Publication Type: Conference Paper/Unpublished Manuscript Review Method: Peer Reviewed Abstract: The United States was an early advocate of including greenhouse gas (GHG) emissions trading in the Kyoto Protocol. American officials pointed to the success of the domestic sulfur trading program in the United States and argued that emissions trading provided an efficient mechanism to reduce emissions in a cost-effective manner. The United States attempted to frame the issue as one of efficiency. It does not matter where greenhouse gases are emitted. They have the same effect on climate change. Therefore, it does not matter where emission reductions are achieved. American negotiators argued that the marginal cost of reducing GHG emissions in other countries were much lower than reducing emissions in the United States. It would thus be more cost effective to purchase emission reductions achieved in other countries. The European Union and environmental NGOs attacked the trading initiative as an attempt by the United States and its supporters to avoid their responsibilities to reduce domestic emissions. They framed the issue as one of national responsibility and equity. All developed countries should rely primarily on domestic initiatives to reduce GHG emissions. The way the issue was framed made it difficult for several EU member states to openly support the emissions trading initiative – despite their need to utilize emissions trading to meet their individual emission reduction commitments. However, the European Union has become much more supportive of emissions trading and is actively working to develop a viable trading mechanism. The evolution of the EU's position provides an interesting case study to explore the relative value of the Constructivist literature's emphasis on social interaction, persuasion, and learning on the framing of emerging problems and the definition of national preferences versus a materialist focus on the costs and benefits of policy options. To what extent did the framing of the problem constrain the policy preferences of EU member states? Does the evolution of the EU's position primarily reflect a process of persuasion and learning, or does it indicate a shift in the understanding of the costs and benefits of meeting the Kyoto commitments?