A companion site to Nova's film that examines "human populations and environments." Find some fascinating facts in the interactive slide shows "Human Numbers Through Time," and "Global Trends Quiz."

John Green asks whether globalization is a net positive for humanity. While the new global economy has created a lot of wealth and lifted a lot of people out of poverty, it also has some effects that aren't so hot. [13:54]

Thinking about how we get calories from the land limits human population densities. [12:59]

Where do most people live? What do nations do in an effort to understand their own population distribution? This short video introduces the concepts of population distribution and density. [1:04]