Testing the role of the principle of common but differentiated responsibility in international environmental agreements

The purpose of this dissertation is to test the role of the principle of common but differentiated responsibility (CBDR) in international environmental law by looking at its contribution to treaty negotiations and outcomes. In doing so, I hope to add to the body of evidence that points towards the increasing proximity of CBDR to hard law.;The degree and manner in which the principle contributes to the agreements examined will help determine the salience of the instrument in future environmental treaties. To the extent that using the tools of CBDR foments successful treaty negotiation and outcome, the principle will continue to be used in negotiations to come, 'hardening' its normative character.;I will use a normative framework for testing the role of CBDR in international environmental agreements. In doing so I focus on state practice, and in particular on how states use the principle in specific treaty negotiation processes and outcomes. I will undertake an empirical approach, using case studies as tool for the analysis.;Arguably CBDR can play a useful role in environmental treaties in two ways: first, contributing to the negotiation process by changing hesitant country calculations for entering negotiations, guiding decision making, helping find common ground and bridging political divides; second, enhancing the potential effectiveness of agreements by introducing incentives and mechanisms to insure the necessary changes in country behavior.;Negotiations marked by acute divisions among parties are the ideal testing ground for CBDR. And given that the principle was born as result of the developed/developing country divide, it is in negotiations with a north-south component that its role can be most stark. With this in mind I chose to focus on four representative regimes: climate, biodiversity, ozone and desertification.;I will start with a brief background on the emergence and development of international environmental principles. Next I focus on what is understood by the CBDR principle, review its emergence as tool of international environmental law, and discuss some of the difficulties and controversies surrounding its use. The core of the study will consist on the case studies, where the Biosafety Protocol will be the main one.