, today’s malaria hotspots may actually become too warm for even mosquitoes—posing other human health threats. This is especially the case in many large West African nations (Nigeria, Burkina Faso, Mali), where climate change will reduce cases by ~5 percent. In extremely hot Sahelian countries (Niger, Gambia, Guinea-Bissau, Somalia) the disease may actually be fully eliminated. Of course, these extreme conditions will raise many other risks, such as heat-induced mortality and crop failures.
The opposite is true in southern and East Africa, where communities are less experienced at tackling the disease. In these areas, climate change is slowly making the temperature more suitable for mosquitoes to spread malaria, increasing cases by 5 percent in the Ethiopian highlands (Kenya, Burundi) and in Angola, Zambia, and northeast South Africa. By 2100, the risk could increase by 20 percent in regions like the Rift Valley and coastal southern Africa, creating new malaria challenges in contexts largely unprepared for them. The authors say that governments, health systems and communities in these areas must adapt to the evolving malaria threat and implement more aggressive anti-malaria programs now.