Environmental Science: Fossil Fuels, Fracking, and Human Impact

Fossil Fuels and the Evolution of Energy Production

• Fossil Fuel Definition and Dependence: A fossil fuel is a fuel derived from biological material that became fossilized millions of years ago. Developed countries, such as the United States, are highly dependent on coal, oil, and natural gas.
• Environmental Impact of Fossil Fuels: The utilization of these resources causes various environmental problems, including the release of pollutants into the air and water and significant land degradation.
• Natural Gas Characteristics: Natural gas, also known as methane, is the least harmful producer of air pollution among fossil fuels. It burns more completely and cleanly than coal or oil and contains fewer impurities.
• The Rise of Fracking: Hydraulic fracturing, or fracking, is a method of oil and gas extraction that utilizes high-pressure fluids to force open existing cracks in rocks deep underground.
  • Technological Advancement: Advances in technology have allowed companies to extract natural gas from locations previously considered economically unfeasible.
  • Economic and Strategic Benefits: Fracking has increased reliance on domestic energy sources, created many jobs, and made large quantities of natural gas available in the United States at a lower cost.
• Shifting Energy Trends for Electricity Generation:
  • Roughly $40\%$ of energy in the United States is used to generate electricity.
  • From $1980$ through $2000$, $50\%$ of that energy came from coal and only $15\%$ came from natural gas.
  • In $2017$, due to increased availability and lower prices, natural gas accounted for $33\%$ of electricity generation, while coal dropped to $30\%$.
  • Environmental Trade-offs: Because coal emits more air pollutants, including carbon dioxide ($CO_2$), than natural gas, the initial shift appeared beneficial for the environment.

Environmental Consequences and Controversies of Fracking

• Water Usage and Treatment: The fracking process requires millions of gallons of water, often taken from local streams and rivers. This water is pumped down or injected into each gas well. A portion of this water is later removed and must be properly treated to avoid contaminating local water bodies.
• Chemical Additives: A variety of chemicals are added to fracking fluid to facilitate the release of natural gas. Mining companies are not required to publicly identify all of these chemicals, leading to concerns from environmental scientists and citizens regarding underground water contamination.
• Well Contamination: Some drinking-water wells near fracking sites have become contaminated with natural gas.
  • High concentrations of natural gas in water can make it flammable.
  • Footage of flames shooting from kitchen faucets has been documented in popular media and scientific inquiries.
  • Reputable studies have shown that natural gas concentrations in drinking-water wells near some fracking sites are much higher than in wells further away.
• Induced Seismicity: There has been a higher frequency of earthquakes in the central and southwest United States. In $2016$, the U.S. Geological Survey reported that the injection of wastewater from fracking is believed to be the primary cause of these earthquakes.
• Atmospheric Leakage and Climate Change: Significant quantities of natural gas escape as "leakage" during the fracking and extraction process.
  • Leakage Estimates: Estimates suggest that between $2\%$ and $10\%$ of extracted natural gas leaks into the atmosphere.
  • Methane Heat Trapping: Methane is $25$ times more efficient at trapping heat from Earth than carbon dioxide ($CO_2$). Consequently, the potential impact of methane leakage on global climate change is substantial.

Foundations of Environmental Science and Systems

• The Environment: This refers to the sum of all conditions surrounding us that influence life, including living organisms (biotic) and nonliving components (abiotic) such as soil, temperature, and water.
• Environmental Science: This field of study examines interactions among human systems and those found in nature.
• Defining a System: A system is any set of interacting components that influence one another by exchanging energy, materials, or information. A change in one part of a system (e.g., fracking in a geologic formation) can cause changes throughout the entire system (e.g., in drinking water supplies).
• Ecosystems: An ecosystem is a particular location on Earth with interacting biotic and abiotic components.
  • Biotic Components: Living elements of the environment.
  • Abiotic Components: Nonliving elements of the environment.
• Environmentalism vs. Environmental Science:
  • Environmentalism is a social movement seeking to protect the environment through lobbying, activism, and education.
  • Environmental Science is a scientific discipline following the process of observation, hypothesis testing, and field and laboratory research.
• Environmental Studies: This broader field includes environmental science and additional subjects such as environmental policy, economics, literature, and ethics.

Human Impact and Land Use Transitions

• Scale of Systems: Environmental systems can vary from small populations to global climate systems. They can be human-made, such as a subway system, or natural, such as weather.
• Complex Interactions: The North Atlantic fisheries provide an example of complex systems. A physiologist may study a single codfish as a system; a marine biologist may study the predator-prey relationship between cod and herring; a fisheries manager may study a system involving fish populations, human technology, policy, and law.
• Historical Human Modification: Humans and their ancestors have influenced the environment for about $2.5$ million years.
  • Extinctions: Early humans are thought to be responsible for the extinction of mammoths, mastodons, giant ground sloths, and numerous bird types. More recently, hunting led to the extinction of the passenger pigeon ($Ectopistes\,migratorius$) and nearly caused the loss of the American bison ($Bison\,bison$).
  • Ecosystem Creation: Native Americans used fire to keep trees from encroaching on the Great Plains, leading to the development of the tallgrass prairie ecosystem.
• Modern Challenges:
  • Technological development and rapid population growth have increased the rate and scale of environmental impact.
  • The Los Angeles Example: In $1880$, fewer than $6,000$ people lived in Los Angeles. By $2017$, the population of Los Angeles was $4,000,000$, and the metropolitan area was home to nearly $13,000,000$ people. This density results in unavoidable pollution of water, air, and soil.
  • Global Climate and Land Use: Current changes in land use and climate are outpacing the rate at which natural systems can evolve.

AP Practice Questions

• Question 1: Impacts of fracking include:
  • I. contamination of ground water.
  • II. increased use of coal.
  • III. lower natural gas prices.
  • (a) I only
  • (b) I and II
  • (c) II and III
  • (d) I and III
• Question 2: Which is an abiotic component?
  • (a) an eagle
  • (b) a rock
  • (c) a tree
  • (d) a human
• Question 3: Which is NOT true about ecosystems?
  • (a) They include biotic components.
  • (b) They can be a wide range of sizes.
  • (c) They include no human components.
  • (d) Many interactions among species occur in them.
• Question 4: Each of the following is an example of how humans have negatively affected the environment EXCEPT:
  • (a) hunting large mammals.
  • (b) conversion of arid land to agricultural use.
  • (c) the use of fire to create the Great Plains.
  • (d) slash-and-burn forest clearing.