What Does the International Court of Justice Advisory Opinion on Climate Change Mean for Environmental Impact Assessment?

The document analyzes how a 2025 ICJ Advisory Opinion establishes that states must include end-use emissions (downstream effects) in environmental impact assessments (EIAs) for fossil fuel projects. It highlights that while the opinion is non-binding, it provides authoritative legal guidance that is already influencing national and regional courts in the UK, Norway, and the EU. The brief recommends that governments update their regulations to require the quantification of combustion emissions and align these assessments with global climate objectives, such as IPCC 1.5°C pathways, to mitigate legal risks.

• The ICJ ruled in its July 2025 Advisory Opinion that environmental impact assessments (EIAs) for fossil fuel projects must account for end-use emissions from burning the extracted fuels, moving beyond the previous focus on operational emissions.
• The ICJ's position on EIAs is supported by the view that fossil fuel production is 'relevant conduct' under international law, encompassing both production and consumption activities that adversely affect the climate system.
• Judges Bhandari and Cleveland stated that the obligation to factor combustion consequences into environmental risk assessments stems from due diligence and obligations under Article 2 and Article 4 of the Paris Agreement.
• Prior to the ICJ opinion, the UK Supreme Court in Finch v Surrey County Council (2024) and the EFTA Court (2025) had already ruled that EIAs for fossil fuel projects must include downstream or combustion emissions.
• The ICJ Advisory Opinion has already influenced subsequent judicial decisions, including the European Court of Human Rights in Greenpeace Nordic and Others v Norway (2025) and the Borgarting Court of Appeal (2026), both of which affirmed that EIAs must quantify anticipated combustion emissions.
• To reduce legal risk, states are advised to implement three specific EIA standards: rejecting the 'substitution' argument, maintaining a rebuttable presumption that all produced fuels will be burned, and assessing emissions against global pathways like the IPCC 1.5°C-aligned pathways.

APA

Jones, N. (2026). What Does the International Court of Justice Advisory Opinion on Climate Change Mean for Environmental Impact Assessment? International Institute for Sustainable Development. https://www.iisd.org/system/files/2026-03/icj-advisory-opinion-environmental-impact-assessment.pdf

Chicago

Jones, Natalie. What Does the International Court of Justice Advisory Opinion on Climate Change Mean for Environmental Impact Assessment? International Institute for Sustainable Development, 2026. https://www.iisd.org/system/files/2026-03/icj-advisory-opinion-environmental-impact-assessment.pdf.

Wikipedia

{{cite report |last1=Jones |first1=Natalie |title=What Does the International Court of Justice Advisory Opinion on Climate Change Mean for Environmental Impact Assessment? |publisher=International Institute for Sustainable Development |date=March 2026 |url=https://www.iisd.org/system/files/2026-03/icj-advisory-opinion-environmental-impact-assessment.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{jones2026what, author = {Jones, Natalie}, title = {{What Does the International Court of Justice Advisory Opinion on Climate Change Mean for Environmental Impact Assessment?}}, institution = {International Institute for Sustainable Development}, year = {2026}, month = mar, url = {https://www.iisd.org/system/files/2026-03/icj-advisory-opinion-environmental-impact-assessment.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }