This paper traces the evolution of the debate over a GEO, and analyzes its problems and opportunities in the world trading system. It first considers the genesis of proposals for a GEO, and provides a short historical account. Second, it offers one view of what a GEO might entail. The next two sections offer a brief summary of some of the main arguments for and against such a body. The fifth section discusses issues of implementation, and the relationship between a GEO and existing institutions with environmental or trade responsibilities, such as UNEP and the WTO. It also considers whether a GEO should be built up incrementally, or whether a 'grand stroke' would be more effective in establishing it. The sixth section takes up three related issues: the role of developing countries, issues of subsidiarity and the effective use of sanctions or conditionality. The seventh and final section offers a summary and conclusions.