Ebbeson's research focuses on various aspects of environmental law, usually with an international, European Community or transnational dimension. This includes studying environmental law and governance across state borders, and how issues previously considered as national are becoming increasingly international or transnational in character.

Much of his research has been devoted to the development of international and European Community rules on public participation in decision-making and access to justice in environmental matters. The topic concerns the relationship between environment protection, human rights and ‘environmental democracy´.

Ebbeson has been involved in the United Nations´work on these issues, e.g. within the framework of the 1998 Aarhus Convention (UNECE) and in UNEP´s Expert Group. He has served as a member of the Aarhus Convention Compliance Committee since 2005.

Other research themes of interest include the is environmental responsibility of transnational corporations and justice considerations in environmental law. He is currently working on a project concerning transboundary rights and duties in environmental law; an issue that links to notions of multi-level governance.