Since the Earth Summit in Rio 1992, several calls have been made for a world environmental organisation (WEO), and only during the last year, in the run-up to Rio+10, five more have been added. In total, we have found 17 proposals for a WEO. We review, compare, and briefly discuss rationales, models, tasks, organisational set-up, relations to multilateral environmental agreements (MEAs) and organisations such as UNEP and the WTO, as well as the role of principles, compliance and the interest of developing countries. We conclude that a majority of proposers is in favour of an autonomous coordinating agency, that is, a medium level of integration. Frequently the WTO is mentioned as a precursor agency on which a WEO should be based. We question the effectiveness of a ‘WTO for the environment’ and suggest that other models ought to be considered.