MINQI LI—The technical requirements for climate stabilization are clear. The global energy infrastructure needs to be fundamentally transformed to be based on renewables. Much of the world’s economic infrastructure will have to be changed accordingly. Agriculture will need to be reorganized to follow sustainable principles and to be freed from dependence on fossil fuels for fertilizers and machinery. The entire transportation system will have to be re-built, with railways and public transportation operated by renewable electricity playing prominent roles. The scale of the world economy will need to be reduced in accordance with the emissions reduction objectives. All of these need to be accomplished without undermining the basic needs of the world’s population.