Introduction

The Rio Meeting of the UN Commission on the Environment and Development (UNCED) in 1992 showed that environmental issues have moved to the centre-stage of political and economic debate. Green concerns, which were once limited to a vocal fringe of society, have become a preoccupation of our age. It is now clear that a finite earth cannot bear an infinite burden, and untrammelled economic growth is unviable. This is exemplified most starkly by global problems such as global warming, acid rain, deforestation and loss of biodiversity, as well as more local ones such as urban pollution and contamination of water resources.