APES un 5

Tragedy of the commons

Individuals will use shared/public resources in their own self interest, degrading them. e.x., Air Pollution, Pesticide runoff, Overfishing

How to solve the TOC

Taxes or Fees for use, charges for pollution, shared resources, Clean Air Act, Clean Water Act, Safe Water Act, BLM (Bureau of Land Management)

The oceans of the world are often referred to as a commons. Identify one other such commons, explaining how human activities affect that commons, and propose a solution for managing that commons.

• air, pollute air through usage of fossil fuels, solution can be more tax for car usage, encouragement of public transport

Direct Effects of Clearcutting

• Soil Erosion

• Increased Soil and Stream temp

• Flooding and Landslides

Tree Plantations

Areas where the same tree species are repeatedly planted, grown and harvested

Forest Benefits

• Filtering of Air Pollutants

• Removal & storage of CO2

• Habitat for organisms

Consequences of Deforestation

• Reduces air filtering and carbon storing services

• Cutting trees down releases CO2 from decomposition of leftover organic material

• Slash & burn method of clearing land for agriculture by cutting trees and burning them releases greenhouse gasses into atmosphere

Describe TWO ecosystem services provided for humans by forests. Explain how clear-cutting would affect each ecosystem service you describe.

• Regulating, controlling for climate change

• Supporting services

• Less filtered air because less trees, more GHGs

• no more habitats for other animals

Green Revolution

Shift in agriculture away from small, family operated farms to large, industrial-scale agribusiness

Benefits of Green Revolution

• Increased use of mechanization, GMOs, irrigation, fertilizers, and pesticides

• Greatly increases efficiency of lands, short-term profitability, and food supply

• Decreased world hunger and increased earth's carrying capacity for humans

Mechanization

Increased use of tractors for plowing and tilling fields

benefits of mechanization

increased yield and profits

consequences of mechanization

• more reliance of fossil fuels

• more GHGs in atmosphere, climate change

• heavy machinery compacts soil, decreases H2O holding capacity

• topsoil more prone to erosion

what does HYV stand for?

High Yield Variety crops

define HYV crops

Hybrid, or genetically modified crops that produce a higher yield

benefit of HYV

Increased yield and food stability in regions previously prone to famine (India, Pakistan, Mexico)

what are GMOs in terms of crops?

Genetically Modified crops with genes for drought tolerance, pest resistance, faster growth and larger fruit/grain

benefits of GMOs

• increases profitability b/c fewer plants are lost to drought, disease or pests
• larger plant size
• more yield/acre

Consequences of GMOs

• genetically identical so diversity is decreased and it is easier for them to get disease

What is Synthetic Fertilizer?

shift from organic fertilizers (manure, compost) to synthetic (man made ammonium, nitrate, phosphate)

benefits of Synthetic Fertilizer

• more yield
• more profits
• more key nutrients (N P K) added to soil

consequences of Synthetic Fertilizer

• Excess nitrate, phosphate are washed off fields and into nearby waters where they cause eutrophication (algae blooms)
• Requires Fossil Fuels for production, releasing CO2 (climate change)

What is Irrigation

Drawing water from the ground or nearby surface waters and distributing it on fields to increase plant growth

benefits of Irrigation

• makes agriculture possible in parts of the world that are naturally too dry (not enough rain)

consequences of Irrigation

• can deplete groundwater sources, esp aquifers
• Over watering can drown roots (no O2 access) and cause soil salinization (more salt level in soil)

what are Pesticides

chemicals sprayed on crops that kill weeds, insects, rodents and other pests that eat or damage crops

benefits of Pesticides

• more yield and profits with fewer plants lost to pests

consequences of Pesticides

• can wash off crops in runoff and kill or harm non target species in local soil or waters (like bees), make fish and frogs intersex

Describe one environmental advantage and one environmental disadvantage of using GM crops.

• advantage, larger plant size
• disadvantage, more susceptible to disease bc less diversity genetically

Monocropping

growing one single species (corn wheat soy) of crop

Benefits of monocropping

Highly efficient for harvest, pesticide and fertilizer application

Consequences of Monocropping

• decreases biodiversity (prone to pests)
• increases soil erosion (crops harvested all at once and soil left bare)
• decreases habitat diversity for all species living in area

Tilling

Mixing and breaking up soil

benefits of tilling

makes planting easier, loosens soil for roots

Consequences of Tilling

• more erosion b/c top soil is loosened, breaking up leftover root structure from harvest
• loss of organic matter and topsoil nutrients over time
• increased PM in air and sediments in nearby water (turbidity)

Slash & Burn

Cutting down vegetation and burning it

benefits of Slash and Burn

• clears land for agriculture
• returns nutrients in plants to soil

Consequences of Slash and Burn

• loss of habitat
• loss of biodiversity
• less CO2 sequestration (storage)
• loss of air pollution filtration
• deforestation
• releases all GHGs that lead to global warming
• increases PM in air, asthma
• lower albedo, warmer area

consequences of Synthetic Fertilizers II

• dont return organic matter to soil, no increased H20 holding cap
• no soil decomposers
• Leaching
• contaminates groundwater for drinking
• eutrophication of surface waters

what is Leaching

water carries excess nutrients (nitrates, phosphates) into ground water or surface water as runoff

Explain one disadvantage of using inorganic, commercial fertilizers

contaminates groundwater for drinking because of Leaching, when water carries excess nutrients into the groundwater as runoff

Furrow Irrigation

● Trench dug along crops & filled with water
● Easy & inexpensive; water seeps into soil slowly
● ~66% efficient, 33% lost to runoff & evap.

Flood irrigation

● Flood entire field; easier but more disruptive to plants
● Can waterlog the soil & drown plants
● 80% efficient - 20% runoff/evap.

Drip Irrigation

● Most efficient, but also most costly
● Over 95% efficient
● Holes in hose allow water to slowly drip out
● Avoids waterlogging & conserves waters

Spray Irrigation

● Ground or surface water pumped into spray nozzles
● More efficient (less water loss) than flood or furrow
● More expensive (requires energy for pumps & movement of sprinklers

Waterlogging

A form of soil degradation that occurs when soil remains under water for prolonged periods.

what can Waterlogging do

• saturate the soil, filling all pore space with water
• no air in pores, roots cant take in O2 they need
• stunt growth or kill crops

Solution to Waterlogging

drip irrigation, or soil aeration - poking holes or cores in soil to allow air in & water to drain through soil

What is salinization?

the buildup of salts in soil over time

how much salt does groundwater for irrigation naturally have

small amounts

Explain soil salinization.

Water evaporates, and salt is left behind in soil. Over time, it can reach toxic levels, dehydrating plant roots & preventing growth

Solution to soil salinization

• drip irrigation

• soil aeration

• flushing with fresh water

• switch to freshwater source

Industrial water use

power plants, metal/plastic manufacturing

Municipal water use

households (toilet, shower, drinking water)

agriculture water use

water for livestock, irrigation water for crops

Groundwater

H2O stored in pore space of permeable rock & sediment

Aquifers

useable groundwater deposits for humans

Aquifers and Groundwater recharge by

rain percolating down through soil into aquifer

Confined vs Unconfined aquifer

Confined recharge slow, Unconfined recharge quickly

Saltwater Intrusion

exessive pumping near coast lowers water table pressure, allowing saltwater to seep into groundwater

Cone of depression

forms when water table is lowered by excessive pump, depleting water and drying nearby wells

Describe how soil salinization occurs. Propose a solution to prevent or remediate soil salinization. Identify one disadvantage of the solution you propose

water evaporates and salt is left behind in soil. Over time, it can build up and become toxic. Solution: drip irrigation, Soil aeration, flushing with fresh water, switch to freshwater source

Pesticides

chemicals that are toxic to rodents

• Rodenticides kill rodents
• Fungicides kill fungi
• Insecticides kill insects
• Herbicides kill plants

Roundup ready crops have..

increased herbicide use since crops can't be harmed by it

Bt corn has…

decreased insecticide use, since corn makes its own insecticide

Describe ONE economic advantage and one economic disadvantage of using GM crops

• more yield and profit
• if disease, wipes out all the crops, huge setback

Urbanization

Removing of vegetation to convert natural landscape to city (urban)

What are soil vegetation and wetlands replaced with in urbanization

Impervious surfaces (concrete, asphalt, cement) which don't allow water to infiltrate into the ground

What does urbanization prevent?

groundwater recharge, causing precipitation to runoff into local bodies of water

Why are there more CO2 emissions in Urbanization

• construction machinery
• cement production
• deforestation (loss of future carbon sequestration + decomposition of cut trees)
• landfills needs for disposing trash from large population

Population growth in coastal cities can lead to…

Saltwater intrusion

Why can population growth in coastal cities lead saltwater intrusion

Excessive groundwater withdrawal near coast, lowering water table pressure, allowing saltwater to seep into groundwater

sea level rise in coastal cities due to…

Warming of ocean (thermal expansion) and melting of ice caps (increasing ocean volume) can contaminate fresh groundwater with salt

What are population trends leaning towards in terms of where to live? Why?

Overall trend in US and many other nations is away from less dense rural areas and towards more urban areas. For jobs, entertainment, cultural attractions

Urban areas are more densely populated, minimizing…

Driving and land use per person (decreases environmental impact per person)

Highest growth in population trends is currently…

Suburban population

What are suburbs?

less dense areas surrounding urban areas

Urban sprawl

population movement out of dense, urban centers to less dense suburban areas surrounding the city

causes of urban sprawl

• Cheaper property in suburbs than in cities (larger home for same price)
• Cars make it easy to still get from the suburbs into the city for work, entertainment, cultural attractions
• Domino effect (neighbors leave, so you leave)
• Fewer residents in cities leads to decline in tax revenue for city (decrease in city services)
• Residents leave, so businesses follow
• Abandoned homes + businesses create blight (unsightly, rundown infrastructure) so more people leave

More causes of urban sprawl

• expanded highway system makes travel easier and increases driving
• increase in driving increases fuel tax revenue, used to build more highways
• highway expansion makes it easier and easier to commute from suburbs into urban areas

Solutions to urban sprawl

• urban growth boundaries: zoning laws set by cities preventing development beyond a certain boundary
• public transport and walkable city design that attract residents to stay
• mixed land use: residential, business, and entertainment buildings all located in the same area of a city (enables walkability and a sense of place)

Describe a possible solution to the issue of urban sprawl. Identify one possible economic consequence of this solution.

• zoning laws, prevent development beyond a certain point
• lose potential profitability of the land

Ecological footprint

A measure of how much an individual consumes, expressed in area of land

Factors of Ecological Footprint

food production, raw materials(wood, metal, plastic), housing, electricity production (coal, natural gas, solar wind etc.), disposing waste produced (landfill space)

Ecological footprint vs Carbon footprint

Measured in land (gha - global hectare) which is a biologically productive hectare (2.47 acres) vs. measured in tonnes of CO2 produced per year

carbon footprint

the total carbon dioxide emissions produced by an individual or group's consumption and activities

• material goods
• food production

Factors that increase ecological footprint

wealth, meat consumption, fossil fuel usage

Factors that decrease ecological footprint

renewable energy use, public transportation, plant based diet, less consumption, travel, energy use

Describe one factor that accounts for the difference in carbon footprint between the United States and Uganda. Explain one environmental consequence of this factor

• more industrialized
• global warming accelerated

Sustainability

refers to humans living on earth and their use of resources without depletion of the resources for future generations

Environmental indicators that can guide humans to sustainability

biological diversity, food production, average global surface temperatures and CO2 concentrations, human population, and resource depletion

Sustainable yield

the amount of a renewable resource that can be taken without reducing the availible supply

Ore

commercially valuable deposits of concentrated minerals that can be harvested and used as raw materials

Metals

elements that conduct electricity, heat, and have structural properties for building (found within ores)

Reserve

The known amount of a resource left that can be mined.
Usually measured in years left of extraction.

Overburden

soil, vegetation, and rocks that are removed to get to an ore deposit below

Tailings & slag

leftover waste material separated from the valuable metal or mineral within ore

Surface mining

removal of overburden to access ore near surface

different types of surface mining

open pit, strip, mountaintop removal, placer

As ore near surface becomes more scarce, mining moves deeper underground to…

subsurface mining