IMPACT OF GLOBAL WARMING ON PUBLIC HEALTH

It has been known for thousands of years that climate has an impact on human health. Increasing recognition of the process of climate change, hence, global warming, has led to a growing interest by health researchers in assessing the potential mechanisms by which changes in climate could influence health. Over the past one hundred years, the global average temperature has increased by approximately 0.6 degrees Celsius and is projected to continue to rise at a rapid rate. This increase is attributed to the build up of greenhouse gases in the atmosphere where they trap heat and cause the earth to warm by the combustion of fossil fuels. There are several mechanisms by which climate can affect health. Extremes of temperature and rainfall, such as heat waves, floods and drought, have direct immediate effects on mortality as well as longer term effects. For example, populations that have experienced flooding may suffer from sustained increases in common mental disorders. Climate change is also likely to affect biodiversity and the ecosystem goods and services that we rely on for human health. Changes in temperature and rainfall may also affect the distribution of disease vectors, e.g. those of malaria and dengue, and the incidence of diarrhoeal diseases. Climate can affect levels of air pollutants, for example tropospheric ozone pollution may be higher in some areas of Europe and lower in others but the relationships are still imperfectly understood. Sea level rise is likely to threaten low lying coastal populations, particularly in countries where economic conditions do not allow construction of sea defences and other counter measures. There are also concerns that flooding, drought and environmental degradation associated with climate change may lead to population displacement and more environmental refugees. DEFINITION OF KEY TERMS:  Global warming: The term used to describe a gradual increase in the average temperature of the Earth's atmosphere and its oceans, due to emission of greenhouse gases from the burning of fossil fuels and land use chan