kWh - if a problem provides you how much an electricity provider charges for electricity (e.g. $.10/kWh), and the problem tells you the power of an appliance (the wattage) and time (how many hours in a day the appliance is being used), be able to calculate how much the person is being charged for electricity usage (kWh) per unit of time (e.g. a day, several days, or a month)
- Nonrenewable Energy (fossil fuels and nuclear power) exist in fixed quantities and cannot be replenished. Why? Fossil fuels take 100’s of millions of years to form. Radioactive isotopes (nuclear atoms) only exist in a fixed amount within the Earth’s surface.
- Renewable Energy (biomass, solar, wind, hydroelectric, etc.) can be replenished ONLY if we use the resources that produce them in a sustainable manner.
- Fossil fuel characteristics:
- come from organisms’ remains in anaerobic environments - swamps and ocean floors
- took millions of years (subjected to heat & pressure under the Earth’s surface) for them to form
- Coal characteristics:
- mostly used for electricity; comes from plant remains only
- peat → lignite → bituminous (or sub-bituminous) → anthracite (low-grade → high-grade)
(anthracite has the lowest impurities - e.g. sulfur oxide, mercury and the greatest amount of energy; lignite is found in half of the world’s proven coal reserves but it produces less energy than anthracite when burned)
-largest coal reserves - China, India, United States, and Australia
- Advantages:
Energy dense
Plentiful amount in the U.S.
Cheap
Needs little refining
-Disadvantages:
Releases the greatest CO2 (major contributor to global warming - climate change)
Releases SO2 (major air pollutant - contributor to smog - reduces visibility & interferes with your lungs getting oxygen it needs)
Releases mercury (major contributor to toxic chemicals infiltrating water environments)
Coal has to be mined (leads to these problems: habitat destruction, acid mine drainage)
- Petroleum characteristics:
- mostly used for transportation, comes from dead remains of ocean-dwelling phytoplankton
- top 5 oil producing countries: U.S., Russia, Middle East (Saudi Arabia, Iraq), Canada, and Russia
- crude oil can be refined into other products - gasoline, kerosene, plastics, asphalt, polystyrene, DDT, and crayons
- bitumen - a “black substance” comes from boiled oil extracted from tar sands in Canada - used to make asphalt
- advantages:
Energy dense
Can be transported
Doesn’t emit as much CO2 like coal when burned
- disadvantages:
Still emits CO2 (a greenhouse gas)
Can emit SO2 (not as much as coal) - an air pollutant (along with other impurities)
Has to be extracted from the ground and transported to be refined (leads to these problems: oil leaks contaminating soil and water ecosystems)
- Natural Gas characteristics:
- mostly used for cooking and heating; can be used for generating electricity
- comes from the remains of ancient marine organisms (e.g. Barnett Shale that underlies Ft. Worth - has one of the greatest amounts of natural gas in the U.S.)
- top 5 natural gas producing countries: U.S, Russia, Canada, China, and Iran
- advantages:
Releases the least amount of CO2 compared to coal and oil (and doesn’t release hardly any impurities)
Relatively cheap (if demand for it is not high)
Plentiful reserves in the U.S.
- disadvantages:
If unburned, methane (CH4) is a potent greenhouse gas
Hydraulic fracturing (or “fracking”) - most commonly used method in extracting natural gas from shale deposits - the pores in shale rock (mostly comprised of clay) are so small that natural gas has a hard time squeezing out of the pores, so fracking causes the pores to open wider using high water pressure & chemicals
Fracking problems - possible groundwater contamination, process uses a lot of water for the pressure, unburned natural gas (methane) can leak out & contribute to global warming
Cogeneration - heat generated by a process (e.g. incinerator -burning trash) can be funneled to a power plant and provide the heat in converting water into steam so that electricity can be produced.
Topic 4.7 Key Terms -
Insolation = solar radiation ↑
Area ↓
Angle of incidence (angle of sun’s rays hitting the Earth’s surface, the Earth’s surface most perpendicular to the Sun receives the greatest amount of solar radiation-equator); 300 N = Tropic of Cancer, 300S = Tropic of Capricorn, 600 N = Arctic Circle, 600S = Antarctic Circle
Earth tilts at 23.50 (the tilting causes seasons to happen); Northern Hemisphere Winter solstice (Dec. 21-22)-shortest day of year; Polar Night - Arctic receives 24 hrs of darkness - Vernal Equinox (March 20-21) - equal day and night lengths; Summer Solstice (June 20-22) - longest day of year; Midnight Sun - Arctic receives 24 hrs of daylight; Autumnal Equinox -September 22-23
Topic 4.6 Key Terms:
Watershed - a land area that drains into a waterbody (e.g. creek, river, lake)
Watersheds are characterized by their area, vegetation, type of soil that supports vegetation, and slope of the watershed. Human activities known to pollute/impair watersheds include: logging, streets in communities & cities releasing pollutants into storm drains, industrial sites, farmland/ranchland and dams.
Topic 8.1 - Sources of Pollution:
Key Terms from Video:
(discuss point and nonpoint sources of pollution and the differences between those sources)
-Point sources of pollution - enter the environment from a single source and are clearly defined; examples are pipes, drainage, and factory smokestacks, wastewater treatment plants, oil refineries, leaking underground gasoline storage tanks
-The Clean Water Act requires industries to get a permit from the state and/or EPA before they can discharge any effluent into a body of water
- Nonpoint sources of pollution - is pollution that cannot be traced back to a single point, CAFOs, property or a single pipe; contaminants come from many sources accumulating over a wide area until it impairs water quality.
Examples of nonpoint sources of pollution are agricultural lands and residential areas where they have runoff of excess amounts of fertilizers and pesticides; water running off of parking lots, roads, & lawns may carry toxic chemicals, oils & grease.
Sediment is one of the most significant nonpoint sources of pollution; sources of sediment include: improperly managed construction sites, crop and forest lands, & eroding stream banks; Nonpoint sources are not regulated through permitting but managed through programs that encourage partnerships between private landowners & local and state governments.
Sedimentation is a Nonpoint source pollutant.
Sediment is particles of soil, clay, and sand that can be carried from the land to water sources; this is caused by poorly managed construction sites, road building, tilling of farm fields, and overgrazing of riparian habitats.
Producers and consumers are impacted by sedimentation.
1) Sediments suspended in the water column can affect primary producers (plants) because light infiltration will be reduced; this impacts plants’ ability to photosynthesize and add oxygen to water.
2) Predators that use vision as their primary sense for hunting are also impacted.
3) As sediment settles, it can disrupt the eggs and larvae of aquatic species like fish, insects, and mollusks.
Topic 4.9 Key Terms -
El Nino (occurs every 3-7 years) near equatorial Pacific Coast of South America - easterly trade winds stall & may even reverse - warm sea surface waters remain near Pacific coast of South America - no upwelling occurs (upwelling usually occurs when cold water rises to the surface when tradewinds force warm water to move west across Pacific Ocean - cold water bring nutrients and dissolved oxygen to the surface - upwelling produces vibrant food chains & fishing industry thrives) - Cooler & wetter conditions happen in the southeastern U.S. and unusually dry weather in the northern U.S., Canada, southern Africa, and Southeast Asia.
- El Nino can last from a few weeks to a few years
La NIna (tradewinds moving to the northwest from South America are stronger than usual; southeastern U.S. becomes drier, northern U.S., Canada, southern Africa, and Southeast Asia become wetter).
Topic 4.8 Key Terms -
large bodies of water stabilize land temperatures nearby due to the fact that water has a high specific heat + high movement to migrate the warmer temp. (water takes a longer time to increase its temp.); land, on the other hand - has a low specific heat + no movement - land is unable to migrate warmer temperatures (land has a quicker temperature increase); examples of large bodies of water - Great Lakes, Gulf of Mexico, & Mediterranean Sea; ocean current temperatures influence land temperatures
Topic 4.8 Key Terms continued – rainshadow effect - the leeward side of a high mountain that doesn’t receive rainfall (it has dry and desert-like conditions); the windward side of a mountain that faces a large body of water will receive high rainfall due to ocean breezes carrying moisture onto land that condenses into rain droplets (it is wet and has an abundance of vegetation)
Diagram of Rainshadow
Topic 5.1 Tragedy of the Commons Key Terms:
-Tragedy of the Commons - individuals use shared resources for their own self-interest rather than maintaining the common resource therefore resulting in a depletion of common resources
-Common Resource - public (limited) resource that is used by everyone and regulated by no one (e.g. oceans, forests, grazing land, air)
-Private Resource - owned and used by one individual, family
-Methods used maintaining common resources - 1) regulate use/have rules (e.g. licenses, permits, quotas), 2) replenish (e.g. replant trees, throwback pregnant (gravid) fish, rotational grazing), 3) ensure compliance (e.g. treaties, laws, oversight of laws & treaties: fines, incentives: debt for nature - one country excuses or lessens another country’s debt if that country commits to preserving/conserving more of its land) and 4) privative commons
Topic 5.2 Clearcutting Key Terms:
-Ecological & economic services provided by forests
- timber vs lumber
Negative Impacts of Clearcutting on Terrestrial environments:
-carbon cycle - removal of trees causes more CO2 to stay in the atmosphere
-soil stability - ↓ in soil stability - the roots of trees hold the soil in place
-↓albedo (loss of trees will cause more sunlight to be absorbed by soil)
Impacts of Clearcutting on Atmosphere
- ↑CO2
Impacts of Clearcutting on Aquatic environments:
- ↑turbidity, ↓primary productivity and ↓albedo (reflection of light/heat) since surfaces are darker (a ↓albedo = ↑absorption of sun’s rays)
-↑ water temp., ↓ dissolved oxygen levels
- ↑ eutrophication
- ↓ biodiversity/habitat availability
Topic 5.3 The Green Revolution Key Terms:
Green Revolution - movement from small scale, human labor farming to large scale, mechanized farming with the main goal of increasing food production
Green Revolution features include:
1) Mechanization
2) Monoculture (GMOs)
3) Artificial Fertilizers
4) Irrigation
Creation of GMOs: inserting desirable genes into crops, animals to produce a beneficial trait
Artificial selection: humans breeding plants & animals to obtain a desirable organism with beneficial traits
GMOs benefits:
1) GMO crops can be made to tolerate almost any type of environment (e.g. drought, heat, and salt resistant) and herbicides - so that farmers can apply herbicides early
2) GMOs can be made to produce their own “insecticide” - therefore no synthetic insecticides are needed
GMO drawbacks:
1) GMO crops grown in arid environments will still need fertilizers added to the soil
2) some weeds are naturally resistant to herbicides (ex: Roundup herbicide)
3) Bt crops may kill nontarget species & lead to insect-resistant pests
4) moral/ethic/economic issues with patented GMO crops
Topic 8.5 Eutrophication Key Terms:
- algal blooms
- sources of eutrophication: farms, feedlots, sewage treatment plants, & detergents
- oligotrophic
- eutrophic
- hypoxia
Topic 5.7 Meat Production Key Terms: (meat production benefits & drawbacks):
Problems with Meat Production:
- overconsumption of meat is a major problem in developed countries
- runoff of animal waste into waterways leads to 1) decrease in DO (dissolved oxygen) - this is due to aerobic bacteria using animal waste as a source of nutrients for cell respiration and therefore they deplete the water’s DO and 2) an increase in fecal coliform bacteria (E. coli)
- antibiotics and growth hormones given to animals (leads to artificial selection
- soil compaction (less groundwater recharge)
Benefits & drawbacks of CAFO(s) - concentrated animal feedlot operation - cattle fed grain (high calories),
benefits: cost to consumer is cheap because maintaining CAFO doesn’t require a lot of human labor; uses less land per head of livestock than other methods; problems: produces a lot of animal waste which will have potentially lots of E.coli; uses antibiotic and growth hormones - antibiotic leads to resistant bacteria and growth hormones - can lead to health problems for animals & humans that consume these animals
Benefits & drawbacks of free-range grazing: pros - no antibiotics & growth hormones; cons - 1) uses more land - roaming animals can interfere with native habitats (disrupting biodiversity), less head of cattle produced - ranchers have to spend more time trying to get to each cow, will take longer for cattle to increase their weight 2) overgrazing problems: tragedy of the commons, ↑ in soil erosion, animal waste can end up in waterway, 3) desertification
(conversion of grassland to desert in arid areas), and 4) costs more money - more human labor involved and land usage
Topic 5.8 Impacts of Overfishing Key Terms:
Methods of Commercial Fishing:
- Long-line - a long fishing line with hooks containing baits for catching fish, held in place with buoys; pros- catch a lot of fish
- Drift net/gill net - kind of like a long volleyball net, that can be dragged at different depths by a fishing boat
- Purse seine - looks like a drawstring bag, but contains 2 drawstrings - used for capturing school of fish
- Trawling - net shaped like a cone, dragged along the middle or bottom of water by a boat
- Sonar - a device that can detect and locate fish by using sound waves reflected by the fish (Sound Navigation Ranging); con - interferes with whales navigation
Major drawbacks for all of these fishing methods:
1) Overfishing (example of tragedy of commons when fishing is not regulated)
2) capturing non-targeted fish = bycatch (reducing their biodiversity)
Ways to Make Commercial Fishing More Sustainable:
1) Have catch limits in place based on MSY (maximum sustainable yield) - (maximum amount of a renewable resource that can be harvested without compromising the future availability of that resource)
2) Limit age/size of fish caught
3) Modify techniques to reduce bycatch
4) Have laws/treaties in place to protect critical species
5) Have incentives/fines
6) Encourage consumers to purchase fish using sustainable fishing methods
Topic 5.6 - Pest Control Methods Key Terms:
Pesticides pros: 1) easy to use and 2) increases crop yields and profits
Pesticides cons: 1) pesticide treadmill, 2) artificial selection of resistant pests,
3) persistent in the environment (difficult to breakdown), and 4) harm/kill non target species
- Pesticide treadmill - a cycle in which farmers continuously pay for stronger (more concentrated) pesticides but the pests continue to be resistant
- biomagnification (Topic 8.8)
Topic 8.7 Persistent Organic Pollutants (POPs) Video #1 Key Terms:
(define what a persistent organic pollutant is, then discuss common types of persistent organic pollutants)
What are persistent organic pollutants?
- Persistent means that the pollutant is stable, it doesn’t break down, wind, water nor microbes break it down
-Organic means that POPs have carbon in them; their molecular structures are comprised of rings, with chlorine atoms attached to outside of ring
-Synthetic means that POPs are produced in a lab
- Nonpolar means that the POPs do not have charges to them; therefore they can readily diffuse across cell membranes.
What are some specific examples of POPs?
-1) DDT - stands for
Dichloro-diphenyl-trichloroethane (you don’t have to remember the chemical name for the AP exam)
- DDT is an insecticide (used in farming to kill pests and vectors causing disease such as mosquitoes), colorless crystal, and is banned for use in the U.S. because of its persistence
- Rachel Carson’s Silent Spring book is about the environmental and human health problems associated with the use of POPs such as DDT (e.g. there would be a spring with no bird songs if we continued to use DDT)
-DDT is still used in a few other countries as a chemical in nets to combat malaria
-2) PCBs - stands for polychlorinated biphenyl (you don’t have to know the chemical name for the AP exam)
- it was used as an industrial fluid such as a coolant, lubricant, flame retardant
*diphenyl and biphenyl refer to benzene rings (rings of carbon containing double bonds)
Topic 8.7 Persistent Organic Pollutants (POPs) Video #2 Key Terms:
(discuss the impacts of persistent organic pollutants on non-target organisms)
POPs do contaminate water and soil.
There are several U.S. laws that pertain to the control & management of the POPs so they are less likely to enter water and soil environments:
- Clean Water Act
- Safe Drinking Water Act
- RCRA - Resource Conservation and
Recovery Act
- CERCLA - Comprehensive
Environmental Response,
Compensation, and Liability Act
- FIFRA - Federal Insecticide, Fungicide, and Rodenticide Act
And 1 international treaty - Stockholm Convention of 1991 - banned & reduced the manufacture of these chemicals in countries because these chemicals could end up affecting the world
POPs are fat-soluble.
-Once these POPs become introduced to fat/non-polar molecules, such as cell membranes, they can diffuse across the cell membranes and stay within the
cells. Remember, they are persistent, which means they can’t be broken down.
POPs can travel long distances.
-Water and wind carry these chemicals a long distance (in some cases to other continents)
Topic 8.8 Bioaccumulation and Biomagnification - storing of persistent organic toxins in lower trophic level organisms (e.g. DDT) - the problem is that as energy (organic matter) moves up a food chain, the organic toxins also move through the food chain
Topic 8.8 Bioaccumulation and Biomagnification Key Terms Video #1: (really important!)
(explore the processes of bioaccumulation and biomagnification & identify common substances that can bioaccumulate)
Biomagnification refers to these chemicals increasing in concentration as they travel up a food chain; apex predators suffer the greatest effects of these POPs because bioaccumulation has concentrated these substances in their fatty tissues
.
Bioaccumulation refers to the “build-up” of a persistent organic pollutant (POP) within an organism’s fatty tissue cells - why does this happen? - because these chemicals are nonpolar so they can easily diffuse across a cell membrane and remain within the cells
Persistent = pollutant is very stable (can’t be broken down by wind, water, nor microbes)
Organic = pollutant is made of carbon, hydrogen, oxygen
What are some examples of chemicals that bioaccumulate?
- 1) DDT -insecticide - synthetic organic chemical
- 2) Methylmercury (CH3Hg+) - is made when mercury enters a water body or soil & certain bacteria convert
mercury into methylmercury - a partly organic chemical
- 3) PCB (polychlorinated biphenyl) - organic chemical that was used in the manufacturing of electrical equipment such as transformers and capacitors
Picture showing the difference between bioaccumulation and biomagnification:
Picture in Google Document
Topic 8.8 Bioaccumulation and Biomagnification Video #2 Key Terms:
(discuss the impacts bioaccumulation and biomagnification have on the environment and on human health)
Apex predators and biomagnification.
Examples of apex predators impacted by biomagnification of POPs include:
-birds
-raptors
-bald eagle
-California condor
-peregrine falcon
*all of these organisms are 20 and 30 consumers; these organisms have been heavily impacted by the effects of DDT - when DDT reaches a certain threshold concentration in these organisms, it inhibits the processing of calcium in their bodies; egg shells are made of calcium, and when these birds have exposure to DDT, they end up producing thin egg shells that may not survive during the nesting process; even if offspring emerge from the eggs, the offspring may have some deformities
Humans and biomagnification.
-Example: Humans ingesting top predators in an aquatic ecosystem may have ingested chemicals such as mercury which has an impact on the nervous system; humans can also have kidney/liver dysfunction, damage to reproductive & circulatory systems & human babies may have birth defects
Topic 5.9 Impacts of Mining Key Terms:
Video #1 (Types of Mining & when they are used)
Mining - gathering minerals from the ground (e.g. gold, diamonds, phosphorus from rocks, gravel, coal)
When these are 1st harvested, they are called ores (high-quality ore - less impurities; low-quality ore - higher impurities which requires lots of energy, water & other resources to refine it)
Refining - is an industrial process that removes impurities from ores
2 Methods of Mining:
1) Surface Mining Types:
a) Open-pit Mining - type of surface mining where the Earth’s surface is dug to the point of producing a “crater” hole
b) Strip Mining - the Earth’s surface is being “scraped” by machines
c) Mountaintop removal - mostly used for extracting coal; involves the use of explosives
2) Sub-surface (underground) Mining
- expensive, only used when a target mineral is hard to access
Overburden - soil covering the ore deposits
Spoils - refers to overburden removed away from ores
Tailings - refer to the impurities removed when ores are refined and then you are left with your target mineral
Cyanide Heap leaching - uses liquid containing cyanide in removing impurities from gold ore -the end result of the impurities is a “slurry” (used for refining gold)
Topic 5.9 Impacts of Mining
Video #2 (environmental problems that happen with mining):
- vegetation removal to access areas containing ores leads to soil erosion and removal of species habitats
- road building for mining could bring in invasive species
- machinery used in mining releases greenhouse gasses when fossil fuels are combusted → contributes to climate change (e.g. melting of polar ice caps, viral/bacterial infections happening more due to warmer weather) and machinery burning fuels releases air pollutants that would make it difficult for animals to breathe in oxygen
- Acid mine drainage (mostly happens with abandoned mines) - occurs when tailings containing some pyrite (Fool’s gold -FeS2) sulfur reacts with water and oxygen to form sulfuric acid (H2SO4) - this acid can runoff into a waterway, causing the waterway to become too acidic
- cyanide could leak into a nearby waterway if nothing is put in place to capture liquid containing cyanide
Video #3 (remediation techniques that are used to correct the environmental problems with mining and Mining Practice FRQ)
- remediation - fixing something back to the way it was (or close to the way it was)
Steps to restoring land after overburden has been removed:
(start from the “ground” or “base” and then move up to the “top”)
1) recontouring/regrading land to its
original topography (very helpful for open-pit mining)
2) replace and/or add topsoil and nutrients (gives the soil stability)
3) replant vegetation (e.g. fast-growing plants or early successional plant)
4) monitor the location for 5 to 10 years
Remediating acid mine drainage methods:
- add a base (e.g. limestone (CaCO3), sodium hydroxide (NaOH) or sodium bicarbonate (NaHCO3) to neutralize the acid
- remove or cover tailings (to prevent precipitation from interacting with it)
- Bioremediation (use genetically engineered bacteria that can digest the sulfuric acid)
Topic 5.10 Impacts of Urbanization Key Term Videos #1 (define what an urban area is & a discussion of urbanization benefits)
Urbanization - a shift from agricultural (rural) jobs to non-agricultural jobs (high density areas) - move towards cities and away from rural areas
Urban sprawl - a change in population distribution from high population density areas to low density suburbs that spread into rural lands, leading to potential environmental problems; in other words, it occurs where urban areas meet each other
Benefits of Urbanization: - mass transit! (yay! 😀- lowers amount of fossil fuel use per person and uses land space efficiently (e.g. travel underneath land, above land can be used for other purposes) - everything to close together (e.g. residential area close to grocery stores) - build up not outward - minimize land impact - multi-use of land- also referred to as smart growth - e.g. residential buildings are close to work locations; services, stores are also close by
Topic 5.10 Impacts of Urbanization Key Term Videos #2 (a discussion of the disadvantages of urbanization for both humans & the environment)
Drawbacks of Urbanization Negative Impact on Water Cycle: 1) Water Diversion Projects such as Dams (Hydroelectricity) - destroys natural habitats of organisms 2) Saltwater Intrusion - where urban areas receive their drinking water from aquifers near coastal waters, when aquifers begin depleting, saltwater moves in to replace the freshwater. 3) Loss of vegetation leads to lower transpiration and more soil erosion 4) Urban areas have lots of impermeable surfaces such as concrete and asphalt (problems: doesn’t allow the recharge of aquifers and lots of surface water runoff occurs potentially carrying pollutants into a waterway)
Negative Impact on Carbon Cycle:
1) Industries and cars use fossil fuels (e.g. coal and oil) - releases toxic air pollutants and GHGs which contribute to climate change
2) Waste Production- increase in land area devoted to landfills- problem with landfills is that they take up more land (decrease species habitats) & they can produce methane gas (CH4) when anaerobic bacteria break down food wastes in landfills
3) Heat Island Effect - occurs when impermeable surfaces (e.g. asphalt) absorbs Sun’s rays instead of reflecting it (low albedo)
Topic 5.10 Impacts of Urbanization Key Term Videos #3:Really Good FRQ in the Video about Urban Sprawl (discuss remediation of the effects of urbanization & apply this information to an FRQ)
Remediation - means to “improve or correct a situation”.
Ways to Remediate the effects of Urbanization: 1) Keep vegetation in place - reduces water runoff, it increases albedo (reflection of solar energy) which reduces the heat island effect 2) Extend mass transit into suburban areas (e.g. use commuter trains) 3) Cities can install “permeable pavement” - a pavement material that allows water to flow through it into the soil underneath it 4) Cities can implement urban planning so that they can do more “growing up” rather “growing outward” - example: have multi-use buildings - (where everything is in walking distance) 5) Brownfield development - converting abandoned businesses or buildings into community parks, playgrounds
Topic 5.12 - Intro. to Sustainability Video #1 Key Terms: (explain the concept of sustainability with regard to environmental indicators) Sustainability - refers to the ability to use and maintain a resource indefinitely or for future generations. Sustainability example: Input=output; use of resource=replenishment of resources Unsustainability example: Input>output; use>replenishment → examples: overuse of water, burning fossil fuels Wasteful example: Input<output; use<replenishment; natural spring in an area that gushes out water, if people lessens their consumption of that resource (spring water), the water could potentially flood an area
Environmental indicators used to determine if humans are implementing sustainable practices: 1) Biological diversity - preserve biodiversity 2) Food Production - incorporate sustainable farming and ranching 3) Global Surface Temp. & CO2 Concentration - decrease energy use 4) Human Population Growth - it would be helpful if countries provided more women’s rights, this would decrease the fertility rate 5) Resource Depletion - reduce, reuse, & recycle → this will decrease our extraction of limited, natural resources
Topic 5.12 - Intro. to Sustainability Video #2 Key Terms: (explore the meaning of sustainable yield) Sustainable Yield - amount of a renewable resource that can be taken without reducing its available supply
Maximum Sustainable Yield - taking about 50% of the population’s carrying capacity - is most efficient for the harvester and the population to replenish itself; for example organisms (e.g. fish) would still have enough mates & food in continuing population growth <taking less than 50% of a population’s carrying capacity → underusing a population (problem? Leads to greater competition within a population) >taking more than 50% of a population’s carrying capacity → overusing a population (problem? Not leaving enough of a population to replenish itself)
*A population grows the fastest and most efficiently when at 50% of its carrying capacity (we should harvest organisms when they are at their exponential growth phase)
How can we harvest sustainable yields? 1) Research and planning —> research reproductive abilities of a resource; research how long it takes a resource to replenish itself
2) Set quotas → set limits for harvesting
3) Require permits → manage harvesters in their taking of resources
4) Focus on long-term → implement sustainable practices
5) Reforest → replace trees that were harvested
Topic 5.13 Methods to Reduce Urban Runoff Key Terms:
(discussion of methods for mitigating problems (mitigate means to minimize the degree of any loss or harm) related to urban runoff, using permeable pavements, planting trees, increasing public transportation, and building up, not out). By doing these things, we can lessen pollutants entering our waterways and we can recharge our groundwater. ← these are 2 major problems with urban runoff (1. Water pollution and 2. Inability to recharge groundwater)
Permeable pavements allow water to infiltrate and recharged the groundwater.
Trees -increase the percolation of water through the ground & prevents flooding of streets)
Smart City Design - “building up not out” - having multiple homes in less space decreases paved areas (prevents flooding & allows more recharging of the ground) |
Topic 5.14 Integrated Pest Management Key Terms:
(learn about IPM (Integrated Pest Management) and how it is used to control pests but at the same time minimize disruption to the environment)
Integrated Pest Management - is a combination of methods used to reduce pest species; it includes biological, physical, and chemical controls. (ultimate goal is to reduce the use of chemical controls - this helps reduce pesticide treadmill and killing and harming of non-target pests including humans)
The following are part of IPM: 1) Biological control - use a natural predator of the pest (e.g. cat, dog, parasitic wasps, praying mantis, lady bugs, green lacewings, specific bacteria, & fungi
2) Physical control examples: (these examples are used to protect the crops) a) crop rotation (rotating process in which you grow & produce one crop (e.g. corn) & then you switch out that crop with another plant (e.g. soybean plants) → this helps to reduce certain pest species in a particular area over a period of time
b) intercropping (have one row of crops that you are trying to grow and another row of crops used to block pests → both crops are in the location at the same time)
c) Other methods of physical control: use traps, mesh screens, tilling of the soil, weed blocker, fence
3) Chemical control examples: glyphosate - herbicide, atrazine - herbicide, DDT - insecticide (these chemicals are broad-spectrum - kill/harm not only target pest species but also non-pests including humans)
Topic 5.14 Integrated Pest Management Key Terms Video #2: (benefits & drawbacks of IPM and the effect of IPM on wildlife, water supplies, and human health)
What are some problems with using heavy amounts of pesticides? 1) Pesticides kill non-target species 2) Pesticides can runoff into surface water and harm aquatic life; and pesticides that are water-soluble can be carried by water into the groundwater and pollute our drinking water 3) Pesticides can cause harm to human health: can cause problems such as rashes, nausea, diarrhea, blindness, can act as a mutagen and cause your cells to become cancerous
Benefits of IPM:
1) Decreases usage of pesticides 2) Economic Savings for farmers since they don’t have to pay a lot of money for purchasing pesticides frequently 3) Sustainable - IPM reduces harm to non-target species, IPM reduces the pollution to natural resources such as water, soil, and air 4) Targeted - IPM is best in reducing a specific pest population than just using only chemical pesticides 5) Minimizes loss of pollinators 6) Minimizes human health risks 7) Decreases pest resistance in pest population
Drawbacks of IPM: 1) Complex - using a combination of pest control methods to see which ones are most effective can be challenging and time consuming 2) Slow process - may take weeks, months to reduce a pest population 3) Expensive - using methods such as GMOs (creating crops with genes that make them resistant to certain pests can cost a farmer a lot of money - some GMOs are patented and farmers have to pay the companies to purchase these GMOs & that can decrease their profits
Topic 5.15 Sustainable Agriculture Key Terms: (soil conservation practices and methods to improve soil fertility)
Soil Conservation Practices: - Contour plowing - happens to farms on hills/mountains, rows of cropland are created along the contour (or outline) of the terrain; used to slow down water velocity as water flows downhill - Windbreaks - using trees between rows of crops or along the perimeter of crops to block wind from hitting crops - Strip cropping or Intercropping - alternate a row of crops with plants that will not be harvested but merely are there to hold the soil in place - use Perennial crops - examples: strawberries, raspberries (crops remain in the soil for several years), crop roots hold soil in place since farmers only remove the fruit & not the roots - Terracing - having “steps” or tiers for farms on a hill/mountain to slow water velocity movement of soil downhill - No-till agriculture - no plowing, leaves soil in place and keeps the soil full of nutrients
Methods to improve soil fertility: - Crop rotation - produce & harvest desired crop, then plant crops that built up nutrients in the soil (e.g. soybeans) - addition of Green manure - plow cover crops into the soil to add nutrients (N,P, K) when crops are decomposed by bacteria - addition of Limestone - adding calcium carbonate, increases soil pH (makes soil more alkaline) - most crops benefit from basic soils
Topic 5.15 Sustainable Agriculture Video #2 Key Terms: (describe how rotational grazing between different pastures prevents overgrazing)<--good sample FRQ at the end of the video
Overgrazing - extensive grazing in one area that causes damage to plants and leads to soil erosion → With no vegetation in place, cattle walking on bare soil will compact it too much → this leads to a much drier soil in warm and dry climates
Rotational grazing - the movement of livestock around their pasture to prevent overgrazing from happening → this allows the cover crop (example: grass) to reproduce and prevent soil erosion |
Topic 6.1 Renewable and Nonrenewable Resources Key Terms: (identifying differences between renewable and nonrenewable energy sources)
1) Nonrenewable energy sources - sources that exist in a fixed amount (not replenishable) and are involved in energy transformation that cannot easily be replaced (examples: nuclear, coal, oil, and natural gas - these are depletable); it takes millions of years to form/produce nonrenewable energy sources; even radioactive isotopes used in nuclear power plants exist in a fixed amount
2) Renewable energy sources - sources that can be replenished naturally, at or near the rate of consumption, and can be reused if managed properly (examples: biomass - (wood, corn, cow manure), hydroelectric, solar, wind, waves and geothermal)
Topic 6.2 Global Energy Consumption Key Terms Video #1: (examine the trends in energy consumption between developed & less developed countries & why fossil fuels are the most widely used source of energy globally)
- Coal was the 1st major source of energy during the Industrial Revolution, but now has been replaced with oil and natural gas. - Nuclear energy was popular in the 1970s but lost public faith due to catastrophes. - Renewable energy use is rising but not as much as oil and natural gas.
Topic 6.2 Global Energy Consumption cont’d Key Terms Video #2: good video with a practice math problem (explain why countries become more reliant on fossil fuels as they become developed & factors that influence what energy sources people use) - As countries develop, they’re reliance on fossil fuels increases - they use fossil fuels in obtaining more sources of technology. - Developing countries move from human/animal labor (agrarian)to machinery (industrialization) = necessitates fossil fuel usage
Factors that influence what energy sources people use: 1) what’s available to people? 2) price of energy source (supply and demand) 3) governmental regulation (what fuels can consumers access?)
Topic 6.4 Distribution of Natural Energy Resources Key Terms Video: (describe global patterns of distribution of natural energy sources - ores of Uranium, coal, crude oil, and natural gas, as well as geologic conditions under which these sources form) - energy resources are not uniformly distributed - resource locations are dependent on regional geological history - *coal is also referred to as coke - a refined version of coal - Uranium - is mostly found in Australia, Kazakhstan, Canada, and Namibia - Crude Oil - is predominantly found in the Middle East, but Canada and Venezuela has crude oil in tar sands - Natural Gas - mostly found in Russia and the United States - Coal - mostly found in United States, Russia, China, and Australia
How do organisms from 300-400 million years ago get converted into fossil fuels such as oil and natural gas? *As the geologic formations changed millions of years ago, marine organisms became buried under sediment,fossil remains were then exposed to high heat and pressure (under the sediments), and were converted into oil and natural gas. *The age of the rocks determines if fossil fuels are produced *Coal comes from the breakdown of vegetation millions of years ago. *Oil & natural gas are formed at the same time. |
Topic 6.3 Fuel Types and Uses Key Terms (Video #1): (identify & examine different types of fuel - wood, charcoal, and peat - and the 3 different types of coal - lignite, bituminous, and anthracite)
Wood and charcoal - primarily used in developing countries for fuel - cooking and heating; charcoal is made from wood but has to be processed -charcoal is created by heating wood in an non-oxygenated environment-this removes impurities - although it doesn’t remove carbon monoxide & charcoal burns hotter than wood
Disadvantages to using wood & charcoal? Removal of trees - leads to soil erosion and less sequestered CO2 which will exacerbate the problem of global warming Peat - partially decomposed vegetation that can also be used for fuel; it is the precursor for making coal
← Pictures of Peat and 3 Different Types of Coal
Coal - is used for heating and producing electricity
Major Environmental Disadvantage to using Coal - burning coal releases high amounts of CO2 - a greenhouse gas and sulfur dioxide (SO2) - a major air pollutant that is a contributor to acid rain
Topic 6.3 Fuel Types & Uses Key Terms (Video #2): (explain how crude oil can be recovered from tar sands, the cleanest fuel - natural gas, and cogeneration; explain how fossil fuels are made into specific fuel types) Natural Gas - doesn’t release as much impurities as burning coal does - which explains why natural gas is “the cleanest fuel”; but it does release a greenhouse gas called CH4 - methane along with CO2; natural gas is used for cooking and heating
Tar Sands - is another source for extracting crude oil; tar sands contain clay, sand, water, and bitumen (very common in Canada); bitumen is a black substance; also called “asphalt” - that comes from boiled crude oil
Problems with using tar sands? - very time consuming & energy intensive to remove it from its source and process it into refined oil Crude oil can be converted into other types of fuel: gasoline, diesel, jet fuel, heating oil At refineries, crude oil is boiled and different fuels are produced at different boiling points.
Cogeneration - burning a fossil fuel to not only produce electricity but also produce useable heat that can be pumped into another system for a purpose (e.g. heating water, producing electricity); i.e, - also referred to as combined heat and power (CHP) - is the simultaneous (same time) production of multiple forms of energy from a single fuel source (thermal (heat) and electrical (electricity) are the two major forms of energy produced in many types of cogeneration applications). |
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*A key point = sometimes a problem will tell you a power plant’s capacity - this refers to the maximum amount of electricity the plant produces per hour. For example, if a power plant has a capacity of 500 MW (megawatts), then for one day (24 hours), its maximum capacity is 500 MW x 24 hours/day = 12000 MWh (or 12,000,000 kWh).
A power plant’s capacity factor refers to the fraction of time it is operating, such as .90 (or 90%); Most power plants are not operating 24 hrs a day, 365 days a year - they have to be shut down for maintenance, refueling, & repairs; most power plants have a capacity factor of .9; Wind turbines have a capacity factor of .25
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Topic 6.5 Fossil Fuels Key Terms Video #1: (examine the process of combustion of fossil fuels, how burning them allows for the production of electricity, and environmental problems associated with extracting and burning coal)
- Combustion is a chemical process (Fuel + O2 → CO2 + H2O) → this is the main chemical combustion of coal and natural gas) - Pulverization - process in which coal is broken down into smaller pieces so that coal can be easily burned.
- Steps to producing electricity in a coal power plant: 1) Coal is burned. 2) Steam is created. 3) Steam turns a turbine. 4) Turbine turns a generator. (the spinning turbine blades - by way of a shaft-will rotate copper coils through a magnetic field in a generator - called an electromagnetic induction 5) Generator produces electricity. (as the copper coils are spinning in a generator, an electric current is induced)
Scherer Power Plant in Georgia https://www.usgs.gov/media/images/georgias-plant-scherer-coal-fired-power-production-method
(one of the largest power plants in the U.S.) it provides 3,250 Megawatts of electricity per hour
Topic 6.5 Fossil Fuels Key Terms Video #2: (explore variety of methods humans use to extract fossil fuels from the Earth for generating energy and electricity and environmental problems associated with these extraction methods)
- Oil & Natural gas must be pumped out (drilling happens at sea as well) - Natural gas is extracted by a process called hydraulic (or hydrologic) fracturing - Coal is extracted by mining - surface & subsurface mining; mostly coal is extracted by surface mining.
Environmental Problems? 1) Coal Extraction Mining- Habitat Destruction, removal of tailings may cause runoff of Sulfuric acid, Mercury into waterways 2) Oil Extraction: Habitat destruction, problems with oil spills 3) Gas Extraction: Habitat destruction, water contamination, earthquakes
*Key Takeaways from Video #2: 1) Each fossil fuel forms differently. 2) Different formation leads to different extractions 3) Many different environmental problems can result from these extraction methods; habitat destruction is a common environmental problem.
Topic 6.5 Fossil Fuels Key Terms Video #3: (explain the process of hydrologic fracturing - or fracking- in greater detail and the effects of the process on the air, land, and water resources)
- extraction of natural gas (found underground) can contaminate groundwater - Hydraulic fracturing - a process of drilling and opening up rocks to extract natural gas and oil; this process uses water, sand, and hazardous chemicals; lots of water is used during fracking!!
Steps to Fracking: 1) Well is made (usually made of clay lining so that it won’t allow water with hazardous chemicals to permeate through) 2) Pipe is inserted to extract natural gas 3) Fracking fluid is inserted (fracking fluid contains water, volatile chemicals) 4) Inserting fracking fluid “breaks” the ground so that pockets containing natural gas will open up to release the natural gas 5) Natural gas will flow upwards through the same pipe
Source: https://www.nature.com/articles/477271a/figures/1 Environmental Problems with Fracking: 1) Fracking well can contaminate groundwater/destroy species habitat 2) Pipe not lined properly with clay can also contaminate water 3) Fracking fluid contains VOCs (volatile organic compounds) - can be released and contaminate groundwater & atmosphere when the fracking fluid is removed from the well 4) Natural gas (CH4 methane) may leak out - it is a greenhouse gas - contributes to climate change 5) May be the cause of earthquakes - destabilizes the geology of the area due to the pressure added to extract natural gas 6) Fracking uses up a lot of freshwater → deprives natural aquatic habitats of freshwater |
Topic 6.7 Energy from Biomass Key Terms Video #1: (focus on the use of biomass in developing countries and environmental costs associated with their use)
Biomass - organic matter from organisms that can be burned for heating and cooking (e.g. wood, charcoal, animal manure, peat, and crop residue); Biomass is the #1 source of renewable energy worldwide. Positive consequences to using Biomass: 1) easily accessible, 2) low cost, and 3) used for cooking & heating Environmental Problems with using Biomass: 1) burning biomass releases a variety of air pollutants - carbon monoxide, nitrogen oxides, particulates, & volatile organic compounds 2) burning it indoors is worse - people are more likely to inhale air pollutants since they’ll be more concentrated in one area, and 3) overharvesting of trees prevents the trees ability in replenishing their population
Topic 6.7 Energy from Biomass Key Terms Video #2: (investigate the advantages & disadvantages to using biofuels as a substitute for gasoline) Biofuels - liquid fuels made from plant matter that are used as substitutes for common petroleum products (e.g. gasoline & diesel) -Two major types of biofuels are ethanol and biodiesel - Ethanol - is produced when bacteria ferment (breakdown) plant-based starches; Ethanol can be mixed with gasoline to form gasohol (90% gasoline and 10% ethanol); E85 and flex-fuel vehicles can run on a mixture of 85%ethanol and 15% gasoline or gasoline by itself - Biodiesel - chemically modified oil that comes from plants - Sources of Ethanol: Corn (United States) Sugarcane (Brazil) Sugar beets - secondary source in United States and Brazil - Sources of Biodiesel Soybeans (U.S. and Brazil) Palm oil (Southeast Asia) Rapeseed (Europe) - Biomass represents 43% of the renewable energy used in the U.S. -Biofuel usage makes up about half of the total biomass percentage
Positive Consequences of using Biofuels: 1) Combustion is carbon neutral (biofuels come from recent plant matter that represents modern carbon - naturally part of the current carbon cycle, whereas fossil carbon comes from fossil fuels that’s not part of the current carbon cycle, therefore it is adding additional CO2 to the atmosphere) 2) Potentially renewable and produced domestically
Topic 6.7 Energy from Biomass Key Terms Video #2 continued: Negative Consequences of using Biofuels: 1) Net energy is low (i.e. energy output is very low). More gasohol is needed to drive the same distance as conventional gasoline 2) Harvesting crops to be used in producing biofuels causes these problems: a) Increased fossil fuel usage in harvesting crops such as corn b) Increased deforestation c) Destruction of native species habitats
Sustainable Solutions for using Biofuels: 1) Instead of using crops such as corn for producing ethanol, switchgrass is a good alternative - switchgrass is perennial and native to the Midwest. Farmers can harvest switchgrass without replanting it- this minimizes soil erosion (benefit of it being perennial) 2) Substitutes for biodiesel fuel such as soybean, palm oil could be algae grown in oceans (NASA - Omega System) and SVO (straight vegetable oil). Companies that use biodiesel for their vehicles could encourage residents and restaurants to give them their left over vegetable oil. The major benefit is that hardly any land would need to be used to grow these types of biofuels. |
Topic 6.8 Solar Energy Video #1 Key Terms: (identify 3 types of solar energy transformations and explore how each can be used to meet global energy needs)
3 Types of Solar Energy: 1) Photovoltaic cells (PV or Solar Panels) - transform sunlight energy directly into electricity. 2) Active Solar System (or Concentrated Solar Power)- use mechanical & electrical equipment to transfer solar heated liquid to transfer heat or create electricity 3) Passive Solar - occurs where heat is absorbed naturally without the use of mechanical or electrical equipment.
Photovoltaic Cells - are made of silicon; when silicon absorbs light energy, its electrons are released & flow through the circuit producing low-voltage electricity
Pros of using Photovoltaic Cells? 1) Generates electricity 2) Can be installed on homes, buildings - lessens habitat destruction 3) doesn’t emit produce air or water pollution or CO2 while producing electricity 4) can provide “off the grid” electricity for homes/businesses (off the grid means that these buildings are not connected to electricity providers transmission lines); these buildings can store excess electricity produced in batteries
Drawbacks of using Photovoltaic Cells? 1) Use is limited by available sunlight 2) Limited lifespan of nonrenewable PV cells 3) Expensive to make 4) Mining for silicon and lithium (used in batteries) causes habitat destruction of native species, soil erosion, air pollution from machinery 5) Solar farms may have a negative impact on fragile desert ecosystems
Picture of PV cells on a house:
Active Solar System Types: 1) CST (Concentrated Solar Thermal) Electricity Generation System - uses mirrors and tracking systems to reflect sunlight onto a power tower - cold water within the power tower will be converted into heated water → the heated water will generate steam → steam spins turbines → turbines generate electricity
2) Active Solar (Heat Pump) – cold liquid is pumped to the roof of a building where solar collectors are located, the liquid is heated by the Sun’s rays, the heated liquid flows downward towards an insulated storage tank, the storage tank will transfer the heat to liquid water; this heated liquid water can be used for showering/bathing, washing dishes, etc. (the storage tank acts as a heat exchanger) image of solar collectors
Pros for Active Solar Systems: Same as PV Cells (listed above) Drawbacks for Active Solar Systems: 1) Expensive 2) Requires maintenance 3) CSTs may negatively impact fragile desert ecosystems 4) Requires high solar intensity to maximize efficiency
Passive Solar Description: 1) Windows should face Sun’s direction (Northern Hemisphere houses face south - during the winter, this allows the Sun to warm the house when the Sun is lower in the sky) - during the summer, the Sun is higher in the sky, so the home’s overhang blocks incoming sunlight
2) House should have double-pane windows - this insulates while still allowing Sun’s rays to warm the house 3) Houses should have stone or concrete indoors -they have high thermal inertia/mass - great for retaining indoor heat or cold temp. (this reduces demand for heating at night and cooling during the day); objects such as stone have high mass and high specific heat and have the ability to retain heat. 4) Landscaping - having trees provide shade during the summer
Picture of Passive Solar Design:
Pros for Passive Solar: 1) Inexpensive 2) Low maintenance Drawbacks of Passive Solar: 1) House has to already be situated facing the South (difficult to implement retroactively) 2) Energy cannot be collected or stored long-term
Picture of Concentrated Solar Thermal System:
Picture of Active Solar (Heat Pump) System:
Topic 6.8 Solar Energy Video #2 Key Terms: (investigate trends in data for solar energy to draw conclusions) In this video, the instructor gives examples of how to appropriately identify the data that is shown, describe trends in data, determine if extraneous (unnecessary) data is given, and draw conclusions using patterns and trends (e.g. can something be extrapolated from the data)
Topic 6.9 Hydroelectricity Video #1 Key Terms: (examine how moving water can be used to produce electricity in reservoirs, rivers, and oceans)
Hydroelectricity - uses the kinetic energy of moving water to generate electricity (moving water, either falling over a vertical distance or flowing with a river or tide, contains kinetic energy) Steps to producing electricity in a hydroelectric plant: 1) kinetic energy of moving water → 2) causes the spinning of a turbine → 3) Turbine rotates coils in a magnetic field of a generator → 4) rotating coils in the generator produces an electric current
3 Types of Hydroelectric plants: 1) Large-scale 2) Small scale (Run-of-the-river system) 3) Tidal Energy
1) Large-scale hydroelectric plant Diagram of a large-scaled hydroelectric plant:
2) Small-scale hydroelectric plant - these are typically called run-of-the-river systems; water is retained behind a low dam or no dam; run-of-the-river systems don’t store water in a reservoir nor generate a lot of electricity
Diagram of Run-of-the-river system:
3) Tidal Energy - the kinetic energy of water (ocean tides) is driven by the gravitational pull of the Moon; tidal currents move in 2 directions - incoming & outgoing - turbines harness energy from tides
Picture of a Tidal Energy System:
Topic 6.9 Hydroelectricity Video #2 Key Terms: (examine the advantages and disadvantages of using hydroelectricity from an economic and environmental angle)
Positive Consequences of using Hydroelectricity: 1) No air pollution 2) No waste produced (since no combustion of fuel is needed) 3) Relatively inexpensive electricity generation (electricity cost to consumers is relatively cheap compared to nuclear power) 4) Downstream flood control 5) Additional services provided by reservoir (e.g. recreational activities, reservoir water can be used for irrigation, economic opportunities - individual or business-based fishing)
Negative Consequences of using Hydroelectricity: 1) Potential flooding of land near reservoir 2) Disruption to flow rates of river (problem for species that live downstream) 3) High maintenance cost for tidal energy (saltwater may hurt components of tidal energy systems) 4) High construction costs for dams 5) Most viable sites are already used 6) Large standing water reservoirs hold more heat & contains less dissolved O2 7) Siltation - refers to the accumulation of sediment at the bottom of a reservoir - can have a negative effect on plants, animals, & the production of electricity 8) Destruction of native species habitats during the construction of the dam |
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Studied by 43 people
