While it's true that the requirement for energy is rising, oil use specifically is not rising rapidly at all right now. It's been fairly flat the last few years and most of the majors are planning to cut back on drilling between now and 2017.

Not to say that we won't ever run out, but we've barely scraped the surface of shale and deepwater prospects,let alone Arctic.

It's quite possible that new technology for powering flight or other transport will come to the fore some day merely by its own awesomeness rather than waiting for oil to run out or prices to rocket above $1,000/bbl. As they say, the Stone Age didn't end because we ran out of stones.

Maybe so, but that's not to say that there will be enormous reserves in those places that are easy enough to get to. I can't help but feel many people are so optimistic about the amount of oil left just because it's convenient to believe there is a lot of it!

That's certainly true. Although it's hard to imagine what it would be, isn't that always the case before a major breakthrough? I can't imagine many people had visions of digging up black liquid from the ground, burning it and running cars and planes on it before they were invented!

I don't know about 15 mins, but if you think nuclear-powered planes are the way forward, I think you are 60+ years late. Under the NEPA programme (Nuclear Energy for the Propulsion of Aircraft) from the late 40's to early 60's, the USAF succeeded in building a nuclear-powered plane (a converted Convair X-6 bomber) in 1956.

Unfortunately, the program was cancelled in 1961. In any case, it was concluded that it was too dangerous for a manned air force plane to be nuclear-powered, never mind a civilian aircraft.

Well, judging by what I hear and read many people are actually pessimistic, probably due to relentless onslaught from media about negative effects of hydrocarbons or imminent collapse of supply. Not that these issues aren't real, but they seem devoid of an understanding of beneficial effects and real costs and likelihoods. This pessimism hasn't led to much action apart from hand-wringing protests and governments throwing subsidies and taxes about with little positive effect.

So in that sense some optimism would be welcome to give hope for action and offset the paralysis brought about by doom-saying.

But that optimism must be well-founded and not just a matter of believing what we want to believe, as you rightly imply.

So to answer your point about "easy enough to get to" - I'm in the drilling technology business (mostly our clients are oil & gas but also geothermal, gas storage and carbon capture) - and can see that "hard" is getting easier every day.

Just think of shale oil - many of these reserves were known about since at least the 1930s but were considered impossible to release and expensive anyway. With technology breakthroughs by some very brilliant and determined people, plus $85/bbl oil, production of shale oil and gas became more feasible. Then, once large scale drilling had got under way, an economy of scale was reached where it didn't even need as much as $85/bbl because costs came down and technology improved again, as it does when everyone is busy applying technology, and is still improving incrementally but inexorably.

So it will go with deepwater . I hope I've explained briefly above why I'm reasonably optimistic.
I also believe optimism is a greater spur to action than pessimism.

Not many, but a determined few persisted with their vision,. Meanwhile, others were probably fretting about "peak whale oil" .

It is just a function of cost - if oil hits $250-300 a barrel (due to supply/demand or taxation) the alternatives become very attractive.

I doubt there are alternatives for long haul air travel so it will only translate in higher ticket cost.

I heard one guy at a renewables conference here state that , if you took all the taxes away from oil, and all the subsidies and inflated feed-in tariffs away from wind & solar (the examples he used) , oil would have to be $2,000/bbl before those alternatives made pure economic sense.

Possibly true then, and things change all the time, so maybe not true now, , but I think when people say they'd pay more for alternatives, they imagine a bit more, or maybe double at most , but not the sort of 20-fold increase that this guy was talking about.

Then again, when I entered this business in 1979, oil was around $30/bbl (oil shock days!) then went down to $6 in 1986 (I lost my job along with thousands of others, as almost all drilling was cancelled) and slowly rose to $30 again until 2004 when it shot up again.

Now it's hovering around $100/bbl - more than triple the price ten years ago, or 16 times the price 27 years ago if you want to cherry-pick.

And what has happened? Nobody has stopped flying or driving, not in USA , nor in Europe where fuel is 2 or 3 times the price.

So:
I think we would live with $250/bbl oil. And I don't think today's alternatives would be much more attractive at that price than they are now.

So my argument is that , most likely, new transport technology or fuel source will assert itself when it's so good that it can't be ignored, but not by manipulation of the oil price by taxes and prohibitions, and not by lavishing subsidies on official favourites.

In fact that kind of thing could slow down development of better options.

Anyone who is concerned that 'oil will run out':

U.S. to overtake Russia as world’s top oil and gas producer

Sounds like nonsense. Oil and gas exploration are subsidized as well. Besdies, jetfuel isn't taxed.

All things come to an end - cheap enough oil included.

It is just a matter of when (30/50/100 years?) and at what price ($200/$300/$400?). We might still be around to see it.

As far as subsidies on oil and gas exploration goes, I'm aware of one or two historically in countries that thought they might ultimately benefit, but mostly what you read in the media is references to tax breaks as "subsidies". Given that most states charge big royalties on oil and gas production - 65% is not uncommon - before you get to all the company taxes, and I think that's what the speaker meant.