For years, those alarmed by fears of overpopulation have cited dire scenarios of the world’s numbers climbing to levels of 30, 40, or even 50 billion people over the next two centuries. But are such concerns warranted? Well, according to recent U.N. findings, they simply arenâ€™t, and the reason is because of declining fertility levels. In short, although the world’s population did quadruple in the 20th century, the global fertility rate has since dropped from 6 children per woman in 1900 to only 2.7 children today. Since this level is likely to further diminish, according to U.N. experts, this means that by the year 2300 there should only be 9 billion of us here on planet earth – which leaves plenty of room to be fruitful and multiply.