Faced with climate change, we must combine two types of action: reducing our greenhouse gas emissions to contain the speed of global warming; adapting our societies to the now inevitable changes in the climate to limit its damage. The reduction of emissions must be committed on a global scale: a ton of greenhouse gases released into the atmosphere from Asia, Africa or anywhere in the world contributes exactly the same way to global warming. That is why collective action is organized within the framework of the United Nations at the international level.