Climate change is a pressing issue that goes beyond rising temperatures and extreme weather events. It's also about the spread of infectious diseases to new regions, as revealed by the COP30 report. The report highlights how pathogens and their vectors, such as mosquitoes, midges, and ticks, are thriving due to changing climate conditions. This is particularly concerning as it affects vulnerable populations in Africa and Europe, where deadly diseases like West Nile virus, dengue, and chikungunya are now spreading to new areas. But what makes disease risks even worse under climate change? It's a complex interplay of factors. First, pathogens can adapt to new vectors and climates, as evidenced by the chikungunya virus mutations that enabled its spread by Aedes albopictus mosquitoes. Second, extreme weather events like droughts and floods disrupt ecosystems and human settlements, allowing waterborne pathogens to thrive. Third, climate-driven migration forces people into overcrowded areas with limited access to water and sanitation, increasing their exposure to endemic diseases and new pathogens. This problem is especially severe in Africa, where health systems are often under-resourced and populations are highly vulnerable. But what can be done to respond to these climate-related epidemics? Surveillance and genomic tracking are critical tools for early detection and response. By integrating genomic data with climate and epidemiological data, scientists can predict where and when outbreaks might occur. For instance, a recent modeling analysis pinpointed the location of midges that transmit the Oropouche virus and predicted its resurgence in the Amazon. The One Health approach, which involves sampling from the environment, animals, and humans, has been effective in responding to Rift Valley Fever virus in Kenya. However, if nothing is done, the consequences could be dire. Climate-driven migration in Africa is projected to displace up to 113 million people internally by 2050, straining already vulnerable health systems. The movement of people can also spread pathogens to new regions, requiring coordinated responses and investments in health systems to prevent frequent epidemics. What needs to happen next? Governments must prioritize building resilient healthcare systems that can withstand and respond to climate-related shocks. They should ensure equal access to vaccines and diagnostics, invest in community-based surveillance, and make low-cost disease diagnosis available at all local healthcare centers. Sustainable funding and regional cooperation are essential to support research, capacity building, and public health interventions. On November 13, 2025, the COP30 Health Day will promote regional cooperation by presenting the Belém Health Action Plan, which supports the implementation of the report's recommendations. Addressing climate-amplified diseases is not just a health issue but a matter of climate justice. The global south, which contributes the least to climate change, bears the greatest burden. Governments and private industries that contribute the most to climate change should be held accountable and contribute their fair share to the response.
