CK-12 Foundation: Earth Science: Growth of Human Populations
It took all of human history until 1802 for the human population to reach its first billion. It took just 12 years for it to acquire its most recent billion. A recent estimate by the United Nations estimates that 10.1 billion people will be here by the end of the century. For World Population Day (7/11) examine charts on the rate of growth and watch a National Geographic video titled 7 billion.