The Vice-Chancellor of the University of Lagos, Prof. Folasade Ogunsola, has warned that Africa’s rapidly expanding cities are on the brink of a climate-driven public health emergency.

Ogunsola delivered the maiden Distinguished Lecture titled “Climate Change, Cities and Infections” at the Federal University of Health Sciences, Ila-Orangun, Osun State. She said the convergence of climate change, rapid urbanisation and infectious diseases is creating a “perfect storm” that threatens the continent’s urban future.

The microbiologist and public health expert stressed that climate change is no longer a distant environmental concern but an escalating health crisis. “Climate change does not create most pathogens,” she said, “but it changes the environmental conditions that determine transmission, exposure and vulnerability.”

Ogunsola noted that although Africa contributes the least to global greenhouse gas emissions, it bears a disproportionate burden of climate-related disease risks due to fragile health systems, widespread poverty and heavy reliance on climate-sensitive livelihoods such as agriculture.

Citing global health projections, she warned that climate change could result in an additional 250,000 deaths annually between 2030 and 2050 from malaria, diarrhoea, malnutrition and heat stress alone.

Urban areas, she said, are particularly vulnerable as African cities expand at unprecedented rates, often without adequate infrastructure. Informal settlements lacking proper drainage, sanitation and waste management systems are multiplying, creating ideal conditions for infectious disease outbreaks.

According to her, many African cities are experiencing intensified urban heat island effects, where concrete structures, paved surfaces and vehicle emissions trap heat, pushing temperatures significantly higher than surrounding rural areas.

She explained that rising temperatures, combined with erratic rainfall, flooding and drought, are reshaping disease patterns. Mosquito-borne diseases such as malaria, dengue and chikungunya are spreading into new urban zones as warmer and wetter conditions extend breeding seasons.

Flooding contaminates water sources and damages sanitation systems, triggering cholera and other diarrhoeal outbreaks.
Drought, she added, concentrates pathogens in shrinking water supplies, increasing infection risks.

“Cities are both contributors to and victims of climate change,” she said. “The density that drives economic productivity also heightens exposure to climate hazards and infectious disease transmission.”

Ogunsola also highlighted the growing intersection between climate-related disasters and Antimicrobial Resistance (AMR). Extreme weather events that displace populations and damage health facilities often lead to spikes in infections and increased antibiotic use, accelerating the emergence of drug-resistant strains.

More than half of Africa’s public health emergencies between 2001 and 2021 were climate-related, she noted, many involving diseases already complicated by rising resistance. “AMR reduces treatment options and increases mortality, complicating responses to climate-linked disease outbreaks,” she warned.

While cities offer proximity to healthcare and economic opportunities, she stressed that deep social inequalities limit access to essential services for millions living in informal settlements. Air pollution driven by fossil fuels, diesel generators and unregulated transport systems is worsening respiratory illnesses, while extreme heat disproportionately affects the elderly, children and other vulnerable groups.

“If urban challenges are not addressed at their source,” she cautioned, “their consequences will reverberate far beyond city boundaries, affecting national stability, regional health security and global sustainability.”

Ogunsola called for integrated climate and health policies anchored in a “One Health” approach, strengthened disease surveillance systems, investment in climate-resilient infrastructure and empowerment of local governments and communities.

She urged African leaders to prioritise green urban planning, including improved drainage systems, expanded green spaces, resilient housing and cleaner public transport to reduce emissions and build healthier cities.

“Cities are climate frontlines,” she concluded, “but they are also hubs of innovation. The choices we make now will determine whether Africa’s urban future becomes a story of resilience or catastrophe.”

Chairman of the occasion and Registrar of the Joint Admissions and Matriculation Board (JAMB), Prof. Isiaq Oloyede, called for holistic measures to safeguard public health by addressing climate change in Nigeria.

Represented by the Vice-Chancellor of Obafemi Awolowo University, Prof. Simeon Bamire, Oloyede said climate change poses grave risks not only to the environment but also to human health, stressing that human and environmental wellbeing are inseparable. He described the lecture as timely and urged stakeholders to accelerate implementation of its recommendations.

The Vice-Chancellor of the University of Ila Orangun, Prof. Akeem Lasisi, also commended the lecturer and chairman for their insights, describing the lecture as a wake-up call for urgent action.