The impact of climate change on human health
and well-being has already been observed. Direct
effects such as those related to heat, cold, floods,
storms and solar ultraviolet radiation have been
documented. Some vector-, food- and water-borne
diseases and other infectious diseases influenced by ecosystems
are likely to increase in incidence. Respiratory health is affected
by near-surface ozone exposures, episodes of acute air pollution,
and aero-allergens. Indirect health impacts also exist. For example,
changes in agricultural production, and loss of crop yield and the
nutritional value of food have detrimental effects on nutrition.
Increasing ambient temperatures can lead to loss of work capacity
and occupational health concerns. The impact on mental health,
mass migration, conflict and violence associated with changes in
climate should not be underestimated.