The Environment Consultant

Photo from the UN Stockholm Declaration where the need for environmental protection was stated.

Though now considered a standard component of major development projects, and a cornerstone of responsible decision-making around the globe, Environmental and Social Impact Assessments (ESIAs) have evolved over decades—shaped by environmental movements, legislative changes, and increasing global awareness of social and ecological risks.

This article explores the history of ESIA, tracing its development from early environmental concern to a globally recognized planning tool.

The Early Environmental Movement (1960s–1970s)

The seeds of ESIA were sown in the 1960s, a time marked by growing public concern over pollution, habitat destruction, and industrial impacts on human health. Influential works such as Rachel Carson’s Silent Spring (1962) helped ignite awareness of the environmental consequences of unchecked development.

In the United States, this growing concern culminated in the National Environmental Policy Act (NEPA) of 1969, which came into force in 1970. NEPA was the first legislation in the world to require environmental impact assessments (EIAs) for federally funded projects. This act established the concept of systematically evaluating the potential environmental effects of development proposals before decisions were made—marking the birth of formal EIA.

1972 United Nations Stockholm Declaration

The 1972 United Nations Stockholm Declaration played a foundational role in shaping modern environmental governance. As the first major international environmental conference, it produced a declaration with 29 principles that emphasized the interdependence of environmental protection and human development.

Key principles, such as Principle 2 (the safeguarding of natural resources), Principle 15 (the planning of human settlements to avoid environmental harm), and Principle 17 (the need for environmental assessments), laid the conceptual groundwork for integrating environmental concerns into development planning.

This declaration established the notion that states have both the right to exploit their own resources and the responsibility to prevent environmental harm beyond their borders. It helped to legitimize and propel the adoption of ESIAs as a tool for achieving sustainable development, influencing national policies and international frameworks in the decades that followed.

Spreading Globally: 1970s–1980s

The U.S. lead served as a catalyst and inspired other countries to adopt their own EIA regulations. Industrialized nations like Canada (1973), Australia (1974), Germany and Thailand (1975), Brazil (1977), Costa Rica (1982), and others started introducing EIA legislation within national legal frameworks and development policies.

Later, international institutions such as the World Bank began to require EIAs for large-scale projects they funded, as part of their ‘Environmental Policy and Procedures’ published in 1984. This shift helped standardize EIA practices globally, particularly in the developing world, where infrastructure and natural resource projects often intersect with vulnerable communities and ecosystems.

In 1985, the European Union made EIA a legal requirement through the EU EIA Directive, setting a biding framework for assessing the environmental consequences of public and private projects.

In 1987, the United Nations Environment Programme (UNEP) adopted the ‘Goals and Principles of Environmental Impact Assessment’. This document outlined 13 fundamental principles intended to guide countries — particularly developing nations, in establishing effective EIA systems. These principles emphasized the importance of integrating environmental considerations into decision-making processes from the earliest stages of project planning.

Earth Summit

With the 1992 United Nations Conference on Environment and Development (UNCED) in Rio de Janeiro, also known as the Earth Summit, EIA had gained broad international recognition as a fundamental instrument for environmental management.

The conference marked a significant milestone in the global commitment to sustainable development, and EIA was formally endorsed in Principle 17 of the Rio Declaration. This principle explicitly states that environmental impact assessment should be undertaken for proposed activities that are likely to have significant adverse effects on the environment and are subject to a decision by a competent national authority.

The inclusion of EIA in the Rio Declaration elevated its status from a recommended practice to a globally acknowledged obligation, encouraging countries to adopt and strengthen legal frameworks for its implementation. It also emphasized the preventive nature of EIA, aiming to identify and mitigate potential environmental harm before irreversible damage occurs, making it an essential component of responsible development planning.

The Rise of Social Considerations

Initially, EIAs were focused primarily on biophysical impacts such as air quality, water, biodiversity, and land use. However, as development projects increasingly affected indigenous communities, cultural heritage, and local economies, the need for social impact assessment (SIA) gained recognition.

In the 1990s and early 2000s, SIA began to be integrated into environmental assessments, giving rise to the more holistic Environmental and Social Impact Assessment (ESIA). This approach recognizes that environmental issues cannot be separated from their human context and that sustainable development must consider social equity, health, livelihoods, and cultural values.

From Process to Practice: 2000s–Present

In the 21st century, ESIAs have matured into a structured, multi-disciplinary process that informs decision-makers, engages stakeholders, and supports legal compliance and international standards. Organizations like the International Association for Impact Assessment (IAIA) and the Organisation for Economic Co-operation and Development (OECD) have helped shape best practices, while tools like Strategic Environmental Assessment (SEA) have extended the reach of impact assessment beyond individual projects.

Today, ESIAs are a requirement for major infrastructure, extractive, energy, and urban development projects around the world. It is embedded in the safeguards of international financial institutions such as the International Finance Corporation (IFC) and the World Bank. While the foundational purpose of ESIA remains the same—to predict and mitigate adverse impacts—its methods, focus areas, and stakeholder expectations continue to adapt to a rapidly changing world.

Explore more in this EIA Timeline