That's basically what we already do for copper. A copper "mine" takes something that isn't much different from random rocks, and separates out the copper. Copper ores that have a high percentage of copper have been gone for a while now. Copper used to be so cheap they used it for pennies, now it's so expensive that people break into houses to steal the wire. But we haven't run out.
>Scaling up our energy production with a factor 100 just by replacing traditional power plants with nuclear will never reach that factor.
Well obviously we'd need to build new plants. What's the limiting factor preventing us from creating 100x as many nuclear plants, provided sufficient money to build them?
> The claim that the use of greenhouses could scale up our global food production with a factor 100 is absurd.
Why? Greenhouses produce far more than 100x the calories/acre than wheat or corn land. It's far less absurd than urban vertical farming which uses artificial light instead of sunlight, yet there are several startups that think vertical farming is viable and have received tons of investment.
To change food for everybody, it has to scale. Greenhouses are a pretty expensive way to grow food. Just look at the prices charged for greenhouse vegetables.
100X would be hard to hit. Iowa grows enough corn to feed 2 USAs (if we were content to eat just corn). But that's a long way from 100X.
I say we could easily do so. But you need all three 100X's: miss one and it would be probably impossible, as you say.
And most any place else has less yield per acre. So now what? Its a big world but the low hanging fruit is already in use.
100X is a mighty stretch. Even Wallace and Borlaug would throw up their hands.
http://www.livescience.com/16493-people-planet-earth-support...
Freshwater is synthesized from seawater now. If the GDP increases 10,000% it will be inexpensive.
http://blogs.ei.columbia.edu/2013/04/01/phosphorus-essential...
Just because it is somewhere in the Earth's crust, it doesn't mean that we are able to harvest it.
> 2: With enough money, we could do this with nuclear power today. I don't think we're too far away from being able to do this with solar, again given enough money.
You are talking about producing 100X as much energy as we do today. Nuclear power is already used in many countries. Scaling up our energy production with a factor 100 just by replacing traditional power plants with nuclear will never reach that factor. And solar power is not even able to fulfill our current energy need, there is just not enough free surface on the earth for all those solar panels.
> 3: Greenhouses.
The claim that the use of greenhouses could scale up our global food production with a factor 100 is absurd.