Fossil Fuels: Energy of the Industrial Age

13.1 What Are Fossil Fuels, and How Important Are They Today?

Fossil fuels are energy sources formed from living organisms from earlier geologic eras.
Nearly 80% of all energy used to power modern lifestyles comes from fossil fuels.
The original source of all fossil fuel energy is the sun.
Oil and gas are hydrocarbons, made of hydrogen and carbon molecules derived from ancient, solar energy-capturing photosynthesis.
Oil is the liquid fossil fuel.
Natural gas is a gaseous fossil fuel that is primarily methane.
Coal is a solid carbon-based fossil fuel.
Reserves are known resources of a fossil fuel that can be economically accessed with current technology.
Conventional reserves are easily obtained deposits of fossil fuels.
Unconventional reserves are difficult-to-extract deposits.
Fossil fuels account for 80% of global energy use, with oil, gas, and coal as the top three sources.
World energy consumption increases every year by about 2%.
Uses for primary energy sources include:
- transportation
- industrial processes
- heating and cooking in residential and commercial properties
- increasing varieties of electrical demands for air-conditioning and appliances
Oil is primarily used for transportation, while other energy sources are used to generate electricity.
Fossil fuels take millions of years to form from the remnants of organisms.
Fossil fuels are a nonrenewable resource because we consume them far more quickly than they can form.

Fossil fuels must be mined and burned to provide energy.
Fuel extraction, processing, and combustion all have environmental impacts.
These processes result in air, water, and land pollution, as well as the release of large amounts of greenhouse gases.

Coal is a sedimentary rock. It was the first fossil fuel to be widely used and is still the most abundant.
The United States, Russia, China, and Australia account for more than two-thirds of global reserves.
Coal is mostly used to produce electricity.
China accounts for nearly half of the world’s total coal consumption.
Coal is extracted from underground mines through boring machines, and from surface mines through blasting and machinery.
Some regions use mountaintop removal, removing entire mountaintops to scoop out underlying coal, then depositing waste in adjacent valleys.
Water that drains from coal mines is often acidic and contaminated with heavy metals, resulting in the destruction of aquatic habitats.
Coal mines contribute 7% of US methane emissions as this gas must be vented to prevent explosions.
Mining can cause land subsidence as tunnels collapse, resulting in craters on the surface.
Coal production uses twice as much water per unit of energy than natural gas.
Coal-fired power plants emit 40% more CO_2 per unit of energy than oil and 50% more than natural gas.

The refined form of oil is gasoline.
Oil is the most consumed fuel in the world.
Global oil reserves are sufficient to provide a 54-year supply at current levels of production.
The Middle East has more than half of the world’s proven oil reserves at 55%, followed by North America at 15%.
Oil extraction also occurs through hydraulic fracturing (fracking) and tar sands, which require the use of steam and direct heat application to separate the oil.
Oil extraction impacts local and regional environments, as do the pipelines that transport oil or natural gas.
Burning oil produces many of the same emissions as coal, including carbon monoxide, sulfur dioxide, nitrogen oxide, particulate matter, and CO_2.

Natural gas, which is primarily methane, has been the fastest growing fossil fuel energy source, and has surpassed coal consumption.
Most of this growth in use comes from natural gas turbine power plants for electricity.
Natural gas can be found with oil deposits or bound in layers of shale or other impermeable rock formations.
Natural gas requires a large network of pipelines for distribution.
Natural gas releases 30% less CO_2 than oil and 50% less than coal.
Gas pipelines can leak up to 12% of the methane they extract, contributing to greenhouse gas.
Methane leaks can also ignite, creating fires.
All fossil fuels when burned produce greenhouse gases and other pollutants, such as CO2, NOx, and SO_2.
Their extraction also degrades the environment, through either the direct destruction of the land during mining or the leaks and waste products that result from extraction.
Hydraulic fracturing (fracking) has permitted the increased extraction of less-polluting fuels from unconventional reserves, but it has environmental drawbacks of its own.

The collective share of the energy market for fossil fuels has been gradually shrinking over the past decade due to advancements in alternative technologies and increased costs of fossil fuels.
As the environmental and economic costs associated with fossil fuels continue to rise, the choices we make regarding energy options may change quickly.

Since fossil fuels are a finite resource, extraction will continue to be more difficult as resources decline.
Competition for fossil fuels has been a source of international conflict and raises national security concerns and costs in many countries.
- e.g., China's artificial islands in the disputed waters of the South China Sea.
If the profits from fossil fuels decline relative to alternative energy, fossil fuel extraction could become a stranded asset, which is an investment that becomes obsolete and does not yield a profit.
The social cost of carbon, an economic measure used to estimate damage to property, agriculture, and human health from fossil fuel use, is estimated to be at least $51 per ton of greenhouse gas emissions.
Pollution and climate change contribute to public health costs that are avoided using alternative energy.
Climate change also disrupts the distribution infrastructure of fossil fuels.

Governmental policies that increase the cost of fossil fuels, such as pollution regulations, taxes, and market mechanisms, encourage energy conservation and the development of alternative energy resources.
A carbon tax taxes carbon emissions from homes, vehicles, businesses, and industry.
A carbon tax was levied on fossil fuels in British Columbia, Canada, in 2008. Since then, per capita gas consumption dropped by 16%.
Another policy approach is a cap-and-trade program, where a government sets an overall maximum allowable emissions standard (cap), then allots pollution allowances to companies.
An open market enables pollution allowances to be bought, sold, traded, or saved for the future.
This creates an incentive for companies to reduce pollution and higher operating cost for companies that pollute more.
Fossil fuels have been our dominant source of energy for the past century, but their share of the energy market is shrinking as we transition to alternative energy resources.
The costs of fossil fuel use, especially the many environmental impacts but also international security issues, make them less appealing when compared to alternative sources of energy.
Governments at various levels are enacting policy responses to aid in a shift away from fossil fuels.