We have been taught this at school & university, we also see it everyday in the news. The whole world surrendered to the fact that we are such a stupid species that we are going to deplete the key source of our modern civilization.
Don't get me wrong, I am not saying that we as humans have a good record when it comes to protecting our environment and thus our existence, it's enough to look at how many different species we hunted till extinction, the amount of pollution we pumped into our atmosphere and many, many more examples. So I'll admit that we are selfish by nature YET we are not stupid. And for me, the simple statement that Petrol will run out at someday is equivalent to us saying, yes we humans are dumbest species on Earth as we'll sit there and do nothing while our key source of Energy runs dry.
So, yes, I believe the only dignified way for us to come out of this is simply if Petrol never runs out. Let's look at historically what used to happen we'd over-use one fuel, some other alternatives would come out and then we slowly shift to the new fuels, while keeping the original fuel. We still have coal don't we? and I think Petrol is no exception, on several fronts Nuclear Energy has already replaced Petrol, however our everyday life still heavily depend on Petrol, cars, planes, factories ..etc all still run mainly on Petrol. But there is also hope there, Hybrid cars are become more and more common, with fighter planes and space shuttles already running on Liquid fuels for some time (basically Hydrogen, Oxygen, maybe Nitrogen.. not a rocket scientist! :D)
So you see my point? I refuse to acknowledge the fact that Petrol will run out, because we as humans aren't stupid. When it comes to securing our livelihood we’ve been so far successful, and I'd like to think we'll continue to be so. And for that to happen, Petrol MUST NOT run out.