When I was in primary school, the global population was around five billion. Now it's over 7 billion. This video from the American Museum of Natural History explains where the growth is coming from and why it's out of control.
It took humankind 200,000 years to reach a population of one billion but only 200 years to hit seven times that number. This fascinating map tracks how our species spread across the globe like a virus and the important historic events that contributed to our growth. Here's the spiel from the American Museum of Natural History:
It took 200,000 years for our human population to reach 1 billion—and only 200 years to reach 7 billion. But growth has begun slowing, as women have fewer babies on average. When will our global population peak? And how can we minimize our impact on Earth’s resources, even as we approach 11 billion?