The UN population projections assume that world lifespans increase from 72.6 today to 77 in 2050 and then about 82 in 2100.
There are already populations that have life expectancy over 92 years. Asian American women in New Jersey life the longest. Decent genetics, near-optimal lifestyle and good healthcare can enable a life expectancy of 95 years without new technology.
The World Bank has projections that most of Asia will be at current Japanese levels of per capita income by 2060.
Calorie-restricted diets on monkeys showed males lived about two years longer, while calorie-restricted females lived about six years longer. There were also lower rates of heart disease and cancer in these monkeys. These are the major causes of death in people, lending support to the idea that the results apply to humans, says Luigi Fontana of the University of Brescia in Italy. The monkeys live about one-third as long as humans. There was a 30% effect on mice that live about 3 years in total. The longevity effect would likely impact human longevity by 5 to 9 years. This would mean a lot more people could make it to 95 and significantly more could make it 100.
There are combination longevity treatments that appear to have stronger life extension than just calorie restriction. There are indications that existing combination treatments could be twice as good as calorie restriction and combination gene therapy could be four times as good as calorie restriction. These treatments are also mainly just periodic injections.
If the longevity translate in a similar way as the mice to monkeys and then to humans, then human longevity technology of 2030 could enable living to 110 to 120 on a regular basis. It would take longer for this to appear in life expectancy statistics. This is because someone getting new treatment while in their 60s in 2030 would be expected to die in 2060 but would then live to 2090.
Around 2035-2060, there will be molecular nanotechnology and other second-wave radical longevity technologies.
The change in the population pyramid from 1950 to 2019 in Japan has been that the pyramid has inverted. There are now fewer kids than old people. Radical longevity will mean that instead of population pyramids having populations disappearing by 95 or 100, the pyramid will extend out to 105, 115 and then beyond. The width of those outer years will depend upon how many people adopt or can afford the longevity treatments as they appear.
Complete aging reversal and rejuvenation would mean that people would remain at peak health and fertility even if they are 200+ years of age. They would appear as if they were 25-35 years of age.