Five case studies on mitigation actions (MAs) in developing countries illustrate the rich diversity of climate action. Researchers from Brazil, Chile, Colombia, Peru and South Africa reflect on what is possible in their countries. Case studies reflect the sheer diversity of NAMAs: from a ‘Pronami’ on efficient lighting in Peru, to longer-term challenges of rising energy emissions in Brazil, and much else. The book compares the similarities and differences across eight elements that could assist in developing and implementing mitigation. The comparative analysis highlights both how challenging implementation can be in the context of development, but also points to factors that might enable ambitious mitigation. The comparison suggests that choice of Mas may be linked to institutional capacity, the resources a country is endowed with and hence its emissions profile. International support can be an important global enabler. The authors find that addressing both development and climate objectives is key. This book fills an important gap in the literature from developing country authors about mitigation actions in their own countries.This book was published as a special issue of Climate and Development.