Do you really believe that, absent some catastrophe, demand, in the long run, will diminish anywhere?
Well, if it doesn't, so what? If the end of civilization as we know it is inevitable, does that mean we should be energy hogs now and use everything up as quickly as possible (which would bring on that catastrophe)?
Demand will level out or diminish at some point: we'll either lean to live within our means, or we'll use up our resources and return (perhaps violently) to lower populations and older lifestyles.
I favor trying to learn to live within our means. The sooner we start, the greater chance that we'll avoid a catastrophe. Technology can help. Conservation can help. That's what Carter was talking about 30 years ago. And if people had paid more attention, I think we could have been about 25 years ahead of where we are today.
And there are a few trends towards decreasing energy consumption. Population is a big driver of demand, but many developed nations are experiencing close to zero or even negative population growth. There's little reason why we couldn't reduce our gasoline consumption if we all got more fuel-efficient vehicles over the next decade, and if we didn't have population growth we wouldn't need more cars.
I agree that near-term global demand will go up, but I don't see why it needs to go up indefinitely. And that growth will stand a better chance of being sustainable if it's done more efficiently rather than less. No outcome is certain, but I think it's worth making the effort.