ioxles said:
I think we all need to calm down here. ...
[Snipped out some very poorly chosen links] ... Please do not take it as given that overpopulation even exists. To consider such drastic measures as have been listed such as depopulation/extermination or outright war chills me to the bone.
Your very gullible bones. Ioxles, I strongly urge you to be more critical in your reading. The various links that you have provided are fraught with political attacks, speculative nonsense, and a lot of dreamy dreams. All are warning signs against using them as information sources. They prove nothing beyond your willingness to accept rosy ideas as established processes. I strongly suggest you do some research on vetting sources of information.
For example; It's true that rainwater generally starts out as drinkable water. However, there are also industrial emissions, and shoddily constructed ponds of fracking fluid (containing diesel fuel, radium, and some other interesting things) that are going into our air and water. This is being done "legally", right now, in the United States. Bioaccumulation - its so much fun that you are doing it right now.
Another example: I'm sure you could fit 6 billion people into an area the size of Texas. But why would you want to? Texas can be an inhospitable place. The people there are generally friendly, but I attribute that to sunstroke. Who's going to pay airfare for the 4 billion asian people to get there? I think the people who live in Myanmar would like to relocate to Texas right now, so long as you're buying?
No? Well, would you mind sending about 500,000 hamburgers to them instead? Yes, sure, there is plenty of WAFLE for everyone, but the people who are starving right now don't particularly care what you call it. They'd like to eat.
Here's a fun fact; the Native Americans thought that the Pilgrims were nuts. The Pilgrims were sick a lot. They didn't seem to know that the local rivers flowed inland from the ocean. So when they dug their wells, they kept getting brackish water.
Technology is a great thing - if anyone actually APPLIES it. Application requires that someone takes the initiative. For companies, that means that there should be a profit involved somewhere. The video of getting oil from plastic is pretty neat - but it takes energy to melt those plastics. A lot more energy than you can recover in the resultant hydrocarbons. [And that 'oil' is very different from Brent crude oil.] Governments could force these applications of technology - but they'd rather get the easy money from oil and mining industries, and then squander that. So the number of entities willing and able to apply any of these population-preserving technologies is going to be vanishingly small. Like right now.
What would I do about overpopulation? Not much I can do. I can't even prevent my own government from doing 'damn fool' things. But I'll keep trying.