Studied by 1 person
tragedy of the commons
individuals will use shared/public resources in their own self interest, degrading them (must be public resource and must be used-up in some way)
examples of tragedy of the commons
overgrazing, overfishing, water and air pollution, overuse of groundwater
why tragedy of the commons happen
when no one owns the resource, no one directly suffers from overusing it, people assume if they don't use it, others will
problems with tragedy of the commons
overfishing can lead to fishery collapse (loss of income and starvation); air pollution can lead to bronchitis and asthma (increased healthcare cost); pesticide runoff from farms contaminate drinking water
solutions to the tragedy of the commons
private land ownership; fees or taxes for use; fines, taxes, criminal charges for pollution or shared air/soil/water resources
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
problems with tree plantations
lowers biodiversity, all the same age (lowers biodiversity further)
general forest benefits
filtering of air pollutants, removal and storage of CO2 from the atmosphere, habitat for organisms
deforestation consequences
reduces air filtering and carbon storing services; cutting trees down releases CO2 from decomposition of leftover organic material
slash and burn
method of clearing land for agriculture by cutting trees and burning them (releases CO2, N2O and water vapor into the atmosphere (all GHGs))
the green revolution
shift in agriculture away from small, family operated farms to large, industrial-scale agribusiness; increased use of mechanization, GMOs, irrigation, fertilizers, and pesticides;
positives of the green revolution
greatly increases efficiency of lands, short-term profitability, and food supply; decreased world hunger and increased earth's carrying capacity for humans
negative consequences of the green revolution
mechanization
increased use of tractors for plowing and tilling fields, and combines for harvesting
positives of mechanization
increased yield and profits
negatives of mechanization
increases reliance on fossil fuels (gasoline/diesel fuel); emits GHGs to atmosphere (climate change); heavy machinery compacts soil, decreasing H2O holding capacity (makes topsoil more prone to erosion)
high-yield variety (HYV) crops
hybrid, or genetically modified crops that produce a higher yield (amount of crops produced per unit of area)
hybrid
cross-pollinating different species, or parent plants with ideal ration
positives of HYV crops
increased yield and food stability in regions previously prone to famine (India, Pakistan, Mexico)
negative of HYV crops
decreased biodiversity
GMOs
genetically modified crops have genes for drought tolerance, pest resistance, faster growth, and larger fruit/grain
positives to GMOs
increases profitability with fewer plants lost to drought, disease, or pest; larger plant size and yield
negatives to GMOs
GMO crops are all genetically identical so genetic diversity is decreased and susceptibility to diseases or pests is increased
synthetic fertilizer
shift from organic fertilizers (like manure and compost) to synthetic fertilizers (man made ammonium, nitrate, phosphate)
positives to synthetic fertilizer
increases yield and profits with more key nutrients needed for plant growth (N, P, K) added to the soil
negatives to synthetic fertilizer
excess N and P are washer off fields and into nearby waters where they cause eutrophication; require FFs for production, releasing CO2 (climate change)
irrigation
drawing water from the ground or nearby surface waters and distributing it on fields to increase plant growth
positives of irrigation
makes agriculture possible in many parts of the world that are naturally too dry (don't receive enough rain)
negatives of irrigation
can deplete groundwater sources, especially aquifers; overwatering can drown roots (no O2 access) and cause soil salinization (increased salt level in soil)
pesticides
chemicals sprayed on crops that kill weeds, insects, rodents and other pests that eat or damage crops
positives of pesticides
increases yield and profits with fewer plants lost to pests
negatives of pesticides
can wash off crops in runoff and kill or harm non-target species in local soil or waters (bees especially) (Ex: DDT thinned shells of bird eggs, especially eagles; atrazine turns amphibians and fish intersex)
negatives of the green revolution
soil erosion, biodiversity loss, ground and surface water contamination
monocropping
growing one single species of crop (highly efficient for harvest, pesticide and fertilizer application)
negatives of monocropping
greatly decreases biodiversity; increases soil erosion; decreased habitat diversity
tilling
mixing and breaking up soil to make planting easier and loosens the soil for the roots
negatives of tilling
increases erosion by loosening topsoil and breaking up leftover root structure from harvest; loss of organic matter and topsoil nutrients; increase particulate matter in the air
negatives of slash and burn
deforestation (loss of: habitat, biodiversity CO2 sequestration (storage), loss of air pollution filtration); release CO2, CO, N2O which leads to global warming; increases particulate matter in air (asthma), lowers albedo, making the area warmer
leaching
water carries excess nutrients (nitrates & phosphates) into groundwater or into surface waters (as runoff)
furrow irrigation
trench dug along crops and filled with water; easy and inexpensive (water seeps into soil slowly); 66% efficient, 33% lost to runoff and evaporation
flood irrigation
flood entire field (easier, but more disruptive to plants); can waterlog the soil and drown plants; 80% efficient, 20% lost to runoff and evaporation
drip irrigation
most efficient, but also most costly; over 95% efficient; holes in hose allow water to slowly drip out; avoids waterlogging and conserves water
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 and movement of sprinklers)
waterlogging
overwatering can saturate the soil, filling all soil pore space with water (doesn't allow air into pores, so roots can't take in the O2 they need; can stunt growth or kill crops)
solution to waterlogging
drip irrigation, or soil aeration
soil aeration
poking holes or cores in soil to allow air in and water to drain through the soil
soil aeration
salinization
the process of salt building up in soil overtime (groundwater has a little salt and overtime, watering and evaporation can lead to salinization)
industrial global human water use
power plants, metal/plastic manufacturing
municipal global human water use
households (toilet, shower, drinking water)
agricultural global human water use
water for livestock, irrigation water for crops
groundwater
H2O stored in pore space of permeable rock and sediment layers
aquifers
usable groundwater deposits for humans (recharged by groundwater recharge)
groundwater recharge
rain water percolating down through soil into aquifer
unconfined aquifers recharge ________
quickly
confined aquifers recharge ________
slowly
solution to salinization
drip irrigation, soil aeration, flushing with fresh water, switch to freshwater source
saltwater intrusion
excessive pumping near coast lowers water table pressure, allowing saltwater to seep into groundwater
cone of depression
forms when water table is lowered by excessive pumping, depleting water & drying nearby wells
overuse of pesticides leads to ________
pests becoming resistant to them
how are GMOs used in pest control
gene for pest resistant trait is added to the plant through genetic modification
roundup ready crops
genetically modified to be resistant to broad herbicide (roundup), meaning roundup will kill weeds, but not crops
roundup ready crops have increased ________
herbicide use
GM crops are ________
all genetically identical, so there is no genetic diversity in the pop.
CAFOs (feedlots)
densely crowded method where animals are fed grain (corn) to raise them to as quickly as possible
positives of CAFOs
maximizes land use and profit (most meat production per/unit of area); minimizes cost of meat for consumers
negatives of CAFOs
given antibiotics and growth hormones to prevent disease outbreak and speed meat production; animals produce large volume of waste which can contaminate nearby surface/groundwater; produces large amounts of CO2, CH4, and N2O (climate change)
manure lagoons
large, open storage pits for animal waste (manure); heavy rain can flood lagoons and contaminate nearby surface/groundwater with runoff; produces N20 (GHG); can be emptied and buried in landfills, or turned into fertilizer pellets
free range grazing
animals (usually cows) graze on grass and grow at a natural rate without growth hormones
positives of free range grazing
no need for antibiotics with dispersed pop.; doesn't require production of corn to feed animals; waste is dispersed over land naturally, acting as fertilizer instead of building up in lagoons; animals can graze on land too dry for most crop growth
negatives of free range grazing
requires more total land use/pound of meat produced; more expensive to consumer
overgrazing
too many animals grazing an area of land can remove all the vegetation (grass) which leads to topsoil erosion; animals also compact soil, decreasing H2O holding capacity (more erosion)
desertification
can occur if plants are killed by overgrazing and soil is compacted so much that it can't hold enough water anymore
rotational grazing
moving animals periodically to prevent overgrazing; it can also increase the growth of grass by distributing manure and clipping grass back to size where growth is most rapid
inefficiency of meat
producing meat for humans to eat is far less efficient than producing plants in terms of energy, land, and water use
energy used for meat
all of the energy needed to plant, grow, and harvest plants to feed animals, plus energy needed to bring water to animals, energy needed to house animals, energy needed to slaughter and package
land used for meat
all of the energy needed to grow plants to feed animals, plus room the animals will take up
water used for meat
all of the water for crops animals will eat, plus the water the animals will drink
fisheries
populations of fish used for commercial fishing
negatives of fisheries
decreases genetic biodiversity of fish populations and species biodiversity of ocean ecosystems if species are lost from ecosystem
fishery collapse
when overfishing causes 90% population decline in a fishery
negatives of fishery collapse
population may never recover from fishery collapse due to: decreased biodiversity, inability to find mates, and inbreeding depression
economic consequences of fishery collapse
lost income for fishermen, lost tourism dollars for communities
bottom trawling
especially harmful fishing method that involves dragging a large net along ocean floor
bycatch
unintended species like dolphins, whales, turtles caught in nets used in bottom trawling
negatives of bottom trawling
bycatch; stirs up ocean sediment (turbidity) and destroys coral reef structure; decreases biodiversity by killing non-target species and removing coral reef habitat
fishing down the food web and trophic
as we deplete large, predatory fisheries, we move down to smaller fish species; depletion of smaller fish population limits fishery recovery and decreases food supply of marine mammals and seabirds
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 and slag
leftover waste material separated from the valuable metal or mineral within ore (often stored in ponds @ mine site)
surface mining
removal of overburden to access ore near surface
different types of surface mining
open pit, strip, mountaintop removal (especially damaging to landscape and habitats), placer
negatives of surface mining
removal of vegetation and soil - topsoil erosion, habitat loss, increased stream turbidity, increased PM in air
subsurface mining
more expensive due to higher insurance and healthcare cost for workers; vertical 'shaft' drilled down into ground
risks of subsurface mining
poor ventilation leading to toxic gas exposure; mine shaft collapse; injury from falling rock; lung cancer; asbestos; fires; explosions
acid mine drainage
rainwater leaks into abandoned mine tunnels and mixes with pyrite, forming sulfuric acid
environmental impacts of mining
rainwater carries sulfuric acid into nearby streams, or infiltrates ground water; lowers pH of water, making toxic metals more soluble in water
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Flashcard (111)