A transition from oil to some new source of energy and materials may seem scary, but in truth it has already happened before, and it will happen again more than once in the future.
When it happened before
You may not know it, but at one time humanity got all of its energy and most if its chemicals from renewable sources. Think about it; before coal and oil, we used firewood, windmills, and water wheels for energy, and we used plant fibers and certain parts of animals for chemicals (firewood ashes and lard can be used to make soap, for example). This might sound environmentally friendly, but in fact it was lacking in a few areas. First, how many trees would it take to run a city? How expensive would it be to use beeswax candles as the sole source of light in your home at night? Is it even possible to live in a place that didn't have either of these? This is where coal came in; coal is energy dense, easy to move, and has been in use for more than 1,000 years already as a source of heat. When we learned to get it easily out of the ground and make electric power and light from it in the 1800s, cities no longer needed to dedicate huge plots of forest land to heat houses, and previously unlivable areas became livable with coal power.
With coal there was a downside; it's very dirty, and in some countries their coal supply has already run out! Oil, what we use today, was the next answer. Oil of course has been used for thousands of years in medicine (think petroleum jelly), but once again, once we learned to refine it and get it out of the ground, we were able to replace candles with kerosene lamps, which made cheap, reliable nighttime lighting possible for the first time ever. When we later replaced it with electric lights, we had something even better! Imagine life without these! So there were times in the past where conventional energy was expensive, and new sources were found.
How could it happen in the future?
No one knows the future exactly, but there are a few candidates for major, large-scale alternatives to oil and coal:
- Biorenewables: For materials, we are already making alternatives to oil. You may have seen polylactic acid (PLA, one of the #7 recycling symbol plastics) water bottles already, which can be made from sugar or starch. For fuels this is an expensive option, but the technolgies used to make renewable fuels can and are being used with different "trash" sources to convert waste materials into fuels and energy.
- Waste to fuel: According to a friend of mine from Waste Management, big garbage companies are coming up with new technologies to convert plain old trash into energy. "Trash gas," or natural gas from trash, has already been around for decades.
- Shale gas/tar sands: Once conventional oil and natural gas goes above a given real price, there are a lot of unconventional sources of oil and gas, and there are a lot of these sources in North America. The main concern of course is possible damage to the environment, as these technologies are not yet as "clean" or "safe" as the traditional way of punching a hole in the ground and pulling up oil.
- Nuclear: You can't get materials from nuclear power, but there is quite a lot of uranium and thorium out there that we could use, but the main concern is to make nuclear power safer during natural disasters.
- Wind and Solar: These two are a lot more expensive and environmentally unfriendly than a lot of people realize, but what is nice about solar in particular is that you can install a panel and draw power with little further work for decades. These two technologies still need a lot of work to be cheaper, and solar power needs an innovation to use less metals, and less exotic metals (like indium) to become real energy alternatives.
My own personal view is that biorenewables and unconventional oil and gas are going to be what carries us for the next generation. After this, it's hard to say what's next, because a new technology may show up that we haven't seen before.