This report concerns institutional reform of the environmental pillar of sustainable development. Its focus is on legal issues that arise in the context of institutional reform. The report discusses three models of institutional reform. These three models have been defined on the basis of the current debate in international institutions and on the basis of an identification of strengths and weaknesses of the current regime for international environmental governance. The three reform models are:
1) strengthening UNEP within its current mandate, combined with enhanced cooperation coordination within groups of MEAs;
2) strengthening UNEP by adding new elements to its mandate, including establishment of a High Commissioner for the Environment; and
3) the establishment of a World Environment Organization.

In relation to each of these models the report analyses potential legal implications of reform for existing MEAs and modalities for how MEAs can be associated with the reformed institutions. The MEAs in question are all 15 global MEAs with significant links to UNEP, including MEAs concerning pollution, hazardous substances and biodiversity.