The most common concern associated with the impact of radical life extension technologies is that of overpopulation. Advocates of life extension have made many arguments for why they believe population growth can be managed.
- What many people think is overpopulation is actually urban overcrowding.
- Reproduction in Third World countries is a much larger driver of population growth than life extension. If no one had died since 1900, there would be "only" 4 billion additional people on the Earth. When women are better educated and contraception is available, birth rates (the primary driver of population growth) plummet, and the focus actually shifts to getting people to reproduce more. Many parts of Europe plus Japan are actually experiencing a demographic crisis where not enough babies are being born.
- In the longer run, humanity will expand into space, where there is enough room for an unimaginable number of humans. The two primary resources required to sustain life: sunlight, carbon, and water -- are abundantly available in the solar system. The moon Titan alone has several times more fresh water than contained on the Earth.
- Concern about "overpopulation" tends to be more based on concern that more authentic, traditonal ways of life are eroding rather than concern over overpopulation per se. However, it is possible to live authentic, traditional lifestyles in any of the world's many huge empty areas. To live this lifestyle, it is necessary to leave the city and work the land. Since this is difficult for many city dwellers, they decide to focus on overpopulation instead. It would be much easier for them to just leave urban areas.