1. Resources and Reserves

• Resources - total amount of material that may be available in the future. Includes all known and hypothetical deposits.
• Reserves - the amount of known deposits that are economically recoverable today.

Estimates of resources and reserves are continually changing due to changing economics and technology. Makes it difficult accurately predict into the future.

• Oil and Natural Gas:

High organic productivity and depositional site that is anoxic and/or rate of sedimentation is rapid to prevent decay. Sedimentary basins on continental shelf, near river deltas, and inland seaways satisfy these conditions. Organic matter is slowly converted to hydrocarbons due to burial. Source rock (black shales) compaction forces oil and gas to migrate to more porous reservoir rocks (sandstones). Traps: where oil and natural gas accumulate; (1) Structural - anticline, fault, salt domes; (2) Stratigraphic - pinchouts, unconformities.   World Distribution: about 2/3 of oil reserves are found in the Middle East. Eastern Europe, Russia, Gulf of Mexico/Caribbean regions account for much of the rest. How much is left?: Reserve production will slow in about 30 to 40 yrs. and probably be depleted in 100 years. This will probably be extended (perhaps 200 years) mainly due to changes in technology and use rates.  Estimates of natural gas reserves have been rising and will (probably already have) exceed those of oil in the future. Much cleaner-burning than oil.

• Coal:

Produced by the burial and metamorphism of plant matter, mostly accumulates in swamps and bogs. Rapid burial and anoxic environment necessary. "Metamorphic sequence": Peat, Lignite, Bituminous, Anthracite (C content increases). Huge resource; about 10x larger than oil. Probably 1000 to 2000 year reserves. In the future, coal may be processed to produce syncrude.
 
• Oil Shale and Tar Sands:

Oil shales is an organic-rich shale that can be heated and oil is extracted. Tar sands are sandstones that have very viscous hydrocarbons in pore spaces. These are syncrude resources, 2x more abundant than oil reserves. US has 50% of the worlds syncrude reserves (including coal).

• Nuclear Power:

Energy generated by the fission of 235U. Thus, the fuel is U and must be extracted; found in very small quantities (ppm) associated with granites and some sedimentary rocks. US, Canada, Australia, S. Africa have large reserves.  
•  Solar Power: energy derived directly from sun
• Photovoltaic Conversion: direct conversion of sunlight to electricity, solar panels.
• Hydroelectric: conversion of gravitational energy of flowing water.
• Wind: conversion of kinetic energy of flowing air.
• Biomass: conversion of stored solar energy in biomass. Produce methane/alcohol.

• Geothermal: Energy generated by the internal heat of the Earth. Heated groundwater is the transfer mechanism. Natural steam is most valuable for generated electricity. Feasible in active volcanic areas (Iceland, Japan, New Zealand).