actually I'm not so sold on the high-energy lifestyle that I think losing some large percentage of it is the same thing as losing civilisation or "a decent life."  so how "screwed" we are [and I'll remark in passing that a wealth of gender politics is expressed by that colloquialism] depends on whether life without SUVs or strawberries in December seems like life in Hell, or not.  my feeling is, not so much.

people are pretty much happy or unhappy based first on the core needs -- water, food, clothing, shelter, meaning, human company -- and then on invidious comparison (misery is knowing that the other monkey's heap of nuts and berries is larger than your own, even if your own is enough to live on).  I think we could meet the core needs with only a fraction of our current energy expenditure -- that most of oour present energy profligacy is just a form of Pyramid-building, i.e. just showing off for imperial or national or caste aggrandisement.  chest-beating with terajoules.  and much of our energy wealth is invested in grotesque accumulation which only feeds individious  comparison and the ensuing misery and stress.

I'm not sure life would be all that horrible under a lower-energy regime.  my big worry -- and I don't think anyone has really got the math together on this because the problem is too big and most of the necessary numbers too obfuscated and falsified -- can we actually feed everyone a decent health-sustaining diet if we have to revert to sustainable agricultural practises?  note that I don't suggest a "western" diet which is not feasible even with all the fossil fuel we're throwing at the problem currently, but a livable diet.

attached to this big feasibility worry is the inevitable fear that there will not be sufficient political will for resource justice (or that elites with a lot of firepower at their disposal and zero conscience have too iron a grip), and that even if we could feed our current numbers with sustainable practises the attempt will never be made because the global elite will cling like limpets to their profligacy ("The American way of life is not negotiable") and not give a tinker's damn if millions starve per day, even as we don't give much of a damn when tens of thousands starve per day... as they presentiy do.  cornucopianism has substituted for responsibility and conscience for so long now that the latter qualities may have become mostly vestigial.

I'm not so much afraid of some of the shapes human life might take in a lower-energy paradigm, as I am of the global tantrum I expect from the spoilt-brat social stratum (which is larger than ever in human history thanks to the fossil fuel orgy, and I'm a part of it too) we can anticipate on our (looking pretty much inevitable) way there.

The difference between theory and practise in practise ...