A strategic environmental assessment (SEA) is a systematic review of the impact of a project, program, or policy on the environment. Functional components of the assessment differ depending upon the environmental regulations existing in each country. The assessment results in a written report that is used to make a final decision on the viability of moving forward. If the decision is made to proceed, the SEA is used as the basis for a project-based environmental impact assessment, which takes the strategic analysis to the tactical level.
Environmental impact study became a popular topic in the 1980s with standards set in the US for identifying and cleaning up locations contaminated by government and corporate actions and the imposition of requirements on new projects to determine the environmental impacts beforehand. Over time, environmental impact assessments became a critical part of obtaining community approval and permits for local projects and formed the basis of legal liability whenever contamination resulted. This swell of support for the issue solidified the strategic environmental assessment as an indispensable first step in any proposed action in the US.
The European Union (EU) also passed specific legislation requiring members to adopt the protocol in the SEA Directive. The Directive established formal standards and procedures for conducting a strategic environmental assessment for projects and programs. Members of the EU adopted the Directive over the course of a decade, until 100 percent of members subscribed to the SEA protocol.
The procedure for a strategic environmental assessment can vary by country or context, but the basic framework tends towards an international standard. Perhaps the most formalized structure is the one outlined in the EU's SEA Directive, so it is reasonable to look to that legislation as a guide. The first step in a SEA is a screening process to determine if the action at issue falls within the Directive. In the EU, the Directive does not cover proposed policy within member countries. In a general context, this step determines if an SEA needs to be conducted at all, in the jurisdiction at issue.
Once it is determined that an SEA is required, the reviewer sets the scope of the investigation. It is impossible to determine with certainty every possible environmental impact of a proposed action. This step sets limits on what the assessment is designed to reveal. Next, the reviewer determines the current state of the environment to serve as the baseline against which the impacts of the proposed action are measured.
The reviewer uses statistical modeling, historical examples, and professional judgment to reach a conclusion on the likelihood of environmental impacts. His conclusions are presented in a report that is used to inform the public and as a basis for making the final decision on the action. If the decision is made to go forward with the proposed action, the strategic environmental assessment is used as the starting point for a tactical impact assessment that determines how best to proceed.