Wow, the before-and-after pictures of some Asian cities (Shenzhen, Singapore, Hong Kong) are arresting. Hong Kong in 1967 looks so idyllic and clean! The poll

Wow, the before-and-after pictures of some Asian cities (Shenzhen, Singapore, Hong Kong) are arresting. Hong Kong in 1967 looks so idyllic and clean! The pollution in the "now" photo is heartbreaking.