We are so stupid as a species sometimes. Houses because they are made of wood will not last more then 200 years at best. If we built homes from stone and concrete and limited the population it would have been so much better. The home would last thousands of years and have very good buffer against heat and cold.
With dwindling resources I would hope all the governments of the world get together and have a unified plan to control population and change how we do things. Since we are all greedy and self centered this will not happen, more likely we will horde our resources and start launching nukes to get what we want. So either way, the population will drop.
My opinion is that we will not go back to the stone age. Our books in the library's across the world will last for thousands of years. We will still have technology, solar, wind, and with research fusion. It is just that in the future we will start with a lower population and the energy we get from renewable resources only be available to a lower population.
Fusion power is promising but not available at present. Also from what I read the government is stretching a ribbon from earth to space as a way to transport stuff to space easier and cheaper. This may sound like science fiction but would it not be possible to send thousands of reflective mirrors in space to redirect the sunlight to a single point on earth and use that as a massive energy source. That is one idea I have, but don't flame me for it as I really have not given that one much thought yet.
One article on ribbon to space
http://www.sciencenews.org/articles/20021005/bob9.asp
Mirrors in space (an article)
http://peakoildebunked.blogspot.com/200 ... rrors.html
also: Space Elevator 1000 foot climb test
http://www.youtube.com/watch?v=QjcaQT_ssE4
Also here is another good way to generate electricity (Humans are such clever beings)
http://www.youtube.com/watch?v=C-EvV90MeDY
We are the Borg. Resistance is futile. Your culture will adapt to service ours. We will add your biological and technological distinctiveness to our own.