Introduction

While the biodiversity assessment framework that this book promotes is relatively new, the process into which this framework should be integrated is not. Environmental assessment has been around for more than 40 years and is practiced in some form or another in most countries around the world. The principle behind environmental assessment is deceptively simple: it directs decision makers to ‘look before they leap’. An environmental assessment should bring into focus what the likely environmental effects of a project or plan could be, before decisions on that project or plan are made. When there is a clear insight into the environmental consequences, decision makers are in a better position to direct development into a more sustainable course. Of course, decision makers do not direct development on their own. Most plans or projects concern a range of actors, from governments to the business sector and the public arena. For this reason, environmental assessment does not merely provide information but brings the various parties together to discuss this information. It provides a process for them to come to a shared understanding of the possible effects and to determine what this knowledge should mean for the plan or project at hand.

Since its early beginnings, the field of environmental assessment has expanded, both in scope and in application. Practitioners now recognise two levels of environmental assessment: (i) Environmental Impact Assessment (EIA) that is applied at the level of individual projects, and (ii) Strategic Environmental Assessment (SEA) which is applied to policies, plans, and programmes (see Box 5.1). First, the origins and early development of EIA and SEA are briefly described in this chapter. It then continues to set out, for EIA and then for SEA, some basic concepts, as well as a selection of best practice principles that have been drawn from practice and from academic research into the effectiveness of these tools.