An increasingly complex governance architecture has become a major characteristic of current global environmental governance, often resulting in different degrees of complexity and fragmentation within global environmental regimes. Social learning processes are introduced by scholars and policy makers alike as management approaches for governing complex dynamic systems in situations that feature a high degree of complexity and uncertainty. Scholars argue that actors in complex environmental issue areas can learn in their social context and could develop the necessary knowledge, attitudes and (...) behaviour to enhance their capacity to effectively address the environmental problem. This is where this article picks up the discussion and assesses the impact of a regime's complexity on its learning capabilities. It further identifies major drivers and barriers of regime learning processes in international environmental regimes. (shrink)