OK ToucanSam, forget about the need for consuming luxuries, which I am assuming you are referring to with "building larger more consuming societies". Take just the essential need of FEEDING society. Only the use of cheap energy to increase the efficiency of food production has allowed civilization to grow to the level it has (billions). If energy was suddenly a lot scarcer, food production will suffer and I believe just feeding the billions will be a very serious issue. The use of energy is involved in every aspect of human activity, like powering farm machinery, to cheaply producing insecticides and powering the logistics chain to distribute the food. Only about 25% of energy is used for motivating personal transportation. That 25% is also vital to the economy however because people need to get around efficiently in order to facilitate the exchange goods and services. Yes, one day the oil will run out, and it will not be a good day for mankind, as it was a very important factor in our rise from a pre-industrial civilization. It is still vitally important however that the production of this resource is not hindered by social instability (re Islamic fanaticism, sociopathic dictators) for AS LONG AS POSSIBLE. Hopefully a fairly affordable alternative will be developed. No alternative exists today or will be developed for the foreseeable future. Take the much heralded hydrogen energy source. Hydrogen is not abundant as H2, the necessary form for energy use. It must USE ANOTHER energy source to convert it to H2. Therefore all that is happening is the transfer of existing energy, such as that in fossil fuels, to the hydrogen, like a battery.
When it comes down to it, the fundamental problem is not the "consuming" but it is population growth. Population growth is the primary problem as any gains made by more efficiency or consuming less will be quickly negated by more consumers. World population growth should be attacked relentlessly rather than consuming. The problem is that it is more emotionally acceptable to restrict purchasing behavior than the right to have babies.