Earlier quoted context omitted.
The costs involved in turning Mars into an experimental environment, call it a "twin", would likely eclipse the sum total of human activity to date (300k years worth) by several orders of magnitude.
That's fine, unless we have something better to do. If it takes 10,000 years or 100,000 years, it doesn't matter, unless the work being done is detracting from more important work. Many people, myself included, would struggle to think of more impactful goals for humanity to accomplish. Feeding, clothing, and housing everyone would be nice, but those things are still far more personal than any project that aims to pro…
why care about the long-term existence of our species? certainly we should strive to leave a better world for our children, their children, and their children's children, but past a certain point it seems very abstract to me. even 10,000 years is about three times as long as the totality of recorded history. in 100,000 years, our genome may have diverged enough that whatever humans live at that point in the future wouldn't be the same species anyway. why should I, a sentient sack of meat living in the year 2020 care about these things? more to the point: why should I sacrifice improving the lives of any currently living beings for the sake of ones that may live in future millennia?