Over the past decades, global environmental governance has significantly developed and now includes a large number of international agreements, mechanisms and institutions. However, as 2019’s climate strikes and demonstrations have highlighted, no significant improvement has been achieved. In order to achieve long-term and profound progress in environmental governance, policy focus needs to be complemented by intensified efforts to strengthen environmental rule of law. To do so, the capacity of international courts to pronounce judgements on environmental matters, the clarity and scope of environmental legal principles, and compliance with and implementation of judgements must be further strengthened. This policy brief outlines concrete steps which justice and foreign ministries can take, both nationally and internationally, in order to strengthen environmental rule of law.