Oil depletion
Over many millions of years, plankton, bacteria, and other plant and animal matter became buried in sediments on the ocean floor.
When capped by impermeable rocks such as shale, salt, or igneous intrusions, they formed the petroleum reservoirs which are exploited today.
[4][5] For the short and medium-term, oil production decline occurs in a predictable manner based on geological circumstances, governmental policies, and engineering practices.
As with individual wells, the production curves for oil fields vary depending on geology and how they are developed and produced.
Despite this, and the quadrupling of prices during the 1973 oil crisis, the production decline was not reversed in the lower 48 states until 2009.
[12] The actual U.S. production curve deviates from Hubbert's 1956 curve in significant ways: The 1970 extraction peak of conventional oil fields in the U.S. caused many people to begin to question when the world production peak would occur.
The use of fossil fuels allows humans to participate in takedown, which is the consumption of energy at a greater rate than it is being replaced.
The industrial economy is currently heavily dependent on oil as a fuel and chemical feedstock.
The increase in food production has allowed world population to grow dramatically over the last 50 years.
Pesticides rely upon oil as a critical ingredient, and fertilizers require natural gas.
For example, by far the biggest fossil fuel input to agriculture is the use of natural gas as a hydrogen source for the Haber-Bosch fertilizer-creation process.
Oil shortages may force a move to lower input "organic agriculture" methods, which may be more labor-intensive and require a population shift from urban to rural areas, reversing the trend towards urbanisation which has predominated in industrial societies; however, some organic farmers using modern organic-farming methods have reported yields as high as those available from conventional farming, but without the use of fossil-fuel-intensive artificial fertilizers or pesticides.
A large proportion of the developed world's population live in suburbs, a type of low-density settlement designed with the automobile in mind.
A more modest scenario, assuming a slower rate of depletion or a smoother transition to alternative energy sources, could still cause substantial economic hardship such as a recession or depression due to higher energy prices.
There are, however, concentrated solar power plants using thermal storage that can store energy efficiently for up to 24 hours.
