Coal is a
combustible
A combustible material is something that can burn (i.e., ''combust'') in air. A combustible material is flammable if it ignites easily at ambient temperatures. In other words, a combustible material ignites with some effort and a flammable mat ...
black or brownish-black
sedimentary rock
Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particle ...
, formed as
rock strata
In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as e ...
called
coal seams
Coal mining is the process of extracting coal from the ground. Coal is valued for its energy content and since the 1880s has been widely used to generate electricity. Steel and cement industries use coal as a fuel for extraction of iron fro ...
. Coal is mostly
carbon
Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—its atom making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon makes ...
with variable amounts of other
elements
Element or elements may refer to:
Science
* Chemical element, a pure substance of one type of atom
* Heating element, a device that generates heat by electrical resistance
* Orbital elements, parameters required to identify a specific orbit of ...
, chiefly
hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...
,
sulfur
Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formul ...
,
oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as we ...
, and
nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seve ...
.
Coal is formed when dead
plant matter
Organic matter, organic material, or natural organic matter refers to the large source of carbon-based compounds found within natural and engineered, terrestrial, and aquatic environments. It is matter composed of organic compounds that have c ...
decays into
peat
Peat (), also known as turf (), is an accumulation of partially decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires, moors, or muskegs. The peatland ecosystem covers and is the most efficien ...
and is converted into coal by the heat and pressure of deep burial over millions of years.
Vast deposits of coal originate in former
wetland
A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The ...
s called
coal forest
Coal forests were the vast swathes of wetlands that covered much of the Earth's tropical land areas during the late Carboniferous (Pennsylvanian) and Permian times.Cleal, C. J. & Thomas, B. A. (2005). "Palaeozoic tropical rainforests and their e ...
s that covered much of the Earth's tropical land areas during the late
Carboniferous (
Pennsylvanian Pennsylvanian may refer to:
* A person or thing from Pennsylvania
* Pennsylvanian (geology)
The Pennsylvanian ( , also known as Upper Carboniferous or Late Carboniferous) is, in the International Commission on Stratigraphy, ICS geologic timesca ...
) and
Permian
The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Pale ...
times.
Many significant coal deposits are younger than this and originate from the
Mesozoic
The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Creta ...
and
Cenozoic
The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configu ...
eras.
Coal is used primarily as a fuel. While coal has been known and used for thousands of years, its usage was limited until the
Industrial Revolution
The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...
. With the invention of the
steam engine
A steam engine is a heat engine that performs mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. This pushing force can be ...
, coal consumption increased. In 2020, coal supplied about a quarter of the world's
primary energy
Primary energy (PE) is an energy form found in nature that has not been subjected to any human engineered conversion process. It is energy contained in raw fuels, and other forms of energy, including waste, received as input to a system. Pri ...
and over a third of its
electricity
Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as describ ...
.
Some
iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in ...
and
steel-making and other industrial processes burn coal.
The extraction and use of coal causes premature death and illness.
The use of coal
damages the environment, and it is the largest
anthropogenic
Anthropogenic ("human" + "generating") is an adjective that may refer to:
* Anthropogeny, the study of the origins of humanity
Counterintuitively, anthropogenic may also refer to things that have been generated by humans, as follows:
* Human i ...
source of
carbon dioxide
Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is t ...
contributing to
climate change
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to ...
. Fourteen billion tonnes of carbon dioxide was emitted by burning coal in 2020,
which is 40% of the total
fossil fuel emissions
[ and over 25% of total global ]greenhouse gas emissions
Greenhouse gas emissions from human activities strengthen the greenhouse effect, contributing to climate change. Most is carbon dioxide from burning fossil fuels: coal, oil, and natural gas. The largest emitters include coal in China and ...
. As part of worldwide energy transition
The energy transition is the process of Fossil fuel phase-out, downshifting fossil fuels and re-developing whole systems to operate on Low-carbon power, low carbon energy sources. More generally, an energy transition is a significant structura ...
, many countries have reduced or eliminated their use of coal power. The United Nations Secretary General
The secretary-general of the United Nations (UNSG or SG) is the chief administrative officer of the United Nations and head of the United Nations Secretariat, one of the six principal organs of the United Nations.
The role of the secretary-g ...
asked governments to stop building new coal plants
A coal-fired power station or coal power plant is a thermal power station which burns coal to generate electricity. Worldwide, there are about 8,500 coal-fired power stations totaling over 2,000 gigawatts capacity. They generate about a th ...
by 2020. Global coal use peaked in 2013.global warming
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate variability and change, Climate change in a broader sense also includes ...
below coal use needs to halve from 2020 to 2030, and phasing out coal was agreed upon in the Glasgow Climate Pact
The Glasgow Climate Pact is an agreement reached at the 2021 United Nations Climate Change Conference (COP26).
The pact is the first climate agreement explicitly planning to reduce unabated coal usage. A pledge to "phase out" coal was changed ...
.
The largest consumer and importer of coal in 2020 was China, which accounts for almost half the world's annual coal production, followed by India
India, officially the Republic of India ( Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the ...
with about a tenth. Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...
and Australia export the most, followed by Russia
Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eigh ...
.
Etymology
The word originally took the form ''col'' in Old English, from Proto-Germanic
Proto-Germanic (abbreviated PGmc; also called Common Germanic) is the reconstructed proto-language of the Germanic branch of the Indo-European languages.
Proto-Germanic eventually developed from pre-Proto-Germanic into three Germanic bran ...
*''kula''(''n''), which in turn is hypothesized to come from the Proto-Indo-European
Proto-Indo-European (PIE) is the reconstructed common ancestor of the Indo-European language family. Its proposed features have been derived by linguistic reconstruction from documented Indo-European languages. No direct record of Proto-Indo- ...
root *''g''(''e'')''u-lo-'' "live coal".Old Frisian
Old Frisian was a West Germanic language spoken between the 8th and 16th centuries along the North Sea coast, roughly between the mouths of the Rhine and Weser rivers. The Frisian settlers on the coast of South Jutland (today's Northern Frie ...
''kole'', Middle Dutch
Middle Dutch is a collective name for a number of closely related West Germanic dialects whose ancestor was Old Dutch. It was spoken and written between 1150 and 1500. Until the advent of Modern Dutch after 1500 or c. 1550, there was no overarch ...
''cole'', Dutch
Dutch commonly refers to:
* Something of, from, or related to the Netherl