World Population Day began in 1987 after public imagination was sparked by the idea that there could be 5 billion people on Earth. Today, we’re well past 7 billion and according to the latest UN projections, headed north of 9 billion by mid-century.

“Population is critical to thinking about sustainability and human wellbeing, and how we live and subsist on the planet,” says ECSP’s Roger-Mark De Souza on this World Population Day.

As the largest-ever generation of young people enters adulthood, armed conflict is having a profound effect on their future. People under the age of 24 comprise nearly half the world’s population but are the primary participants in conflict today. Conflict is more prevalent in younger societies, and half of all forcibly displaced people are children.

Adaptation, mitigation, or suffering – those are the three choices people the world over face when confronted with climate change, wrote guest contributor Paul Wapner in one of last month’s most popular posts. Joining him were new posts on population, climate, and peacebuilding efforts in Africa and how “smart city” technologies are being applied in growing urban areas around the world.

My grandmother was pleased when I told her I was heading to Ethiopia last November for an international conference focused on population, health, and the environment.

“You can look into the future a couple decades and get a very good idea about where countries are going,” said Richard Cincotta during a presentation at the National Defense University last summer – at least when it comes to demography.

The May edition of Reproductive Health Matters is a special edition on sustainable development and reproductive health and rights. Our own Roger-Mark De Souza writes that in the quest to build resilience, development practitioners can learn from integrated population, health, and environment (PHE) programs.