Fossil record The fossil record of fire first appears with the establishment of a land-based flora in the
Middle Ordovician period, . These land plants contributed large amounts of
oxygen to the atmosphere when they released it as a waste product. When this concentration rose above 13%, it made a
wildfire possible. Wildfire is first recorded in the
Late Silurian fossil record, , by fossils of
charred plants. Apart from a controversial gap in the
Late Devonian, charcoal is present ever since. Fire also became more abundant when grasses became the dominant component of many ecosystems, around , providing excellent
tinder for more rapid spread of fire.
Human control The period of history characterized by the influence of human-caused fire activity on Earth has been dubbed the
pyrocene. This epoch includes the burning of
fossil fuels, especially for technological uses.
Early human control { "type": "ExternalData", "service": "page", "title": "ROCEEH/Early_fire.map" } The ability to control fire was a dramatic change in the habits of early humans.
Making fire to generate heat and light made it possible for people to
cook food, simultaneously increasing the variety and availability of nutrients and reducing disease by killing pathogenic microorganisms in the food. The heat produced would also help people stay warm in cold weather, enabling them to live in cooler climates. Fire also kept nocturnal predators at bay. Evidence of occasional cooked food is found from , suggesting it was used in a controlled fashion. Other sources put the date of regular use at 400,000 years ago. Evidence becomes widespread around 50 to 100 thousand years ago, suggesting regular use from this time; resistance to
air pollution started to evolve in human populations at a similar point in time. above fire in
South Africa. By the
Neolithic Revolution, during the introduction of grain-based agriculture, people all over the world used fire as a tool in
landscape management. These fires were typically
controlled burns or "cool fires", as opposed to uncontrolled "hot fires", which damage the soil. Hot fires destroy plants and animals and endanger communities. This is especially a problem in the forests of today where traditional burning is prevented to encourage the growth of timber crops. Cool fires are generally conducted in the spring and autumn. They clear undergrowth, burning up
biomass that could trigger a hot fire should it get too dense. They provide a greater variety of environments, which encourages game and plant diversity. Humans make dense, impassable forests traversable. Another human use of fire in landscape management is to clear land for agriculture.
Slash-and-burn agriculture is still common across much of tropical Africa, Asia, and South America. For small farmers, controlled fires are a convenient way to clear overgrown areas and release nutrients from standing vegetation back into the soil. However, this useful strategy is also problematic. A growing population, forest fragmentation, and a warming climate are making the Earth's surface more prone to ever-larger escaped fires. These harm ecosystems and human infrastructure, cause health problems, and send spirals of carbon and soot into the atmosphere that may encourage even more warming – and thus feed back into more fires. Globally today, as much as 5 million square kilometres – an area more than half the size of the United States – burns in a given year. During the 17th century, a study of combustion was made by
Jan Baptist van Helmont who discovered that burning charcoal released a
gas sylvestris, or wild spirit. This was subsequently incorporated into
Phlogiston theory by
Johann Joachim Becher in 1667 and more formally by
Georg Ernst Stahl in 1697; a concept that would strongly influence alchemical thinking for nearly two centuries. It was
Antoine Lavoisier who demonstrated that combustion did not involve the release of a substance, but rather something was being taken up. and
coal in a
wood-burning stove, 2025 Fire has been used for centuries as a method of torture and execution, as evidenced by
death by burning as well as torture devices such as the
iron boot, which could be heated over an open fire to the agony of the wearer. There are numerous modern applications of fire. In its broadest sense, fire is used by nearly every human being on Earth in a controlled setting every day. Users of
internal combustion vehicles employ fire every time they drive. Thermal
power stations provide
electricity for a large percentage of humanity by igniting fuels such as
coal,
oil or
natural gas, then using the resultant heat to boil water into
steam, which then drives
turbines.
Use in war The use of fire in
warfare has a long
history. Fire was the basis of all
early thermal weapons, including
incendiary devices, heated projectiles, and the use of smoke. This class of weapons was particularly evident during naval battles and
siege warfare. The
Byzantine fleet used
Greek fire to attack ships and men. The invention of
gunpowder in China led to the
fire lance, a flame-thrower dating to around 1000 CE, a precursor to
projectile weapons driven by burning gunpowder. The earliest modern
flamethrowers were used by infantry in the
First World War, first used by German troops against entrenched French troops near Verdun in February 1915. They were later successfully mounted on armoured vehicles in the Second World War. Hand-thrown
incendiary bombs improvised from glass bottles, later known as
Molotov cocktails, were deployed during the
Spanish Civil War in the 1930s. During that war, incendiary bombs were deployed against
Guernica by Fascist
Italian and Nazi
German air forces that had been created specifically to support
Franco's Nationalists. Incendiary bombs were dropped by
Axis and
Allies during the Second World War, notably on
Coventry,
Tokyo,
Rotterdam,
London,
Hamburg and
Dresden. In the latter two cases,
firestorms were deliberately caused, in which a ring of fire surrounding each city was drawn inward by an
updraft created by a central cluster of fires. The United States Army Air Force extensively used incendiaries against Japanese targets in the latter months of the war, devastating entire cities constructed primarily of wood and paper houses. The incendiary fluid
napalm was used in July 1944, towards the end of the
Second World War, although its use did not gain public attention until the
Vietnam War.
Productive use for energy in China Burning
fuel converts chemical energy into heat energy;
wood has been used as fuel since
prehistory. The
International Energy Agency states that nearly 80% of the world's power has consistently come from
fossil fuels such as
petroleum,
natural gas, and
coal in the past decades. The fire in a
power station is used to heat water, creating steam that drives
turbines. The turbines then spin an
electric generator to produce electricity. Fire is also used to provide
mechanical work directly by
thermal expansion, in both
external and
internal combustion engines. The
unburnable solid remains of a combustible material left after a fire is called
clinker if its
melting point is below the flame temperature, so that it fuses and then solidifies as it cools, and
ash if its melting point is above the flame temperature. == Physical properties ==