Immigration to outer space is unrealistic on economic grounds
That doesn't sound like the optimistic tasmodevil pondering CO2
because something has to be done about overpopulation or else all the technology fixes in the world will only buy a little more time rather than save us...the planet is finite and only so large...in fact,it seems to shrink all the time.
How small is the world? What do you mean by 'overpopulation'? To use the (in)famous example:
6,602,224,175 people in the world. 261,797.12 square miles of land area in the state of Texas (7.3 × 1012
That works out to ~1,100 square feet per person, for every person in the world, if they all lived in Texas.
Heck, my wife and I don't have 1,100 square feet in our apartment. The world is large enough that every single person in the world could live alone by themselves in their very own 1,100 square foot apartment with every apartment located in Texas. Imagine what we could fit in Texas if families combined their 1,100 square feet and if we build multi-story apartment buildings... Or if Oklahoma joined in on the fun...
The only realistic option that is humane is to toe the line when it comes to controlling the birth rate...not allow so many people to be born in the first place.
Who gets to decide how many kids a woman can have? You? the UN? The WHO? What happens when, inevitably, someone gets pregnant with that n+1th
child? Forced abortion? Exile to an 1,110 square foot apartment in Texas? Anything except allowing that child to live begins to sound like increasing the death rate - which we both agree is inhumane disrespect for human life. How do you control birth rate? Taxpayer-subsidized condoms? Forced sterilization? And how does the agency in charge of artificially controlling birth rate divine what the 'ideal world population' is?
You throw out a number of options, but have you given thought to their consequences?