Climate change and human health

Change in world climate would influence the functioning of many ecosystems and their member species. Some of these impacts would be beneficial. However, scientists consider that most of the health impacts of climate change would be adverse. The first detectable changes may well be alterations in the geographic range and seasonality of certain diseases. By contrast, the public health consequences of the disturbane of natural and managed food-producing ecosystems, rising sea-levels and population displacement for reasons of physical hazard, land loss, economic disruption and civil strife, may not become evident for up to several decades. Recent studies have revealed worldwide significant changes in frequency and persistence of extreme high temperatures. The increase of temperature can represent a risk for human health and acclimatization. Humanitarian and material losses that result from an increase in extreme weather and climate events are very important. Extreme temperatures can be associated with increased daily mortality in many regions of the world and nonlinear relations have been observed with the increase in mortality rates and very high or very low temperatures. There is not a specific definition of "heat wave" because it changes from region to region and the tresholds of air temperature vary geographically. The vulnerability of the population depends on the local climate, and the sanitary impact of heat waves seems to be higher in cold and temperate regions. During June-August 2003, extremely high temperatures are reported across Europe. Also Italy experimented with a period of excessively high temperatures and with an excess of mortality, especially in north-western cities, which are generally colder. A recent study regarding Tuscany in the last 50 years showed an increase of maximum, minimum temperature and an enhancement of frequency and timing of extreme daily summer temperature. Also the occurrence of heat waves showed a sharp increase with the 80% of total heat waves concentrated in the lasty 15 years in the most important Tuscany chief towns.