Kluwer Law's International Encyclopaedia of Laws: Environmental Law has an encyclopaedic entry for international environmental law (University of Melbourne staff & student access only).
The Max Planck Encyclopedia of Public International Law IEL category provides a comprehensive and authoritative overview of all aspects of IEL and is a great starting point for your research. Each entry in the Encyclopaedia is linked via the Oxford Law Citator to other relevant entries in the Encyclopaedia and to relevant decisions in international courts in the Oxford Reports on International Law. (University of Melbourne staff & student access only).
Oxford Bibliographies Online - International Law provides authoritative research guides combining encyclopaedic entries and annotated bibliographies on all aspects of international environmental law. (University of Melbourne staff & student access only).
Disputes between States concerning international environmental law can be heard in the International Court of Justice (provided the dispute is between States that have declared that the ICJ has compulsory jurisdiction). The ICJ is a court of general jurisdiction that provides Advisory Opinions and decides contententious cases. Full text ICJ IEL decisions can be found on ECOLEX (open access). Inter-State litigation is based on the remedial principle of 'State Responsibility' or international tort law. THE ICJ is only able to determine disputes between States: individuals and other non-state actors are not able to be parties to a dispute.
Environmental protection disputes between States and non-state actors such as individuals, communities and corporations can also be heard in international human rights courts such as the European Court of Human Rights and the African Commission of Human and Peoples' Rights. IEL decisions from human rights courts are available on ECOLEX.