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. In the last year a number of authoritative scientific bodies have questioned the integrity of the evidence quoted and called for more study. 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 shortge 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.
International environmental programmes have been developed to protect the global water supply. At a regional level, the US federal government and the EU have enacted a series of laws with strict environmental targets and regulations. The rapid development of previously slow growing economies throughout the world has given a push to efforts to clean up water supply and improve waste water treatment and disposal. The first area of investment for infrastructure in these growing economies is generally communications and energy, with drinking water supply and quality the next issue. China is suffering from an acute water shortage already and it is predicted to become much worse.
Half of China’s 617 largest cities face water deficits. Beijing is among the most water-short and with a water table which fell 59 metres between 1995 and 2000, it has been reduced to taking irrigation water from farmers and over-pumping its ground-water supplies. A 1998 Chinese assessment, reports that the water table under much of the North China Plain, a region responsible for nearly 40% of China’s grain production, has fallen by an average of 1.6 metres in each of the last five years.. A Sino-Japanese analysis has shown that water tables are falling almost everywhere in China where the land is flat and millions of farmers are finding their wells pumped dry.