The document discusses environmental impact assessment (EIA), which identifies and evaluates the potential environmental effects of proposed projects. The purpose of EIA is to ensure decision-makers consider environmental impacts when deciding whether to approve a project. The EIA process involves scoping, evaluating the baseline environment, identifying alternatives and their impacts, developing mitigation measures, and documenting the assessment. EIA began in the 1960s and was codified in legislation like the US National Environmental Policy Act of 1969 and Philippine laws in the 1970s-1980s that require assessing impacts of projects affecting the environment. The EIA process generally involves initial screening of a project followed by a preliminary assessment or full EIA study if significant impacts are possible.