Overview

The world's environment is continually changing. Originally this was caused by physical factors, for example erosion by rivers leading to mountains and valleys. Different forms of vegetation were caused by different climatic conditions depending on nearness to the equator. Cycles of long-term climate change led to glacial erosion followed by a return to warmer conditions; deserts were created by sun and wind.

Man has caused his own changes and in the last centuries, since the Industrial Revolution, the rate of change has become faster and faster. We need to use the world's resources to live and create all the things that we regard as necessary to live a good life. In the process we create pollutants and wastes that cause more and more damage and put the remaining resources at risk. For the sake of future generations some control has to be exercised.

Think for a moment of some of the biggest items which hit the news headlines fairly regularly. The holes in the ozone layer caused by volatile organic compounds reaching the stratosphere result in an increase in skin cancers. Greenhouse gases, particularly carbon dioxide from burning fuels and car exhausts and methane generated in rubbish tips will cause the temperature of the earth to rise, with potentially catastrophic results if the ice caps melt and sea levels rise. These are truly global in that the whole world contributes to the problem to a greater or lesser degree and the whole world has to find the solution. On...