ABSTRACT
Environmental issues are not new phenomena. People have always interacted with the natural world and these interactions have always thrown up challenges to human societies. Mistakes have been made and solutions often found to problems encountered or created. However, as human society has become more complex, as our numbers have increased, so the range and scale of environmental issues have multiplied. Although there are still many sizeable portions of the Earth that show little obvious evidence of human impact (e.g. many hyper-arid deserts, the deep oceans, parts of the polar regions and some of the tropical rain forests), there is nowhere that is not affected to some extent by changes in the chemical make-up of the atmosphere and associated changes in climate and pollution levels (Fig. 22.1). Likewise, the nature of relatively unaffected parts of the planet also has an impact on those regions that are directly used by human populations, through their effects on global climate and biogeochemical cycles.
