How much oil is left in the Earth?

Oil is running out. It is not a useful renewable source of energy. It takes a long time to renew the source, like millions of years, so running out is a big concern. There are over 34 billion barrels of oil that are consumed on average every year. At this given huge rate of consumption, it is estimated by the Organization for Petroleum Exporting Countries that there are somewhere around 1.5 trillion barrels of crude oil left in all the reserves in the world.

That's not near enough. Finding alternative ways to generate energy seems to be smarter than figuring out how to conserve or get more oil, but that is not the focus of oil-rich companies as they enjoy the profit that it brings. What will happen when it runs out is often a subject that's ignored, but it is one that needs to be addressed.