Studied by 4 people
📖 Garrett Hardin's "The Tragedy of the Commons"
Written in 1968.
Parallels resource depletion & pollution worldwide.
The commons (seas, air, water, animals, minerals) are for human use, but exploitation makes some people rich.
🌍 Environmental Issues Related to "The Tragedy of the Commons"
Air pollution
Burning fossil fuels causing global warming
Logging of old-growth forests & slash-and-burn practices
Habitat destruction & poaching
Over-extraction of groundwater from excessive irrigation
Overfishing
Overpopulation
⚖ Limits to "The Tragedy of the Commons"
Dividing the commons into privately owned parcels fragments policies.
Different standards/practices on one parcel may or may not affect others.
Environmental decisions are long-term, while economic decisions are short-term.
Discount rates could encourage investors to pay a short-term price for a long-term gain.
Market pressures affect privately owned land.
Controlling some commons (air/oceans) is harder than others (land/lakes/forests).
🌳 Clear-cutting
All trees in an area are cut at the same time.
🌍 Environmental Impacts of Clear-cutting
Habitat loss reduces biodiversity.
Sunlight reaches the ground, making it warmer and drier, unsuitable for many forest plants.
Temporary wood availability followed by long periods without wood.
Reduces carbon sinks, increasing atmospheric CO2.
Runoff increases, leading to soil erosion.
🌿 Edge Effect
Local environment changes along boundaries (edges).
Forest edges are created when trees are harvested (especially with clear-cutting).
Tree canopies provide shade, maintaining a cooler and moister environment.
🌍 Deforestation
The conversion of forested areas into non-forested areas for agriculture, mining, or urban development.
💥 Impacts of Deforestation
Runoff into aquatic ecosystems, climate change, and erosion decrease soil fertility.
Without shade, forest soils dry out quickly.
Degraded environments with decreased biodiversity and ecological services.
Forests house 80% of land animals and plants.
Increases habitat fragmentation and CO2 emissions from burning and tree decay.
Reduces habitats for migratory birds and butterflies.
Endangers niche-specialized species.
🌱 Deforestation Mitigation
Adopt uneven-aged forest management practices.
Educate farmers about sustainable forest practices.
Monitor and enforce timber-harvesting laws.
Grow timber on longer rotations.
Reduce fragmentation in large forests.
Reduce road building in forests.
Eliminate clear-cutting practices.
Sustainable tree-cutting methods.
🌾 First Agricultural Revolution (2000+ B.C.E.)
Transition from hunting and gathering to the domestication of plants and animals.
Allowed people to settle in areas and create cities.
Settled communities enabled people to observe and experiment with plants.
🚜 Second Agricultural Revolution (1700–1900 C.E.)
Occurred alongside the Industrial Revolution, with mechanization playing a major role.
Advances in livestock breeding increased agricultural output.
Enabled large urban populations to be fed.
Improved methods of soil preparation, fertilization, crop care, and harvesting.
Banking and lending practices helped farmers afford new equipment.
New crops arrived in Europe from trade with the Americas.
Railroads facilitated product distribution.
The seed drill prevented seed waste and allowed for row planting.
Tractors and farm machinery improved efficiency.
🌱 Third Agricultural Revolution (1900 C.E.–present)
Mechanization like tractors and combines requires less labor and lowers food prices.
Scientific farming methods include biotechnology, genetic engineering, and pesticides, with a focus on sustainable methods.
🌾 First Green Revolution (1940s–1980s)
Introduction of inorganic fertilizers, synthetic pesticides, new irrigation methods, and disease-resistant, high-yielding crop seeds.
🌱 Second Green Revolution (1980s–Present)
New engineering techniques and free-trade agreements shaped agricultural policies and food production.
Development of genetically modified organisms (GMOs) with genes that don't exist in nature.
Examples: BT corn (modified with bacterial insecticide genes) and Golden Rice (modified with daffodil genes to produce more beta-carotene, which converts to Vitamin A).
🌱 Agricultural Productivity
Refers to producing greater output with less input.
Increases efficiency on farms, stabilizes food prices, and provides more food availability, especially important for developing countries.
🏜 Desertification
The conversion of marginal rangeland or cropland into more desert-like land types.
🐮 Overgrazing
Occurs when plants are re-grazed before their roots recover, reducing root growth by up to 90%.
🌾 Fertilizers
Provide plants with the nutrients they need to grow healthy and strong.
⚗ Inorganic Fertilizers
Fertilizers mined from mineral deposits or manufactured from synthetic compounds.
🌱 Organic Fertilizers
Fertilizers from organic sources like bone meal, compost, fish extracts, manure, or seaweed.
🥗 Genetically Modified Foods
Foods produced from organisms (plants or animals) that have had changes introduced into their DNA.
🧬 Genetic Engineering Techniques
Allow for the introduction of new traits and greater control over them compared to previous methods.
🌿 Rangelands
Native grasslands, woodlands, wetlands, and deserts grazed by livestock or wild animals.
Managed through livestock grazing and prescribed fire, not intensive agricultural practices like seeding, irrigation, or fertilizers.
🔥 Slash-and-Burn Agriculture
A method where wild or forested land is clear-cut, and any remaining vegetation is burned to clear land for farming.
🌬 Soil Erosion
The movement of weathered rock or soil components from one place to another due to flowing water, wind, and human activity.
💧 Soil Degradation
Decline in soil condition caused by improper use or poor management, typically for agricultural, industrial, or urban purposes.
🏜 Salinization
Occurs when water evaporates from the soil, leaving behind dissolved salts in the topsoil.
💦 Waterlogging
Occurs when soil becomes saturated with water, causing a rise in the water table.
🌾 Tillage
An agricultural method where the surface is plowed and broken up to expose the soil, which is then smoothed and planted.
💧 Irrigation
The controlled application of water to plants at needed intervals.
Has been essential for agriculture for over 5,000 years.
🚜 Ditch Irrigation
Ditches are dug, and seedlings are planted in rows.
Water is moved through canals or furrows between the rows using siphon tubes to bring water from the main ditch.
🌱 Drip Irrigation
Water is delivered directly to the root zone of plants through small tubes.
Water is dispensed at a measured rate, minimizing waste.
🌊 Flood Irrigation
Water is pumped or brought to the fields and allowed to flow across the ground among the crops.
Simple, inexpensive, and commonly used in less-developed countries.
📏 Furrow Irrigation (Channel)
Small parallel channels are dug along the field length, usually along the slope.
Water is applied to the top of each furrow and flows down the field, infiltrating more at the start and less at the end.
🌧 Spray Irrigation
Uses overhead sprinklers, sprays, or guns to spray water onto crops, mimicking natural rainfall.
💥 Pesticides
Used to control pests, but their use has drawbacks such as toxicity and environmental accumulation.
🌱 Integrated Pest Management (IPM)
An ecologically based approach to pest control.
Combines biological, chemical, and physical methods to manage pests, requiring an understanding of pest ecology and life cycle.
🦠 Types of Pesticides
Biological Pesticides: Living organisms used to control pests.
Carbamates (Urethanes): Affect the nervous system of pests, causing tissue swelling.
Fumigants: Used to sterilize soil and prevent pest infestation of stored grain.
Inorganic Pesticides: Highly toxic substances (e.g., arsenic, copper, lead, mercury) that accumulate in the environment.
Organic Pesticides: Natural poisons derived from plants, such as tobacco or chrysanthemum.
Organophosphates: Extremely toxic but break down quickly in the environment.
🔬 Persistent Organic Pollutants (POPs)
Organic compounds that don’t break down chemically or biologically, so they accumulate in organisms' fatty tissues.
Biomagnification occurs in food webs.
🚫 The Pesticide Treadmill
Pesticide Resistance: Pest populations evolve resistance to pesticides, making them less effective.
Pesticide Treadmill: Farmers must use increasingly toxic chemicals to control resistant pests.
🌍 Integrated Pest Management (IPM) Methods
Mechanical controls, such as traps.
Genetically modified crops that are pest-resistant.
Intercropping: Planting multiple crops on the same land.
Natural insect predators: Encouraging beneficial insects.
Pest-repellant crops: Planting crops that naturally repel pests.
Polyculture: Raising multiple types of crops or animals together.
Regular monitoring and traps.
Releasing sterilized insects.
Crop rotation to disrupt insect life cycles.
Using mulch to control weeds.
Pheromones and hormone interrupters to disrupt pest behavior.
Pyrethroids or natural microorganisms for pest control.
🌱 Benefits of IPM
Reduces bioaccumulation and biomagnification of pesticides.
Prevents pests from becoming resistant to pesticides.
Avoids destruction of beneficial organisms and non-target species.
🐮 Concentrated Animal Feeding Operations (CAFOs)
Intensive animal feeding operations where large numbers of animals are confined in feeding pens for over 45 days a year.
💩 Environmental Impact of CAFOs
Large amounts of animal waste from CAFOs present a risk to water quality and aquatic ecosystems.
States with high concentrations of CAFOs experience 20-30 serious water-quality problems annually due to manure management issues.
🌊 Water Pollution from CAFOs
CAFO waste can negatively impact water quality through two main pollutants:
Soluble nitrogen compounds
Phosphorus
Both can contaminate water sources, leading to pollution.
💨 Gas Emissions from CAFOs
CAFOs release several types of harmful gases:
Ammonia
Hydrogen sulfide
Methane
Particulate matter
Decomposition of animal manure stored in large quantities is the primary cause of these emissions.
🎣 Fishing Industry Pressures
The fishing industry is under pressure from growing demand and falling supply.
Both marine and terrestrial life depend on primary producers, like aquatic plants.
🌊 Importance of Coastal Waters
Aquatic plants require sunlight and are restricted to shallow coastal waters.
These waters make up less than 10% of the world's ocean area but contain 90% of all marine species.
🐟 Aquaculture
Aquaculture (also known as mariculture or fish farming) involves commercially growing aquatic organisms for food.
It includes stocking, feeding, protecting from predators, and harvesting.
💡 Key Factors for Profitable Aquaculture
For aquaculture to be profitable, the species must be:
Marketable
Inexpensive to raise
Efficient at converting feed into fish biomass
Disease-resistant
🌍 Methods to Manage Marine Fishing
Eliminate government subsidies for commercial fishing.
Increase the number of marine sanctuaries.
Prevent fish imports from unsustainable fishing countries.
Label fish products caught or raised sustainably.
Require fishing licenses, open inspections, and trade sanctions if limits are exceeded.
🌱 Methods to Restore Freshwater Fish Food Webs
Control erosion.
Control invasive species.
Create/restore fish passages.
Enforce laws that protect coastal estuaries and wetlands.
Plant native vegetation on stream banks.
⛏ Mining
Mining is the process of removing mineral resources from the ground.
It can involve various methods like underground mines, drilling, room-and-pillar mining, open pit, dredging, contour strip mining, and mountaintop removal.
🌍 Surface Mining Methods
Contour mining: Removing overburden along a ridge or hillside to follow the contours of the land.
Dredging: A method for mining below the water table, often used in gold mining. Small dredges use suction or scoops to bring material from the water’s bottom.
In situ: Small holes are drilled into the Earth, and toxic chemical solvents are injected to extract the resource.
Mountaintop removal: Removing the mountaintops to expose coal seams and disposing of overburden in adjacent valley fills.
Open pit: Extracting rock or minerals from the Earth by removing material from an open pit.
Strip mining: Removing soil above coal seams to expose the coal.
🏗 Underground Mining Methods
Blast: Uses explosives to break up material, which is then loaded onto conveyors for transport.
Longwall mining: A rotating drum with teeth pulls back and forth across a coal seam, breaking the material loose for transport.
Room and pillar: Leaves pillars of coal to support the roof of the mine, which are later removed, causing the mine to collapse.
⚠ Environmental Damage from Mining
Acid mine drainage
Disruption of natural habitats
Chemicals from in situ leaching entering the water table
Disruption of soil microorganisms, impacting nutrient cycling
Dust release, causing lung problems and health risks
Land subsidence
Large consumption and release of water
🏙 Urbanization
Urbanization: The movement of people from rural areas to cities and the changes that come with it.
The greatest urbanization growth is occurring in Asia and Africa.
✅ Pros of Urbanization
Better educational delivery system
Better sanitation systems
High tax revenues from large populations
Mass transit reduces fossil fuel reliance
Point-source pollution is easier to manage
Efficient recycling systems
Urban areas attract industries due to resources, distribution, and labor
❌ Cons of Urbanization
Overcrowded schools
Sanitation systems struggle with high waste volumes
High demand for social services due to poverty
Infrastructure struggles to keep up with growth
High pollution levels in dense populations
Solid-waste buildup and landfill shortages
Higher crime rates and job shortages due to population increase
🏡 Urban Sprawl
Urban Sprawl: Expansion of low-density, car-dependent communities outward from city centers.
Job Sprawl: Spread-out employment centers outside city centers.
Impacts:
Loss of agricultural land
Single-family homes dominate, separated by roads and lawns
Single-use development: Separates living, work, and recreation, requiring more car use
🌿 Smart Growth
Smart Growth: Encourages compact, walkable, transit-oriented communities to limit urban sprawl.
Strategies:
Mixed-use planning (residential, commercial, cultural, industrial in one area)
Greenbelts & undeveloped land around cities
Tax incentives for urban-centered businesses
Subsidies for mass transit
Converting abandoned buildings into green spaces
🏗 Urban Development
Urban Development: Designing cities for functionality, sustainability, and attractiveness.
Strategies:
Recycled materials & waste-minimizing designs
Energy conservation (solar, clean energy incentives)
Indoor air quality improvements
Public transit-focused building locations
Preserving community history & culture
Water-efficient landscaping (xeriscaping)
🌊 Urban Runoff
Urban Runoff: Rainwater runoff from cities, causing flooding & pollution.
Effects:
Erosion & sedimentation, reducing water quality
Warmer urban water harming aquatic life
Pollution from gasoline, oil, metals, fertilizers, pesticides, and trash
💡 Solutions for Urban Runoff
Construct wetlands to filter water before it enters larger bodies
Retention basins to absorb stormwater into groundwater
Street-sweeping vacuums to remove trash & debris
Urban parks & green spaces to increase infiltration
🌍 Ecological Footprint
A measure of human demand on Earth's ecosystems.
Standardized to compare natural resource use vs. Earth’s ability to regenerate.
📏 What It Represents
The amount of biologically productive land & sea needed to:
✅ Supply resources a population consumes
✅ Absorb and process the waste produced
♻ Why It Matters
Helps determine sustainability of human activities.
Larger footprints indicate greater resource consumption & environmental impact.
Can be reduced by:
✅ Using renewable energy
✅ Reducing waste & pollution
✅ Sustainable agriculture & fishing
🌱 Sustainability
The ability of human civilization & the biosphere to coexist by balancing resource use.
Ensures that resources are not depleted faster than they can be replaced.
🔢 IPAT Formula
I = P × A × T
I = Environmental Impact
P = Population
A = Affluence (Consumption per person)
T = Technology (Impact per unit of consumption)
⚠ Threats to Sustainability
🌾 Sustainable Agriculture
Focuses on long-term solutions for food production, environment, and energy efficiency.
✅ Practices Include:
Ecological pest management
Diversifying farms to reduce risks
Increasing energy efficiency
Crop rotation for better yields & pest control
Water conservation & quality protection
Cover crops & manure for soil fertility
🌍 Soil Conservation Techniques
1⃣ Contour Plowing – Plowing along land contours to reduce erosion
2⃣ No-Till Agriculture – Leaving soil undisturbed, preserving nutrients
3⃣ Perennial Crops – Long-living plants (e.g., fruit trees)
4⃣ Strip Cropping – Alternating strips of different crops
5⃣ Terracing – Creating step-like levels on slopes to reduce runoff
6⃣ Windbreaks – Rows of trees to protect against wind erosion
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