It was just over two centuries ago that the global population was 1 billion in 1804. But better medicine and improved agriculture resulted in higher life expectancy for children, dramatically increasing the world population.
Watch how our global population exploded from 300 million to 7 billion in this brilliantly visualized video by Adam Cole and Maggie Starbard for NPR.
For more detailed information on the topic, read the related article on NPR.
Moreover, I highly recommend you to watch Hans Rosling’s eye-opening and entertaining talk on global population growth (infact, this is a must-see).