An environment risk assessment (ERA) is either a standalone procedure or as an extension to an EIA. It is also known as Probabilistic Risk Assessment and Probabilistic Quantitative Risk Assessment and is often undertaken when uncertainties of environmental impact are large and prudent decisions are crucial.

ERA can make an EIA a more holistic assessment by integrating the environmental, social and economic aspects through quantifying the frequency and severity of the environmental impact caused by any activities or planned interventions. It allows the management to compare risks in monetary terms, allocate limited budgets and prioritize issues.