ACDI researchers, Christopher Trisos and Romaric C. Odoulami, co-author landmark study on the past and future impacts of climate change on malaria in Africa
Grounding health and climate science in the southern African context
On the 29th of July 2026, a landmark and internationally recognised study co-authored by ACDI researchers Dr Christopher Trisos and Dr Romaric C. Odoulami was published in Nature, highlighting how past and future impacts of anthropogenic climate change are reshaping where childhood malaria risk falls across Africa.
Dr Trisos and Dr Odoulami’s contributions ground international climate modelling in the African context through regional data sets, which include a century of over 50 000 geolocated blood sample surveys across sub-Saharan Africa that capture the prevalence of childhood malaria at any moment in time. They then used climate data to build a model that links malaria prevalence to temperature and precipitation.
Previous studies looking at the impact of climate change on malaria have struggled to isolate climate change’s direct contribution from other contributing factors to the prevalence of malaria. This study was the first of its kind to develop this type of model and account for other factors like healthcare, economic development, and population change. This study is the most comprehensive look at the effect of climate change on any infectious disease and has finally put decades-long debate in malaria research to an end.
How malaria is moving – warning signs for South Africa and parts of East Africa
The study found that climate change has caused a net increase of roughly 1 excess malaria case per 1000 children across sub-Saharan Africa since 1901. This is a modest continental figure that doesn't show the sharp regional contrast and predicted shifting of malaria hotspots.
In cooler regions and those of higher elevation, including parts of Southern and Eastern Africa, climate-change related warming has pushed conditions closer to the optimum temperature (25 °C) for mosquito-borne transmission of malaria, which the study predicts will drive increases of over 8 cases per 1000 children in some areas.
In Limpopo, Mpumalanga, and KwaZulu-Natal specifically, these figures could be close to 18 additional cases per 1000 children by the end of the century. Dr Trisos, director of the Climate Risk Lab, explains these projections and their implications for South Africa’s provinces below:
“We are seeing a notable increase in the number of children contracting malaria in Limpopo, Mpumalanga and KwaZulu-Natal due to human-caused climate change. By 2050, these provinces of South Africa are projected to see some of the largest increases in malaria risk from climate change in Africa. South Africa and its global health partners need to prepare local malaria control and health systems now for this growing risk.”
On the other hand, the study also projects that by the end of the century, climate change could accelerate malaria elimination in parts of West and Central Africa that were previously hotspots. This is because the rising temperatures move beyond the optimal range for the mosquitoes and malaria parasite to thrive. Dr Odoulami explains this complexity and shifting prevalence:
“Our study shows that climate change’s influence on childhood malaria risk is not uniform across Africa, underscoring the difficulty and complexity of adaptation and health planning across the continent.”
A cautionary tale where hope is predicated on immediate action
“Governments, health systems and communities must adapt to the evolving malaria threat”, says Dr Trisos.
Despite some of the sobering findings and regional projections, the researchers are clear that the outcome is not final. Limiting global warming to below 2 °C could prevent an estimated 5 excess malaria cases per 1000 children in southern Africa and the East African highlands by 2100.
Dr Trisos highlights how the current tools, including disease surveillance, vector control and improved healthcare systems, can reduce the projected malaria risk highlighted in the study:
“The hopeful part is that the malaria control and prevention tools we have today, if we deploy them in a timely and well-resourced way, are capable of completely offsetting that increase.”
In terms of the local South African context, Dr Trisos alludes to the way forward for vulnerable provinces:
“South Africa has had malaria for a while, but what these results show is that we can expect that risk to increase because of human-caused climate change and so, at the provincial level, enhanced surveillance, enhanced planning and resourcing for malaria prevention and control is critical.”
The paper emphasises the importance of acting now to meet the global climate and health goals of eliminating malaria and reducing greenhouse gas emissions. Some of the clear warning signs noted in their conclusion include the increasing fragility of current global healthcare systems, the resurgence of malaria in parts of South America and the evolution of strains of malaria in urban areas that may mean that elimination could “hang in the balance”.
This study forms a part of a broader effort by the Climate Risk Lab at ACDI to help decision makers target where and when future adaptation investments and strategies will be needed most, and as the authors note in the paper, further work should build on their findings to focus on more “near-term” climate predictions, which will be essential for keeping malaria under control in the years to come.
The ACDI would like to congratulate Dr Trisos and Dr Odoulami on this momentous achievement, along with the other pioneering researchers, Colin J. Carlson from Yale University School of Public Health and Tamma Carleton and Cullen D. Molitor from the University of California, Berkeley.
If you would like to read more, please refer to the links provided below: