lifespans

The fact that the mid-range projections for world population rose by nearly a billion people this week should have garnered a lot more attention than it did. The UN offers biennial updates of its world population estimates, and for the last few years, the mid-range (ie, the most likely scenario) has suggested that the world will peak around 9.2 billion people near the middle of this century, and then slowly begin to decline. The 2010 estimate, however, found that the decline is no longer considered likely, and that by 2100, the world may have as many as 10.1 billion people. This raises a…