The Impact Assessment Act of 2019 replaces the Canadian Environmental Assessment Act, 2012. The Act provides the overall architecture for the federal environmental impact assessment regime in Canada. The Act broadens the scope of environmental impact assessments to include environmental, social, health and economic aspects. Section 22(1)(b)(i) requires that the body conducting the assessment must consider the extent to which the project may contribute to or hinder the Government of Canada's ability to meet its obligations and commitments in respect of climate change. Section 63(e) provides that in granting Ministerial approval to a designated project the relevant Minister must consider the extent to which the project may contribute to or hinder the Government of Canada's ability to meet its obligations and commitments in response of climate change.The Canadian government indicated in a June 2021 policy statement its intention to phase out thermal coal mining by 2030 in order to meet the Impact Assessment Act's requirements with regard to the assessment of public interest of new projects.
On October 13, 2023, the Supreme Court of Canada released its judgment in a legal challenge to the Act (Reference re Impact Assessment Act), brought by the government of Alberta. The Supreme Court found that parts of the act were in violation of Canada's constitution. Recent news reports state that, in spite of the Supreme Court's ruling, the federal government has decided to amend the existing Act to align with the Supreme Court's judgment, rather than striking down the Act in its entirety.