Introduction

Environmental impact assessments (EIAs) are essential due diligence tools in environmental governance, increasingly used for climate mitigation and adaptation. Despite being embedded in over 180 legal regimes, domestic implementation often lacks explicit methodologies for integrating climate change. This report examines EIA regimes across 20 major economies in Latin America and the Caribbean (LAC), and East, South, and Southeast Asia (ESSEA), alongside an analysis of EIA-related climate litigation.

Climate impacts in EIA legal regimes

The integration of climate impact assessments varies significantly. One-third of the reviewed countries do not incorporate climate impacts into their EIA regimes. Where integration exists, it is often narrow, focusing primarily on direct greenhouse gas emissions evaluated late in the assessment process. Comprehensive cumulative assessments are rare, and only a few jurisdictions explicitly require Scope 3 emissions quantification. Furthermore, climate adaptation remains underdeveloped, though the Philippines and the Dominican Republic provide comprehensive guidance on incorporating climate risks and resilience measures. The report highlights the need for effective monitoring and enforcement to ensure compliance throughout a project’s lifecycle.

Climate impact assessments in litigation

Litigation is increasingly used to clarify legal obligations and enforce accountability where EIA laws are weak or silent. The report identifies 57 project-level cases and 14 policy-level cases across the reviewed jurisdictions. Most project-level cases originate in the LAC region, predominantly targeting fossil fuel projects, though legal challenges are expanding to infrastructure, mining, and data centres. Rights-based arguments are prevalent, with most project-level cases invoking constitutional rights, such as the right to a healthy environment. While not always successful in halting projects, litigation has driven policy reforms, enhanced public participation, and forced decision-makers to account for broader climate and social impacts.

Conclusion and recommendations

Uneven integration of climate impacts in EIAs creates legal uncertainty and inconsistent decision-making. To align projects with national and international climate commitments, legislators should mandate the assessment of greenhouse gas emissions, climate contributions, and climate-related vulnerabilities within EIA legislation. Regulators must develop detailed, context-specific technical guidance for significance determination, mitigation, and monitoring, particularly for high-emitting sectors and Scope 3 emissions. Project proponents are advised to transparently document assessment methodologies and seek early regulatory clarity. Additionally, project finance providers should mandate climate risk and material emissions assessments as conditions for financing, while judges should interpret EIA obligations in light of their preventative purpose and evolving international due diligence standards.