Human Population 6,000,000,000 and Growing

The world has reached a population of six billion, meaning the number of the globe’s inhabitants has doubled in less than 40 years.

It took all of human history for the planetary population to reach one billion in 1804, but then little more than 150 years to reach three billion in 1960. Now there’s twice the number.

While the world adds another 3,500 humans every 20 minutes it loses an entire plant or animal species in that same time — or about 27,000 species a year.

Despite a gradual slowing in the overall growth rate, world population is still increasing by 78 million a year-the equivalent of adding a city almost the size of San Francisco every three days.

The number of people on the planet Earth is now...