Introduction

Chemistry has done a great deal to improve the quality of everyday life, but that same progress has put human health and the global environment under threat. Rising human population together with the industrial revolution have made energy crises and environmental pollution two of the most pressing global problems of the 21st century. Minimising these problems requires adopting green chemistry -- an approach to chemistry that aims to maximise the efficiency of chemical processes while minimising their hazardous effects on human health and the environment. Formally, green chemistry is the use of chemistry for pollution prevention: the environmentally conscious design of chemical products and processes so as to reduce or eliminate the use and generation of hazardous substances. The concept of green chemistry was coined by Paul T. Anastas, and reducing the impact of energy crises and pollution -- while conserving natural resources -- calls for implementing, wherever possible, the twelve principles of green chemistry that Anastas enunciated. Before working through those twelve principles, the chapter opens by asking the student to recall what 'environment' means, which factors affect it, what pollution is and its types, and why pollution occurs -- prior knowledge the rest of the chapter builds on.