Refer back to Part I here, where we discuss that despite the many stunning advances in medicine, there is still something within us that doubts that our present lives could be extended to 100 years.
The exponentially progressing advances in genomic and proteomic science will cure many genetic predispositions that an individual may have to certain diseases, again, with medical knowledge currently doubling every 8 years. Programmable nanobots that can keep us healthy from inside, by detecting cancerous cells or biochemical changes very early, are also a near-certainty by the 2020s. Furthermore, if just half of the world's 8 million millionaires were each willing to pay $500,000 to add 20 healthy, active years to their lives, the market opportunity would be (4 million X $500,000) = $2 trillion. The technological trend and market incentive is definitely in place for revolutions in this field.
But that is still not quite enough to assure that the internal mechanisms that make cells expire by a certain time, or the continuous damage done by cosmic rays perpetually going through our bodies, can be fully negated.
Ray Kurzweil, in his essay "The Law of Accelerating Returns", seems confident that additions to human lifespan will grow exponentially. While I agree with most of his conclusions in other areas, over here, I am not convinced that this growth is accelerating at the moment. I feel that the new advances will be increasingly more complex, and only the most high-informed and disciplined individuals will be able to capitalize on the technologies available to them to extend their lifespan. This will benefit a few people, but not enough to lift the broader average by much.
However, where I do agree with Kurzweil and other Futurists is the concept of a Technological Singularity and Post-Human existence. The advances in biotechnology and nanotechnology will become so advanced that humans will be able to reverse-engineer their brains re-engineer their entire bodies down to the molecular level. In fact, you could effectively transfer your 'software' (your mind) into upgraded hardware. This is not as crazy as it sounds, as even today, many devices are used within or near the body in order to prolong or augment human life, and many of these are fully part of The Impact of Computing; so both their sophistication and number could rise rapidly.
This potentially will afford immortality to the human mind for those fortunate enough to be around in 2050 or so. Of course, as the years progress, we will have a better idea of how realistic this possibility actually is.
So that is my conclusion. Average human life expectancy will make moderate but unspectacular gains for the next 50 years, with only those who maintain healthy lifestyles and are deeply aware of the technologies available to them living past the age of 100. This will be true until the Technological Singularity, where humans *may* be able to separate their minds from their bodies, and reside in different, artificially engineered bodies. This is a vast subject which I will describe in more detail in future posts. For some reading, go here.
Also read about The Longevity Dividend.