ACB and sierra have such blinkered views. As long as mankind...

ACB and sierra have such blinkered views. As long as mankind survives self destruction and other forms of global disasters (asteroid, disease, etc.) then our population will grow. There's no shortage of resources. Asteroid mining is one of many ways we can find sufficient mineral and other resources. This is not new - in time we will have the technology to achieve this. More advanced forms of energy creation such as nuclear fusion will also be possible. Food production using highly scalable and advanced methods are on the drawing boards. etc. etc.

So, there's no real need to go back to prehistoric times to have a good quality of life. As to whether we will survive any of the possible disasters I mentioned above, well only time will tell. Most are not within our current means to do anything about. In the future most will be. For example plans to avert asteroid collisions are being discussed, although not much is being done at the moment. Self destruction via some nuclear war or such like is a distinct possibility but helpfully not likely.