Over the period since the early 1990s, the EU has made much of its claim to lead international efforts to address climate change. This EU role would have appeared unlikely in the early days of the integration project. The Treaty of Rome contained no explicit environmental provisions, but since then EU environmental policy has developed from an ‘incidental’ policy in the 1970s, which focused primarily on removing barriers to trade between member states (Hildebrand 1992), to a ‘system of environmental governance’ (Weale et al. 2000). However, the story of the development of EU climate change policies and institutions is one of uneven development. There was much hope and ambition in the 1990s with strong targets (by global standards) for greenhouse gas emission reductions, but little success with respect to the development of concrete policies to implement those targets. By contrast, the 2000s saw deepened Community-level climate change policies, but in the period since 2010 there has been a noticeable dampening of enthusiasm for EU climate policy development, though policies and institutions developed in the late 2000s remain in place. A substantial literature has developed seeking to analyse and assess domestic and international aspects of EU climate policy (Gupta and Grubb 2000; Oberthür and Roche Kelly 2008; Schreurs and Tiberghien 2007; Wurzel and Connelly 2010b; Jordan and Rayner 2010; Jordan et al. 2012). Some scholars have sought specifically to understand EU climate policy as an instance of regional institution-building (Sbragia 1998; Sbragia and Damro 1999). With few exceptions, however, the existing scholarship has not adequately connected the dots between the domestic and international aspects of the development of EU climate change policies and institutions (for partial exceptions, see Costa 2008; Oberthür and Pallemaerts 2010). This chapter contributes to the existing literature by emphasising in particular the interaction of internal and external drivers of integration in the area of climate change policy. It seeks to answer the question of how and under what conditions the challenge of responding

to climate change has driven processes of regional integration in Europe. In particular, how can we understand the timing and trajectory of EU climate policy development, and what is the relative importance of internal and external factors? To answer these questions, the chapter traces the relative importance of three drivers of EU climate change policies and institutions: prointegration policy entrepreneurs, issue-specific factors including concern to tackle climate change and interest in developing new low-carbon industries, and the external context. It makes two principal arguments. First, the principal factor that explains variation in regional integration in this policy area over time is the level of commitment of member states to taking action to combat climate change. However, the external context has had a strong effect on the timing and trajectory of European integration in this area. Attempts to build strong European institutions and policies to combat climate change have been driven significantly by, and have been partly a response to, external circumstances – particularly the process of international negotiations to build a climate regime. The chapter is structured as follows. The second section sets out three drivers of EU integration in the area of climate policies and institutions. The third, fourth and fifth sections then trace the relative importance of these drivers over the periods 1990-1999, 2000-2009, and from 2010 to the present. The chapter concludes with reflections from the European case on the prospects for the development of Asian regionalism in the area of climate change.