Every minute, dozens of people in East Asia move from the countryside to the city. The massive population shift is creating some of the world’s biggest mega-cities including Tokyo, Shanghai,…

Axel van Trotsenburg |

There were more than 7 billion people on earth in 2013. While this is the highest number ever, the population growth rate has been steadily declining, in part due to declining fertility rates. …

Emi Suzuki |