Resource use is a separate axis to longevity. The right industry (we already have the tech) and a hundred billion can live sustainably on what is currently desert. Remove all the tech and the sustainable population of the entire planet is mere tens of millions.
World population is also a separate axis.
If lifespan is unchanged, population goes up or down depending on rate of new children. Rich and resource-hungry westerners have the lowest reproductive rate. If we get a perfect fountain of youth, we can’t forecast how society will or won’t change. More kids, or fewer?
Likewise resources per person, will we stay in the rat race forever, or shift to working as little as possible as soon as the mortgage on the third mansion has been paid off?
Also, “no ageing” doesn’t mean “immortality”, because current rates imply there’s a 50% chance of dying from accidents or malice in roughly any thousand year period. Though again, no way to predict how that might change with eternal youth.
World population is also a separate axis.
If lifespan is unchanged, population goes up or down depending on rate of new children. Rich and resource-hungry westerners have the lowest reproductive rate. If we get a perfect fountain of youth, we can’t forecast how society will or won’t change. More kids, or fewer?
Likewise resources per person, will we stay in the rat race forever, or shift to working as little as possible as soon as the mortgage on the third mansion has been paid off?
Also, “no ageing” doesn’t mean “immortality”, because current rates imply there’s a 50% chance of dying from accidents or malice in roughly any thousand year period. Though again, no way to predict how that might change with eternal youth.