This article draws on the findings of the international research project on the Institutional Dimensions of Global Environmental Change to evaluate current proposals for reforming organizational arrangements that address environmental protection and especially calls for strengthening the UN Environment Programme or creating a UN Environment Organization. The first section explores pitfalls arising when policy-makers focus on form before sorting out functional matters. The next section examines institutional challenges confronting efforts to create effective environmental governance systems. The final section broadens the scope to address issues extending beyond environmental protection in a world of nation states. The goal is not to throw cold water on specific proposals of those who advocate organizational reform. Rather, the article argues that form should follow function in this realm as in others. By itself, organizational reform cannot achieve environmental protection, much less the broader goal of sustainable development.