Interpreting States’ General Obligations on Climate Change Mitigation: A Methodological Review

A variety of norms in international and domestic law imply that States have a general obligation to mitigate climate change (e.g. no-harm principle, obligation to protection human rights, public trust doctrine). Yet, a major methodological difficulty is faced when interpreting this general mitigation obligation: how to determine the requisite level of mitigation action? This article identifies and discusses various methods for the interpretation of States’ general mitigation obligation in light of domestic cases. On the one hand, a top-down approach seeks to determine a State’s requisite mitigation action in the light of a global objective on climate change mitigation and of effort-sharing criteria. On the other hand, bottom-up methods put emphasis on the demand for internal consistency, on the obligation for a State not to downplay its contribution to environmental impacts unfolding beyond its territory, and on various emerging transnational standards. The article argues that the top-down and bottom-up approaches enable a sound interpretation of States’ general mitigation obligations especially when these approaches are used in combination.