What Are The Environmental Effects Of Fossil Fuels?

We explain the main ecological and environmental effects of fossil fuel extraction and combustion including: rising global temperatures; pollution of natural ecosystems and water supplies; and air pollution such as acid rain and smog.
Acid Mine, Ohio, USA
Acid mine drainage pollution from coal mines in the Ohio Valley, USA. Photo: © Jack Pearce

Ecological Impacts of Fossil Fuels Felt Throughout Biosphere

The ecological and environmental impacts of fossil fuels are felt throughout the biosphere and cover three major areas:

(a) The impact of global warming due to greenhouse gas emissions from fossil fuel combustion in factories and power plants. (b) Pollution of natural ecosystems and water supplies before, during and after mining or drilling. The most harmful activities include: mountaintop removal mining, opencast or strip mining, fracking (hydraulic fracturing) and gas flaring. Oil slicks occurring during shipping represent a constant danger to marine ecology and coastal wetlands. (c) Air pollution, such as acid rain caused by sulfur dioxide emissions from burning coal; and phytochemical smog, caused by the discharge of particulate matter from vehicles in urban areas.

Until the Industrial Revolution, which began in Britain about 1760, the main source of power was water. True, fossil fuels had been used in small quantities by the Babylonians, Egyptians and Chinese, but it wasn’t until the Industrial Revolution that they were really put to work. As a result, over the course of 250 years, the world has been transformed. But now things have changed. We know now that fossil fuels are the root cause of our present climate crisis and must be replaced with cleaner forms of energy, such as biomass, wind, solar, geothermal or hydropower.

So just like the Industrial Revolution opened a new era of material progress, we must now start an Environmental Revolution in which we learn to value our planet. Our major challenge is to phase out fossil fuels as soon as practicable. In their Special Report on Global Warming of 1.5°C, the IPCC states that man-made emissions of CO2 need to fall 45 percent by 2030, reaching “net-zero” by 2050. 1 To do this, fossil fuels – meaning coal and its precursor, peat, as well as petroleum and natural gas – must be phased out as rapidly as possible and replaced with cleaner, renewable energy, such as biofuels, wind, solar, geothermal, tidal, hydroelectric and nuclear energy. For more on the topic, see: Is Nuclear Energy a Replacement for Fossil Fuels?

Does this mean we should we stop investing in fossil fuels? Yes. Because in order to limit global warming to 2 degrees Celsius (2°C), we can afford to emit only a limited amount of greenhouse gas like CO2. This may mean leaving up to 80 percent of our fossil fuels in the ground. 2

According to a widely-cited study by Carbon Tracker – an independent financial think tank noted for its analysis of energy transition issues – if capital investment in fossil fuel infrastructure continues at recent rates, up to 6.74 trillion US$ (nearly twice as much as Germany’s 2016 GDP) will be wasted over the next decade trying to develop reserves that will eventually be unburnable. 3 For more on the politics of fossil fuels, see: Root Cause of Climate Change.

After fossil fuels, the next biggest source of greenhouse gas emissions is the cement industry. For details, see: Cement CO2 Emissions are Bad for Climate Change.

Why Is Mining And Drilling For Fossil Fuels Bad For The Environment?

There are two main techniques for removing fossil fuels from the ground: mining and drilling. Mining – the most environmentally destructive and expensive form of extraction – is used to dig out solid fuels, like coal. Drilling is the main method of accessing liquid or gaseous fuels, like oil and natural gas. Both these extraction methods have serious effects on the global biosphere as well as local ecosystems. They also cause a wide range of human health problems. 4

Ptolemaida coal mine, Greece, shows clearly the environmental effects of fossil fuels.
Depressing landscape of Ptolemaida coal mine in Greece. The mine spans 625 square miles and includes a few deserted villages. Ptolemaida is the biggest mine in the Balkans and reported to account for the 30% of Greece’s electricity production. Unfortunately, it’s a poster-child for the environmental effects of fossil fuels. Photo: © Anna Pantelia

Coal Mining

Engineers use two basic methods to mine for coal: underground mining and surface mining. Underground pits are expensive to build and maintain, therefore they tend to involve only the best grades of coal. The most common forms are longwall and continuous mining, accounting for roughly 95 percent of all underground operations. Surface mining is cheaper, more productive and much more popular but involves highly invasive techniques, such as open cast, strip mining, contour mining and mountaintop removal, all of which are best suited to isolated or wilderness locations.

Underground Mining

Types Of Coal Mines: Infographic
Different Methods of Coal Mining. Mountaintop mines account for some of the worst environmental effects of fossil fuels. Image: © Coal Industry Archives, ASGCO

One of the biggest hazards of underground coal mining is the threat it poses to the health of miners themselves. In the United States, according to the Mine Safety and Health Administration, more than 100,000 coal miners have been killed in accidents during the period 2010-2013. In China, according to the State Work Safety Supervision Administration, 4,749 coal miners died in work-related accidents in 2006 alone.

Coal mining also causes a number of chronic health conditions. Pneumoconiosis (black lung disease), caused by the inhalation of coal dust, is the most common condition affecting miners around the world. It accounted for the deaths of roughly 10,000 former miners between 1990 and 2000. 5

Damage to the environment from mining is also substantial and frequently permanent. Empty mines can cause subsidence or collapse of the surface, affecting surface and sub-surface streams. They are also prone to catching fire. According to the U.S. Environmental Protection Agency (EPA), if mines (active or abandoned) are not properly managed, rainwater running through them can become contaminated by chemicals causing harm to human, plant, and animal life. 6

Surface Mining

Surface mining involves removing the top layers of soil and rock in order to access the coal underneath. Depending on the size of the mine, the effects can be ruinous to the topography, vegetation, and water resources of the local environment and its ecological systems.

Mountaintop removal, in particular, is especially destructive as it typically involves stripping all trees and other vegetation from the hilltops (destroying wildlife habitats in the process), and then gouging away the earth below with machinery or explosives. This has numerous environmental impacts.

In the short term, large volumes of excess rock and soil are typically dumped into adjoining valleys, transforming their ecosystems and diverting streams. In addition, mudslides and flash floods can become more common.

In the long term, the exhausted mines are left with under-nourished soils incapable of supporting traditional vegetation, while the destruction of large tracts of deciduous forests has threatened several endangered species and led to a loss of biodiversity. 7

Another problem is acid drainage. This happens when rainfall washes off the upturned topsoil into streams, allowing any heavy metal residues to seep into the water table contaminating streams, soil, plants, animals and fish. Acid drainage is instantly recognizable by the orange color of the affected water. Acid mine drainage can continue for decades even centuries after a mine is closed, unless the area is properly restored.

Toxic pollution is one of the environmental effects of fossil fuels, as illustrated here in the Doce river, Brazil.
In November 2015, the Fundão waste dam in Mariana, Brazil, collapsed, polluting all 600 kilometers (375 miles) of the Doce River. The dam, which stored poisonous residues left over from mining activities, released around 43 million cubic meters of mud, silica, manganese, iron oxide and other heavy metals into the local river system, resulting in 19 deaths and the destruction of several villages. It was one of the worst environmental effects of fossil fuels in Brazil. It also contaminated the coral reefs in the Abrolhos Marine National Park, a 914-sq km nature reserve in the South Atlantic. Four years later, fishing remains forbidden in some areas of the Doce River, due to excessive concentrations of heavy metals. Photo by Gabriela Bilo/Estadao Conteudo/AP Images. 8

Surface mining also harms the health and safety of local communities. One Harvard University study into the public health effects of coal, noted a clear link between open cast coal mining and a range of diseases, including: cardiovascular, lung and kidney diseases, diabetes and high blood pressure. 4 . What’s more, toxic chemicals in the ground being mined – such as arsenic, hydrogen sulfide, iron, lead, manganese or selenium – can poison local drinking water. 9

“Surface mining of coal completely eliminates existing vegetation, destroys the genetic soil profile, displaces or destroys wildlife and habitat, degrades air quality, alters current land uses, and to some extent permanently changes the general topography of the area mined.”

U.S. Department of the Interior (1979) 10

Switching To Gas From Coal Saves Water

The switch from coal to natural gas in the US electricity generation sector is saving significant amounts of water, research shows. For every megawatt of electricity produced using gas instead of coal, the amount of water extracted from rivers and groundwater reduces by 10,500 gallons, and water withdrawn for cooling and other operations and not returned to the local environment falls by 260 gallons. Replacing coal with solar or wind power would boost these savings further. 11

Strip Mining

The least expensive and most productive form of coal mining is strip mining, a process used in 40 percent of the world’s mines. The layer of earth above the coal (the overburden) is removed by massive machines, the coal (typically lignite) is extracted by other huge machines such as bucket-wheel excavators capable of shifting up to 12,000 cubic metres of earth per hour, after which the layer of rock and soil are replaced.

Under current legislation (like the U.S. Surface Mining Control and Reclamation Act of 1977) strip-mined land must be restored to its original contour with appropriate ground cover. But much of the land that was mined before this type of legislation was passed has not been restored. Many potential strip mines in America are located in the arid west, where restoration is both difficult and costly. As a result, most new electric power plants being built are fuelled by cleaner natural gas.

In the United States, during the period 1930-2000, surface coal mining disfigured about 5.9 million acres (2.4 million hectares) of natural landscape, most of it (originally) forest. It included some of the worst environmental effects of fossil fuels ever seen.

What’s more, projects to re-seed land destroyed by coal mining rarely succeed because the mines have damaged the soil so thoroughly. In Montana, for instance, replanting projects had a failure rate of only 70-80 percent, while in some places in Colorado 90 percent of oak aspen seedlings that were planted died due to the unhealthy state of the soil. See also: Why is Soil So Important to the Planet?

In China, according to a 2004 estimate, coal mining has spoiled an estimated 7.8 million acres (3.2 million hectares). The restoration rate (the amount of affected land that has been successfully reclaimed) of mine wasteland was about 10–12 percent.

Do Coal Mines Give Off Toxic Emissions?

Yes. Coal mines generate unhealthy levels of carbon aerosols and other particulate matter. In 2014, a methane cloud occupying about 2,500 square miles was recorded by NASA scientists as it floated over the Four Corners region of the south-western United States. 12 Strip mining – especially in places like Canada’s boreal forests – can release giant stores of carbon dioxide held naturally in the wild.

In a recent study, researchers investigated emissions from the storage and handling of coal stockpiles. The study found that wind blowing over uncovered coal piles, plus emissions from the piles, significantly increased concentrations of particulates within a 25-mile range.

In fact, coal stockpiles emit fine aerosols in several ways. First, wind blowing over uncovered stockpiles results in coal dust emissions that include microscopic particulate matter (PM2.5), consisting of particles less than 2.5 micrometers in diameter – about 30 times smaller in diameter than a human hair. Secondly, these coal heaps emit volatile gases that can also lead to formation of PM2.5. Thirdly, almost 70 percent of coal delivered from mines to power plants or coal export terminals is delivered by train, usually in uncovered freight cars. Coal carrying barges and trucks are also typically uncovered. As it travels, all this uncovered coal emits a range of fine particulates, as does coal that arrives at a power plant and is subject to handling and unloading procedures.

Thus, people living near mines, rail lines or coal-fired power plants are almost certain to experience air pollution from fine particulate emissions from coal. 13

Particulate matter air pollution is one of the major environmental effects of fossil fuel in Australia.
Coal mine in Maules Creek, Australia. A study of air pollution emissions from Australian coal mining (2008-2018) showed that coal mines accounted for 42% of national PM10 air emissions. PM2.5 from coal mines accounted for 19.5% of the national total, metals for 12% and nitrogen oxides for 10%. 14 Photo: © Northern Daily Leader

Fine particulate pollution is linked to increased ill-heath due to heart and respiratory conditions. As a result, in the United States in 1990, the Clean Air Act was amended to limit emissions of sulfur dioxide and nitrogen oxides, which are significant sources of fine particulates. According to the U.S. Environmental Protection Agency, this will save something like 230,000 adult deaths in 2020 alone. Unfortunately, this federal legislation does not cover emissions from coal storage and handling.

Coal Waste

One of the worst effects of fossil fuels is the waste it leaves behind. Fossil fuels typically lie trapped deep beneath the earth, amid layers of rock, adulterated with numerous other organic compounds, or else they lie close to the surface in a relatively impure form. Either way, they need to be refined and purified into a usable form – a process that inevitably leaves behind a great deal of waste and waste water.

After coal is mined it is washed, creating a huge amount of coal slurry, a watery pre-combustion waste often containing arsenic, cadmium, chromium, mercury, and other heavy metals. The slurry might be stored at the mine itself or at a coal preparation plant (CPP) that prepares coal for transport to a power-plant.

After coal is burned at the power plant to generate electricity there are always residues left behind. They include residues of fly ash (from chimneys) and bottom ash (from furnaces) – known collectively as coal combustion residuals (CCRs) – which also typically contain high levels of toxic metals.

This waste is stored in large ponds, impoundments or landfills, many of which are huge and contain hundreds of millions of gallons of waste. There are more than one thousand waste ponds and some 435 landfill sites across the United States. 15 Over 40 percent of these holding areas are unlined, making it easy for toxic materials to gradually drain into the local water table, poisoning water supplies and causing cancer, birth defects and other serious complaints. 16 As of 2019, utilities have acknowledged the presence of enough health-harming pollutants like arsenic, to trigger mandatory clean-up procedures at 70 coal-fired power plant sites. 17

The mining and processing of oil and gas also generates substantial waste problems. All drilling and fracking operations generate enormous amounts of wastewater, which is often contaminated with toxic, even radioactive, metals, and other pollutants. Fracking in particular can be incredibly unfriendly to the environment and its ecosystems.

Drilling For Oil And Gas

The environmental and health issues linked to onshore and offshore oil and gas drilling are also significant. The impacts of modern extraction methods, like fracking have rightly received a good deal of attention, but all methods of oil and gas extraction are hazardous to the environment.

Water Pollution

When drilling for oil and gas, water that had been trapped in the rock formation is brought to the surface. This water can contain naturally-occurring heavy metals and radioactive materials in concentrations that make it unfit for human consumption and therefore difficult to dispose of naturally. 18

When fracking is employed, this waste water is greatly increased by the large volume of water and chemicals injected into the rock during the fracking process. Fracking shale gas-containing rock formations typically calls for 3 to 6 million gallons of water per well, plus up to 60,000 gallons of chemicals, many of which have been undisclosed to regulators. 19

One Congressional report found that, between 2005 and 2009, a total of 14 oil and gas companies used an eye-popping 780 million gallons of hydraulic fracturing liquid containing 750 chemicals and other components 20. Of these, researchers could verify only 353 chemicals, 25 percent of which were found to be carcinogenic, while about 50 percent were found to cause serious damage to neurological, cardiovascular, endocrine, and immune systems 21.

Land Abuse

Land abuse also ranks among the worst effects of fossil fuels. Vast stretches of land are leased by the fossil fuel industry to accommodate its commercial infrastructure. The latter includes oil and gas wells, processing, storage and waste disposal facilities, access roads and pipelines. This development places an enormous strain on the land, its biodiversity and ecosystems.

According to oil and gas industry experts, the introduction of horizontal drilling technology, used principally in fracking extraction, has significantly reduced the environmental boot print of drilling operations as it enables multiple shafts to be drilled from a single well pad. On the other hand, a great deal of shale gas drilling – in the United States at least – is happening in far flung locations where oil and gas production has not previously taken place. As a result, an unusual amount of infrastructure development and land disturbance is inevitable. (See also: Land Use and Climate Change.)

Offshore Drilling

Offshore oil and gas drilling has many of the same risks as onshore drilling. However, these risks are magnified considerably because of the remote locations of offshore drilling platforms as well as the more complex engineering needed. Environmental and safety incidents are regular occurrences in the offshore oil and gas industries. During the period 2008-2012, offshore drilling rigs counted 34 deaths, 1,436 injuries, and 60 significant oil spills. 22

Oil Exploration In The Arctic 

In the Arctic, where offshore drilling is about to recommence following green lights from both the Kremlin and the White House, the animals and organisms likely to be worst affected include: (a) Polar bears who depend on ice floes and clean water to hunt their prey; (b) Narwhals and walruses, who are especially vulnerable to oil spills. (c) Walruses, whose habitat is particularly vulnerable to climate change. (d) Cold and deep-water corals, who play vital roles in their ecosystems but who remain highly sensitive to environmental damage, such as oil spills, acidification or warming water temperatures.

Deepwater Horizon Oil Spill

The Deepwater Horizon oil spill (April 20, 2010), in the Gulf of Mexico on the BP-operated Macondo Prospect, considered to be the largest marine oil spill in the history of the petroleum industry. Reports in early 2012 showed that oil was still leaking from the well site two years later. 23

Deepwater Horizon Disaster. Oil spills are one of the major environmental effects of fossil fuels.
April 20, 2010. Gulf of Mexico. Support vessels struggle to control fires raging on BP’s Deepwater Horizon oil drilling plaform 64 km (40 miles) off the Louisiana coast, while rescue helicopters search for missing crew. Photo: © US Coast Guard

Among the widespread and well-documented effects of the oil spill on human health as well local habitats and marine ecosystems, oil-and-dispersant mix was found under the shells of tiny blue crab larvae. 24 Dispersant chemicals are believed to have caused huge numbers of marine mutations witnessed by scientists, including 50 percent of shrimp found without eyes or eye sockets. 25 According to researchers with extensive experience in post-spill mortality assessments, over 1 million coastal birds perished as a direct result of the Deepwater Horizon spill.

Dolphins were particularly affected by the oil spill. In December 2013, a study in the journal Environmental Science & Technology disclosed that of 32 dolphins briefly captured from a 24-km stretch off southeastern Louisiana, half were seriously ill or dying. 26 A 2015 study by the National Oceanic and Atmospheric Administration (NOAA), ties the sharp increase in dolphin deaths to the Deepwater Horizon oil spill. 27

In April 2016, a study in the journal Diseases of Aquatic Organisms revealed that 88 percent of 360 baby or stillborn dolphins within the spill area had “abnormal or under-developed lungs”, compared to 15 percent in other localities. 28

Tar Sands Bitumen Mining

Tar sands – also called “oil sands” or “bituminous sands” – are a type of unconventional petroleum deposit, consisting of a mixture of water, clay, sand and bitumen, a heavy black viscous oil. Natural bitumen deposits are found in many countries around the world, notably Canada, which has the world’s third largest oil deposits (after Saudi Arabia and Venezuela) of which 95 percent are in the form of bitumin tar sands. 29

Tar oil sands mining, Canada
Oil sands mining at the Suncor Energy plant near Fort McMurray, Alberta. Photo: © Larry MacDougal

The bitumen in tar sands cannot be pumped out of the ground in its natural state. Instead, bitumen deposits are extracted using, surface mining techniques or by in-situ pumping methods, before undergoing a complex refining process to turn them into oil. Unfortunately, bitumin requires significantly more energy to mine and refine than conventional oil.

Producing and processing tar sands oil results in roughly 14 percent more greenhouse gas emissions than the average oil used in the U.S. 30

Environmental Impact

The environmental effects of tar sands operations in Canada’s Alberta province, arise as a result of the extraction and processing of bitumen from the strip mine or well head. The core issues include:

Greenhouse Gas Emissions

Life cycle greenhouse gas emissions from tar sands operations are significantly larger than those incurred by conventional crude oil works. In April 2019, a study published in Nature Communications found that GHG emissions from the Canadian oil sands, measured directly from aircraft, are around 30 percent higher than the figures reported by the oil industry. 31

Tailings Ponds

Tailings ponds represent one of the most unpleasant effects of fossil fuels. They are found wherever mining or drilling takes place. In the case of bitumen mining, these ponds contain the waste residues left over from the oil sands extraction and upgrading. The ponds, some of which are among the largest man-made structures on Earth, can be extremely hazardous due to their content of unrecovered hydrocarbons, heavy metals and other toxic contaminants left over from the bitumen separation process. They attract and kill literally thousands of migrating birds. And they emit methane and other greenhouse gases. 32

Water System Damage

The surface mining of bitumen requires an enormous amount of water. Roughly 2.4 barrels of fresh water required to extract and process one barrel of bitumen. In situ extraction requires between 0.8 and 1.7 barrels of water. 33 According to National Geographic, the oil sands industry uses up three barrels of fresh water for every one barrel of oil produced. 32

Although the water is recycled, it is usually contaminated and, if other mines are any guide, may end up poisoning the local ground water. Ecosystems that depend on a water source, such as the Athabasca River in Alberta, are especially at risk from water withdrawals since the majority of water used for mining in withdrawn from here. 34


The repair and return of land to its natural state once mining operations are over, is a key element in Alberta’s regulatory regime. According to Alberta law, “oil companies are required to return the lands they develop to a natural state.”

But in the Spring of 2018, an oil firm with licences for 2,300 wells filed for bankruptcy protection without decommissioning and cleaning up 4,000 wells, pipelines and other facilities, as required of all tar sands oil companies. The High Court ruled in the firm’s favor allowing it to avoid all its clean-up responsibilities. 35

Sea Otters: Exxon Valdez Oil Spill
Two seat otters, victims of the Exxon Valdez oil spill, recover at a special rehabilitation centre in July 1989. Photo: © Jim Lavrakas

Clean-up Costs

Prior to February 2018, the Alberta Energy Regulator (AER) had announced that the oil industry’s “accumulated environmental liability” was C$58.65 billion. But during that month, Rob Wadsworth, the AER’s Vice President of Closure and Liability, admitted that the “worst case” cost of cleaning up the Alberta oil sands would actually be $260 billion (US$195 billion). 36 37

Unfortunately, relatively little land has been cleaned up and reclaimed, while the Alberta authorities have collected only $1 billion (via the so-called Mine Financial Security Program fund) from companies to help remediate pond tailings – a problem that is now projected to cost about 100 times that. Meantime, the tailings ponds are polluting the air and leaking into the surrounding land, possibly reaching the nearby Athabasca River.

“The ponds have just grown and grown for five decades,” said Jodi McNeill, policy analyst for environmental think-tank Pembina Institute. “If we just continue kicking the can down the road, we could be leaving a legacy of at least tens of billions in cleanup costs … to future generations.” 37

According to the research, communications, and advocacy organization Oil Change International (OCI), tar sands oil is more hazardous to produce, transport and process than conventional oil because it contains more carbon and more toxic chemicals, like heavy metals and sulfur. No matter what methods are employed to extract it, these pollutants will inevitably find their way into the environment one way or another.

NOTE: A growing number of environmentalists are calling for our present era to be renamed the Anthropocene epoch, to reflect the impact of human actions on Planet Earth’s fragile environment. After reading about the disaster of tar sands pollution, you can see why.

Transporting Fossil Fuels

Fossil fuels give off harmful air pollutants (greenhouse gases and fine particulates) long before they’re burned. In fact, every day, about 12 million Americans are exposed to health-threatening air pollution from active oil and gas wells and from oil and gas transport and processing activities. This kind of (mainly methane) seepage is another one of of the many adverse effects of fossil fuels.

In 2015, U.S. methane emissions from natural gas and petroleum systems totalled a whopping 8.1 million tons. 38 Pollution from benzene (associated with childhood leukemia and blood disorders) and formaldehyde (a carcinogenic chemical). And a flourishing fracking industry will spread that pollution to more playgrounds and backyards, despite mounting evidence of the industry’s hazards.

Transporting Coal

The majority of coal movements involve coal being transported from mines to power plants. In 2016, according to the Energy Information Administration (EIA) roughly 68 percent of the coal used for electric power in the United States was transported by rail: 13 percent was moved by river barge and another 11 percent by truck 39. Trains, barges, and trucks all run on diesel fuel, a major source of nitrous oxide and other nitrogen compounds, as well as soot (carbon aerosols), all of which carry substantial health risks 40. The movement of coal also produces fine particulates of coal dust, which itself carries serious cardiovascular and respiratory risks for communities living close to transportation routes.

Transporting Natural Gas

Natural gas is moved over long distances by transmission pipelines, while distribution pipelines deliver gas locally to homes and businesses. But because natural gas is highly flammable, the process of transporting it from wellhead to customer can be a dangerous business. During the period 2008-2015, there were 5,065 significant safety incidents involving transmission and distribution pipelines, involving 108 deaths and 531 injuries 41.

Massive gas explosion,  San Bruno, California
Massive gas explosion, San Bruno, California (2010). A federal jury found Pacific Gas & Electric Co., California’s largest utility, guilty in 2016, of misleading investigators about how it was identifying high-risk pipelines after the deadly gas line explosion in the San Francisco Bay Area. Photo: © AP Photo/Noah Berger

In addition, leaks and seepage from the pipeline network are a significant source of methane emissions (natural gas being 85 to 95 percent methane), and are probably much more widespread than we imagine. For example, a recent study conducted by the University of Boston, found 3,356 separate leaks under the city’s streets, due to the aging nature of the city’s pipeline infrastructure. 42

The fact is, during the production, storage and transmission of natural gas, a significant amount of the gas seeps into the atmosphere, through normal procedures, routine maintenance and venting, as well as fugitive leaks and system failures. In the United States, for example, according to a 2016 report by the U.S. Environmental Protection Agency, the methane leakage rate from natural gas and petroleum installations is 2.3 percent – that’s a massive 8.1 million tonnes. Of this, 6.5 million tonnes from the natural gas system, 1.6 million tonnes from petroleum supply chains. 38

But two years later, a 2017-18 review of emissions studies revealed that the figure of 8.1 million tonnes cited by the EPA was actually a huge underestimate. The true figure was 13 million tonnes – roughly 60 percent more than the figure in the original EPA report. That’s a seepage rate of roughly 3.6 percent. 43

Transporting Liquified Natural Gas (LNG)

Liquefied Natural Gas (LNG) is natural gas that has been cooled and condensed into a liquid form. It is already attracting controversy for its carbon footprint.

To understand the range of environmental and public health dangers posed by LNG, consider a 2014 report commissioned by the Lower Rio Grande Valley Sierra Club on the environmental dangers posed by several local LNG facilities in the Rio Grande Valley. In the report, researchers listed: the visual impact of flare towers 200-500 feet in height; toxic runoff; risk of explosion; toxic emissions (of greenhouse gases, carbon monoxide, sulfur dioxide, and volatile organic compounds); discharge of particulate matter; significant habitat loss (of local mangrove swamps) dooming the ocelot colony and threatening the aplomado falcon and the piping plover.

The report closes by saying that while liquefied natural gas is a relatively clean-burning fuel, by the time it is fracked, piped, purified, liquefied, transported overseas, and re-gasified, the pollution picture is quite different. The report cites a recent environmental study conducted by the U.S. Department of Energy (DOE) which analyzed the lifecycle greenhouse gas emissions from LNG exports. 44 The DOE report found that LNG exports did almost as much harm as coal when exported to Europe, and much more harm than coal, when exported to Asia. 45

Following the 9/11 terrorist attacks, deliveries of liquefied natural gas have faced stricter regulations and tighter security as officials debate the risks of an attack on LNG carriers and facilities, particularly where LNG terminals are situated near densely populated areas. 46

Transporting Oil

Oil is transported across the globe in super tankers, and across continents by pipeline, rail, and truck. In all cases, there is a constant risk of oil spillage or seepage, with adverse effects on the global environmental.

As well as catastrophic incidents such as the notorious 1989 Exxon Valdez oil spill, which released 262,000 barrels of oil into the Prince Williams Sound in Alaska, leaks from onshore oil pipelines are also a serious threat to the environment. Examples in the United States include: the 2010 Enbridge spill that released approximately 840,000 gallons into Michigan’s Kalamazoo River; the 2013 ExxonMobil spill in Mayflower, Arkansas, 25 miles northwest of Little Rock. Roughly 500,000 gallons of oil (mixed with water) was recovered within 2 days; the 2017 leak of 210,000 gallons of oil from TransCanada’s Keystone Pipeline in Marshall County, north-eastern South Dakota. 

Burning Fossil Fuels

All fossil fuels give off carbon dioxide and other harmful air pollutants when burned. These emissions have adverse effects on public health, as well as the local and global environment.

Fossil fuels are the main contributor to climate change. 47 They account for roughly three quarters of all man-made greenhouse gases in the atmosphere. So, like it or not, every time we burn petroleum, coal, or gas, we’re responsible for emitting a mini-cloud of greenhouse gas. These emissions trap heat in the atmosphere and heat up the planet to unnatural levels, indiscriminately destroying untold numbers of ecosystems and habitats. Burning coal also emits radioactive elements into the lower atmosphere such as thorium (Th) and uranium (U).

What Are the Main Alternatives to Fossil Fuels?
Sustainable alternatives to coal, oil and gas, include: hydropower (hydroelectricity), solar energy, organic biomass, underground geothermal energy, offshore and onshore wind power, as well as tidal energy and wave power. The life cycle carbon footprint of these renewable energy sources is far lower than that of fossil fuels.

How Much CO2 Is Produced When Fossil Fuels Are Burned?

It depends on the type of fossil fuel used. Different fuels give off different amounts of carbon dioxide (CO2). The amount of CO2 emitted is usually determined by the fuel’s carbon content. The higher the carbon content, the more CO2 is discharged. 

Carbon Dioxide Emissions Of Different Fossil Fuels

Carbon Dioxide Emissions of Different Fossil Fuels
Diagram: 48

Methane Emissions

Are methane emissions as bad as carbon dioxide emissions? No. They’re much worse. That’s because methane absorbs 84 times more heat than carbon dioxide over 20 years. Unfortunately, levels of methane in the atmosphere have surged since 2007, and much of this (30-60 percent) is coming from the United States, says a recent study by Harvard University. Researchers say it is impossible to pin down the exact cause, although the increase appears to coincide with America’s shale oil and gas boom, which has been associated with significant methane leakage from oil and gas wells and from pipelines nationwide. 49 Global methane emissions from fossil fuel sources is around 100 million tonnes each year. For more on this, see also: Why Are Methane Levels Rising?

How Do Fossil Fuels Contribute To Emissions Of Methane?

As coal slowly forms underground, methane is also formed and pockets of this gas remain trapped until released by mining operations. Usually, the deeper the coal seam, the more methane is trapped. In shallow and open cast mines, the trapped methane typically escapes into the atmosphere during mining. In deeper mines the gas is often freed via ventilation shafts in order to prevent a dangerous build-up.

In a similar way, methane gas can also accompany the geological formation of oil. During oil drilling, the trapped methane is released into the atmosphere.

Natural Gas
Natural gas is 85 to 95 percent methane, so although burning natural gas results in fewer emissions than either coal or oil, it is a major source of atmospheric methane emissions, notably from drilling wells and pipelines. It is estimated, for example, that in the 1990s as much as 6 percent of all methane piped across continental Russia was lost because of leaks. As stated above, the current U.S. seepage rate is 3.6 percent. 50

What Is Methane Capture?

Methane can be captured at the gas/oil well head and rechannelled for use as an energy source. The gas is often either flared (burned) or vented (released). Vented methane goes directly into the atmosphere as a greenhouse gas. Flaring converts the methane into carbon dioxide (a less harmful greenhouse gas) before allowing it to escape into the atmosphere. The World Bank estimates that 5.3 trillion cubic feet of natural gas, the equivalent of 25 percent of total US consumption, is flared annually worldwide, generating some 400 million tons of unnecessary carbon dioxide emissions. 51

What Causes Methane Emissions?

Sources Of Methane Emissions

How Do Fossil Fuels Contribute To Smog And Air Pollution?

When burned, fossil fuels give off a range of harmful air pollutants that cause serious damage to both the environment and public health. 52

Coal burning, for example, plays a key role in the man-made sulfur cycle because of its connection with acid rain, due to its emissions of pyrite (iron sulfide) and other sulfur-containing compounds. When coal is burned in power plants it is oxidized to yield sulfur dioxide (SO2), which – when mixed with air – forms sulfuric acid (H2SO4). This then mixes with clouds and water vapor in the atmosphere to produce acidic precipitation (rain, fog, sleet, snow), commonly called acid rain.

Acid rain has many ecological effects, especially on trees and forests, lakes, streams and other wetlands. Although this acidification process has been lessened by processes that remove sulfur from coal (desulfurization) and by switching to coals with a low sulfur content, U.S. coal-fired power plants still emitted more than 3.1 million tons of SO2 in 2014.

Coal combustion also produces microscopic aerosol particles known as particulates, which are especially damaging to human health because they are small enough to evade the human lungs’ natural filters. 53 One of the worst effects of fossil fuels, these tiny particles are either emitted in the form of black carbon directly from the power plant or furnace, or are formed in the atmosphere as a result of reactions between oxygen and either sulfur dioxide (SO2) or nitrogen oxide (NOx). Both SO2 and NOx are associated with several health conditions, including: asthma, bronchitis and decreased lung function, as well as other respiratory diseases.

In Africa and Asia, coal (along with wood) is a significant contributor to indoor air pollution from indoor open fires. In addition, coal-fired power plants contribute to the vast toxic haze, known as the Asian Brown Cloud, that envelopes parts of the Indian sub-continent during the dry winter months and to the urban smog that blights Delhi and many other cities in India and China.

The World Health Organization has said that, globally, air pollution from coal is responsible for about 1 million premature deaths per year. Most fatalities occur in China and India. One study shows that in 2011-2012, pollution from coal plants in India led to 80,000 to 115,000 premature deaths and more than 20 million asthma cases from exposure to PM10 particulate pollution. 54

According to the U.S. Environmental Protection Agency, coal-fired power plants are the largest source of atmospheric mercury emissions in the United States, accounting for 44 percent of all emissions. 55

Why Are Fossil Fuel-Powered Vehicles Bad For Climate Change?

All engines than run on petrol, gasoline or diesel are damaging the planet as well as the local environment.

They give off greenhouse gases like carbon dioxide, which is the biggest single driver of global warming. In 2018, greenhouse gas (GHG) emissions from transportation accounted for roughly 28 percent of all U.S. GHG emissions. More than half of all GHG emissions come from cars, vans, SUVs and pickup trucks. The remainder comes from freight trucks, commercial aircraft, ships, and trains. 56

Vehicle engines also spew out a range of other air pollutants that lower urban air quality by causing photochemical smog. All impact adversely on public health. These pollutants include:

  • Particulate matter. One type of particulate material is the soot emitted from vehicle exhausts. (Soot is a mass of carbon particles resulting from the incomplete combustion of petroleum. 57 Diesel exhaust pollution is one of the largest sources of the world’s hazardous air pollution. 58
  • Volatile Organic Compounds (VOCs). In sunlight, VOCs react with nitrogen oxides to form ground level ozone, one of the main constituents of smog.
  • Nitrogen oxides (NOx). This gas also forms ground level ozone and particulate matter.
  • Sulfur dioxide (SO2). Motor vehicles produce SO2 by burning sulfur-containing fuels like diesel. As stated above, SO2 reacts in the atmosphere to form fine particles that are extremely damaging to public health.
  • Carbon monoxide (CO). This poisonous gas is emitted primarily from cars and trucks. This accounts for over a third of all carbon monoxide emissions.

These toxic chemicals are linked to a host of serious respiratory illnesses, such as asthma, choking, lung irritation, pneumonia and influenza. Some are associated with cancer. All are implicated in the creation of smog, which itself is an independent risk factor for most respiratory conditions.

This is why electric vehicles (EVs) are so much better for the environment and for the air quality in cities around the world. Electrically powered cars emit no pollutants or pollution of any kind.

One study, published in Nature magazine, revealed that smog episodes in the city of Jinan (pop: 8,700,000), in eastern China, during 2011–15, were linked with a 5.87 percent rise in the rate of overall mortality. In 2016, the Ontario Medical Association announced that smog is responsible for an estimated 9,500 premature deaths in the province each year. 59

Delhi is the most polluted urban area in the world, suffering about 10,500 pollution-related fatalities every year. 60 The city has the highest level of PM2.5, the most harmful type of particulate matter. Rising air pollution levels have led to a noticeable increase in lung-related ailments (notably asthma and lung cancer) among Delhi’s women and children. 61


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