Fossil fuels are what's left of ancient (dinosaur-type era) living things, crushed and simmered deep in the Earth for millions of years as more and more layers of mud covered their bodies. As the mud turned to rock, the organic matter turned into a rich soup of molecules called hydrocarbons. Then some hairless monkeys started digging it out, and found that it burnt real good. They called this hydrocarbon-rich material coal if it was solid, crude oil if it was liquid, or natural gas. And they burnt it, and it produced a lot of energy, more energy than anything the monkeys had burnt so far. It was really light for the amount of energy it had in it, too, so you could take a bottle or a lump of it with you and use it for transport without it weighing you down. And the monkeys used more and more of it for more and more things — oil could be turned into waterproof, mouldable, lightweight materials, which were just great for making disposable beverage containers and costume jewellery.
None of the monkeys thought about where this magical stuff came from for a long time. Even when some of them realised it was made of extinct creatures underground for millions of years, they thought the supply was as near infinite as made no difference. Besides, these fuels were so damn good it would be dumb not to use them! So they used them more and more, for planes and rocketships and carring their shopping home, for encasing their goggleboxes and making artificial ski-slopes, for wrapping food and for burning to make electricity. So much electricity.
But it was still a finite supply, and as the monkeys used more and more every day, they ran out of oil that was easy to get to. They had to go deeper into the Earth, or go to more and more remote locations that they'd hoped to save for something else. And still they used more, because hey, this shit was good, you know?
Fossil fuels are called non-renewables for a reason, and that's not because we've got them coming out of our earolls (lit. 'ear-holes' — colloquial English). They are going to run out. My school science textbook (in 1997) claimed that natural gas would run out by 2005. It seems this was wrong, but it's true that supplies are dwindling. Unless you live in a hole (can I come and join you?) you might have noticed that oil prices, and hence petrol prices, are rising. That's partly because of a couple of inconvenient wars, but it's also a symptom of the output of the reliable sources dropping off, and more expensive techniques being used to get at more remote oilfields. As these sources become less profitable, people are starting to cast greedy little eyes at Antarctica, the last (relatively) unspoilt continent. Check out some statistics and graphs here to see the numbers on what we've got, what we want and what we're gonna get.
We do have a lot of coal, though. Another couple of hundred years worth, assuming our growth isn't exponential. But coal can't make plastics, coal can't make fertilizer, and coal can't go in cars (what a shame). It's possible to turn coal into oil via the Fischer-Tropsch process, but it costs a lot.
And it's a shame we're running out of fossil fuels, because they have been really good for us. High energy, low-weight fuels like petrol and kerosene enable us to travel distances daily that were unimaginable for our ancestors. We scoot across oceans to 'get away for a week'. We've been to the moon! This is great, yes?
The products we make from fossil fuels are great too. Disposable syringes, DVDs and even my favourites, organic photovoltaic cells are just a few of the more worthy things we use plastic for. (Of course, there's a lot of trash as well.)
We could use the fossil fuels we've got left for what they're really great at — transport, where you really need concentrated lightweight fuel, and plastics where you need disposable, smooth, lightweight products — and find substitutes for everything else we do with oil that's drinking up all our resources?
Electricity is the biggie. If we could generate all the electricity we use by not using fossil fuels, we'd save so much we wouldn't need to worry about them running out, unless we run a moon mission a week. We could generate electricity in a few ways, each appropriate for different countries.
Plastic products could be replaced in most instances. Food packaging is mostly unnecessary, and can be replaced with biodegradable alternatives like good old fashioned paper, corn starch for see-through windows, and cloth. Recycled textiles make great new clothes. Use your imagination.
I want to save what oil we have left so we can use it for the good stuff, like road trips and space flight and safe medical equipment. This means finding alternatives to oil use now, so we can make the transition to doing things differently and better as painless as possible. This seems obvious. I don't want to be the last generation who got to fly. Am I alone here? Is everyone so entrenched in the status quo they can't see what we have the potential for?
I guess what I'm trying to say is WHAT IS WRONG WITH YOU PEOPLE, HUH? Wake up and find an alternative.