Peak oil is defined as the time when the maximum production of crude oil is reached. Some people believe we have reached this point now, and that we will be unable to increase production in the future to meet demand. This will lead to huge deficits and large spikes in the prices of crude oil as it will become more and more expensive to drill for oil. However, other people believe that increases in technology in the near future will lead to greater oil production that will be able to keep up for market demand, and that renewable energy sources will slowly replace fossil fuel demand.