GREGG EASTERBROOK: What Happens When We All Live To 100?

Viewed globally, the lengthening of life spans seems independent of any single, specific event. It didn’t accelerate much as antibiotics and vaccines became common. Nor did it retreat much during wars or disease outbreaks. A graph of global life expectancy over time looks like an escalator rising smoothly. The trend holds, in most years, in individual nations rich and poor; the whole world is riding the escalator.

Projections of ever-longer life spans assume no incredible medical discoveries—rather, that the escalator ride simply continues. If anti-aging drugs or genetic therapies are found, the climb could accelerate. Centenarians may become the norm, rather than rarities who generate a headline in the local newspaper. . . .

If medical interventions to slow aging result in added years of reasonable fitness, life might extend in a sanguine manner, with most men and women living longer in good vigor, and also working longer, keeping pension and health-care subsidies under control. Indeed, the most-exciting work being done in longevity science concerns making the later years vibrant, as opposed to simply adding time at the end.

I wrote about this in Forbes back in 2009.