What I haven't heard much of in this discussion, given our propensity for technological solutions, sometimes at the last minute, is quality of life issues.
If we do continue this trip toward technological advancement, allowing the population of the world to increase "unchecked", who relishes the idea of never having a place of solitude (except perhaps the really rich, the so called 1%?), living in what might amount to rabbit warrens for humankind? Is this the type of world we want to leave for future generations?
It's already happening in East and South Asia, folks there in the last few decades have seen a substantial increase in their standard of living, and they want more (of what we've had for a century or so). Next will be some of the Central and South American countries (they're already on the way), some of the failed Soviet republicks in the borderland of "Eurasia", (think Kazhakstan etc), and lets not forget what basically amounts to the whole continent of Africa.
Our corporations, and those of India, Japan, Brazil, China and so on, already have starry eyes over the hoards of consumers they would just love to provide "goods" to. And there's no doubt in my mind, those folks will have their Toyotas, Hyundais, Radar Ranges, Kitchen Aid dishwashers, etc. Those corporations have no, wait make that NO reason to push for a reduction in birth rates, or eugenics, forced sterilization, incentives to have less kids, etc. They want as big a market as they can get.
I talk to my older brother about the changes we have seen in the past few decades, we don't like where it's going, we're happy we (most likely?) won't be around to see it get really bad, but feel sad for our nephews and nieces and particularly for the newest "grand nephew".
Wish it wasn't so, but it's what's likely going to happen, and perhaps there will be a major "correction" sometime down the road so that the newest member of our clan can have some semblance of a (forbid I say such a thing) natural world.
Geno
PS, please forgive I think of such a crazy idea as a "natural world". One must realize I am rapidly approaching "ancient" status in the eyes of many. Some of the places I can still get to show little or light impact of human use and therefor get the natural nod from me. Others, like the High Sierras, have gotten so crowded I hear folks are packing their poop out, can't have a fire, can't camp near a water source, the trails look like something people have been using daily since Moses was around, in other words nothing at all like the slightly used trail I hiked 45 years or so ago, that helped me realize there was a "natural world" way different from suburban SoCal and Queens NYC.
