Every once in a while, Al Gore and his buddies will say something like "support renewable energy!" "quit burning oil!" and "ride a bike/drive a prius!". Well, it turns out that we do need to do all of those things, but it's not because of global warming.
It's because of peak oil.
The issue is not one of oil "running out"; it's an issue of there not having enough to keep our economy running. This is because all oil production follows a bell curve. That's true whether we're talking about an individual field, a country, or on the planet as a whole.
Oil is increasingly plentiful on the upslope of the bell curve, increasingly scarce and expensive on the down slope. The peak of the curve coincides with the point at which the endowment of oil has been 50 percent depleted. Once the peak is passed, oil production begins to go down while cost begins to go up.
In practical terms, this means that if 2005 was the year of global Peak Oil, worldwide oil production in the 2030 will be the same as it was in 1980. However, the world’s population in 2030 will be both much larger and much more industrialized (oil-dependent) than it was in 1980. Consequently, worldwide demand for oil will outpace worldwide production of oil by a significant margin. As a result, the price will skyrocket, oil dependent economies will crumble, and resource wars will explode.
That's what we need to be worried about.