"Since the Industrial Revolution, the world's human population has burgeoned as never before. In 1700 the world was home to some 700 million humans. In 1800 there were 950 million of us. By 1900, we almost doubled our numbers to 1.6 billion. And by 2000, that quadrupled to 6 billion. Today [as of this writing] there are just shy of 7 billion Homo Sapiens."