After the Spike: Population, Progress, and the Case for People

Humanity is approaching a moment of demographic transition. Dean Spears and Michael Geruso show that the “spike” in world population in modern times is reaching its apogee and will be followed by a major depopulation of the world. The global population, which was about five million ten thousand years ago and eight billion today, is likely to peak at 10 billion in this century and then fall to two billion over the ensuring 300 years. This shift is driven by the worldwide collapse of birth rates, to levels below what is necessary to maintain population stability. The change is dramatic and is already affecting the geopolitical positions of states and regions. If nothing happens to alter trends in below-replacement birth rates, the consequences of depopulation will reverberate through every domain of human life, including the geopolitical distribution of power.