<P>More than 500 international agreements and institutions now influence the governance of environmental problems ranging from climate change to persistent organic pollutants. The establishment of environmental institutions has been largely ad hoc, diffused, and somewhat chaotic, because the international community has addressed key challenges as they have risen. The World Summit on Sustainable Development in Johannesburg in 2002 underscored the need to reform the current institutional framework for environmental governance, but failed to come up with any substantive recommendations. This book takes up the question left unanswered at Johannesburg: what international institutional framework would best promote the protection of the global environment? The contributors take a systematic approach to formulating proposals for institutional changes in international environmental governance and examine three potential models: enforcement, centralization, and cooperation through increased collaboration. They review alternative institutional arrangements to address identified weaknesses, and they elaborate upon specific reform proposals generated through recent policy debates and evaluate the potential of each proposal to remedy current weaknesses within the international environmental governance system. Reforming International Environmental Governance provides useful information about the costs and benefits of different models and approaches to reforming international environmental governance and contributes substantive analysis to future debates. </P>