<Snipped quote by DMZ>
Really bloody advanced, that's the level.
It would bloody have to be to be able to sustain 14 billion people on it. We don't even have the resources to sustain the 7 billion of today. I propose you at least have some lore in regards to this, e.g mining facilities on other planets and, more importantly, fresh water supplies coming from other planets since there's no way in hell there'd be enough fresh water on Earth by 6000s let alone to sustain twice as many people. At least for the sake of realism (no idea why I'm insisting on it considering the plot, but it bugs me) let's say humans have been bringing fresh water from Europa, Jupiter's moon, which allegedly might have oceans of water beneath it's icy surface.
Then there's the problem with food. Apparently all of Earth is one giant urban area (which is unrealistic even with 14 billion people), that means there's no place for agriculture.