I don't understand why no one noticed this happening for so long.
| In the late 2010s, a new generation of military leaders was brought in on a long-standing secret, that we had millions of people living their entire lives, miles beneath our country. During the cold war, various scenarios were run and the potential for the loss of all life on Earth from one of many possible weapons caused backup colonies to be created. One of these was on the Moon, but nine others were placed in natural and artificial caverns when they were available. The moon colony cost more than the other nine put together but it also had all of the biggest names attached. Since everyone already knows everything that goes on in that place, I wanted to concentrate on what was happening in the other nine. The technological breakthroughs are well studied now of course but no one seemed to notice the statistical anomalies involved in the deaths of residents of these bases.
The doctors living in the bases assumed that people were living longer lives everywhere, not just underground. Children grew up at the same rate and everyone just assumed that real pure air, water, and food while not being able to smoke or drink in excess eliminated most age-related issues like heart disease, strokes, and mental decline. The colonists were rigorously screened for genetic issues like dwarfism or anything obvious in their family histories so the lack of aging wasn't as obvious. There were not many people who might lose their hair, to begin with, and everyone just forgot what old people looked like. It wasn't until we had a video conference going with one of the colonies and I called one of the senior scientists a young man that I found out how old they really were.
He looked to be in his early thirties but was apparently one of the original scientists which would have made him in his mid-seventies to possibly early eighties. Everyone who was living in these bases was living extremely long lives with nearly no aging once people reached maturity. They continued to be healthy and fertile for decades past our surface lifespans. No one had been suffering from age-related problems. Even animals were living multiple times longer than they did on the surface.
The scientists underground had assumed the surface world was experiencing the same thing with improvements in medicine and access to clean air, food, and water but sadly it was not the case. Animal experiments since then have determined that the combination of high air pressure and lack of radiation from space and the sun kept us from suffering most of the age issues that we have been used to.
Our research indicates that animal life on Earth will experience extreme lifespans once the current ice age fully ends and the water frozen in ice around the world flows back into the oceans and the air pressure rises back to normal once more. Being able to live healthy fertile long lives will mean that there will be far more animals living at any given time.
Further research will be performed to determine if there is a limit to the benefits of increased air pressure.