Climate change is an unequivocal fact and one of the main threats that society faces both as an environmental challenge and for health and social well-being. The United Nations Framework Convention on Climate Change in its article 1 defines it as “the climate change attributed directly or indirectly to human activity that alters the composition of the world atmosphere and which adds to the natural variability of the climate observed during comparable time periods. "

Scientific evidence on health effects shows that climate change (Confalonieri et al. 2007):

  • It has modified the distribution of some infectious disease vectors.
  • It has modified the seasonality of some allergenic pollens.
  • The number of deaths related to heat waves has increased.

On the other hand, other estimated effects that exposure to climate change will cause are:

  • Increase in malnutrition and its associated effects such as growth disorders and child development.
  • Increase in victims of heat waves, floods, fires and droughts.
  • Greater alteration of the distribution and scope of some infectious disease vectors.
  • Changes in the seasonality and distribution of malaria increasing in some regions and decreasing in others.
  • Increase in diarrheal diseases.
  • Increased cardiorespiratory morbidity and mortality associated with tropospheric ozone.
  • Increase in the number of people exposed to dengue.
  • It will also cause the decrease in cold deaths but this decrease will be greatly exceeded by the negative effect of rising temperatures.

These direct effects are inseparable from those derived from the social, demographic and social changes that climate change entails, as well as the synergistic effects of global warming with other causes of alteration of the Earth's biophysical and ecological systems such as the depletion of the stratospheric ozone layer, the accelerated reduction of biodiversity, the degradation of ecosystems, the overexploitation of terrestrial and marine resources, the decrease in freshwater reserves and the extent of contamination with persistent chemical compounds among others. In this way, the spectrum of impacts on health increases while the complexity of its causes increases.

It is essential to keep in mind that the harmful impacts of climate change are greater on disadvantaged populations. Thus, climate change promotes the increase in health and social inequalities. Another especially vulnerable group is the child population in which the health effects of the different dimensions of environmental degradation are more serious and cumulative, and that requires special attention when planning adaptation measures, as well as the population Elderly and the chronically ill.