Natural gas is a naturally occurring hydrocarbon gas mixture consisting primarily of methane and ethane. It is derived from both land plants and aquatic organic matter. Natural gas is used as a fuel for electric power generation, for industrial, domestic, and commercial uses, and as a feedstock for chemical products. The clean-burning characteristics of natural gas have led to its use as a nonpolluting transportation fuel. It is also used to make ammonia, a plant food, and chemicals such as hydrogen cyanide, urea, and fertilizers. However, methane is a potent greenhouse gas, and methane releases contribute to global warming. Some consider natural gas a transition fuel as we phase out coal and oil and phase in alternative energies.

Where does natural gas come from?

Natural gas is a hydrocarbon mixture that is more common than oil and is made of light paraffins like methane and ethane. It can be derived from land plants and aquatic organic matter and is generated above, throughout, and below the oil window. During petroleum formation's biological stage, anaerobic microbes decompose organic material and produce biogenic methane. In the mature stage, thermal methane gas is generated along with the oil. In the postmature stage, the main hydrocarbon product is thermal methane gas, a product of the cracking of existing liquid hydrocarbons.

How is natural gas used in homes?

Natural gas is a versatile fuel with several residential applications. It is primarily used in central-heating systems like furnaces and boilers, which provide heat by burning the gas and circulating either warm air or hot water throughout the house. Natural gas is also used for cooking , water heating , and powering appliances. Because natural gas burns cleanly, produces almost no sulfur dioxide, and is easy to control, it has become a popular choice for home energy.

What are the main components of natural gas?

Natural gas is primarily a mixture of hydrocarbons, notably methane and ethane, which are light saturated paraffins that are gaseous under atmospheric conditions. It can also contain propane, butane, pentane, and hexane. Other gases like nitrogen, carbon dioxide, hydrogen, helium, and argon are commonly found mixed in with hydrocarbon gases. Nitrogen and carbon dioxide are noncombustible and, if found in significant amounts, must be removed to improve the gas's heating value and combustion properties. Natural gas may also contain hydrogen sulfide or other organic sulfur compounds, in which case it is referred to as "sour gas." These sulfur compounds are removed during processing due to their toxicity and corrosive properties. Commercial natural gas typically contains 85 to 90 percent methane, with the remainder being nitrogen and ethane, and has a heating value of approximately 38 megajoules per cubic meter.

How is natural gas transported and stored?

Natural gas is primarily transported through an extensive network of pipelines . These pipelines range in size, with larger ones for transmission and smaller ones for distribution to customers. Automated compressor stations are located along the pipelines to maintain pressure. For long-distance oceanic transport, natural gas is liquefied, reducing its volume, and transported in specialized tankers. At the destination, it is stored in refrigerated tanks and then regasified. Underground gas reservoirs , including depleted gas fields and salt domes, are also used to store gas for later use.

What are some advantages and disadvantages of using natural gas as an energy source?

Natural gas is a significant energy source with notable advantages and disadvantages. It's often seen as a cleaner alternative to coal and oil because its combustion produces relatively fewer pollutants like soot, carbon monoxide, nitrogen oxides, and sulfur dioxide. Natural gas is also considered a practical "bridge fuel" for transitioning to renewable energy sources. The extensive pipeline infrastructure in the U.S. and other countries facilitates its transportation, making it readily accessible. However, natural gas is primarily methane, a potent greenhouse gas. Methane emissions from storage, pipelines, and transportation contribute significantly to global warming, offsetting some of its benefits as a cleaner-burning fuel. Extracting natural gas often involves fracking , which has its own environmental concerns.

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Temane, Mozambique: natural gas pipeline

Large white tanks and pipes form a compressor station on a natural gas pipeline in Texas, with a fence in the foreground and solar panels and grassy hills in the background.

Cross-sectional diagram showing three principal types of petroleum traps: an anticline trap with oil and gas beneath a cap rock, a fault trap where gas accumulates along a fault line, and a stratigraphic trap where gas is trapped in permeable limestone beneath impermeable rock layers. Labels identify geological features and fluid locations.

$Diagram illustrating the hydraulic fracturing process for shale gas extraction, showing a drilling rig, underground well casings, fracking fluid injection, horizontal drilling in shale, and surface equipment for separating gas and fluids. Insets highlight the well structure, fluid injection into shale, and gas flow pathways.$

Thematic map of Europe, Russia, Transcaucasia, and Central Asia highlighting major sedimentary basins in purple and marking the locations of major oil and gas fields, with triangles indicating supergiant and selected giant fields. The map shows regional seas, geographic features, and the distribution of hydrocarbon resources across northern Eurasia.

Thematic map of North America showing major sedimentary basins shaded in purple and the locations of significant oil and gas fields, including supergiant and selected giant fields marked with symbols. The map highlights key regions such as the Gulf Coast, Alberta, Permian, Williston, and Prudhoe Bay, and includes both onshore and offshore areas.

Thematic map showing the Arabian-Iranian basin region highlighted in purple, spanning parts of Saudi Arabia, Iraq, Iran, Kuwait, United Arab Emirates, Qatar, Oman, Jordan, and Syria. Major oil fields, including supergiant fields such as Al-Ghawar, Kirkuk, and Ahvaz, are marked with black shapes within the basin. Major water bodies like the Persian Gulf, Red Sea, Gulf of Oman, and Caspian Sea are labeled.

Large white cylindrical tanks with attached yellow and blue pipes at a gas-compressor station in Siberia, set outdoors under a partly cloudy sky.

Map of Europe showing the extent to which each country was supplied by Russian gas in 2012, using shades of purple to indicate percentage levels, with darkest purple for 100% dependence and lighter shades for lower percentages. Orange lines mark major gas pipelines from Russia into Europe, with high dependency in Eastern and Central European countries and lower or no dependency in Western Europe and the British Isles.

At a Glance

natural gas summary

natural gas

fossil fuel

Also known as: methane gas, natural methane gas

Written by

Joseph P. RivaAll

Fact-checked by

Britannica Editors

Last updated

Oct. 23, 2026 •History

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UK government approves a natural gas project off Scotland despite environmental concerns • Oct. 21, 2026, 11:18 AM ET (AP)

natural gas, colourless highly flammable gaseous hydrocarbon consisting primarily of methane and ethane. It is a type of petroleum that commonly occurs in association with crude oil. A natural resource and fossil fuel, natural gas is used for electricity generation, heating, and cooking and as a fuel for certain vehicles. It is important as a chemical feedstock in the manufacture of plastics and is necessary for a wide array of other chemical products, including fertilizers and dyes.

Natural gas is often found dissolved in oil at the high pressures existing in a reservoir, and it can be present as a gas cap above the oil. In many instances it is the pressure of natural gas exerted upon the subterranean oil reservoir that provides the drive to force oil up to the surface. Such natural gas is known as associated gas; it is often considered to be the gaseous phase of the crude oil and usually contains some light liquids such as propane and butane. For this reason, associated gas is sometimes called “wet gas.” There are also reservoirs that contain gas and no oil. This gas is termed nonassociated gas. Nonassociated gas, coming from reservoirs that are not connected with any known source of liquid petroleum, is “dry gas.”

History of use

Discovery and early application

The first discoveries of natural gas seeps were made in Iran between 6000 and 2000 bce. Many early writers described the natural petroleum seeps in the Middle East, especially in the Baku region of what is now Azerbaijan. The gas seeps, probably first ignited by lightning, provided the fuel for the “eternal fires” of the fire-worshipping religion of the ancient Persians.

The use of natural gas was mentioned in China about 900 bce. It was in China in 211 bce that the first known well was drilled for natural gas, to reported depths of 150 metres (500 feet). The Chinese drilled their wells with bamboo poles and primitive percussion bits for the express purpose of searching for gas in limestones dating to the Late Triassic Epoch (about 237 million to 201.3 million years ago) in an anticline (an arch of stratified rock) west of modern Chongqing. The gas was burned to dry the rock salt found interbedded in the limestone. Eventually wells were drilled to depths approaching 1,000 metres (3,300 feet), and more than 1,100 wells had been drilled into the anticline by 1900.

Natural gas was unknown in Europe until its discovery in England in 1659, and even then it did not come into wide use. Instead, gas obtained from carbonized coal (known as town gas) became the primary fuel for illuminating streets and houses throughout much of Europe from 1790 on.

In North America the first commercial application of a petroleum product was the utilization of natural gas from a shallow well in Fredonia, New York, in 1821. The gas was distributed through a small-bore lead pipe to consumers for lighting and cooking.

Improvements in gas pipelines

Throughout the 19th century the use of natural gas remained localized because there was no way to transport large quantities of gas over long distances. Natural gas remained on the sidelines of industrial development, which was based primarily on coal and oil. An important breakthrough in gas-transportation technology occurred in 1890 with the invention of leakproof pipeline coupling. Nonetheless, materials and construction techniques remained so cumbersome that gas could not be used more than 160 km (100 miles) from a source of supply. Thus, associated gas was mostly flared (i.e., burned at the wellhead), and nonassociated gas was left in the ground, while town gas was manufactured for use in the cities.

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Long-distance gas transmission became practical during the late 1920s because of further advances in pipeline technology. From 1927 to 1931 more than 10 major transmission systems were constructed in the United States. Each of these systems was equipped with pipes having diameters of approximately 50 cm (20 inches) and extended more than 320 km (200 miles). Following World War II, a large number of even longer pipelines of increasing diameter were constructed. The fabrication of pipes having a diameter of up to 150 cm (60 inches) became possible. Since the early 1970s the longest gas pipelines have had their origin in Russia. For example, in the 1960s and ’70s the 5,470-km- (3,400-mile-) long Northern Lights pipeline was built across the Ural Mountains and some 700 rivers and streams, linking eastern Europe with the West Siberian gas fields on the Arctic Circle. As a result, gas from the Urengoy field, the world’s largest, is now transported to eastern Europe and then on to western Europe for consumption. Another gas pipeline, shorter but also of great engineering difficulty, was the 50-cm (20-inch) Trans-Mediterranean Pipeline, which during the 1970s and ’80s was constructed between Algeria and Sicily. The sea is more than 600 metres (2,000 feet) deep along some parts of that route.

Natural gas as a premium fuel

As recently as 1960, associated gas was a nuisance by-product of oil production in many areas of the world. The gas was separated from the crude oil stream and eliminated as cheaply as possible, often by flaring (burning it off). Only after the crude oil shortages of the late 1960s and early ’70s did natural gas become an important world energy source (see oil crisis).

Even in the United States the home-heating market for natural gas was limited until the 1930s, when town gas began to be replaced by abundant and cheaper supplies of natural gas, which contained twice the heating value of its synthetic predecessor. Also, when natural gas burns completely, carbon dioxide and water are normally formed. The combustion of gas is relatively free of soot, carbon monoxide, and the nitrogen oxides associated with the burning of other fossil fuels. In addition, sulfur dioxide emissions, another major air pollutant, are almost nonexistent. As a consequence, natural gas is often a preferred fuel for environmental reasons, and it has supplanted coal as a fuel for electric power plants in many parts of the world. Nevertheless, methane is a very potent greenhouse gas that possesses about 25 times the heat-trapping capacity of carbon dioxide. Despite the long-standing reputation of natural gas as a relatively clean energy source, methane releases from storage facilities and pipelines and during transport contribute to global warming and remain a subject of much concern.

natural gas

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History of use

Discovery and early application

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Improvements in gas pipelines

Natural gas as a premium fuel