With the U.S. population approaching 300 million and the world's having passed 6 billion, I started wondering how many people had ever lived on Earth. I started looking around on the Web and finally found someone who addressed the question. You have to go almost to the bottom, but the answer is 106.5 billion, which makes today's 6.2 billion about 5.8 percent of the total. There are lots of qualifiers for the estimate, as we might expect:
Any such exercise can be only a highly speculative enterprise, to be undertaken with far less seriousness than most demographic inquiries. Nonetheless, it is a somewhat intriguing idea that can be approached on at least a semi-scientific basis.
And semi-scientific it must be, because there are, of course, absolutely no demographic data available for 99 percent of the span of the human stay on Earth. Still, with some speculation concerning prehistoric populations, we can at least approach a guesstimate of this elusive number.
