Originally, oil was used as a source of energy, but over the last hundred years, it's slowly seeped into every corner of our lives.

Many advances such as plastics, ink, medicine, fertilizer, crayons, bubble gum, soup, glass and tires are heavily dependent on cheap oil. Besides the environmentally-hazardous nature of oil extraction, transportation, refinement and use, one major problem is that oil is finite.

At some point, it will run out, and Earth isn't making any more.

For years, experts have been warning the world about "peak oil," a time when "the maximum rate of global petroleum extraction is reached, after which the rate of production enters terminal decline."

Eventually, oil will become too expensive and too sparse to viably meet our current energy demands and then we’ll need something new. Scroll on to learn why many say peak oil is already here...and why that's not as scary as it sounds.

CarSort's Peak Oil Infographic

Image Credit: Flickr - madaboutasia