Surprisingly little scholarly attention has been paid to the role which environmental non-governmental organisations (ENGOs) have played in EU climate change politics, although there are exceptions (e.g. Long et al. 2002; Wurzel and Connelly 2011a; Schoenefeld 2014). This stands in contrast to a reasonably extensive literature on ENGOs in EU environmental policy in general (e.g. Long 1998; Adelle and Anderson 2013). This chapter starts with an overview of the historical development of climate change-related activities by Brussels-based ENGOs. It then assesses the four main themes of this book, namely leadership, multi-level and polycentric governance, policy instruments and the low-carbon economy.