China's rapid development is influencing global patterns of resource use and their associated environmental and geopolitical impacts. Trend projections suggest that China's rise will have unprecedented impacts on the rest of the world. I examine three key drivers affecting China's emergence (scale of development, government policy decisions, and globalization), along with four factors that may constrain development (environmental degradation, political instability, coal and oil consumption, and carbon dioxide emissions). China's rise represents a tipping point between fossil fuel–based economies and still emergent sustainable alternatives. Policy precedents between the United States and China over the next decade may well determine the future course of global sustainability.