September 28, 2013
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In the year 1900, our planet held 1.6 billion people. Now, just over 100 years later, the world’s population has doubled — twice. It took an unbelievable “twelve years…to go from 6 to 7 billion” people. For scientists, that’s a sobering cause for concern — especially since humans add another 80 million people to the earth each year.