Unit 5 APES

Sustainability

• The Tragedy of the Commons 

  • Overusing of common resources that are available to the public

  • Occurs because there are no fines or incentives to aviod this

  • People think that if they don’t use something, somebody else will

  • Commons

    • Parks

    • Atmosphere

    • Ocean

    • Soil

• Ecological Footprint 

  • The amount of land and water required to support your type of lifestyle

  • Can be measured in global hectares or in terms of the # of Earths 

    • If the entire world were to live like the average American, 5.1 Earths or 5.1 times the resources Earth can produce in a year would be needed to support that person’s lifestyle

  • Ways to Reduce

    • Using more public transit

    • Eating less meat

    • Reducing urban sprawl and building cities up

• Introduction to Sustainability

  • Living in a way that supports ourselves as well as out future generations

  • Using ½ the carrying capacity when it comes to resources is the best to keep sustainable and max yields of crops

    • This is because in the middle, the population is growing the quickest and will rebound quickly, not hurting the ecosystem

  • Indicators of Sustainability

    • Decrease in Biodiversity

      • This means that the environment is being drastically changed beyond the ecological tolerance of these species and they are declining

      • Shows that the land is not being used with the species diversity in mind

    • Increase in Meat Production

      • Unsustainable because it takes far more energy to produce meat than having a plant-based diet

    • Climate Change

      • Shows that more carbon dioxide is being released into the atmosphere 

      • Increased heating of the planet can lower biodiversity

      • Thickening of the greenhouse gas layer can indicate unsustainable actions

    • Growing Human Population

      • Shows how resources are being depleted far faster to accommodate for a rapid growth in population

      • Being used faster than they can be replenished

1. Urbanization

• Impacts of Urbanization

  • High population growth in urban regions leads to resources being used faster than they can be replenished naturally

  • Building a city takes a lot of machinery and tools that can lead to an increase in fossil fuel burning

  • Landfills

  • Impervious surfaces

  • Urban Sprawl

    • When people leave the city to settle suburban areas

    • Happens due to loss of place and hard/expensive ways of life

    • Urban sprawl can be reduced by building cities that are more walkable and more public transport, along with good land use to entice people to stay

• Methods to reduce Urban Runoff

  • Urban runoff or storm-water runoff is excess water that runs off impervious surfaces in cities due to ashpalt as and concrete

  • Urban runoff can lead to excess flooding during heavy rainfall events

  • Ways to Reduce

Mining and Forestry

• Mining 

  • Ores are extracted from mines and can be used for economic purposes

    • Surface mining

      • Open Pit Mining

      • Mountain Top Mining

        • Using dynamite and explosives to whack the top off a mountain to look for ores

        • Most ecologically damaging as explosives and runoff is common

      • Strip Mining

        •  taking off strips of overburden to find ores

        • More sustainable as less overburden is being removed

    • Subsurface mining

      • After surface mining has exhanusted ores, miners look deeper

      • Supsurface is more dangerous because of the risk to workers

        • Asbestos, mine collapses, fires and health issues

      • Requires shafts to bring miners down, and up, as well as do bring the ores up

• Ecological and Economic Impacts of Mining

  • Mining waste

    • Tailings are waste crumbs from the mine that cannot be used

    • Slag is the liquid waste stored in a pond from mine residue

  • Habitat destruction

    • When the ground is dug up, trees are cut down and water supplies are contaminated by tailings and slag

    • Species may undergo allopatric speciation if the mine is dug up and the geography of the habitat changes

    • Plants can losen soil, and erosion can become common

  • Groundwater contamination

    • Slag can run into groundwater

    • Acid mine drainage can lead to acids seeping into groundwater from tailings and slag, leading to contamination

  • Air pollution

    • Greenhouse gasses like sulfur dioxide, nitrous oxide, and carbon dioxide are let out in the atmosphere

    • Cutting down trees to create mines destroys the “lungs of the planet” releasing more carbon dioxide

• Clearcutting

  • When the entire forest is cleared through machinery to create land for agriculture

    • Positive

      • Cheaper and quicker to prepare land for farming

    • Negative  

      • Clearing all the land sets back ecological succession since pioneer species take about 2 years to develop 

      • No more trees loosen soil and are not held in place leading to more soil erosion

      • Fewer trees to sequester CO2 creates an increase in greenhouse gas in the atmosphere

      • Burning of land during clearcutting leads to more greenhouse gasses and pollutants being sent to the atmosphere

      • Fewer trees decrease albedo, heating up the surface of the forest

      • Increased runoff in heavy rain events leads to higher turbidity of streams (bad for marine ecosystems)

• Sustainable Forestry

  • Reforestation

    • Planting new trees after clearcutting helps the forest ecosystem from completely collapsing

  • Sustainable forest techniques

  • Protect forests from pathogens

  • Prescribed burns

    • Purposely burning land so that the ecosystem can regrow healthy

    • If there has not been fire for a long time in an ecosystem, then a prescribed burn can get rid of fuels that could eventually cause a megafire or conflagaration

    • As drought and climate change increase, days with prescribed burns possible are getting lower and lower, increasing wildfire risk

  • Reusing wood

2. Agriculture

• The Green Revolution

  • Mechanization

  • Genetically modified organisms - GMOs

  • Fertilization

  • Irrigation

  • Pesticides 

    • Chemicals sprayed on plants to kill insects 

    • DDT and Atrezene are the most dangerous, as they were changing the sexuality of birds

    • Rachel Carson warned about the effects of DDT in the ‘60s

• Impact of Agricultural Practices

  • Tilling

    • Overplowing the land and plowing freqnetly to change crops

    • Loosens the topsoil, and does not allow enough time for pioneer species to grow back, affecting the ecosystem

    • Soil erosion is more likely and soil dries out, being unable to support as many plants

    • Overtilling can eventually lead to desertification

  • Slash-and-burn farming

    • Setting the forest on fire to clear the land for farming practices

    • Releases a host of greenhouse gasses into the atmosphere (CO2, N2O, methane, etc…)

  • Use of fertilizers

    • Causes eutrophication due to runoff of fertilizer

    • Synthetic fertilizers tend to run off more than natural fertilizers and synthetic don’t replenish nutrients in the soil as well as natural ones do

    • Organic fertilizers are made from humus and organic material in the soil, so they recharge the nutrients well

    • Fertilizer runoff enters the ocean, causing algal blooms, and when the algae die, decomposers use most of the surface oxygen to break down the algae, leading to hypoxia and dead zones. The Gulf Dead Zone is one of the biggest, covering almost the entire LA coastline

• Irrigation Methods

  • Flood 

    • Flooding the entire field with water to irrigate crops

    • Plants that grow here must be emergent plants like rice or cranberry

    • 66% effective

  • Furrow

  • Spray

    • Spraying water onto the field using a hose and 

  • Drip

• Benefits and Drawbacks

  • Flood 

    • Uses a lot of excess water 

  • Furrow

  • Spray

  • Drip

  • Salinization

  • Aquifers

    • Areas where groundwater is stored for human use

    • Can be depleted by overuse, especially during a drought when recharge is low

    • Some recharge faster than others

• Pest Control Methods

  • Pesticides

    • Chemicals sprayed on crop yields to vy off predators

    • Can runoff into waterways, contaminating the water supply

    • Aerosol pesticides can get into the atmosphere and become secondary pollutants as well

  • GMOs

    • Introducing a new gene into a plant

    • Allows for the plants to be resistant to pests and predators and produces higher yield

    • Negative in that it lowers biodiversity, and if a disease were to hit the crop, the entire harvest would be wiped out

• Integrated Pest Management

  • Biological

  • Physical

  • Chemical

• Benefits and Drawbacks of IPM

• Sustainable Agriculture

  • Soil conservation

  • Crop rotation

  • Rotational grazing

Animal Husbandry

• Meat Production Methods

  • Feedlots/concentrated animal feeding operations (CAFOs) 

    • Areas with a high population density that are used to package meat

    • Animals are often held in high concentration and given antibiotics to prevent disease

    • Requires a whole lot of energy as an agriculture field is required to grow crops as well as provide food for the animals, all the water for crops + water for animals, and all the energy for the crops + resources to take care of the animals

    • Going vegetarian is more sustainable for the planet than CAFOs (vegetarian takes a fraction of the energy meat takes)

  • Free-range grazing

    • When animals are allowed to graze openly on a farm and are not held close on a CAFO

    • Benefits

      • Density is lower, which decreases the risk of disease and concentrated waste lagoons, reducing the use of antibiotics

      • Less manure lagoons allow for lower risk of waterway contamination

    • Drawbacks 

      • Overgrazing is a problem, as animals are constantly eating the same grass

      • Rotational grazing where animals are often moved around can solve this problem and is also a benefit to the environment becuase the grasses are always staying the same height

• Impacts of Overfishing

  • Causes 

    • Net Fishing

  • Problems

    • Collapse of the Fisheries

    • Coral Bleaching and 

    • Economic Losses

• Aquaculture

  • Creating breeding grounds for fish under controlled conditions underwater

  • Uses a net and creates a captive location for fish to breed in

  • 4 Types

  • Benefits

    • Allows for food production without overusing land and soil

    • Avoids depletion of fisheries which is a tragedy of the commons

  • Drawbacks

    • Similar to CAFOs, antibiotics must be given to prevent disease which can spark endocrine issues in other fish if the captives escape

    • High density causes disease and heavy waste problems (waste may float around the ocean)

    • If the fish escape, they may spread non-native traits by interbreeding, and might also become an invasive species, reducing biodiversity