Malaria-carrying mosquitoes are extending their range and transmitting the disease over a lengthening season in SA, warns a new report from the Lancet medical journal.
It is just one example of how climate change is taking an increasing toll on human health, as higher temperatures and shifting weather patterns raise the risk of a growing list of insect and water-borne pathogens, from dengue to cholera, in many parts of the world.
In SA, the malaria transmission season in lowland areas was 13% higher in the decade to 2024 than it was in the 1950s and 5% longer in highland areas, according to the latest Lancet “Countdown on Health and Climate Change”.
The record-breaking heat of 2024 had catastrophic consequences worldwide, including SA where extreme heat cost the economy an estimated $373m in lost productivity, says the report.
The effects of climate change on health were profound but often underappreciated in SA, said Tafadzwa Mabhaudhi, director of the Lancet Countdown Africa at the University of Pretoria.
“The conversation in SA around climate change is mostly around infrastructure — floods in KwaZulu-Natal and fires in the Western Cape or people going hungry because of drought — and less about how people’s health is being affected,” he said.
The report, compiled by an international team of almost 300 researchers, projects an expanding area of risk for mosquito-borne diseases such as dengue, and water-borne diseases such as bilharzia and cholera, said Mabhaudhi.
The report has been released ahead of the UN Climate Change Conference (COP30), due to take place in Belem, Brazil, in November, where delegates are expected to take stock of progress towards the goals set at the 2015 Paris Agreement. That landmark agreement sought to limit global warming to below 2°C compared with pre-industrial levels, with signatories committing to reduce their greenhouse gas emissions.
The report estimates that the world’s continued reliance on fossil fuels and failure to curb global warming has sent heat-related deaths surging 23% since the 1990s. The picture is even worse in SA where the estimated number of heat-related deaths tripled to 4,500 in the decade to 2021, compared with the 1990s.
People in SA were exposed to, on average, 13 heatwave days in 2024, 80% of which were likely due to climate change, the report finds. Delays in transitioning away from fossil fuels ― which saw CO₂ emissions from burning fuel fall by just 6% in 2016-22 in SA ― are also costing lives due to air pollution, warn the report’s authors. SA had Africa’s highest mortality rate for air pollution due to coal, at 16 deaths per 100,000 people in 2022.
Twelve of the 20 indicators for health threats tracked by the report’s authors have reached unprecedented levels. These include air pollution from wildfire smoke, which was linked to a record 154,000 deaths worldwide, and air pollution from burning fossil fuels, which resulted in 2.5-million deaths a year — 219,000 of them in SA.
“This is perhaps what worries us the most — that all these threats are increasing in parallel, as they often compound each other,” said Maria Romanello, executive director of the Lancet Countdown at University College London.
“This year’s stocktake paints a bleak and undeniable picture of the devastating health harms reaching all corners of the world, with record-breaking threats to health from heat, extreme weather events and wildfire smoke killing millions. The destruction to lives and livelihoods will continue to escalate until we end our fossil fuel addiction,” she said.
The report says rapidly phasing out fossil fuels is the most powerful means to slow climate change, but shifting to more climate-friendly diets and agricultural systems could also cut pollution, greenhouse gas emissions and deforestation, and save millions of lives annually.
kahnt@businesslive.co.za
