Visualising How a Population Reaches 7 Billion
About this video
How we've grown so much, so fast.
In 1804, there were less than a billion people across the globe. Now, there are seven billion of us.
This video from NPR visualises the increasing population rate over time: Water drips in as each baby is born, and water drips out as each person dies.
For centuries birth rates and death rates cancelled each other out, so the level of water in the glass stayed the same. Relatively recent improvements in medicine and agriculture have slowed the leak from the bottom of the glass. More women are having babies, and these babies are surviving. The more the population grows, the fuller the glass gets.
It’s difficult to estimate exactly how big our population will be at the end of this century. The United Nations suggest it could peak at 10.1 billion before starting to decline. But even a tiny variation in fertility rates could lead to a population of 15 billion or more by 2100. Will the world overfill?
For more population data, watch Hans Rosling plot life expectancy for 200 countries over 200 years.