I will give you the benefit of the doubt, as I was talking more about scaling the existing American style diet rather than everyone growing fungus or soylent green in the basement.  I guess it's possible we will also stop eating real meat and only grow synthetic meat, but I think no matter what technology does, if population stays the same or increases, we will probably do things like wipe out a majority of life in the ocean for example, and you can't just ignore that because we now have synthetic hamburgers and synthetic fish to replace them.

The ocean is the best tragedy of the commons example I can think of.  It's like going gold mining and each fish is a swimming gold nugget.  Even if the 1st world transitions to eating fungus, the 3rd world will exploit that resource until it disappears entirely in order to try and catch up to everyone else due to there being no out of pocket overhead to create it.

It's kind of ironic that you advocate technology solving all the world's problems when people like Armstrong are saying the coming financial collapse could send us back to the Dark Ages.  When things like that happen, people could be forced to try and live off the land for extended periods of time, and you can't just have every acre of land on the planet covered with concrete and the ocean devoid of life to do so.  Technology is not a net gain because each problem it solves just create a new dependency to enslave you.

During the Bosnian/Serb war for example, people there were not using technology to grow food in their basements, they were eating pigeons.  That's what it all comes down to, what resources exist in the real world and not in a computer.