I really like this and as a biologist I am quite aware of this problem. What you might want to ask though is what would be a sustainable system... where humans can retain the technology needed to maintain a civilization. Technically I've been working on this problem for decades. My 30 second elevator pitch would be: I look at it in the context of how can humans adapt genetically and strategically to the new ecology they need to find to allow long term survival and development after leaving the "hunter gatherer, tribal ecology" for the farms and cities of civilization. It's pretty solid if maybe a bit mundane. I pretty much solved the Genetics part of that in "Genetics For A New Human Ecology".

Really though, your essay here brings some details into focus... or maybe some questions. I may have an answer for you. Ecology is the basically the study of a species' energetic and reproductive strategies. You can easily see how complicated that gets when talking about human ecology... errr... I mean ecologies. My next project was going to be a description of that "energetic" part, which would include resources. I think it is solvable, but as usual, not the way most people would usually think. Part 1. Recognize, husband and increase the greatest wealth there is, which happens to be completely renewable. That is genetics. My book says how to do that ethically and economically as well as why we have no choice but to do so. Part 2. Describe the energetic requirements of humans. It's higher than it looks, one of the reasons for why slavery has been so common. Genetics can help with that problem, as can some other strategies. Part 3. That would be the part that solves the problem you lay out. I think it could be done. Oh yeah, Part 4. Get people to grow up a bit and take control of their destiny so they aren't just reacting as disasters happen. I think I know how we can do that too. There is one time when humans naturally think about the future.