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When generating electricity, energy from the combustion of fossil fuels is often used to power a turbine. Older generators used steam generated by the burning of the fuel to turn the turbine, but in newer power plants the gases produced by burning of the fuel turn a gas turbine directly.
The burning of fossil fuels by humans is their major source of emissions of carbon dioxide which is one of the greenhouse gases that is believed to contribute to global warming.
There are two theories on the origin of fossil fuels: the mainstream biogenic theory and the abiogenic theory. The two theories have been intensely debated since the 1860s, shortly after the discovery of widespread petroleum. According to the biogenic theory, fossil fuels are the altered remnants of ancient plant and animal life deposited in sedimentary rocks. The organic molecules associated with these organisms forms a group of chemicals known as kerogenKerogens are chemical compounds formed by the low-grade metamorphism (i. diagenesis) of organic molecules derived from decaying plant and animal matter. Kerogens are the precursors to hydrocarbons ( fossil fuels). Labile kerogen breaks down to form heavys which are then transformed into hydrocarbons by the process of catagenesisCatagenesis is a term used in petroleum geology to describe the cracking process which results in the conversion of organic kerogens into hydrocarbons. This chemical reaction is believed to be a time, temperature and pressure dependent process which creat. According to the abiogenic theory, hydrocarbon deposits are primordial , being part of the Earth as it formed.
The biogenic theory was favored early because in the late 19th centuryAlternative meaning: Nineteenth Century (periodical ( 18th century — 19th century — 20th century — more centuries) As a means of recording the passage of time, the 19th century was that century which lasted from 1801- 1900. Events The Little Ice Age ended it was believed that the Earth was extremely hot (possibly molten rock) during its formation. This would have precluded the accretion of hydrocarbons, which would have been oxidized into water and carbon dioxide. When it was later discovered that all fossil fuels contain traces of biological debris, the biogenic theory gained strength because the idea that life (even microbial life) could exist at the depths at which petroleum had been found seemed even less plausible.
Research in the abiogenic theory is in progress. For details on the subject see the article Abiogenic petroleum origin.
The alarmist reports from the early 1970sMillennia: 1st millennium 2nd millennium 3rd millennium Centuries: 19th century 20th century 21st century Decades: 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s 2010s 2020s Years: 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 Events and trends (the 1973 energy crisisThe world oil shock of 1973 began in earnest on October 17, 1973, when Arab members of the Organization of Petroleum Exporting Countries (OPEC), in the midst of the Yom Kippur War, announced that they would no longer ship petroleum to nations that had sup) that oil suppliesCrude oil is considered a limited resource. It is estimated that there is a total of 2,390 billion barrels (380 km³) of crude oil on Earth. Estimates of undiscovered reserves range from 275 to 1,469 billion barrels (44 to 234 km³). However, these numbers would run out in the 1990sCenturies: 19th century 20th century 21st century Decades: 1940s 1950s 1960s 1970s 1980s 1990s 2000s 2010s 2020s 2030s 2040s Years: Events and trends Computers, technology Explosive growth of the Internet; decrease in the cost of computers and other techn have proven wrong, but oil is still believed to be a finite resource. Even if abiogenic oil is the source, the theory is not of practical use unless significant deposits are discovered. Significant usage of hydroelectricity and nuclear power and scientific advances have reduced the dependency on fossil fuels, of which household usage has increased nonetheless.
Sooner or later we will have to find alternatives. However many people share a viewpoint that the time at which we would run out of fossil fuels is far in the future. Some hope that by then we may have presently unavailable power systems such as solar power satellites or nuclear fusion.
The principle of supply and demand suggests that as hydrocarbon supplies diminish, prices will rise. It has therefore been pointed out that higher prices will lead to increased supplies as previously uneconomic sources become more economical to exploit. Artificial gasolines and other renewable energy sources presently require more expensive production and processing technologies than conventional petroleum reserves, but may then become economically viable.