Politicians stand at a crossroads where the path to green policies is fraught with political risks, as the immediate costs to society may overshadow the profound future benefits. Lorenzo Forni sets out the decisions we need to take to collectively save the world from the ravages of climate catastrophe and how politicians might keep voters on board with the green transition. He shows how reaching the net-zero emissions target to forestall further climatic change cannot be achieved by small changes in individual lifestyles alone, but requires big and brave public policy enacted by governments that is properly financed and economically sound.