What happens when the world runs out of oil?

If and when the world runs out of oil, what will take place will depend on if there are alternatives that have been tapped into such as the use of other products to run cars, like corn, for instance. Perhaps things will run on solar power. But, that may not happen because not enough emphasis is being placed on it.

It's like it's just not taken seriously and petrol is a big money maker, even for the US, so they don't try to find workable alternatives. Anything could happen, and it could be the demise of the earth.