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19
Fossil Fuels: Energy and Impacts
History of energy use
People have long exploited energy sources.
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Coal, oil, gas, solar, and wind power were all used before 1200 B.C.
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Fire, animal labor, and hot springs were used long before that.
But only since the industrial revolution have we harnessed energy sources on a grand scale.
Fossil fuels
Fossil fuels = highly combustible substances formed from the remains of organisms from
past geological ages
Compressed tissues of plants (and some animals) from 100–500 million years ago store
chemical energy from photosynthesis.
• This greatly concentrated energy is released when we burn coal, oil, or gas.
•GrowthFossil
fuel use has been rising for years
in coal has slowed, but oil and gas are still rising.
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Fossil fuels:
Formation
Plants and animals die
Organic material settles in anaerobic site and is partly decomposed
Organic material is buried
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Heat and pressure alter chemical bonds
Coal, gas, oil formed
Distribution of fossil fuel reserves
Saudi Arabia has the most oil.
Russia has the most natural gas.
The U.S. has the most coal.
Per capita energy use varies
Nations differ greatly in amounts of energy used per person.
Developed nations like the U.S. use by far the most.
Coal
Coal: compressed under high pressure to form dense
carbon structures
First used 3,000 years ago
Powered the industrial revolution in England, then in other countries
Today is surpassed by oil, but is still the most abundant fossil fuel
Provides 1/4 of the world’s commercial energy consumption
How coal is formed
Peat is partially decayed organic matter near the surface, a precursor to coal.
With more time, more heat and pressure, squeezing out more moisture, coal becomes more
energy-rich.
Anthracite is the most compressed and most energy-rich type of coal.
•ChinaCoal
production and consumption
produces and consumes the most coal, followed by the United States.
•Coal isCoalmined
mining
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either underground, in subsurface mining,
• or from the surface, in strip mining.
•Coal isElectricity
generation from coal
most used to generate electricity. Heat from coal burning boils steam, turning a turbine to
power a generator.
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Oil
Crude oil (petroleum): sludgelike mix of hundreds of types of hydrocarbon molecules;
forms at temperatures and pressures found 1.5–3 kilometers below ground
Oil refineries sort the various hydrocarbons of crude oil, separating those to be used in
gasoline with those used for other purposes (tar, asphalt).
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Modern extraction began in the 1850s in Pennsylvania.
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Today oil is the world’s most-used fuel.
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Estimating recoverable reserves
Technology limits how much oil can be extracted.
Economics determines how much oil will be extracted.
Proven recoverable reserve = amount of oil that is technologically and economically
feasible to remove
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Once oil deposits are identified, oil companies typically conduct exploratory drilling.
Oil: Drilling
Liquid oil exists in pores in rock deep underground.
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We must drill into rock and extract oil by using a pressure differential.
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The more oil is extracted, the harder it is to extract:
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Primary extraction = initial extraction of available oil
Secondary extraction = forcing oil out by pumping water or gas into rock to
displace it
Oil: Drilling
Depletion of oil reserves
We may have already extracted half of the world’s oil reserves (1 trillion barrels).
To estimate how long this remaining oil will last, analysts calculate the reserves-toproduction ratio (R/P ratio)…
…by dividing the amount of total remaining reserves by the annual rate of production.
Depletion of oil reserves: “Hubbert’s peak”
Geologist M. King Hubbert predicted U.S. oil production would peak around 1970 and
then decline.
He was only a few years off.
Refining crude oil
Crude oil from the ground is a messy mix of hundreds of hydrocarbons.
• It is put through a refining process to segregate different components.
• Refining crude oil
•Refined
Petroleum products
components of crude oil are used to manufacture many of the material goods we use
every day.
•NaturalNatural
gas formation
gas: primarily methane, CH , is produced in two ways:
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Biogenic gas = formed at shallow depths by anaerobic decomposition of organic
matter by bacteria
Thermogenic gas = formed at deep depths as geothermal heating separates
hydrocarbons from organic material
Natural gas: History
Seeps known for 2,000+ years
Used for street lighting in the 1800s
Became commonly used after WWII once pipeline technology became safer
Natural gas production and consumption
Russia produces the most natural gas.
The U.S. consumes the most natural gas.
Gas extraction
Initially, gas comes out on its own from natural pressure.
Later, it must be pumped out.
Other fossil fuels
Other fossil fuels could be used in the future:
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Oil or tar sands = dense, hard, oil substances that can be mined from the ground
Shale oil = sedimentary rock filled with organic matter that was not buried deeply enough
to form oil
Methane hydrates = occur under the seafloor
Environmental impacts of fossil fuel use
Using fossil fuels creates a number of environmental impacts.
Most energy experts would like to see a switch to renewable and less-polluting energy
sources.
•Compounds
Environmental impacts
and particulate matter resulting from combustion of coal, oil, and gas:
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Cause air pollution
(from power plants, vehicle exhaust, etc.)
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Drive climate change
(from carbon dioxide emissions)
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Throw the carbon cycle out of balance
(transferring carbon stored underground to atmospheric carbon dioxide)
•WaterEnvironmental
impacts
pollution also results from fossil fuel use:
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Acid deposition (from sulfur pollutants emitted in power plant combustion)
Runoff from non-point sources (cars, homes)
Oil spills (not just large spills from tankers; mostly small spills from nonpoint sources)
•Coal mining
Environmental impacts
has impacts:
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Habitat destruction from strip mining
Erosion from strip mining
Chemical runoff from strip mining through acid drainage
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Human health risks for workers from subsurface mining
Political, social, and economic impacts
The degree of dependence that our modern economies have on fossil fuels is risky.
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This puts all our eggs in one basket.
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Nations that supply oil can call the shots.
• Nations that need oil are dependent on suppliers.
•A smallOilnumber
commerce
of nations export nearly all the world’s oil.
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Alternatives to fossil fuels
Because fossil fuels are nonrenewable and will not last forever the world’s economies must
find alternatives.
Most alternatives are costly and depend on undeveloped technologies.
Three alternatives are the most developed and widely used:
• Nuclear power
• Biomass energy
• Hydroelectric power
Nuclear energy
Nuclear energy = energy that holds together protons and neutrons within the nucleus of an
atom
We harness this energy by converting it to thermal energy, which can then be used to
generate electricity.
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Each conversion process involves transforming isotopes of one element into isotopes of
other elements by the addition or loss of neutrons.
•NuclearNuclear
energy: Fission
fission = energy is released by splitting apart uranium nuclei by bombarding them with
neutrons
This is the process used in nuclear reactors and weapons.
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Nuclear energy
Comes from the radioactive element uranium
The nuclear fuel cycle enriches forms of uranium to make it into usable fuel.
Electricity is generated by controlling fission in nuclear reactors.
Nuclear energy
Uranium is used for nuclear power because it is radioactive.
Radioisotopes emit subatomic particles and high-energy radiation as they decay.
Each radioisotope decays at a rate determined by that isotope’s half-life, the amount of
time it takes for one-half of the atoms to give off radiation and decay.
•In a reactor,
Nuclear reactor
fission boils steam to turn a turbine and generate electricity
•Nuclear
Nuclear energy: Fusion
fusion = nuclei of lightweight elements are forced together
Not efficient for power production, so is not (yet) used.
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Nuclear troubles
Although nuclear power is clean, lacking the pollutants of fossil fuels, it has drawbacks:
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Its waste is dangerously radioactive.
Consequences of accidents can be catastrophic.
• 439 nuclear plants remain operating today in the world.
•The 1986
Nuclear accidents
Chernobyl explosion caused the world’s most severe nuclear power plant accident.
•FalloutNuclear
accidents
from Chernobyl was deposited across Europe.
•NuclearNuclear
waste disposal
waste must be disposed where it will not escape.
•NuclearNuclear
waste disposal
waste is stored at 125 sites in 39 states.
•At Yucca
Nuclear waste disposal
Mountain, all nuclear waste in the U.S. would be buried in a network of tunnels deep
underground.
•Coal,Greenhouse
gas emissions
oil, and natural gas emit far more greenhouse gases than do renewable energy sources
and nuclear energy.
•OrganicBiomass
substances produced by recent photosynthesis
(unlike fossil fuels, products of ancient photosynthesis)
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Uses of biomass energy
More than 1 billion people burn fuelwood or charcoal as their principal power source for
cooking, heating, etc.
New uses:
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Burning in power plants to produce biopower
Converting into biofuels to power automobiles
Many new biomass resources are the waste products of preexisting industries or
processes, e.g., forestry, landfill waste.
•EnergyBiomass
energy consumption
consumption patterns vary greatly between developing and developed nations.
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Biofuels
Ethanol = alcohol produced by fermenting corn and other carbohydrate-rich crops:
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Added to gasoline to reduce automotive emissions
Automakers are producing flexible fuel vehicles that run on 85% ethanol and 15%
gasoline.
Biodiesel = produced from vegetable oil, used cooking grease, or animal fat:
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Used in cars with diesel engines
Cuts down on emissions compared with petrodiesel
•Biodiesel
Biodiesel
has fewer emissions than petroleum-based diesel.
•In hydroelectric
Hydroelectric power
power, moving water is used to turn turbines and generate electricity.
The storage technique
stores immense amounts
of water behind dams.
•For nations
Hydroelectric power
with large amounts of flowing water (Brazil, Norway, Austria, Canada…),
hydropower has been key to their economic development.
98% of U.S. rivers
are dammed.
•WaterHydroelectric
power
flowing through a dam spins turbines that turn generators to create electricity.
• Hydroelectric power
•Commonly
“New renewables”
referred to as “new” because:
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They are not yet used on a wide scale.
They are harnessed using technologies that are still in a rapid phase of development.
It is widely believed that they will play a large role in our energy use in the future.
They provide only 0.5% of our global energy supply.
• “New renewables”
• Solar: from the sun’s rays
• Wind: from the wind
• Geothermal: from heat and heated water beneath the ground
• Ocean sources: from the tides and from waves
• Hydrogen: fuel and fuel cells that store renewable energy in usable form
•Renewable
Growth of renewable sources
sources, esp. wind and solar, are growing at an astounding rate.
These figures are percentage growth per year.
•The outlook
Renewable sources: Outlook
for renewable sources is good.
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But will governments raise subsidies to the level offered to fossil fuels?
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Will research and development proceed fast enough?
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Will companies have incentives to invest in developing these sources?
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Will consumers choose alternative energy sources?
Solar energy
Use of energy from the sun
Huge potential: Each day Earth receives enough sunlight to power human consumption for
27 years, if we could somehow capture it all.
Technology not new:
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First commercial solar water heaters: 1890
Solar energy
Passive solar = designs buildings to maximize capture of sunlight in winter, but keep
buildings cool in summer
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First thermal solar collector: 1767
through window placement, absorbent materials, and thermal mass materials that
absorb, store, and release heat
Active solar = uses technological devices to focus, move, or store solar energy
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solar panels: dark, heat-absorbing metal plates in glass-covered boxes, often
mounted on roofs
•Numerous
Solar energy: Active solar
mirrors focus sunlight on a receiver atop a “power tower” in the California desert.
This facility was the first to generate much solar power commercially.
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Solar energy: PV cells
Photovoltaic cells (PV cells) convert solar energy directly into electrical energy by making
use of the photoelectric effect:
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When sunlight strikes a charged metal plate, electrons migrate to another plate, and
electric current is produced.
In PV cells, light strikes negatively charged phosphorus, and electrons migrate through
silicon to positively charged boron.
•Electrons
Solar energy: PV cells
move from the phosphorus side of the silicon plate to the boron side, creating electric
current. PV cells are arranged in modules, panels, and arrays.
•PROS:Pros and cons of solar power
• Renewable as long as sun keeps on shining
• Sun’s energy abundant, if technology can capture it
• Allows for local control over power
• Solar cookers in developing nations lessen workloads.
•CONS:
No direct greenhouse gas emissions
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Not everywhere is sunny enough
Up-front investment cost is high; takes years to pay for itself
Solar power
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Wind power
Takes kinetic energy of wind and converts it to electrical energy
Fastest growing power source today
Technology = wind turbines, machines with turning blades that convert energy of motion
into electrical energy by spinning a generator
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Windmills have been used for centuries.
First wind turbine for electricity: late 1800s
•WindWind
power: Wind turbines
spins the blades, which turn the gearbox, which turns the generator to produce electricity.
•WindWind
power
speeds vary tremendously from place to place.
Windiest in the U.S. are mountainous areas and parts of the Great Plains.
•PROS:Pros and cons of wind power
• Renewable as long as wind blows
• No emissions after equipment made, installed
• Can allow local decentralized control over power, and local profit from electricity sales
•CONS:Costs low after initial investment; costs dropping
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Not everywhere is windy enough.
Windy sites can be far from population centers.
Some people object to aesthetics.
Blades kill birds, bats.
High start-up costs
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Geothermal energy
Radioactive decay of elements deep in Earth’s core creates heat that rises toward the
surface.
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This heats magma of volcanoes, and also underground water.
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Sometimes water spurts through to the surface in geysers.
• Geothermal power plants use the energy of naturally heated water to generate electricity.
•Underground
Geothermal energy
heat warms water, and steam turns turbines and generators.
Condensed steam is reinjected into the aquifer to keep up pressure.
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Geothermal energy
Iceland uses geothermal energy to heat water for 86% of its homes.
Heat pumps using surface heat can also be very efficient.
• Geothermal energy is growing 9% annually.
•PROS:Pros and cons of geothermal power
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Renewable as long as water is heated naturally
Much lower greenhouse gas emissions than fossil fuels
Can be inexpensive in areas where geothermal heating naturally occurs
CONS:
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Heated water may give out after a while—hotspot moves or aquifer pressure drops
Salts in water can corrode equipment, shorten lifespan
• Limited to geographic areas where geothermal heating naturally occurs
•ThreeOcean
energy sources
sources from oceans:
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Tidal power: The twice-daily flow of tides (rising and falling of seas due to the moon’s
gravitational pull) creates energy of motion that can be converted to electricity.
Wave power: Motion of waves at ocean shores creates energy of motion that can be
converted to electricity.
Thermal power: Exploits differences in warm and cold water. Not yet commercially
developed.
•Bulb turbines
Tidal energy
spin as tidal flow passes through them.
•ThereWave
energy
are several designs for wave energy stations.
In this one, air is compressed in a chamber with each incoming wave, driving a turbine to spin a
generator.
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Ocean thermal energy
Warm surface water is piped into facilities where it evaporates volatile substances (e.g.,
ammonia) to turn turbines.
Cold, deeper water is then used to condense the substances and start the cycle again.
Ocean Thermal Energy Conversion (OTEC) project research has been run in Hawaii and
elsewhere, but there are no commercial operations yet.
•PROS:Pros and cons of ocean power sources
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Renewable as long as oceans behave as they always have
No greenhouse gas emissions
CONS:
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Development could take up large portions of coastline valuable for other uses
Could interfere with ecology of estuaries and intertidal shorelines
OTEC not yet commercially feasible
Hydrogen
Hydrogen = simplest and most abundant element in universe
Could potentially serve as basis for clean, safe, efficient energy system
How it would work:
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Electricity generated from intermittent renewable sources like wind or solar can be
used to produce hydrogen.
Fuel cells can then use hydrogen to produce electrical energy for power.
Production of hydrogen fuel
Hydrogen gas (H2) does not exist freely on Earth.
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We need to make it.
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Electrolysis is the cleanest way:
Split water into hydrogen and oxygen:
2 H2O  2 H2 + O2
• This can potentially be very clean, releasing no greenhouse gas emissions.
• Fuel cells
•However,
Production of hydrogen fuel
cleanliness of hydrogen production depends…
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If the source of electricity needed for electrolysis is
not clean (e.g., from coal), then greenhouse emissions will still occur.
Besides electrolysis, hydrogen can also be produced from organic molecules like fossil
fuels. This entails greenhouse emissions.
• Also, it is possible that hydrogen production could have environmental impacts of its own.
•PROS:Pros and cons of hydrogen
• We will never run out of hydrogen.
• Can be clean and nontoxic, with no greenhouse gas emissions
•CONS:Fuel cells potentially convenient, safe, and efficient
• Depending on way hydrogen is produced, it may not be environmentally clean
• Emission of hydrogen to atmosphere might have unforeseen impacts
• This lecture will help you understand:
• Campus sustainability
• Sustainable development
• Economic welfare and environmental protection
• Consumption, population, technology, and sustainability
• Approaches to sustainable solutions
• That time is limited, but human potential is great
• Central Case: Ball State University Aims for Campus Sustainability
• In 1994, Ball State initiated a program to promote environmental literacy among its faculty.
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More recently, the university signed the Talliores Declaration, a commitment to
sustainability.
Efforts include composting, renewable fuels for school vehicles, campus-wide use of
recycled paper, etc.
Campus sustainability
Campuses consume substantial resources, spending over $200 billion/year on products and
services.
• Reducing their ecological footprints can make a big difference.
• Campus sustainability efforts are a good educational model.
• Students often initiate these efforts.
•TypicalCampus
sustainability
campus sustainability efforts:
• Recycling and waste reduction (most common)
• Green building design (as per LEED standards)
• Efficient energy and water use
• Organic dining and campus gardens
• Institutional purchasing of sustainable products
• Transportation alternatives
• Plant, habitat, landscape restoration
• Campus sustainability
•UN: “Development
Sustainable development
that meets the needs of the present without compromising the ability of future
generations to meet their own needs.”
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definition from the 1987 “Brundtland Report,”
Our Common Future
Development = the act of making purposeful changes to improve the quality of human life
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Is “sustainable development” an oxymoron?
What do we want to sustain?
The natural environment, its species, and its systems in a healthy and functioning state
Human civilization in a healthy and functioning state
• The second goal depends on the first.
•Environmental
Environment and the economy
protection can be good for the economy:
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Reducing consumption and waste can save money.
Environmental protection can enhance economic
employment.
opportunity by providing new types of
People desire to live in areas with good environmental quality.
•What Perceived
economy vs. environment divide
accounts for it?
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Is it because the conservation ethic is new, while our selfish survival instincts are very old,
honed by many thousands of years of natural selection?
Is it because the modern environmental movement has focused too much on command-andcontrol regulation, causing environmental activism to seem anti-economy?
•Our utter
Humans and the environment
dependence on the world around us—and the resources, goods, and services it provides
us—becomes clear when we realize…
•ofHumans
are not apart from the environment, but are a part
nature.
• The “people” vs. “nature” dichotomy is false.
•A recentCostsgovernment
and benefits of regulations
study even found that economic benefits of environmental regulations far
outweighed costs.
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Strategies for sustainability
Redefine our priorities regarding economic growth and quality of life
Recognize that growth is not synonymous with progress.
If we can incorporate external costs into our accounting, then the market can be used as a
force for positive change.
• Implement green taxes; phase out harmful subsidies
•Just because
Consume less
we’ve kept pace with growth in population and consumption so far doesn’t mean
we always will.
Our species has been on this planet only a short time, and our civilization is the blink of an eye
in geological time.
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Consume less
One can reduce consumption and lead a happier life in so doing.
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Indeed, both outcomes will likely be necessary for sustainable development.
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Ways to squeeze more from less:
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Improve technology and efficiency of manufacturing
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Develop a sustainable manufacturing system
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Make personal choices to reduce consumption
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Slow population growth
Never-ending growth in the human population cannot occur.
No organism’s population ever increases without end. Sooner or later limiting factors kick
in and restrain growth.
The question is, how will it happen to us?
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Through war, plagues, famine, environmental ruin?
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Or through wealth, education, and the demographic
transition?
Channel technology toward sustainability
Has increased our impact upon the planet
But can also help us toward sustainability
… if we use it wisely and responsibly
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Mimic natural systems
Human industrial systems can be made circular and recycling-oriented.
Nature is sustainable and operates in cyclical systems that are self-renewing.
If we want our economies and industries to be self-sustaining, then they too should be
cyclical, and recycle their outputs as inputs.
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Base decisions on long-term thinking
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Politicians have incentive to act for the short term.
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Dealing with most environmental issues means paying some small short-term cost for some
larger long-term benefit.
That is the nature of environmental problems, so many do not get addressed by
policymakers.
It is crucial for citizens to keep up pressure on policymakers to act for the long-term good.
Base decisions on long-term thinking
Businesses may have incentives to act for the long term, but too often have short-term
incentives also.
If a business wishes to remain in a community for a long time, it may make long-term plans
and help sustain environmental quality.
But more often, businesses are happy to make a short-term profit and move on.
It is crucial for consumers to patronize businesses that are good community citizens.
Vote with our wallets
Ecolabeling allows consumers to choose products according to how they were harvested or
made.
This gives consumers power to use the marketplace to achieve desired ends.
“Voting” via marketplace incentives can be very effective.
Vote with our ballots
Many, if not most, changes that will need to come
sustainability will
involve political action.
about for our society to attain
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It is crucial in democracies where citizens have the great privilege of the power of the
vote to use it.
Promote research and education
• awareNone
of the preceding approaches will succeed
of their importance.
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As citizens, we each can serve as role models and
• world’s
The discipline of environmental science itself will
greatest and
most-needed teacher.
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fully if the public is not
teachers.
continue to be, arguably, the
Precious time
Environmental impacts are occurring faster than ever before.
The time to deal with them is getting shorter.
• Can we do it? Is there time?
•Although
Precious time
the odds may seem long, human societies have accomplished amazing things in brief
periods of time when they really needed to.
President John F. Kennedy in 1961 said the U.S. would land men on the moon within a decade—
and in 8 years the incredible deed was done. All it took was resources and the pressure of a
space race with an adversary.
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The bottleneck
Human ingenuity and human compassion give us reason to hope that we may achieve
sustainability before doing too much damage to our planet and ourselves.
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We must face up to the challenges ahead: As
E.O. Wilson has noted, we will be passing through an “environmental bottleneck” and must
find a way to come out the other side safely.
•And weThemust
island
always remember to think of Earth as the island that it is:
A planet with finite resources, and our only home.