Changement climatique et santé, entre mythe et réalité

There is unanimous consensus that weather and climate affect human health in many ways. It follows that the recent (globally averaged) warming, whether it is attributable to greenhouse gas emissions generated by human activity or not, may have an impact on the distribution and the incidence of many diseases. However, the examples provided in the published estimates of future health effects of climate change are far from conclusive. For instance, the connection between climate change and malaria would appear to be an unwarranted problem which is talked about a lot, whereas there exist warranted problems that are little talked about. Furthermore, attention so far has mostly focused on adverse effects, while some beneficial effects could also exist. Peopleʼs adaptation capacity has been very often neglected and it was a mistake to consider the potential effects of climate evolution separately, out of context: the meteorological variables never suffice in identifying the meteoropathological risks. Demographic, social, economic and political factors are determinant in the epidemiological dynamics of most diseases, infectious as well non-infectious, and should not be hidden by the potential impacts of small changes in temperature and humidity. All things considered, we must never forget that a deterioration in a state of health is always due to the convergence of an exogenous hazard and a particular vulnerability of the exposed population. Finally, even if we assess the little evidence there is that recent global warming has already affected some health outcomes, anticipation of adverse health effects must strengthen the case for pre-emptive policies, and must also guide priorities for planned adaptive strategies taking into account the widest possible range of climatic evolutions.