Unit I2


All countries want to develop their economies, create employment and improve the lives of their people through development projects. They may also have resources of value on the world market that attract outside developers who hope to make money by exploiting the resources.

It is normal to do an economic assessment or evaluation of a project to see if it is worthwhile financially; the money earned or value generated by the project must be greater than its cost. It is just as important to make an environmental assessment of a project to see what damage it may do and what other resources may be lost. Overall, a project should do more good than harm.

Big projects like mines and factories usually require very complicated studies to determine their effects or impacts on the environment. These are sometimes called environmental assessments or environmental impact statements. Such studies may be done by the government, by an environmental consulting firm, or by the developer, but they are generally reviewed and approved by the government. Smaller projects do not usually need such a detailed study unless they involve dangerous chemicals or occur in very fragile natural environments. But even small projects will be better designed and have a greater chance of success if they are planned with environmental effects in mind.

It is therefore important to understand the principles used in environmental assessments. If you have to deal some day with a big development project, you may need to know what to require of the developer and be able to understand an environmental report. If you are involved with smaller local projects, you should be able to apply the principles of environmental assessment in a simple way to the evaluation of such projects.

Environmental impact assessment

The procedure called environmental impact assessment is a way to put down information about the environmental effects of a development project so that decision-makers can make informed decisions about the project in the best interest of the whole country. The assessment itself is not a decision-making process, although it may lead to recommendations. It tries to explain what changes the project will make in the environment, what those changes may mean to the people in the area, and how the overall impacts may contribute to or detract from the goal of development. An assessment can contribute to the good design of a project, and help those who must approve the project to weigh environmental, economic and social factors in their decision as to whether the project should go ahead.

The following outline gives the steps involved in the environmental impact assessment of any action. An action is any project or activity, like building a road to a new area, approving the import of a pesticide, constructing a fish cannery, or selling timber rights to a logging company, for which an environmental evaluation may be useful in coming to a good decision. You can use this outline as a guide to preparing your own assessment reports of projects.

1. Describe the proposed action (or development). The description should include what is to be done, by whom, when, where and why. Give the steps involved in the construction and operation of the project, the processes and materials to be used, the resources required and areas affected, etc. This description should be as complete as possible, as it will help to identify possible effects.

There should also be a description of alternatives to the proposed action, including the alternative of taking no action at all (which may have its own positive or negative consequences).

2. Predict the nature and size of the environmental effects. For each environmental effect, give the kinds of changes, the rate at which the change will occur, and whether or not the change is reversible.

There are many different methods for predicting environmental effects, including check lists of the different possible effects, matrices (combinations of rows and columns) that list possible effects in one direction and resources that could be affected in the other, flow diagrams that show the processes or relationships between resources that could be affected, and maps with overlays that illustrate sensitive areas or areas with conflicts between uses. For simple assessments, check lists can help as a reminder of effects to look for, and maps with overlays can improve the siting of projects and identify vulnerable areas needing protection.

This section should also include a description of the present or initial state of the environment, and predictions of the probable future state of the environment without the action, and with the action. The predicted future states can be given at different times, such as at the end of the construction of the project, after several years of operation, and perhaps after the project has ended if it has a fixed duration.

3. Identify the relevant human concerns, which are all those areas of life and society where an environmental (or other) effect may have an influence on people. The range of possible human concerns is very great, including economic, social, psychological, health, safety, aesthetic, customary or historical, cultural, political, legal, scientific, conservation, etc.

4. List the impact indicators. The environmental impacts must be measurable in some way, perhaps as the amount of a certain pollutant, or the area of forest cleared, or the change in the water flow of a stream. This section should describe what can be measured, and what size or level of effect should be considered important. This is where environmental standards or emission standards come into the assessment, since these standards involve something that can be measured.

The next step is to determine what importance should be given to the different indicators, or in other words which impacts are the most significant? This is a subjective judgement that is usually based on national goals or policy, or on the views of important decision-makers.

Finally, estimate the level of each indicator for each alternative action and at different points in time (related to the future states described above).

5. Estimate the total environmental impact bringing together the environmental effects, human concerns and impact indicators in a summary evaluation. This may require some kind of broad analysis of the costs and benefits of the action, in which social and environmental effects are normalized or converted to some common units of comparison. The different costs and benefits will also probably need to be weighted in terms of their relative importance. Since this again involves subjective choices, the methods and weightings used should be described so that the influence of the subjective choices is clearly understood.

6. Recommendations may or may not be included in the assessment, depending on the preference of the decision-makers who will use the report. Recommendations could include: acceptance of the project, proposals for remedial action to improve the project or reduce its environmental impact, acceptance of one or more alternatives to the project, or rejection of the project.

7. Inspection procedures and monitoring should also be included. Inspections may be necessary to ensure that restrictions are respected and remedial actions are implemented, and that the project is not modified in ways that were not anticipated in the assessment. Continued monitoring of certain impact indicators may also be required to ensure that the project respects established limits. Inspection and monitoring also provide the basis for a review of the assessment procedure itself to see if it successfully predicted the effects of the project or action.

The above outline may make the environmental assessment of a project seem elaborate, but it is as much a way of thinking about projects as a procedure to be followed. For small projects or where resources are limited, it is possible to focus only on those few environmental effects that are known to be the most important, and to consider the kinds more than the amounts of the impact indicators.

When to make an environmental assessment

Too often today an environmental assessment is made as a kind of token gesture to environmental interests at a late stage in project development when the important decisions are already made.

If assessment is to make a real contribution to project conception, and if the worst environmental errors are to be avoided, then environmental considerations should be introduced at the earliest possible time, and integrated into the whole process of defining a project.

In the first place, environmental planning which describes the resources available and their limits and interactions should be the basis for defining what development projects are the most desirable. An environmental input into project conception should help to identify the areas to be developed, the processes to be used, the infrastructure required, etc. The environmental assessment itself should be integrated with the economic assessment, since environmental factors often have economic consequences that can affect the profitability of the project. Consultations between environmental specialists, engineers and technicians during the design stage can identify the most cost-effective solutions for respecting environmental constraints. In many cases this has led to savings on projects in comparison with the initial design. The results of monitoring during construction and operation can be fed back into better project operation. Finally there will probably need to be environmental restoration or rehabilitation of the site after the project has ended.

Some planners and economists of the old school still see the environment as interfering with their goal of rapid economic development. It is certain that environmental assessment is one more thing to be done, but if it is well integrated in the process of project development it need not lead to any delays. On the contrary it can contribute significantly to project success and often even provide cost savings. Small islands have already suffered from too many projects justified on narrow economic grounds which have been disappointing financially or closed prematurely because of unexpected environmental costs. Today, the wider use of environmental assessment of development projects is a matter of common sense.


Why is the environmental assessment of projects important?

What does an environmental assessment try to do?

What are the steps involved in making an assessment?

What are some of the human concerns considered in an assessment?

Does an assessment include some subjective judgements?

What role does government policy play in an assessment?

How is the total environmental impact of a project estimated?

When should a project be assessed for its environmental effects?

Instructions for trainers in the use of this unit

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UN System-Wide Earthwatch Coordination, UNEP, Geneva
Updated 7 April 1998