Kenya is among countries expected to experience a five per cent increase in malaria transmission as climate change reshapes the spread of the disease, according to a new international study.
Scientists say rising temperatures and changing rainfall patterns are creating conditions that allow mosquitoes and the malaria parasite to thrive in cooler, high-altitude regions such as the East African highlands, where populations have historically faced a lower risk of infection and have limited immunity.
The findings, published on July 29 in the journal Nature, suggest climate change is not simply increasing or reducing malaria but shifting the disease into new regions.
The researchers warn that childhood malaria could continue to rise across East and southern Africa, even as infections decline in some of today’s hottest malaria hotspots.
“Climate change isn’t just making malaria worse or better—it’s moving it,” said co-author Tamma Carleton, Faculty Head of Research for the Climate Impact Lab and Assistant Professor at the University of California, Berkeley.
“Whether a place sees elevated malaria risks or reduced burdens under climate change depends on how hot it is today. We see relief in the current hotspots and new risk nearly everywhere else.”
Malaria remains the world’s deadliest climate-sensitive infectious disease. However, scientists have long disagreed on how climate change has influenced its spread.
The new study, described as the most comprehensive assessment to date, analyses both the historical and future effects of climate change on malaria among children in sub-Saharan Africa, where the overwhelming majority of cases and deaths occur.
It concludes that climate change has so far caused a modest overall increase in malaria transmission.
Researchers say rising temperatures are making cooler regions more suitable for mosquitoes while rendering some of today’s hottest malaria-endemic areas increasingly hostile to the insects.
As temperatures continue to rise, malaria cases are projected to fall by about five per cent in parts of West Africa, including Nigeria, Burkina Faso and Mali, where conditions are becoming too hot for efficient transmission.
In some of the hottest Sahel countries, including Niger, Gambia, Guinea-Bissau and Somalia, the study suggests malaria could eventually disappear altogether because mosquitoes struggle to survive in extreme heat.
The opposite trend is expected in cooler regions, including the East African highlands and southern Africa.
The researchers project that malaria cases will increase by about five per cent in the Ethiopian highlands and neighbouring highland regions, including parts of Kenya and Burundi. Similar increases are expected in Angola, Zambia and north-eastern South Africa.
By the end of the century, malaria risk could increase by as much as 20 per cent in regions such as the Rift Valley and coastal southern Africa if global warming continues unchecked.
The study says limiting global warming to 2°C could significantly reduce future infections, preventing at least five additional malaria cases per 1,000 children in southern Africa and even more in the East African highlands.
Researchers stress that reducing greenhouse gas emissions alone will not be enough.
“The southern and East African regions expected to be hit the hardest are also regions that aren’t accustomed to needing to fight the disease today,” said co-author Christopher Trisos, Director of the Climate Risk Lab and Principal Research Officer at the African Climate and Development Initiative at the University of Cape Town.
He urged governments and health systems to strengthen surveillance, expand disease control programmes and invest in healthcare in areas where malaria has traditionally been rare.
“Governments, health systems and communities must adapt to the evolving malaria threat,” Trisos said.
The authors say both climate mitigation and adaptation measures, including stronger malaria elimination strategies, will be essential.
“Malaria was one of the first health outcomes linked to climate change, but it’s taken a quarter of a century to be sure which direction things are headed,” said co-author Colin Carlson, Assistant Professor of Epidemiology at Yale University.
“The big story here is the opportunity for action: so far, elimination efforts have counteracted climate change impacts by nearly 200-fold. Malaria elimination within a generation is not only possible but one of the best ways to protect frontline populations from climate change impacts.”
The study is the first to identify where future adaptation investments against malaria will be most urgently needed. It forms part of a broader Climate Impact Lab initiative aimed at helping governments target climate resilience and public health interventions.
