A broad lesson from this book is the recognition that climate change is a global phenomenon, which should be accounted for in a multidisciplinary perspective. In fact, it is impossible to deal with climate change and promote its mitigation without taking into account the agents’ choices and priorities in different countries and regions. Those choices determine the politics followed by decision-makers at every opportunity (through elections in democracies) and iterations between countries (and eventually have an effect on the well-being of populations) that should take into account the income level, the income distribution, and the health status of populations. Thus, the interplay between politics, international relations, and economics becomes a stage for the analysis made in the different chapters of this book. Additionally, climate change mitigation is crucially dependent on technological change, as is the economic development of societies.