Ant Forest is an app-based game that is sweeping across China. The game rewards users with green energy points for choosing low-carbon activities like taking public transportation or using less plastic. Once players have earned enough green energy, they can plant a virtual tree in Ant Forest. For every tree planted in the virtual game, a real tree is planted in rural China. The game's creator says one-hundred million live trees have been planted so far. (video by Menglin Huang) (Source: Bloomberg)