Fossil fuels power our world but come with a hefty environmental price tag. Coal, oil, and natural gas provide energy for homes, transportation, and industries. However, their extraction and use release greenhouse gases, causing climate change and air pollution.

The environmental impacts of fossil fuels are far-reaching. Burning them releases carbon dioxide, driving global warming. Air pollution from fossil fuels harms human health, while acid rain damages ecosystems. Extraction methods like fracking raise concerns about water contamination and earthquakes.

Fossil Fuel Types

Coal: Formation and Types

• Forms from fossilized plant matter over millions of years through heat and pressure
• Classified into four main types based on carbon content and heat value
  • Anthracite contains highest carbon content, used primarily for industrial purposes
  • Bituminous coal most abundant type, widely used for electricity generation
  • Subbituminous coal lower heating value, often used in power plants
  • Lignite lowest grade, typically used in power plants near mining sites
• Mining methods include surface mining (strip mining) and underground mining
• Coal remains a significant energy source globally, despite environmental concerns

Oil: Composition and Refining

• Consists of hydrocarbons formed from ancient marine organisms
• Extracted as crude oil, a complex mixture of various hydrocarbon compounds
• Refining process separates crude oil into different petroleum products
  • Fractional distillation separates components based on boiling points
  • Cracking breaks down larger molecules into smaller, more useful ones
• Refined products include gasoline, diesel fuel, heating oil, and petrochemicals
• Global oil reserves unevenly distributed, leading to geopolitical tensions
• Peak oil theory suggests maximum extraction rate followed by terminal decline

Natural Gas: Properties and Usage

• Primarily composed of methane (CH4), with small amounts of other hydrocarbons
• Formed alongside oil deposits or in isolated gas fields
• Considered the cleanest-burning fossil fuel, producing fewer emissions than coal or oil
• Extracted through conventional drilling or unconventional methods (fracking)
• Uses include electricity generation, heating, cooking, and industrial processes
• Liquefied Natural Gas (LNG) allows for easier transportation and storage
• Growing importance as a "bridge fuel" in transition to renewable energy sources

Environmental Impacts

Greenhouse Gas Emissions and Climate Change

• Fossil fuel combustion releases significant amounts of carbon dioxide (CO2)
• CO2 primary greenhouse gas contributing to global warming and climate change
• Methane emissions from natural gas extraction and transportation also contribute
• Climate impacts include rising temperatures, sea level rise, and extreme weather events
• Carbon footprint measures total greenhouse gas emissions associated with individual or organizational activities
• Efforts to reduce carbon footprint include energy efficiency, renewable energy adoption, and carbon offsetting

Air Pollution and Human Health

• Burning fossil fuels releases various pollutants into the atmosphere
  • Particulate matter (PM2.5 and PM10) can cause respiratory and cardiovascular issues
  • Sulfur dioxide (SO2) and nitrogen oxides (NOx) contribute to smog formation
  • Ground-level ozone formation exacerbated by fossil fuel emissions
• Air pollution linked to increased rates of asthma, lung cancer, and heart disease
• Urban areas often experience higher levels of air pollution due to concentrated emissions
• Environmental justice concerns arise from disproportionate impacts on low-income communities

Acid Rain and Ecosystem Damage

• Formed when sulfur dioxide and nitrogen oxides react with water, oxygen, and other chemicals in the atmosphere
• Acidic precipitation can harm aquatic ecosystems, forests, and soil quality
• Effects on aquatic ecosystems include decreased fish populations and altered pH levels
• Forests experience reduced growth rates and increased vulnerability to pests and diseases
• Acid rain can leach nutrients from soil, impacting agricultural productivity
• International efforts (Clean Air Act in the US) have reduced acid rain in some regions

Extraction Methods

Fracking: Process and Controversies

• Hydraulic fracturing used to extract oil and natural gas from shale formations
• Process involves injecting high-pressure mixture of water, sand, and chemicals into rock
• Horizontal drilling techniques allow access to previously unreachable deposits
• Increased natural gas production through fracking led to reduced coal usage in some countries
• Environmental concerns include:
  • Potential groundwater contamination from fracking fluids
  • Increased seismic activity in fracking areas
  • Methane leakage during extraction and transportation
• Regulatory approaches vary by country and region, with some banning the practice

Conventional Extraction and Peak Oil

• Traditional oil extraction methods include onshore and offshore drilling
• Enhanced oil recovery techniques extend productivity of existing wells
  • Water flooding injects water to maintain pressure and displace oil
  • Gas injection uses CO2 or natural gas to increase oil recovery
• Peak oil theory predicts maximum rate of global oil extraction followed by decline
  • Based on finite nature of oil reserves and increasing difficulty of extraction
  • Debate continues over timing and implications of peak oil
• Technological advancements and unconventional sources (oil sands, shale oil) have delayed peak oil predictions
• Transition to renewable energy sources seen as necessary response to eventual decline in fossil fuel availability