1-3 Nature and Scope of environmental issues and impacts

Numerous reports on the state of the world indicate the environmental problems facing society. The Global Environmental Outlook (GEO) prepared by UNEP provides an authoritative statement of the major issues and their regional variations. In the GEO-2000 report, UNEP advises that ‘full scale emergencies now exist on a number of issues’, including water scarcity, land degradation, tropical forest clearance, species loss and climate warming. Some of these issues, such as climate warming and biodiversity loss, are global or so pervasive that they affect all countries. Other environmental problems are concentrated regionally and thus affect only certain countries or are more serious for some than others.

The major environmental challenges facing different parts of the world are listed in the table below. This sample is a starting point for discussion by participants to verify and identify regional and local examples that are of most relevance to their country, taking account of both current issues and future trends. For example, many small island states and delta regions of larger countries are vulnerable to natural hazards and threatened by sea level rise due to climate warming. Other countries are likely to experience increases in water scarcity and associated environmental stresses as a result of climate change.

Another way of subdividing environmental issues is to group them under ‘green’ and ‘brown’ agendas. The green agenda focuses on natural resource management and environmental protection issues, such as rural land and water use, forestry and fisheries and habitat and species conservation. The brown agenda is concerned with issues of industrial pollution, waste management and urban development.

When undertaking EIA, a comprehensive view should be taken of the linkages and interactions among the issues under review. Also, the EIA should identify both the benefits and costs of development. In practice, EIA often focuses on the adverse environmental impacts of proposed actions. This is done by reference to certain key characteristics, which establish the potentially significant effects (see the table below).

The impacts of a development proposal examined in EIA can be direct, such as the effect of toxic discharge on air and water quality, or indirect, such as the effect on human health from exposure to particulates or contaminants, which have built up in food chains. Other environmental and social impacts are induced, for example by a new road opening up an undeveloped area to subsequent settlement or by involuntary resettlement of people displaced by the construction of a large reservoir. Certain adverse impacts may appear relatively insignificant when considered in the context of an individual action or proposal but have a cumulative effect on the environment when added to all other actions and proposals; for example, deforestation resulting from plot by plot clearance for subsistence agriculture. A fuller discussion of environmental impacts and their analysis can be found in Section 6 – Impact analysis.

*Impact significance is not necessarily related to the impact magnitude. Sometimes very small impacts, such as the disturbance of the nest of a pair of endangered birds, may be significant. When determining the significance of the potential impacts of a proposal, all of the above factors should be taken into consideration.

More detail on impact assessment is contained in Section 6.

In many early examples of EIA practice, only the biophysical impacts of proposals were considered (such as effects on air and water quality, flora and fauna, noise levels, climate and hydrological systems). Increasingly EIA processes are used to analyse a range of impact types within a single framework. These include social, health, and economic aspects.

However this trend toward integrated assessment for decision-making is by no means universal or uniform. Even in EIA systems where this trend is well established, the degree and extent of integration varies with legal requirements and accepted practice. In some countries, social impacts are not assessed or are given only limited consideration. In other countries, EIAs are supplemented by related, but separate studies of social and health impacts.

Despite a lack of internationally consistent practice, integrated impact assessment, linking biophysical and socio-economic effects, is identified as an important priority in Agenda 21. As a widely adopted process that already covers other impacts, EIA is recognised as one of the best available mechanisms for implementing an integrated approach. In practice, achieving this approach will require greater attention to be given to the identification of social, health and other impacts in the EIA process. This aspect is addressed further in Section 6 – Impact analysis.