Climate change is a global problem that, in order to be limited, requires strong international cooperation. Therefore, foreign policy is a crucial field that needs to be considered when analysing how effective the global community is in tackling climate change. The construction of a foreign policy strategy is brought about through implementing various policies within several domains, such as trade, energy, and financial affairs (Palmer & Morgan, 2006). Thus, the created portfolio of policies must not be seen as an independent field but has to be considered from a multi-disciplinary perspective. Simultaneously, international climate politics also must be regarded through a foreign policy approach.The European Union, by now consisting of 28 Member States, is an international set of institutions, which can neither be described as a federalized state, nor as a pure international governmental organization (Bache et al., 2014). Being constituted by several institutions, it provides the governments of its Member States and the representatives of the European citizens with various powers to act jointly within the international community on certain matters, including foreign policy on environmental issues (Treaty on the Functioning of the European Union TFEU, 2016). These powers are implemented through several different approaches, which can be understood only with the proper knowledge on the working method of the EU. In general, the European institutions can, depending on their composition, be categorized as ‘intergovernmental’ or ‘supranational’ bodies. Intergovernmental bodies are composed by delegates of the Member States and represent the respective national interests, whereas supranational bodies are acting on behalf of all of the European people (Bache et al., 2014).The European Council and the Council of the European Union are the most important intergovernmental bodies for the shaping of foreign policy (Bache et al., 2014). The European Council is responsible for defining “the EU’s overall political direction and priorities” (General Secretariat of the Council, 2017a, para. 1), whereas the Council of the European Union is in charge of all legislation, coordination of policies amongst the member states, the development of foreign policy (called ‘Common Foreign and Security Policy’), international agreements and the budget of the EU (General Secretariat of the Council, 2017b).Simultaneously, the European Commission and the European Parliament are the major supranational bodies. The European Commission is the EU’s executive body and thus represents the European Union within the international community (European Union, n.d.). This role attributes most of the power to the Commission as the chief negotiator, for instance, in international trade and climate negotiations. The European Parliament (n.d.) is the legislative body amongst the supranational institutions and thus shapes the legal conditions and contractual agreements within the European Union and the international community.Now, the competences for acting upon issues are split between the Member States and the institutions of the European Union, as defined in the TFEU (European Union, Publications Office, 2016). The EU’s institutions therefore have either ‘exclusive competence’ (TFEU, 2016; Art. 3), ‘shared competence’ (TFEU, 2016; Art. 4) or ‘supporting competence’ (TFEU, 2016; Art. 6). For decision-making on international agreements upon climate change, the environment and the Common Foreign and Security Policy are thus the most relevant defined action areas, both falling within the field of shared competences.Besides that, the internal market, transport, energy, and industry are all relevant fields, as international decisions and strategy development require policy changes in these areas. This variety of competence areas first leads to an obscurity regarding the righteous actor and, second, implicitly requires the EU to indirectly negotiate upon issues for which it supposedly only has a supporting competence. Nevertheless, Member States decided to agree upon letting the EU act as a sovereign entity in climate negotiations. This can be explained through a ‘normative institutionalism’ adapted by the Member States (Thomas, 2011b): different benefits appear to the Member States from the perspective of a united European decision-making process. Apparently, a shift towards letting the supranational institutions act independently has been made throughout the period between the first stages of climate negotiation and nowadays (Vogler, 2011).An important step here has been made by implementing the Burden Sharing Agreement of 1997. Through deciding on setting a shared goal which does not count for the Member States individually but for the whole community, the power to negotiate within the international community was also shifted to the European level. Through a shared goal in decreasing Greenhouse Gas (GHG) emissions, single Member States did not have to rapidly diminish their own emissions anymore, as other Member States also declined theirs, so that reaching the common goal was still realistic, although GHG emissions in some Member States even increased (Vogler, 2011).Finally, being legally embedded with the competence to negotiate, legislate and rule on ‘environmental protection requirements’ (TFEU, 2016; Art. 11; Art. 191-193), the institutions of the EU could emerge as at least theoretically independent actor. A united voice and strategy on the crucial issue of climate change was legally possible. How much the practical implementation succeeded so far is nevertheless to evaluate.