[pron]

That number only makes sense of people are unable to reproduce as they age. There is probably no correlation between population growth of mortal humans and immortal humans. They may have 100x more children, and they may have almost none. You can't extrapolate after such a bifurcation in the model.

In 5000 years the human race might be multi-planetary, or extinct. We have absolutely no information to make such predictions or even estimate their likelihood.

[forloop]

Yes. In 5000 or 50000 years there may be a problem with overpopulation—or not.

When someone expresses concern for overpopulation due to life extension, what time span are they referring to? 50000 years? Probably not. Looking at population growth for 100 years as per the model, the conclusion of the paper holds:

> Therefore, the real concerns should be placed not on the threat of catastrophic population consequences (overpopulation), but rather on such potential obstacles to the success of a biomedical war on aging, such as scientific, organizational, and financial limitations.