There's ~75 years left in this century and the world average age of death is currently about 70. So this metric would need to increase by 30 years from 2024 to 2100.

@RemNi it can get up to 80 by simply improve access to existing medical technology, but then getting the extra 20 years would require new treatments that are also widely available.

@RemNi but humans born in 2099 will be living to 100+, even if humans born in 1999 are beyond salvage.

Assuming that humans aren't extinct by then, but that's not a 62% likely outcome.

@MartinRandall This question is for the "age of average death" in 2100 right?

@RemNi Is it? It says "start living", not "stop living"

@MartinRandall but then surely the resolution date should be 2200 and not 2100 if that's the logic

There will be about 10 billion people at the end of the century. Perhaps the rich will life on average for a 100 years, but never humans on average. And in addition: For every one who dies at 20 by an accident or as soldier someone else would need to be 180 years old.

Humans as in the average world inhabitant?

I would love to be proven incorrect, but the past few years have taught me that any one individual living to be 100, let alone the average person, is an exceptional achievement.

With the increased exposure to unhealth lifestyles; from the processed food we ingest, to the air we breathe, to deadly viruses and bacteria, and the virtual life that has a heavy influence on our mental health. Human life expectancy can only decline by the end of the century. Life expectancy in 2019 had risen to nearly 79 years, but it fell to 77 years in 2020 and dropped further, to just over 76, in 2021. Becoming the largest decrease over a two-year span since the 1920s.

@TafadzwaCarolGuzha Thanks for you valuable information, however I would not agree on that.
Thanks to developments in health, living circumstances, and sanitary rules, life expectancy has improved dramatically throughout the years. In pre-modern era, the average life expectancy was between 30 and 40 years, but it is more than 80 years in some of the countries. Life expectancy in 2019 was over 83 years, especially in countries with higher living standards and affluence such as Switzerland and Australia, with Japan having the longest expectancy at 85 years. On the other hand, despite the shrinking gap in life expectancy between low and high income countries, life expectancy of low income countries has decreased in recent years due to different reasons like war and inconsistency of them. However, in the long run, this scenario is likely to be remedied.
https://fredblog.stlouisfed.org/2021/05/in-poor-countries-no-richer-but-living-longer/
https://www.statista.com/statistics/264719/ranking-of-the-20-countries-with-the-lowest-life-expectancy/
https://ourworldindata.org/life-expectancy
https://www.worlddata.info/life-expectancy.php