The transition from dirty electricity to clean sources is not the whole challenge. It’s just the lowest-hanging fruit: smaller than the challenge of electrifying almost everything that uses power, by which he means anything that runs on much dirtier gas engines. That task, he continues, is smaller than the challenge of reducing energy demand, which is smaller than the challenge of reinventing how goods and services are provided — given that global supply chains are built with dirty infrastructure and labor markets everywhere are still powered by dirty energy. There is also the need to get to zero emissions from all other sources — deforestation, agriculture, livestock, landfills. And the need to protect all human systems from the coming onslaught of natural disasters and extreme weather. And the need to erect a system of global government, or at least international cooperation, to coordinate such a project. All of which is a smaller task, than the monumental cultural undertaking of imagining together a thriving, dynamic, sustainable future that feels not only possible, but worth fighting for.