Extreme weather events and continued urban expansion, in many cases driven by a changing climate, will come together to create health hazards previously unknown in some regions, especially large cities in the Global North. In one recent example, the Aedes Aegypti mosquito—which thrives in urban environments and can carry Yellow Fever—invaded normally mosquito-free Las Vegas following unusually heavy rains in 2023. As we note in this forecast, similar spreading of disease-carrying mosquitoes in North America and Europe has been accelerated by warmer, wetter weather.

Meanwhile, ongoing conflicts in places like Ukraine, Myanmar, Sudan and the Gaza Strip lead to bad health outcomes for civilian populations caught up in fighting, which degrades or destroys medical infrastructure. These conflicts, however, represent just one form of insecurity that can impact public health; food and water scarcity can also drive up health risks, something that we examine in this forecast. For travellers, this means that health risks are no longer confined to poor destinations in the Global South, but something that needs to be taken seriously globally.