Foster, Stephen; Chilton, John; Moench, Marcus - 2012
Some 200 million people lived on Planet Earth at the start of the modern era. That number rose to 2.5 billion by 1950. At mid-2008, the population is now 7.0 billion and is expected to reach 9.0 billion by 2040. It thus took 1,950 years for the global population to grow ten-fold but only an...