Asia’s urban population is growing at an unprecedented rate. It took 130 years for London to grow from 1 million to 8 million, but Bangkok did it in 45 years, Dhaka in 37 years, and Seoul in only 25 years. Asia’s rapid urbanization—driven by entrepreneurial and commercial dynamism—has been pivotal for its stellar growth, but often to the detriment of urban environments. Increasingly, the environmental downside of urbanization, rather than its economic upside, is in the public eye. The issues of how cities can continue to be drivers of growth—in an environmentally sustainable way—is rising on the development agenda.