BANGWEULU WETLANDS, Zambia – Out here on the endless swamps, a harsh truth has been passed down from generation to generation: There is no fear but the fear of hunger.

Population projections undergird many important policy decisions, from the U.S. government’s Feed the Future program to the Sustainable Development Goals. But they’re not as straightforward as they appear. Demographers often base their estimates on complicated assumptions that aren’t obvious to the end user.

“There is no magic bullet or solution to resolving climate change quickly,” said the Population Reference Bureau’s Jason Bremner at the Wilson Center on October 28. “Our next 100 years will be far different from the last 100 or the last 1000…and it has become clear that nations will have to pursue many strategies in order to reduce emissions, build resilience, and adapt.” [Video Below]

In his 2007 best-seller, The World Without Us, Alan Weisman explored what would happen to the planet if the human race suddenly vanished – the gradual deterioration of the built environment, the geologic fossilization of our everyday stuff, and the ecological processes that would rebound and thrive without continual and growing human pressure. [Video Below]

“A world in which a quarter of humanity is denied full enjoyment of their rights is an unjust world,” said Kate Gilmore, deputy executive director of the United Nations Population Fund (UNFPA). “It’s a world without the building blocks for human progress, for human peace, for human security.” [Video Below]

A quick scan through the charts and graphs of Pakistan’s most recent Demographic and Health Survey yields more than a few insights into the performance of the government’s health policies and the public health and demographic challenges it will face in the future.