Constitutional international environmental law for the Anthropocene?

International environmental law (IEL) seems unable to comprehensively and effectively respond to the Anthropocene's deepening socio‐ecological crisis. While there are several reasons for this state of affairs, one in particular relates to the argument that IEL lacks higher‐order global constitutional‐type norms that could constrain State sovereignty and the free will of States in their relations with the environment. As a contribution to the debate on the effectiveness of IEL in the Anthropocene, we seek here for such higher‐order constitutional norms in the areas of customary international law and jus cogens. We conduct the ensuing analysis through the lens of the 'normative hierarchy' and 'global constitutionalism' theories of international law and critically reflect on the extent to which these norms could play a meaningful role to mediate the human–environment interface in the Anthropocene. [ABSTRACT FROM AUTHOR]