what is fossil fuel ?






Fossil fuel, any of a class of  hydrocarbon-containing materials of biological origin occurring within Earth’s crust that can be used as a source of energy.



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Fossil fuels include coal,petroleum,natural gas,oil shales, bitumens,tar sands,and heavy oils. All contain carbon  and were formed as a result of geologic processes acting on the remains of organic matter produced by photosynthesis, a process that began in the archean eon  (4.0 billion to 2.5 billion years ago). Most carbonaceous material occurring before the devonian period  (419.2 million to 358.9 million years ago) was derived from algae and bacteria , whereas most carbonaceous material occurring during and after that interval was derived from plants.











All fossil  fuels can be burned in air  or with oxygen  derived from air to provide heat  . This heat may be employed directly, as in the case of home furnaces, or used to produce steam  to drive generators that can supply electricity. In still other cases—for example, gas turbines  used in jet aircraft—the heat yielded by burning a fossil fuel serves to increase both the pressure  and the temperature  of the combustion   products to furnish motive power.
When fossil fuels are burned, they release carbon dioxide and other greenhouse gases , which in turn trap heat in our atmosphere, making them the primary contributors to global warming and climate change.

FORMATION OF FOSSIL FUEL

Forming fossil fuels requires very specific

 conditions.Coal is one type of fossil fuel. 
It was formed very slowly, a very long time
 ago from trees and other plants that were 
submerged under water. Instead of rotting
, the wood and plant matter was covered
 with layers of mud and sand.
 Over time, heat and pressure turned the
 material into coal.Oil is sometimes referred
 to as petroleum. It formed from 
the deep burial and decomposition of 
dead plants and animals. Heat and pressure,
 in the absence of oxygen, changed the 
decomposed material into crude oil. 
Petroleum, or oil, is used for energy and
 many products.Millions of years ago, the
 remains of plants and animals decayed 
and built up in thick layers. Over time, the
 sand and silt changed to rock, covered it,
 and trapped it beneath the rock. Pressure
 and heat changed some of this matter
 into coal and oil. Some of it was trapped
 as pockets of gases known as natural gas.
Because fossil fuels take such a long time
 to form, the supply we have on Earth
 today will one day run out. Our current
 way of life relies heavily on the use of
 fossil fuels. 
We must be wise in our use of this energy
 source (conserve energy) and develop
 other energy sources (alternative energy)
 to meet our current and future energy needs.


Major types of fossil fuels

There are several main groups of 
fossil fuels, including:
Coal: Black or brown chunks of sedimen
-tary rock that range from crumbly to 
relatively hard, coal began to form during 
the carboniferous period  about 300 to 
360 million years ago, when algae and 
debris from vegetation in swamp forests 
settled deeper and deeper under layers 
of mud. Mined via surface or undergrou
-nd methods, coal supplies a third of all 
energy worldwide , with the top coal 
consumers and producers in 2018 being
 China, India, and the United States. Coal 
is classified  into four categories—anthracite,
 bituminous, sub-bituminous, and lignite
–depending on its carbon content.









Carbon dioxide emissions from burning coal
 account for44 percent of the world total ,  
and it's the biggest single source  of the
 global temperature increase above pre
-industrial levels. 
The health and environmental consequences 
 of coal use, along with competition from
 cheap natural gas, have contributed to its
 decline  in the U.S. and elsewhere. But in 
other places, such as India,demand is 
expected to rise  through 2023.
Oil: Crude oil, a liquid composed mainly
 of carbon and hydrogen, is often black, 
but exists in a variety of colors and 
viscosities depending on its chemical
 composition.
 Much of it formed during the Mesozoic
 period, between 252 and 66 million years
 ago, as plankton, algae, and other matter
 sank to the bottom of ancient seas and 
was eventually buried.
Extracted from onshore and offshore wells,
 crude oil is refined into a variety of 
petroleum products ,  including gasoline,
 diesel, and heating oil. The top oil-producing 
countries are the U.S., Saudi Arabia, and
 Russia, which together account for nearly 
40 percent of the world's supply.
Petroleum use accounts for nearly half  the 
carbon emissions in the U.S. and about a
 third  of the global total.
 In addition to the air pollution  released
 when oil is burned, drilling and transport
 have led to several major accidents, such
 as the exxon valdez spill  in 1989, the 
deepwater horizon disaster  in 2010, the
 devastating lac megantic  oil train
 derailment in 2013, 
and thosands of pipeline incidents. 
Nonetheless, oil demand continues to rise,
  driven not only by our thirst for mobility,
 but for the many products— including 
plastics —made using petrochemicals,
 which are generally derived from oil and gas.
Natural gas:
 An odorless gas composed primarily
 of methane,natural gas  often lies in
 deposits that, like those for coal and oil,
 formed millions of years ago from 
decaying plant matter and organisms.
 Both natural gas and oil  production
 have surged in the U.S. over the 
past two decades because of advances
 in the drilling technique most people 
know as fracking.
By combining fracking—or hydraulic
 fracturing—with horizontal drilling and 
other innovations, the fossil-fuel industry
 has managed to extract resources that 
were previously too costly to reach. As a 
result, natural gas has surpassed coal  to 
become the top fuel for U.S. electricity 
production, and the U.S. leads the worldwide 
 in natural gas production, followed by
 Russia and Iran.
Natural gas is cleaner than coal and oil 
 in terms of emissions, but nonetheless 
 accounts for a fifth  of the world's total, 
not counting the so-called fugitive
 emissions that escape from the industry,
 which can be significant. Not all of the
 world’s natural gas sources are being
 actively mined. Undersea methane 
hydrates, for example, where gas is 
trapped in frozen water, are 
being eyed as a potential gas resources.

Reducing emissions from 

fossil fuels

Governments around the world are now
 engaged in efforts to ramp down green
-house gas emissions from fossil fuels
 to prevent the worst effects of climate 
change. At the international level,
countries have committed  to emissions
 reduction targets as part of the 2015 
paris agreement , while other entities—
including cities, states, and businesses
—have made their own commitments.
 These efforts generally focus on replacing
 fossil fuels with  renewable energy sources,
 increasing energy efficiency, and 
electrifying sectors such as
 transportation and buildings.
However, many sources of carbon 
emissions, such as existing power
 plants that run on natural gas and coal, 
are already locked in. Considering the
 world's continuing dependence on fossil
 fuels, many argue that in addition to 
efforts aimed at replacing them,
 we also need to suck carbon from the
 air  with technologies such as carbon
 capture, in which emissions are
 diverted to underground storage or
 recycled before they reach the atmosphere.
 A handful of commercial-scale projects 
around the world already capture carbon
 dioxide from the smokestacks of fossil
 fuel-fired plants, and while 
its high costs have prevented wider adoption , 
advocates hope advances in the technology
 willeventually make it more affordable.https://intersting2020.blogspot.com
/2020/04/global-warming.html

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