People lived on Earth for roughly 3 million years before world population reached 500 million around the year 1500. Until then, the birth rate and death rate were about the same, keeping the population stable. In 1804, world population reached 1 billion and began growing exponentially during the Industrial Revolution due to advancements in medicine, technology and sanitation. Population doubled to 2 billion in just 123 years, and then doubled again to 4 billion in a mere 47 years. Today, global population is over 7 billion and we are projected to continue growing through the end of this century. This 6-minute video is powerful tool to visualize the changes in population over time.
To view the video and explore the content further, please visit www.worldpopulationhistory.org for an interactive timeline and additional teacher resources.