Discussions about climate change and the effects it will have on public health and the global burden of disease have been long in the making. These consequences are now starting to come to fore.
Several examples have recently played out. For example, in Russia, an anthrax outbreak in the remote region of Siberia meant that nomadic communities and thousands of reindeer were affected. The outbreak was due to the bodies of infected people buried in 1941 defrosting and releasing anthrax spores into the water system as the permafrost defrosts with global warming.
Closer to home, prisoners are starving in Malawian jails and suffering from acute severe malnutrition as a result of food shortages due to erratic climate conditions from both droughts and floods. Malawi has since declared a state of national disaster.
These unanticipated public health consequences of unsustainable development reminds the world that the issues are not in the distant future, but instead face us now.
Climate change exerts its influence on public health through three main mechanisms.
First, the effects of extreme weather events such as heat, storms, floods or fire that directly cause loss of life or illness.
Second, there are indirect effects of climate change on natural systems. This leads to, for example, changes in disease vectors such as mosquitoes that spread malaria, availability of fresh water, crop survival, or the concentration of pollen in the air.
Third, the effects on economic and social systems as people migrate or conflict over scarce resources.
These effects can be moderated by the presence of early warning systems and effective disaster and emergency medical services.
More affluent communities with more resources will be better able to adapt and withstand these effects. Having strong primary healthcare systems will also increase the resilience of communities.
But in sub-Saharan Africa, many communities do not have these protective mechanisms in place, and will be particularly vulnerable to the impact of climate change.