Climate change is a serious and contentious issue. There is some disagreement on the issue of climate change as opinions coalesce but reports suggest that temperatures could rise substantially, whilst rainfall is expected to decline and sea levels to rise. The issue, in common with others such as the use of renewable energy and the privatisation of utilities, arouses much dispute and emotion. Some scientists have pointed out that the world’s climate always has changed and others have questioned the extent to which human energy usage and greenhouse gases are the root cause of climate change, while not denying the environmental impacts.
In the worst case scenario, it is predicted that the frequency and severity of droughts could increase, particularly in the Mediterranean and North African areas. Rising sea levels will result in flooding or erosion while rivers and coastal aquifers could become more salty. Initially the biggest impact of climatic change is likely to be greater water scarcity. Some water supplies could become unusable due to the penetration of salt water into rivers and coastal aquifers as sea levels rise. Water pollution could become worse as pollutants become more concentrated with reductions in river flow. Desertification may increase, having an impact on agriculture, with reduced yields of grains and other crops due to water shortages. A United Nations report issued in 2003 predicts that more than half of the global population will be living with water shortages, depleted fisheries and polluted coastlines within 50 years.
However, it should be pointed out that that water shortage is already common and that except for some specific regions which have always been dry; it is currently an issue of distribution rather than lack of supply.
Freshwater supply is threatened by the growing environmental problems of agricultural and industrial pollution. Global demand for freshwater is estimated to have increased four-fold in the last 50 years, due to population growth, growing industrialisation, urbanisation and agricultural development bringing increased irrigation needs.