The series moves to China, whose soaring population and rapid industrialization have created a boom in urbanization that is unprecedented in human history. To try to tackle this global issue, "China: From Red to Green?" explores green design solutions in both theory and practice, including Steven Holl's Linked Hybrid project, which will have the largest residential geothermal heating/cooling and greywater recycling system in the world upon completion. William McDonough shares his innovative plans to make China an entirely sustainable country and the ways architecture can be both profitable and environmentally intelligent.