Pop Quiz: do you know how many people are in the world right now?    The answer is 7.6 billion.    That data point and much more are contained in a report called "World Population Prospects: The 2017 Revision," which was recently published by the UN. The report contains all sorts of facts and figures that are both interesting on its own, but also extremely consequential to understanding the future of our species in a very literal sense.    On the line with me to talk through some of the demographic trends of the world's population, is John Wilmoth, Director of the Population Division at the UN Department of Economic and Social Affairs. We discuss the trajectory of the world's population including where the big population centers of the future will be. We also have a fascinating conversation about the relationship between contraception, child survival and population growth and why, from a policy perspective one of the more useful things you can know is the age distribution of a population -- and here, Europe and Africa represent two extremes that we discuss at length.    I promise after listening to this interview you will about the world demographics and why it matters.   Leave a review on iTunes!    You can EMAIL Mark by clicking here.    Become a premium subscriber to unlock bonus episodes, earn other rewards, and support the show! Bonus episodes for premium subscribers include: #1: International Relations Theory, explained. #2: A Brief History of Nuclear Non-proliferation #3: A Brief History of NATO #4: The Syrian Civil War, explained.  #5: Meet the Kim family of North Korea. #6: Better Know Vladimir Putin #7: How to Get a Job at the United Nations   #8: How to Pick the Right International Relations Graduate School