APES Notes

Unit 1- The Living World: Ecosystems

Module 1

• symbiosis- two species living in a close and long term association with one another in an ecosystem

• community ecology- study of interactions among species

• Ecosystem are not easily defined

• Biosphere is from deepest ocean bottom to highest mountain peak 12 miles

• Competitive exclusion principle- principle stating that 2 species competing for the same limiting resource cannot coexist

• commensalisms- one species benefits, other is neutral

• mutualism- both species benefit

Module 2

• Terrestrial biomes defined by dominant plant growth

• Temps below 41 f - Tundra and Taiga

• Temps between 41 and 68 f- temperate

• Temps above 68 f- tropical

• For every 10 c increase in temp, plants need 20mm of precipitation to grow

• deciduous trees have leaves that fall off yearly. Coniferous trees have needles or scales that do not fall off.

• taiga threat- mining and oil extraction

Module 3

• Rapids allow water and air to mix, increasing oxygen in the water

• Lake Layers- Little Liars Prank Boys

• Littoral- Top layer where algae grows

• Limnetic- open water as deep as sunlight penetrates

• Profundal- no sunlight reaches

• Benthic- Muddy bottom

• phytoplankton- floating algae

• oligotrophic- low nutrients, mesotrophic- moderate fertility, eutrophic- lots of fertility

• Freshwater wetlands- very productive, help reduce flooding

• Estuaries- where river water mixes with ocean

• Coral bleaching- when algae in corals die, from lower ocean pH and high temps

• Ocean layers- photic- with photosynthesis, aphotic zone- no photosynthesis so no plants, but there is bacteria that make energy from methane and hydrogen sulfide (Chemosynthesis)

Module 4

• Biogeochemical cycle- movements of matter within and between ecosystems involving cycles of biological, geological, and chemical processes

• Carbon cycle- C02 is exchanged between atmosphere and water- Largest carbon reservoir is the ocean

• Steady state- input = output so no change

• Carbon taken by photosynthesis ends up in soil

• Nitrogen is often a limiting nutrient

• Nitrogen is most held in atmosphere

• Nitrogen fixation- turns N2 into nitrogen that plants can use- done by bacteria (ammonium) or lighting and combustion (nitrate) that then goes to earth via rain

• Nitrification- conversion of ammonium to nitrite and then nitrate by bacteria

• Assimilation- plants/algae incorporate nitrogen into their tissues

• Mineralization- after organisms die, fungi and bacteria turn organic compounds back into ammonification

• Denitrification- Turning nitrate into nitrous oxide and then plain nitrogen via bacteria in anaerobic conditions.

• Nitrogen use in fertilizers can kill off plants that can survive in low nitrogen conditions

Module 5

• Phosphorous main reservoir is rocks- no gas phase- limiting nutrient especially in aquatic ecosystems

• Assimilation + Mineralization- Plants and animals take up inorganic phosphorus, assimilate it as organic, and upon their death, bacteria mineralize it into inorganic phosphate

• Phosphate undergoes geological uplift, it is not easily leached so it has little runoff

• Human use of fertilizers causes algal bloom which takes up oxygen so the water become hypoxic and becomes a dead zone- Gulf of Mexico

• Household detergents have phosphate

• Leaves releasing water- transpiration

• Harvesting trees reduces evapotranspiration by less biomass

Module 6

• Producers do both photosynthesis and cell respiration

• Primary Productivity- rate of converting solar energy into organic compounds over a period of time

• Gross PP- Total amount of solar energy captured by photosynthesis in a time frame

• Net PP- Energy captured by producer minus the energy they respire

• Measure GPP via C02 produced during photosynthesis- C02 taken up in sunlight plus CO2 produced in dark

• NPP= biomass production over time frame

• Biomass present at a certain time- Standing crop

• Only 1% of solar energy that hits producers undergoes photosynthesis (GPP) 60% of that is lost to respiration while 40% supports growth of producers (NPP)

• NPP is only 25 to 50% of GPP

• Different wavelengths of light move differently through water- blue light goes deeper

• Swamps+ Marshes are most productive aquatic ecosystems

Module 7

• Detrivores- organisms that break down waste into small particles

• Matter only cycles through and ecosystem- its never lost

• Second law of thermodynamics- when one organisms consumes another, not all the energy in the consumed is transferred to the consumer.

• Trophic level energy transfer is 10%

• Ecological efficiency- proportion of consumed energy that is transferred through trophic levels

Unit 2- The Living World: Biodiversity

Module 8

• Population bottleneck- if most species die, when it rebounds there will be low genetic diversity

• Types of diversity lowest to highest- Genetic, Species, Habitat, Ecosystem

• High species diversity- high productivity and resilience

• Biodiversity quantified by species richness (# of species) and evenness (proportion of species)

• Estimates for species on earth 5-100 million, likely around 10 million. (2 million named currently)

Module 9

• Ecosystem services- provisions (Goods that humans use directly), Regulating (regulating environmental conditions), Support (helping processes that would cost humans a lot) Cultural (Economic benefit to humans)

• Global ecosystems are estimated (via replacement method) to contribute over $125 trillion per year, twice the global economy

• pesticides can kill bees

• intrinsic value of an ecosystem- value separate of any human benefit

Module 10

• Island biogeography- study of how species are distributed and interacting on islands

• Species area curve- more land area=more species

• Slope of SAC lines are usually between .2 and .35

• In caroni river Venezuela, large islands species survived

• Model of Island Biogeography curve- Orange line going down for colonization, Blue going up for extinction- equilibrium is where the two values are equal/offset

• This is because when an island has less species, there will be less competition so less extinction, but plenty of species will colonize it

• Large and near islands have more rightward points on the curve

• Island species are often specialists

Module 11

• ecological tolerance/fundamental niche- range of abiotic conditions in which a species can survive, grow and reproduce

• realized niche- range of abiotic and biotic factors that a species actually lives in

• geographic range- areas where species live

• carbon dating- examining how different carbon types (isotopes) change over time to date sediment layers

• 99 percent of all species that have lived on earth are extinct

• Species may move to a different habitat to survive if conditions change

• 5 mass extinctions in earths history, biggest one 251 million years ago- metorite

• We are currently experiencing a 6th max extinction

Module 12

• Natural disruptions can be periodic (regular), episodic (somewhat regular) or random

• Environmental disruptions rarely hit the same place 2 times in a row

• ecosystem resistance- how much a disruption can effect matter and energy flows

• ecosystems have increased CO2 absorption to match C02 increases

• Measuring changing climates- looking at concentration of greenhouse cases in air bubbles in ice

• Scientists use composition change of foraminifera in sediment layers to find temp

• Heavy oxygen found in warmer temperatures of ice

• Increase of C02 leads to warmer temperature

• When oceans warm they cannot hold as much C02

• Humans interfering with natural fire can cause fire adapted species to face more competition and increase fire intensity

• Intermediate disturbance hypothesis- ecosystems experiencing intermediate disturbance will favor a higher species diversity than those with high or low disturbance levels

• Low disturbance favors best competitors, high disturbance favors generalists

Module 13

• microevolution- evolution at population level

• macroevolution- evolution that gives rise to new species

• cell recombination can help defend against invading organisms

• negative pesticide cycle can happen

• adaptation- trait that improves an individual’s fitness

• Evolution by random processes- genetics are altered overtime without a difference in fitness

• Mutation, gene flow (mixing populations), Genetic drift( Random mating, failed mating for certain genes) Bottleneck, Founder effect(founders of population are only genes present there)

• Allopatric speciation (geographic separation)

• Sympatric speciation (evolution of two species without geographic isolation)- often caused by polyploidy mutation (more chromosome sets)- means they cant breed with diploid relatives

• fitness is dependent on speed of adaptations

Module 14

• Ecological succession- predictable replacement of one species by another over time

• primary succession- first stage that occurs on bare rock, has pioneer species that survive with little or no soil

• secondary succession- occurs in disturbed areas that still have soil- rapid colonization via grass and wind-borne seeds

• climax community- succession final stage

• succession happens in aquatic places too- river and intertidal are fast while lake is slow, it becomes land

• Succession originally raises species richness, biomass, and productivity

• Keystone species- necessary but not abundant species

• Indicator species- species that shows a particular ecosystem characteristic- They have quick responses to changes

• Endemic species- species that only live in a very small area of the world

• Hotspots qualified if it has at least 1500 endemic plant species and if it has lost more than 70% of vegetation that contains the plant species

Unit 3- Populations

Module 15

• Population growth rate in a time period= # of offspring individual can produce minus deaths of the individual or its offspring

• Carry capacity- upper limit of individuals that are supported (K)

• r species experience rapid overshoot and dieback

• Survivorship curves- 1 (K spec. and whale) 2- (squirrel) 3-(r spec. sunflower)

Module 16

• Density dependent factor- factor that has different impacts based on pop. size. Density independent factors do not

• Population growth model- math equation that can find population at any time

• fecundity: ability to produce a ton of offspring

• exponential growth model- estimates future pop. size after a given time based on biotic potential and # of reproducing individuals in pop. this is ideal, not realistic

• EGM makes j shaped curve with time on x and pop. size on y

• exponential is density independent

• Logistic growth model shows populations limit by carrying capacity- first exponential then slows down- makes s curve

• LGM is for density dependent factors

• Gause showed density dependent factors

• Carrying capacity can be reduced by overuse- can also be caused by predators

Module 17

• Earth’s carrying capacity is unknown

• Major human increase with agricultural revolution 400 years ago

• Malthus- Population will exceed food supply

• Global Pop. Growth rate (CBR-CDR)/10 (CBR = # of births per 1000 individuals.

• Net migration rate (immigration-emigration)

• National pop. % growth rate= ((CBR+immigration)-(CDR+emigration))/10

• Infant mortality= # of deaths under 1 year of age for 1000 live births

• Child mortality= # of deaths under 5 years of age for 1000 live births

• Environmental justice- show of environmental hazards to disadvantaged people

• Different types of age structure diagrams- pyramid (developing) medium or top heavy- developed

• population momentum- continued population growth after birth control methods

• TFR- avg. # of children a women will bear in reproductive years

• Replacement level fertility- total fertility rate to keep current population size (2.3) High for developing countries, lower for developed

• Likely only 10 billion humans before pop. decline

Module 18

• Adequate nutrition leads to pop. growth in developing countries and pop. decline in developed countries

• High infant mortality leads to pop. decline

• 70/growth rate % = pop. doubling time

• 5 bil people expected to live in urban areas by 2030

• Demographic transition model- birth and death rate start high with pop. low, then death rate decreases first, followed by birthrate as pop. increases

• Theory of Demographic transition: as the transition from high to lower birth a death rates in a country or region occurs, that country moves from a pre-industrial to an industrialized economic system

• Stage 1= CBR=CDR due to poor living conditions

• Stage 2= slighty modern, CDR declines but CBR stays high

• Stage 3= CBR decreases and growth rates slow

• Stage 4= Pop. declines

• Developing countries growing faster than developd

• IPAT= impact= population x affluence x technology

Unit 4- Earth Systems and Resources

Module 19

• Lithosphere: Rigid outer layer composed of the crust and uppermost mantle, responsible for tectonic activity. Around 100 m/ 60km thick

• Asthenosphere: Semi-fluid layer beneath the lithosphere that allows for the movement of tectonic plates.

• Outer Core: Liquid layer composed primarily of iron and nickel, generating Earth's magnetic field through convection currents.

• Inner Core: Solid, dense center of the Earth, primarily made of iron, and extremely hot.

• Mantle: Solid Upper Mantle, Asthenosphere, and Magma

• Theory of Plate Tectonics: A scientific theory explaining the movement of the Earth's lithosphere, which is divided into tectonic plates that float on the semi-fluid asthenosphere beneath. Led by Alfred Wegener’s theory of Pangea

• Evidence of drifting continents: Fossils and Rock Formation

• Hot Spot: where molten material from mantle reaches lithosphere, volcanoes form when plates move over them: shows movement of plates through volcanic activity

• Richter Scale: Measures earthquake force, for each unit increase the force is multiplied by 10

• Continental Plates- less dense with iron so rises above oceanic plates

• Oceanic Plates- more silicon dioxide and more dense then Continental Plates

• Divergent Boundary: area below ocean where plates move away from each other and magma forms new crust (seafloor spreading)

• Convergent Boundary: area where one plate moves towards and collides with another

• Subduction: When an oceanic plate edge goes under a continental plate at a Convergent Boundary

• Island Arcs: island chain formed by volcanoes as a result of subduction

• Collision Zone: When two continental plates collide and the crust is pushed up to form mountains

• Transform Boundary: area where plates move sideways past each other, often causes faults (fractures in rocks caused by crust movement)

• Plate Speed- 1.4 inches/ 36 mm per year

• Human Impacts: earthquakes cause collapsed structures, contaminated water, and death

• Nuclear power plants shut down if ground movement exceeds their withstanding

• 85% of volcanoes occur on plate boundaries

• Ash damages airplane engines

Module 20

• Igneous rocks (Granite) formed by heat (magma)- Balsatic (dark) and Granatic (light). Dominant rock in continental plate crusts

• Sedimentary rocks (Limestone) formed by pressure (mud, sand, gravel being compressed). Hold fossil records

• Metamorphic rocks ( Marble) formed when any of the three rock types are subjected to high heat and pressure

• Rock cycle- cycle governing formation, alteration, and destruction of rock material from tectonics, weathering, and erosion

• Physical Weathering: mechanical breakdown of rocks and minerals (Freeze-thaw and roots)

• Chemical Weathering: breakdown of rocks and minerals through chemical reactions and/or dissolving of chemical elements from rocks (Lichens that produce acids, water that contains acid touches rocks)

• Acid Rain: Rain high in sulfuric an nitric acid

• Human impacts on chemical weathering: sulfur emitted from fossil fuel combustion causes acid rain

• Erosion: physical removal of rock fragments from landscape/ecosystem ( Wind/ice/water with gravity or organisms burrowing)

• Deforestation, Road building, overgrazing causes more erosion

• Soil forms from parent material, climate, topography, organisms, time

• Soil helps plant growth and water quality

• Young/Immature soil: less organic matter and nutrients due to it being mainly fragments of parent rock and less time for organic matter to accumulate

• Old soil: nutrient poor due to plant and water leaching

• Parent material: Rock material that underlies soil and provides inorganic components

• Climate: Temp, humidity, water. (no developed soil in freezing temps- Cold areas have undecomposed organic material)

• Topography: Slope and arrangement of landscape ( Soils subject to erosion less deep then those at bottom of slopes)

• Organisms: Plants remove nutrients, Animals mix soil, Soil organisms recycle organic matter

• Time: How long soils have been around

• Soil Horizons (O,A,E,B,C)

• O horizon: organic matter at the top- includes humus (fully decomposed organic matter)

• A horizon: top layer of soil with mixed organic and mineral material (Top Soil)

• E horizon: leaching zone, found underneath O or A horizon

• B horizon: subsoil, little organic material

• C horizon: underneath b, least weathered, basically parent material

• Soil is eroded by wind and water, furthered by logging and poor agriculture

• Clay (small, 0 slope) Silt (medium, positive slope) Sand (large, negative slope)

• Porosity: size of space between particles

• Permeability: ability of water to move through soil

• Clay used for containing contaminants

• CEC (Cation exchange capacity) ability of a soil to absorb and release cations (positively charged mineral ions)- based on amount and types of clay present

• Tradeoff with CEC and permeability

• Base saturation= proportions of soil bases (promote growth) and acids (detrimental to nutrition) as a percentage

• High CEC and base saturation= high productivity

• Bacteria, fungi, and protozoans make up 80 to 90 % of soil organisms- mostly detrivores

Module 21

• Watershed- area of land that drains into a particular body of water

• Watersheds characterized by area, length, slope, soils, vegetation

• Mississippi river drains from 1/3 of US

• Length of watershed measured from beginning to outlet

• Slope (more slope = more speed and sediment in water)

• Soil Type ( Sand = less water flow, Clay+ Silt= more water and sediments- can prevent photosynthesis)

• Vegetation: More plants= less erosion through roots

• Human impacts on watersheds: Dams, mineral mining, impermeable surfaces

• Hubbard Brook Watersheds- underlain by bedrock- without trees there is more nitrate that overfertilizes the water

• Chesapeake Bay Watershed- 41 mil acres of land- too many nutrients are causing excessive plant growth and too many sediments kill off seagrass, removing habitats for crabs

Module 22

• Insolation: Incoming solar radiation- main source of energy on earth

• At high latitudes it is colder because, the sunlight loses more energy than at the equator because it is passing through more atmosphere, the solar energy is split over a larger surface area, and snow reflects more sunlight

• Albedo: percentage of incoming sunlight that is reflected. Average Earth= 30%. snow = high, asphalt = low

• Earths axis of rotation is tilted at 23.5 degrees - 4 big days - March and September Equinox ( Sun is directly overhead equator) June and December Solstice ( Northern hemisphere is maximally tilted toward/away from the sun)

• Atmosphere extends to 10,000 km above earth, its composition is : 78% Nitrogen, 21% Oxygen, 1% other (greenhouse gases)

• Atmosphere layers:

• Troposphere: closest to surface, extending to 16km, most dense, low temp, global warming expands it

• Stratosphere: Ozone layer, absorbs suns ultraviolet rays, around 0 temp, 16-50 km above surface

• Mesosphere: 50-85 km above surface, low temp, where meteors burn up,

• Thermosphere: 85-600 km above surface, blocks X ray radiation, causes northern lights via charged gas molecules, reaches 2000 degrees Celsius

• Exosphere: outermost layer, 600-10,000 km, where satellites orbit, 0-1,700 degrees Celsius.

• Air circulates in atmosphere due to changing density, water vapor capacity, adiabatic heating/cooling, and latent heat release

• Warm air= low density= rises

• Cold air = high density= falls

• Saturation point: maximum amount of water vapor in the air at a given temp

• Warm air has higher capacity for water vapor

• Adiabatic cooling: As air rises, pressure on it decreases, causing it to expand, which lowers it’s temperature

• Adiabatic heating: As air sinks, pressure increases, causing a reduction in volume, heating it up

• Latent heat release: When water vapor condenses into liquid, energy is released as heat- Meaning that when water vapor condenses in the atmosphere, air will heat up and rise

• Atmospheric convection currents: Global patterns of air movement that are initiated by the unequal heating of earth

• Atmospheric currents: Humid air warms and rises, Adiabatic cooling makes air reach saturation point, Condensation causes clouds and rain, Latent heat release causes air to rise higher, Adiabatic cooling chills air at the top of cycle, Chill air sinks, adiabatic heating warms it as it sinks, it picks up moisture on surface, and the cycle repeats

• These currents show up in Hadley Cells ( current that cycles between the equator and 30 degrees north and south, rising at the equator and falling at 30 degrees north and south)

• The Hadley Cell causes desert as hot, dry air falls and goes towards the equator

• Space where Hadley Cells converge: ITCZ or intertropical convergence zone- dense clouds and thunderstorms, occurs where there is the most sunlight, moves north and south over a year from 23.5 S to N

• Polar Cells: Convection current that rises at 60 degrees N and S and sinks at the poles at 90 degrees N and S

• Ferrell Cells: convection current lying between 30 degrees N and S and 60 degrees N and S. Caused by warm air from Hadley cells moving towards the poles and cold air from the poles moving towards the equator

• Currents are responsible for biome location

• Coriolis effect- deflection of an objects path due to rotation ( Throwing a ball towards equator moves west and towards the poles moves east) ( Ball moves faster at equator)

• Earths equator moves faster than the poles 1670 km vs 291 km/hr

• Hadley causes Northeast and Southeast Trade winds (name is based on origin)

• Ferrell causes Westerlies

Module 23

• Ocean currents are driven by temperature, gravity, prevailing winds, the Coriolis effect, Salinity, continent location

• Due to warm water expanding, the tropical water surface is about 3 inches/ 8 cm higher than mid-latitude waters

• Gyres: Ocean Currents that rotate clockwise in the northern hemisphere and counterclockwise in southern hemisphere

• Surface currents separating causes upwelling, which increases water nutrients producers that feed fish fish

• Thermohaline circulation- oceanic circulation pattern that drives surface and deep water mixing

• TC is driven by surface waters with lots of salt, when it evaporates and freezes in the northern Atlantic then it becomes cold salty water that sinks, travels along the ocean floor, and eventually rises and circles back to the northern Atlantic

• Global warming could disrupt Thermohaline circulation by melting the glaciers and making the north Atlantic less salty- therefore less likely to sink. This would make west Europe cold as it would lose its transportation of warm water

• Rain shadows- humid winds blowing inland meet a mountain range and undergo latent heating and adiabatic heating that results in warm dry air on the other side of the mountains

• El Nino causes bad crop production, La Nina reverses it

Unit 5- Land and Water Use

Module 24.

• Tragedy of the Commons- The tendency of a shared resource to become depleted if it is not regulated in some way- this can happen if the carrying capacity is exceeded and no regulations are made

• TotC- no winners- MUST include degradation- shown in global fisheries and with logging

• Negative externality (The cost/benefit of a good or service that is not accounted for in purchase price or any other way) causes TotC

• How to prevent TotC- Fees/Punishments for overuse- More private land- Government or self regulation

• 209,000 protected areas in world (3.2 bil. ha or 7.9 bill a)

• 42% of US land is publicly held

• US federal agencies- Forest Service (USFS) Bureau of Land Management (BLM), Fish and Wildlife Service (FWS), and National Park Service (NPS)

• if something benefits humans than it is an economic benefit

• Alpo Leopold- Land Management guy

• Rangeland- grasslands used for grazing cattle- most common use of land in USA

• Clear Cutting- harvesting method that removes all or almost all trees in the area- coupled with replanting

• CC benefits- easiest, most economical, ideal for fast growing trees,

• CC costs- high wind and water erosion, low biodiversity, more CO2, more runoff (harming fish populations), less soil organic matter

• CC in heavily forested areas can result in increased habitat diversity

• Selective Cutting- removes certain trees, ideal for shade tolerant species,

• SC costs- Still has habitat fragmentation, harder and more expensive than CC

• Economically Sustainable Foresting- logging technique often without fossil fuels but costly and less yield

• 30% of commercial timber is produced in USA and Canada

• Tree plantation- group of fast growing trees for logging

• 1969 National Environmental policy act requires environmental assessment of all projects with federal money.

Module 25

• 2nd Agricultural revolution-- 1600’s-1930’s- mechanization of farming (agribusiness) instead of subsistence farming

• Green revolution- 1940’s use of fertilization, irrigation, improved crop varieties

• 1920- 32 mil ppl (32%) lived on farms in usa, now only 2.6 mil ppl- 1.3%

• Norman Borlaug- won Noble Peace prize for contribution to world food supply

• Economy of scale- costs of production fall as output rises

• Organic Fertilizer- made from organic matter of plants and animals, lower concentrations but CEC for soil

• Synthetic fertilizer- commercial produced fertilizer- highly concentrated and reliant on fossil fuel energy, risk of runoff that causes algae and oxygen depletion, quicker

• Irrigation turns non-growable land into farmland- can cause waterlogging where roots cant reach oxygen and salinization that traps salt on soil surface through evaporaton

• 454 mil kg (1 bil lbs) of pesticides applied in USA each year

• Monocropping- main agricultural practice in US where single species is planted

• MoC benefits- Improved productivity and easier

• MoC costs- erosion of topsoil, increased vunerablity to pests

• GMO benefits- Increased crop yield and profits- less expensive food, less pesticides

• GMO costs- less biodiversity, possible allergic reactions

• EU barely allows GMOs, US does

• Energy subsidy- fossil fuel and human energy input per calorie of food produced- most for fishing and feedlot beef- least for hunting and gathering

Module 26.

• Plowing- (digging deep into soil and turning it (usually 6-8 inches deep)) breaks up soil structure, done right before planting seeds

• Tilling (preparation of soil but not to the degree of plowing) buries weeds and done right after growing season.

• They both increase CEC and base saturation and loosen soil so roots can enter

• They can cause erosion and CO2 emissions and soil compaction (makes soil less porous).

• Slash and burn farming/shifting agriculture- land is cleared and farmed until all nutrients are gone. It is overused and causes soil compaction, CO2 emission, and erosion.

• ***Nitrogen, Phosphorous and Potassium are the most used fertilizer nutrients. Usually 5 percent nitrogen, 3 percent phosphorous, and 4 percent Nitrogen

• Nutrients are usually produced from crushed rock that uses extreme amounts of fossil fuels\

Module 27

• 70% of freshwater consumption in USA is for irrigation

• unconfined aquifers- porous rock covered by soil that water can flow in and out of

• confined aquifer- covered by impermeable rock or clay that stops water flow

• Water Table- Uppermost area at which groundwater fully saturates rock or soil

• Groundwater recharge- process in which precipitation percolates in groundwater

• Water from aquifers naturally percolates up in the form of a spring

• Artesian well- well in confined aquifer

• Confined aquifer use is safer but unsustainable

• Water footprint (daily per capita use of fresh water) for metric ton of grain is more than 1 mil liters of water

• producing beef in USA takes 11x more water than wheat

• Furrow irrigation (67% of water available), Flood irrrigation (70-80% of water available), Spray Irrigation (75-90%), Drip irrigation (over 95%)

• Largest aquifer in USA is Ogallala aquifer in great plains

• When aquifer removal exceeds it’s renewal, then water table drops, there are less springs, and a cone of depression can be caused that takes water away from shallower wells

• Water withdrawals peaked in 1980

• Non persistent pesticides are not always better for environment as they require more application

• Pesticides can kill other things, hurt farm workers, and pollute groundwater

• IPM- use of crop rotation, intercropping, use of pest resistant crops, use of pest predators, and less pesticides

• Pesticide treadmill is common positive feedback system

• No till agriculture relies on herbicides, because no weeds are killed with tilling

Module 28

• Concentrated animal feeding operations (CAFOs)- large structure for maximum occupancy of animals and maximum yield meat or dairy yield.

• CAFOs are small, efficient, and produce greater yield

• CAFOs use a lot a freshwater, nutrients and growth hormones

• Overapplied manure has caused pollution along 56,000 km over rivers in 22 states

• Manure lagoon- large man made pond lined with rubber to handle manure without groundwater leaking. If leaking takes place or there is overflow than disease outbreaks will occur

• anaerobic decomposition in the lagoons causes the release of CO2 and methane

• 13% of grain grown in world is used to feed livestock

• Diet for a small planet- book by frances lappe that encourages eating lower on food chain for less environmental impact

• Free grazing is more ethically acceptable and has less antibiotics and contamination, but costs more and uses more land, same as nomadic grazing

• overgrazing or over logging can lead to desertification

• Eating less meat would result in less Greenhouse gases from CAFOs

• Fish production provides over 3 billion people with 20% of their animal protien.

• ToC with fisheries due to the fact that countries don’t own migrating fish

• Fishery collapse- decline of a fish population by 90% or more- hurts biodiversity and income of fishermen

• 5 major methods of fishing- Purse seine nets, Bottom trawl, Midwater trawl, Gill nets, Longlines

• Nets can hurt ocean bottom habitats and have bycatch that hurts sharks and turtles

• Northwestern Atlantic fisheries had to be closed due to depleted stocks of fish

• Sustainable fisheries act of 1996- switched goal of sustainable fishery from economic to environmental

• Selling fishing quotas with data of total allowable catch can help with overfishing

• People can follow seafood watch apps that tell you sustainability of fish

Module 29

• Crustal abundance- average concentration of an element in earths crust

• Ore-a concentrated accumulations of. minerals from which economically valuable materials can be extracted.

• Metal- element that can conduct electric and heat energy

• Elements in earths crust with amount Odd (Oxygen) Sticks (Silicon) Attach (Aluminum) Inside (Iron) Massive (Magnesium) Camps (Calcium)

• Ores are formed by magma meeting water or deposition of igneous rock, they can be in veins or disseminated deposits (larger)

• Lower the concentration and accessibility, more environmental impact

• Recycling increases material reserves, and results in less mining with with lesser impacts

• A resource is economically recoverable if it can be profitably mined

• Surface mining: dust and particulate movement, water contamination and habitat destruction

• Strip( removal of overlying vegetation and soil and rock, very susceptible to erosion, used when ore is close to surface)

• Open Pit (Large hole, used when resource is close to ground but extends far)

• Mountaintop removal (When tops of mountains are blown off, lots of mine tailings)

• Placer (Looking in rivers)

• Mine Tailings (unwanted waste material left after mining)

• subsurface mining: when the ore is over 100m deep then it is drilled down- produces fossil fuels and acid mine drainage and human danger, also may produce methane

Module 30

• Urban area- place with more than 1000 people per square mile

• Urban populations represent 55% of the human population

• Urban living is increasing, and 17 of the 20 largest areas are in developing countries

• Urban areas have smaller impacts per person, but still negatively affect the carbon cycle

• Rapid urbanization in developing countries leads to poverty

• Suburbs surround metropolitan centers while exurbs do not

• in the USA 2/3 people live in suburban or exurban areas- which have 2x environmental impact of urban area people

• Urban overuse of aquifers result in saltwater intrusion, where a cone of a depression is created and seawater partially fills it

• less infiltration means more runoff

• Urban sprawl- urbanized areas that spread into rural areas- caused by more highways, better house prices, government policies, and urban blight (lack of support and deterioration of urban communities)

• Cycle for urban blight- Increased gas revenues to more highways to more suburbs to more more traffic to longer commutes to more gas back to more gas money

• Smart growth uses sense of place and walkable neighborhoods along with natural beauty

• Urban runoff pollutes rivers- solutions are rooftop gardens, electric buses (less pollutants), tall buildings, more trees and parks, and permeable pavement

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Module 31

• Ecological footprint is a measure of the area of how much land and water is used to supply the goods and services that individual populations use- developed by professor reese

• EF calculated by land for food we eat, water and energy we use, clothing we wear, and structures we occupy

• developing countries usually have smaller footprints

• Fair Earthshare is 1.6 ha per person

• Carbon footprint- direct and indirect- measures carbon released as CO2 and equivilent amount in other greenhouse gases

• embodied energy- energy used to manufacture a product

• Passenger cars make up 58% of US transportation CF

• China emits most CO2

Module 32

• MSY- largest quantity of a renewable resource that can be harvested indefinitely- harvesting at this rate keeps population of resource at ½ of carrying capacity

• Sustainability q’s: how is resource importance determined?

• MSY problems: very hard to calculate, takes years to know if its actually sustainable,

• Environmental indicators- Biodiversity, Food production (grain), Avg. global surface temp and atmospheric concentrations of CO2( currently 415 parts per million), Human population, resource depletion,

• Outlooks: Biodiversity: extinctions will continue, Food Pro: Unclear, Temp: likely increase, Human Pop. :leveling off, Resource dep. :unknown

Module 33

• Crop rotation: moving crops around each year

• Intercropping: close spacing of different crops growing at the same time

• Biocontrol: using natural predators

• IPM does sometimes use pesticides

• IPM causes less pesticide use and increased yield, but does cost money to train and extra time

• Agroforestry: intercropping trees and vegetables for windbreaks

• Strip cropping- planting crops with different spacing and root characteristics for less erosion

• contour plowing- plowing with topographic lines of land- may use cover crops (crops planted to prevent soil erosion)

• Terracing- turning sloping land into steps to prevent erosion

• People want more perennial plants

• perennial plants- live for many years and do not need to be replanted (asparagus)

• no till causes more herbicide use but less soil erosion

• Green manure- plant material grown in a field with the intent of plowing it

• As crops are removed, they lose base cations like calcium and magnesium and become acidic- this is fixed with limestone

• Organic agriculture: uses ecological principals, works with natural systems, maintains soil, keeps organic matter and nutrients, avoids synthetic fertilizers and pesticides, and reduces adverse affects of agriculture

• OFPA establishes standards for production of organic food

• Organic farming is small, more costly, and less time efficient, also may use propane or tractors and might not be sustainable

Module 34

• Aquaculture is increasing in popularity, it uses four systems

• Open pen (salmon)

• submerged net (seabass)

• pond farm (catfish)

• aboveground tanks (many)

• Aquaculture is efficient, saves wild fish from fishing

• Aquaculture can cause wastewater escape and escaped fish breeding with wild

• Sustainable forestry involves regrowth of natural forests, worker training, less fossil fuels and biodiversity goals.

• Forests certification organizations for sustainability have had scandals with overpricing

• Reusing wood is important

• Natural predators and prescribed burns sustain forests and prevent major fires

• Large fires caused nutrient rich habitat in Yellowstone

Unit 6- Energy Resources and Consumption

Module 35

• In anaerobic conditions where decomposers can’t break up all of the dead biomass, it is buried and creates fossil fuels (whose combustion releases carbon)

• Joule (J)= 1 W-s (watt-second)

• Gigajoule- 1 billion (1×10⁹) joules

• exajoule- 1 billion (1×10⁹) gigajoules

• Quad(US government’s way to report energy)-1 quadrillion Btu (British Thermal Units)

• 1 calorie=4.184 J- used for energy expenditure and transfer in ecosystems

• 1 Calorie= 1000 calories or 4,184 J- used for human food consumption

• 1 Btu- 1,055 J- used for energy transfer in air conditioners or home water heaters

• 1 Kilowatt-hour- 3,600,000 J or 3.6 Megajoules-for electrical appliances energy use

• Fossil Fuels- large amount of energy in small volume and mass

• China and US use the most EJ’s annually

• In 2020, each person used roughly 77 GJ that year

• developed countries use more than 40% of worlds energy each year

• Commercial energy sources- bought and sold, Subsistence energy sources- gathered

• US energy sources- Oil, natural gas, coal

• Urban Areas use less coal

• Energy use follows trends geographically and seasonally

• Energy Intensity- energy use per unit of GDP

• Fossil fuel supplies are very uncertain

• Energy Intensity has decreased in USA past 50 years (more efficient use per dollar)

• Crude Oil migrates to the highest point in a formation of porous rock and accumulates there

• Hubbert Curve- Represents oil use and projects when world oil production will reach a maximum and when world oil will be depleted.

• Hubbert curve uses both upper and lower estimates of reserves

• Peak oil- point at which oil extraction and use would increase until roughly half the oil supply had been used up

• We may have already reached peak oil

• We are running out of conventional oil and gas supplies in next 50 years

• Energy efficiency- ratio of amount of energy expended in the form wanted vs the total amount of energy in the system

• Energy conservation and efficiency are most cheap and environmentally sound action for maximizing resources

• Energy to Mass ratio + energy creation rate makes gas and diesel ideal for vehicles

• Second law of thermodynamics- when energy is transformed, its ability to do work diminishes- 2/3 of energy spent on coal burning electricity generation plant ends up as waste heat

• Energy return on investment (EROEI)= Energy obtained from fuel/Energy invested to obtain fuel- larger # = more efficient

• Nonrenewable resources- Natural Gas, Oil, Coal, Nuclear

• Potentially renewable- wood, biofuel

• Nondepletable- Wind, Solar, Hydroelectric, Geothermal

Module 36

• Sun is ultimate source of fossil fuel energy and most renewable energy

• Biofuel- liquid fuel like ethanol or biodiesel created from processed or refined biomass

• Biomass- wood, charcoal, manure, solid waste, biofuels, etc.- accounts for 40% of renewable and 5% of total energy consumed worldwide- releases lots of carbon in burning

• Modern Carbon- carbon in biomass that was recently in the atmosphere (captured through photosynthesis)

• Fossil Carbon- Old carbon contained in fossil fuels

• In theory, Burning of biomass(modern carbon) does not increase atmospheric C02 concentrations. Ex: If plants grow back where biomass was just harvested, then the plants will take up equal or more CO2 then was released in the burning of biomass

• Carbon neutral- does not change atmospheric CO2 concentrations

• Biomass may or may not be carbon neutral

• Each fuel has optimal applications

• Wood- renewable if regrowth rate = harvest rate. makes charcoal that has 2x energy content of wood per unit mass

• Coal- remains from plants preserved 280-360 million years ago, most prominent under wetlands and river deltas

• Coal process-

• starts with Peat (partly decomposed organic material under soil),

• then after compression it becomes Lignite (brown coal- soft sedimentary rock with occasional traces of plant structure, contains 60 to 70% carbon after millions of years),

• then after further compression over hundreds of millions of years, it becomes bituminous coal (black or dark brown coal with 80% carbon and bitumen/asphalt, hard but can be hand broken)

• After further burial and years of tectonic activity and heat, it becomes Anthracite coal/hard coal (coal with over 90% carbon, highest energy quantity per coal volume, fewest impurities, made after 280-360 million years)

• Natural gas is “clean” because its combustion produced smaller amounts of particulates, sulfur dioxide and carbon dioxide then oil or coal

• Natural gas makeup: 80-95% Methane CH4 and 5-20% ethane, propane, butane

• Main Natural gas uses- electricity and industrial processes, sometimes transportation or fertilizer

• It is used less for vehicles because it requires transport by pipeline

• Liquified Petroleum gas- liquid form of natural gas that is used for heat

• Natural Gas and LPG supply 34% of US energy, 24% of global

• Crude Oil- mix of hydrocarbons (oil, gasoline, kerosene) and water and sulfur that is liquid both underground and at the surface

• Crude oil- used for transportation, can be refined into tar, asphalt, gasoline, diesel, and kerosene

• Crude oil distillation- happens in oil refinery where heat causes boiling and separating of crude oil, very costly and dangerous

• Boiling points: Butane and lighter products- under 85 F, Gasoline blending components- 85-185 F, Naphtha- 185-350 F, Kerosene, jet fuel- 350-450 F, Distillate (diesel, heating oil)- 450-650 F, Heavy Gas Oil- 650-1050 F, Residual fuel oil- 1050 F

• Heavier= higher boiling point, lower= lower boiling point

• Tar sands/oil sands- slow flowing, thick deposits of bitumen (degraded crude oil that forms in certain oil deposits) or asphalts- does not flow at room temp.

• Tar sand extraction leads to more crude oil, but mining takes lots of energy, contaminates lots of water in dry areas, and requires open pit mining

• One barrel of oil= 160L or 42 gallons

• Electric hot water heaters have 99% direct efficiency because any lost heat energy to the surrounding areas is captured by the water that surrounds it.

• Gas water heater only has 60% direct efficiency

• Gas water heaters can have better overall efficiency because the electricity can come from inefficient sources such as a coal-fired powerplant

• Look at both fuel appropriateness for task and overall efficiency

• Other factors in choosing vehicles- convenience, comfort, style

• Smaller cars have less air pollution and better MPG

• Self driving car technology may decrease fuel efficiency by 5 to 10%, but it could be made up for by driving with optimal fuel efficiency

• Electricity is secondary source of energy- obtained from conversion of primary source- meaning it is an energy carrier (moves and delivers energy in convenient, usable form to end users)

• 40% of US energy generates electricity, but only 13% of that 40% is available energy for end uses

• Electricity is clean at point of use, but not location of production

• Energy source that requires fewest conversions to reach end product is likely most efficient

• Improvement in gas combustion technology- led to combined cycle natural gas-fired power plant (uses both steam turbine to generate electricity and turbine powered by exhaust gases from combustion to generate electricity)- with 60% efficiency

• Power plant capacity- max electrical output

• Most power plants don’t operate every day- to calculate plant’s output use capacity factor (fraction of time a power plant operates in a year)

• Most power plants have capacity factor over .9

• It takes time for nuclear and coal fired plants to reach full capacity, so they are often running at all times, hydro plants are easier to power up so they are not

• Cogeneration/combined heat and power- use of fuel to generate electricity and deliver heat to building- leads to greater efficiency as waste heat is used. Can be as efficient as 90% compared to 75% for steam heating and 35% for electricity generation

• Natural gas power plants make 40% of all electricity

Module 37

• Fossil fuel distribution depends on a region’s geology

• Crude oil made from remains of phytoplankton, this and coal material do not decompose like most parts of carbon cycle

• Large flame in oil wells- gas flare caused by purposeful burning of excess natural gas to reduce it and avoid explosion

• Worldwide petroleum consumption- 4 billion gallons per day, US is 21% of this

• Coal Advantages: energy dense, plentiful, low cost of mining, transportation, and refining

• Coal disadvantages: lots of mine tailings, as surface coal decreases subsurface mining is needed, combustion results in sulfur and other bad element releases, lots of ash, leakage can be deadly, lots of C02

• Oil ad.: convenient use and transportation, cleaner than coal, often used for transportation

• Oil dis.: lots of sulfur and trace metals, sulfur removal is costly, need for extraction leaves high risk for leakage or spill, lots of spill in everyday use, oil flaring

• Natural Gas ad.: 50% of US homes use natural gas for heating, less impurities, less CO2, lots of natural gas pipelines make it convenient

• Despite less CO2, there is more methane

• Fracking: uses high pressure fluids to split rocks rocks underground and unearth less accessible natural gas

• Good: Fracking causes less cost of natural gas via a surplus, is a domestic energy source and keeps US jobs, and is cleaner than coal or oil

• Bad: Fracking takes up lots of water, only a portion of which is removed and then must be treated before it goes back to local water bodies. Chemicals are added to fracking fluid that can contaminate aquifers, natural gas can also contaminate wells and make water flammable- but this may be unconnected to fracking

• Fracking releases volatile organic compounds (category of organic compound air pollutants that evaporate at typical atmospheric temps. from both fracking fluid and technology used in fracking) they are a precursor to other types of air pollution

• A large amount of escaped natural gas (fugitive gas), may be leaking from fracking and gas extraction and releasing methane that traps heat

• Fuel is converted to electricity and releases CO2 and heat energy

• In a power plant: Fuel is burned, energy goes to water which becomes steam and rotates a turbine that turns the generator which makes electricity that is transported on the electrical grid. After steam goes through the turbine, it becomes water, which is sometimes cooled or released into nearby water bodies.

• Water use in thermal energy generation is a substantial amount of water consumption in US

• total efficiency= all efficiencies multiplied- rest of energy is lost as waste heat

• Energy quality- ease at which an energy source can be used to do work. High quality has a convenient, concentrated form that does not require much energy for transportation

• Gas energy concentration= 44MJ/kg. Wood energy concentration= 20MJ/kg

Module 38

• Radioactivity- emission of ionizing radiation or particles caused by spontaneous disintegration of atomic nuclei

• Nuclear Reactors use same turbine-style way to generate electricity as fossil fuels, they just use uranium-235 as fuel

• Unstable isotopes are radioactive, Radiation contains energy that is heats the surrounding environment

• Fission- nuclear reaction where a neutron strikes a relatively large atomic nucleus, which then splits into two or more parts, releasing additional neutrons and energy in the form of heat

• Additional neutrons from fission can make more fission, leading to a chain that gives off lots of heat energy

• Nuclear reactors harness this kinetic energy to make a self-sustaining chain of fission as fuel

• Byproduct of Nuclear: radioactive waste that remains hazardous for many half-lives

• 1g of 235 U has 2-3 million times the energy of 1g coal

• containment structure contains nuclear fuel, which is contained in fuel rods inside of it- there can be hundreds of them

• Uranium fuel is processed into pellets that go into fuel rods

• heat from fission is transferred to water that loops around and transfers it to other water, creating steam that turns the turbine and powers a generator

• control rods- rods in between fuel rods that absorb excess neutrons and can slow or stop fission

• Collusions must happen at a controlled speed- water and control rods are used for this to prevent meltdowns and fires

• Up to 900kg of uranium ore to produce 3kg of nuclear fuel- uranium is extracted and concentrated- rest is left as mine tailings

• suitable nuclear fuel has over 3% uranium 235 (rest is Uranium 238 that doesn’t fission as easily)

• Nuclear power A’s: less air pollution (10% of equivalent fuel energy), allows fuel independence in countries without fossil fuels. makes up 70% of energy in France

• Nuclear power disad.: public concern, expensive factories, takes 704 million years for U235 radiation to half (half life of 704 mil. years), thermal pollution

• Radioactive decay- when parent radioactive isotope emits alpha/beta particles or gamma rays- measured by average rate of decay of radioactive element (usually stated in half life)

• Half life allows knowledge of potential danger of elements

• radioactive waste- nuclear fuel that is no longer useful in a power plant but still gives off radioactivity

• Nuclear fuel waste: high level (used fuel rods), low level (contaminated items like clothing), and uranium mine tailings (residue after uranium ore is mined and enriched)

• fetuses and young people are most vulnerable to radiation

• Becquerel/bq= measurement of radioactive decay, 1Bq= decay of 1 atom per second

• Curie= unit of measure for radiation- 37 billion decays per second

• Fuel rods are threat to humans for 10 or more half lives- they are stored at power plant in pool storage or lead-lined dry containers

• Nuclear waste must be stored indefinity, away from humans,

• US Government wanted to store waste in Yucca Mountain Nevada, they never did

• Three Mile Island accident- (1979 PA, caused by lack of cooling water around reactor)

• Chernobyl- (1986 Ukraine, caused by test removal of control rods, 31 deaths and radiation spread, contaminating cows, humans, and causing thyroid cancer)

• Fukushima- (2011 Japan, caused by earthquake, no deaths by radiation)

• Nonrenewable EROIN from most to least: Coal, Natural Gas and Nuclear Energy, Diesel, Gasoline

Module 39

• Charcoal has 2x energy per unit of rate then wood

• Air pollutants with Wood/Charcoal Burning:

• Particulates/Soot: Solid or liquid particles suspended in the air

• Carbon Monoxide: Colorless, odorless gas formed during incomplete combustion of most materials

• Nitrogen oxides: by-product of combustion of any fuel in the atmosphere

• Volatile Organic Compounds (VOCs): Organic Compounds that evaporate easily

• CO2: by-product of all combustion-is modern carbon in biomass combustion

• Manure fuel risks indoor air pollution

• Biofuels- Ethanol (alcohol made by converting starches and sugars from plant material into alcohol and CO2, usually corn) and Biodiesel (diesel substitute made by extracting and chemically altering plant oil, usually soybeans or algae)

• US is world leader in Ethanol production

• Brazil uses biofuels from sugarcane as sustainable fuel

• Ethanol is mixed with gas, Gasohol has high O2 content and less air pollutants

• Ethanol doesn’t introduce fossil carbon, but it does cause lower fuel energy content in gasoline, it also causes inefficient use of corn

• Biodiesel- more expensive than petroleum diesel, typically B20 (80% petroleum diesel, 20% biodiesel)

• Algae produces lots of fuel for biodiesel

• Any diesel vehicle can run on straight vegetable oil (SVO), that is obtained as waste from restaurants and filtered to become fuel

• Passive Solar- use of sun energy without technology- seen in south facing windows to admit solar radiation in the winter and solar ovens (box cooker)

• Solar ovens remove wood as a fuel source, stopping deforestation and extreme travel

• Active Solar- use of sun energy captured by technology (solar water heating, photovoltaic solar cells, solar thermal systems for electricity)

• Solar water heating systems: Heat energy from the sun heats circulating liquid driven by a pump (active) or natural convection (passive), hot water than goes to hot water tank for use- usually have a backup energy source

• Photovoltaic solar cells: systems that capture energy from the sun as light and convert it into electricity. They use semiconductors that generate electric current when exposed to sunlight and convert that current into a higher-voltage alternating current for use.

• PSCs: use solar panels and are either tied to electrical grid where extra energy goes, or to batteries to store extra electricity. Effectiveness limited by the sun being visible and less efficient at higher temps when air contains more moisture

• Concentrating Solar Thermal Electricity Generation: large scale applications of solar energy to electricity generation. They use mirrors and lenses to concentrate sunlight into a small beam. Best in desert areas, but large amounts can reduce NPP and impact habitats

• CST requires lots of land and are ineffective at night

• Active Solar A’s: No CO2 or water pollution, most energy produced when demand is highest on hot days, economically feasible to install and makes homeowners money

• Active Solar DA’s: expensive to make, can take a long time to get return on investment, manufacturing requires energy, water, toxic metals. Improper recycling is dangerous

• Hydroelectricity: energy made by kinetic energy of moving water

• China makes most hydroelectricity

• Hydroelectricity amount depends on flow rate of water and the distance water falls

• Water Impoundment systems: storage of water in a reservoir behind a dam, dam operators control opening and closing of gates to control flow rate of water (how much electricity is produced). Uses turbine to power generator. Three Gorges Dam (China) is the largest

• Run of the River systems: Hydroelectricity generation where water is retained by small dam or no dam, energy generated when water passes through channel with submerged turbine. It has less environmental impact but is small and can be unreliable

• Tidal Systems: use of tidal energy (energy from the movement of water driven by gravitational pull of the moon), they use gates and turbines to convert energy to electricity

• Hydroelectricity A’s: No pollution, cheaper electricity, minimal amount of fuel for use, recreational appeal and economical gains from reservoir

• Hydroelectricity DA’s: Flooding that causes anerobic decomposition of covered plants (releasing methane), relocation, high heat and low oxygen environment in reservoirs that can kill fish and hold parasites. Downstream removal of sandbars and removal of seasonal water movement that disrupts fish lifecycles. Greenhouse gas release in building and filling reservoir, siltation (accumulation of sediments on reservoir bottom) also happens and can reduce capacity and lifespan of dam)

Module 40

• Geothermal energy- heat energy from radioactive decay of elements deep in earth. Convection currents move magma (from radioactive decay) to surface of earth, heating groundwater that either reaches the surface in geysers or can be removed by drilling

• Iceland heats 90% of homes with geothermal energy

• Heat released by radioactive decay is nondepletable, but the groundwater that it heats can be depleted

• Geothermal energy has little growth potential because it is not easily accessible everywhere and can be costly to reach, geothermal plants can also release hydrogen sulfide and methane

• Heat exchangers: collect heat by circulating cool liquid underground, where heat from the ground flows to the cool circulating liquid, and then returns to the surface

• Direct heat- hot groundwater is pumped directly into a radiator

• Ground Source heat pumps- solar energy from heat that is trapped underground- works by fluid being pumped through pipes underground, gives heat in the winter and cool in the summer- uses 30-70% less energy to heat/cool a building than a standard furnace

• Hot water heat pump- extracts heat from air in garage or basement and transfers it to water in a domestic hot water tank- similar to heat removers in refrigerators

• 200-250% of the amount of energy in the electricity used to run the HWHP is transferred to water in the tank because the heat pump takes heat energy from surrounding air

• Fuel Cell- an electrical-chemical device that converts fuel, such as hydrogen, into an electrical current, cell never dies as long as it receives fuel

• How a fuel cell works- H₂ is split into electrons and protons in upper reaction layer. Protons move across membrane while electrons go around (electrical current). O₂ molecules are split and combine with protons and electrons to form water in lower reaction layer- only waste products are energy and water (2H₂+O₂=energy + H₂O)

• Getting hydrogen is hard because it is rare, explosive, and bonds with other molecules so it requires separation

• separation of hydrogen molecules- either use of natural gas hydrogen or electrolysis (electric current applied to water to split hydrogen and oxygen), can be renewable if electricity used is from a renewable source

• hydrogen is an energy carrier

• Hydrogen is not used on a large scale, but the fuel cells are 80% efficient in conversion and it has only water as a waste product (compared to fossil fuel 35-50% efficient with pollutant production)

• Hydrogen DA’s: must find a way to get hydrogen without using more fossil fuels than it’s energy would save, transportation would need larger fuel tanks for hydrogen use than gas, there could be a tank rupture that could cause fire or explosion

Module 41

• Wind energy: energy from the kinetic energy of moving air

• Wind ultimate source of energy is the sun that drives heating for air circulation

• China has largest wind energy capacity in the world

• Texas makes 40% of wind energy in US

• How a wind turbine works: wind turns blades, which transfers energy to gearbox, which turns the mechanical energy into electricity. Motorized drives turn the turbines to face the wind for maximum efficiency

• Larger blades and taller towers increase turbine capacity

• Land turbines have capacity factors of 25-40%, Offshore has factors of 40-50%

• Turbines are usually in wind farms so there can be less electrical transmission lines

• Cape Wind failed due to scenic and regulation issues

• Block Island wind farm- first offshore in US, capacity of 30 MW

• Wind energy A’s: clean, renewable, only fossil fuel use is in manufacturing and worker transport, can share land with other areas

• Wind energy DA’s: rely on batteries that are hard to produce and recycle, bird and bat deaths (turbines are turned off during migration time and painted to reduce this), noise, habitat fragmentation concerns

• Phantom loads- electrical demand by a device when it is turned off (cable boxes and gaming consoles)

• Ways to save energy- Weatherize, plant landscaping, less hot showers, hybrid vehicle, buy energy efficient devices, use power strip, reduce phantom loads, use laptop instead a desktop computer

• Things governments can do to save energy: increase public transport access, high taxes on coal and natural gas, low taxes on hybrid vehicles,

• Hybrid electric vehicles are more efficient than internal combustion engines because they capture kinetic energy of braking, which is converted into electricity and back to the motor

• HEV- hybrid electric vehicle, PHEV- Plug-in hybrid electric vehicles, BEV- Battery Electric Vehicle

• reducing energy during high electrical demand periods- brownout, cutting energy completely- blackout

• Peak demand- greatest quantity of energy used at one time, causes there to be backup generators for times of necessity

• Ways to diminish peak demand- variable price structure (less cost when demand is less)

• When calculating energy saved, add the amount of energy that would have been lost to convert that energy to a useable form

• Use florescent and LED lights over incandescent bulbs

• Energy Star program- set by EPA, measures efficient standards

• Sustainable design- windows on south-facing wall for passive solar, skylight, high efficiency systems, proper insulation, double paneled windows, dark materials on road, building into a hill, green roofs, recycled materials, location close to workplace

• Thermal mass- property of a building material that allows it to retain heat or cold

• High TM: stone and concrete, Low TM: wood and glass

• CA Academy of sciences: uses passive solar, radiant heating, solar panels, green roof, skylights

• Sustainable energy: must combine energy efficiency, energy conservation, renewable and nonrenewable energy resources.

• Amory Lovins- suggested that innovation, not resource depletion, moves humans from one source of energy to the next

• Delivery of renewable energy sources is hard

• 5-10% of energy generated is lost during transport on transmission lines,

• Smart grid: efficient, self-regulating electricity distribution network that accepts any source of electricity and distributes it automatically to end users. It senses when electricity is needed, and when there is excess capacity- coordinates electricity use with electricity capacity

• gas only vehicles always produce carbon monoxide

• Oxygenated fuel- fuel with oxygen as part of the molecule

• Ethanol produces more of many air pollutants than just gas- due to corn plowing, conversions of forest to farmland, production process using coal or natural gas

• Ethanol EROI= 1.3 gas EROI: 15

• Ethanol production has caused cropland to move from food to fuel production

• Cellulosic ethanol: ethanol derived from cellulose (material that makes up cell walls in plants), can be derived from grass or trees instead of corn,

• CE A’s: no fertilizer or plowing for plant growth, can use algae to avoid taking up cropland

• CE DA’s: distillation is expensive, large amounts of land needed

Unit 7- Atmospheric Pollution

Module 42

• Air Pollution: The introduction of chemicals, particulate matter, or microorganisms into the atmosphere at concentrations high enough to harm plants, animals, and materials such as buildings, or to alter ecosystems- usually in troposphere

• Air pollution outputs: components of atmosphere or biosphere that remove air pollutants

• Things that can alter/remove air pollution: Plant surfaces, soil, clouds, particulates, gases

• US Clean Air Act- identified six criteria air pollutants, which EPA uses concentrations of each to decide whether or not an area is clean

• CO2 was not an original air pollutant, but SCOTUS ruled that it should be considered one

• Most to least pollutant release: Coal, Oil, Natural Gas

• Combustion of all fuels in the atmosphere results in the release of nitrogen oxides;

• Combustion of all fuels also lead to CO and hydrocarbon release

• Carbon monoxide (CO)- problem in developing countries where people cook indoors

• Photochemical Oxidants- air pollutants formed by sunlight acting on chemical compounds such as nitrogen oxides. They degrade plant tissue, human respiratory tissue, and construction material. They cause smog, and mainly Ozone is focused on

• VOCs- organic compounds that evaporate at typical atmospheric temperatures (strong aromas)- not necessarily harmful

• Hydrocarbons- Pollutant compounds with carbon-hydrogen bonds (fossil fuels, lighter and dry-cleaning fluid, oil based paints, perfumes), they become hydrocarbons when they evaporate and enter the air through usage or spillage

• Air pollutants can be primary or secondary, or both

• Primary air pollutants: VOCs,CO,CO₂,SO₂,NO_x, most hydrocarbons and suspended particles. They come directly from emission sources

• Secondary air pollutants: SO₃,O₃,HNO₃,H₂SO₄,H₂O₂, most NO^-₃ and SO^2-₄. They are primary pollutants that have transformed with sunlight, water, oxygen, or other compounds

• Conversion to secondary air pollutants happens more during the day and in wet places

• National Ambient Air Quality Standards- specifies concentration limits for air pollutants

• All criteria air pollutants in USA have decreased, Lead the most after being removed from gasoline

Module 43

• Photochemical smog- Smog dominated by oxidants such as ozone (LA-type smog or brown smog)

• Sulfurous smog- smog dominated by sulfur dioxide, sulfate compounds, and particulate matter (London-type smog or gray smog or industrial smog)

• In 2021, 40% of Americans were exposed to poor quality air

• More hours of sunlight= more photochemical smog

• Smog deters tourists and hurts the economy

• Brown smog chemical formation process:

  

• ozone concentration greatest with most sunlight

• ozone destruction occurs after sun intensity decreases- O₃+NO= O₂+NO₂

• Sublimate- processes of converting a solid to a gas or vapor

• formaldehyde- a VOC, natural compound used as a preservative and as an adhesive in plywood and carpeting

• Without VOCs, natural cycle of ozone concentration and destruction happens

• With VOCs, VOCs combine with NO instead of Ozone, causing less ozone destruction

• Reduce nitrogen oxide and VOCs for less photochemical smog

• High temp= more smog

• Smog can cause burning/itchy eyes, aggravate asthma, emphysema, and bronchitis, and premature death

• Long term ozone exposure can cause asthma

• Thermal inversion- when warm air at mid altitude covers, cold dense air below, trapping pollutants- causing severe pollution

• Inversion layer- layer of warm air that traps emissions in thermal inversion

• Conifer trees release terpenes (VOCs)

• Natural VOCs led to smog in smoky mountains

• SO₂ emissions are 30% natural, NO emissions are 44% natural, VOC emissions are 89% natural

• Wind moves some pollution

• The smaller the particulate matter, the more dangerous as it can travel further in respiratory track

• Particulate matter can absorb sunlight, causing haze and reducing photosynthesis

Module 44

• CO can cause death by asphyxiation within minutes- it is the most dangerous indoor air pollutant. it does this by bonding with hemoglobin instead of oxygen.

• Developed world CO pollution comes from malfunctioning exhaust, Developing world CO comes from cooking inside with improper ventilation

• Carbon monoxide detectors are essential

• Second hand smoke- caused by being around someone smoking, source of particulate matter

• Dead human skin cells, the dust mites that eat them, and their droppings all become dust

• Pollen, Dust, Mold, are all Particulates that cause allergies, lung inflammation, and asthma

• Asbestos- long, thin, fibrous silicate material with insulting properties that can cause cancer if inhaled. Six different minerals are classified as this

• Asbestos is in shingles and insulating material in steam an hot water pipes

• Asbestos causes asbestosis (chronic lung condition) and mesothelioma (lung cancer from asbestos exposure). Manufactured asbestos is stable, and not dangerous until it is disturbed

• Asbestos removal must be done by professionals, or else the pollution will get worse

• Radon 222- radioactive gas that occurs naturally from uranium decay and is an indoor air pollutant

• Radon can enter houses through cracks in foundation or groundwater from a well

• Radon decays in 4 days into polonium, which also attaches to air particles which cause lung cancer when inhaled

• Reduce radon by increase ventilation and sealing basement cracks

• formaldehyde is in carpets and pressed wood, sensitivity to it can develop over time

• reduce VOCs by using wood flooring or natural fiber carpeting, and reducing perfumes

• VOCs inside: detergent, dry cleaning fluid, deodorizers, solvents plastics, fabrics.

• lead is in paint chips that can be ingested by young children

• outdoor air pollution can cause indoor air pollution from nitrogen oxide and sulfur dioxide if buildings are not properly insulated and air sealed

• Indoor air pollution kills 3.8 million people annually

• Developed world indoor air pollution- people spend more time indoors, tightly sealed buildings can trap air with pollutants indoors, lots of materials made from VOCs

• Sick building syndrome- buildup of toxic pollutants in weatherized spaces, such as newer buildings in the developing world

• New buildings often have products made with synthetic materials or glues that haven’t dried, meaning off-gassing occurs and releases air pollution

• Reasons for sick building syndrome: inadequate or faulty ventilation, chemical contamination from indoor sources, chemical contamination from outdoor sources, and biological contamination from inside or outside

• Developing world indoor air pollution: caused by inside cooking, but ventilation does occur and lessen pollutants if outside air is clean

Module 45

• Air pollution fuel prevention: use less fuel, use oil instead of coal, lower sulfur concentration in fuels during refining, replace bituminous coal with anthracite coal- but there will always be a need to control exhaust stream after combustion occurs

• Air pollution regulatory practices- requiring vapor recovery nozzles (device that prevents VOCs from escaping into the atmosphere during fueling) at gas stations; restricting evaporation of dry cleaning fluids and use of lighter fluids (VOCs); reduction of wood burning stoves and fireplaces; regulating business emissions

• Cars cause air pollution with NO_x and VOCs; reduce this by restricting automobile use, expanding public transport, and shutdown industries

• Clean air act amendment “Cap and Trade”: institutes buying and selling of allowances for SO₂ emissions. each allowance allows for 1 ton of SO₂ emissions in a year. Allowances are based on amounts of sulfur that sulfur emitters produced prior to 1990- financial penalties if allowances are exceeded. They are on the open market

• Catalytic converter- device that chemically converts air pollutants (NO_x, HC, CO) to N₂, H₂O, and CO₂. Inserted before the muffler in car exhaust systems, contains platinum as a catalyst(increases chemical reaction rate without undergoing change its self)

• Catalytic converters remove oxygen from nitrogen oxides, creating nitrogen gas, and adds carbon to CO, making CO₂, along with treating hydro carbons- very effective

• Scrubber: air pollution control device that uses air and lime (dry scrubber) or air and water (wet scrubber) to separate and remove particles and sulfur dioxide from industrial exhaust streams.

• In wet scrubber- mist collects particles from air, moves them to sludge disposal system in water, water is moved back to scrubber for reuse.

• Scrubbers are used on industrial plants and coal-burning power plants

• Fluidized bed combustion- when granulated coal is burned close to calcium carbonate, the calcium carbonate absorbs SO₂ and produces calcium sulfate for sheetrock for houses

• Ways to filter particulate matter- gravitational, fabric filters that remove particulate matter, electrostatic precipitators (uses electrostatic charge to make particles clump so they can be removed from air)

• In electrostatic precipitators, particles collect on collection electrodes, and clean gas exits- common in industrial plants and coal-burning power plant

• To reduce NO_x, lower temperatures and control oxygen

• Air pollution control devices are less optimal than increasing efficiency or switching fuels

Module 46

• pH- logarithmic, basic-14, acid-0

• acid- a substance that contributes hydrogen oxides to a solution, base- substance that contributes hydroxide to a solution

• Rainwater pH- 5.65, acid rain pH- 4, ocean water pH- 8.1

• more CO₂ in atmosphere- more acidic rain water- more acidic ocean water

• Air pollution adds acidity to water

• Acid rain/ acid deposition- precipitation high in sulfuric acid and nitric acid

• Sources of acid rain- automobile exhaust, stationary fossil fuel combustion, volcanoes

• NO_x+SO₂ turn into nitric acid (HNO₃) and sulfuric acid (HNO₄) in the atmosphere with oxygen, they then split into inorganic compounds (sulfate, nitrate) and hydrogen ions

• Disassociation- when an acid is dissolved in water, it splits into H⁺(positively charged hydrogen ions) and negatively charged ions

• wind causes acid rain to form in places that produce no pollutants, it is hard to regulate internationally

• Ways that acid rain harms things- acidifying soil, mobilizing toxic metal

• Limestone bedrock reduces the effect of acid rain

• Without limestone bedrock, acid rain can mobilize metals that enter surface water and kill species

• skin prevents human damage from acid rain

• acid rain affects places downwind from sources of pollution

• acid rain harms limestone and marble (because it neutralizes calcium carbonate), and paint

• Title 4 of clean air covers acid rain and noise pollution

• db= 1/10 of a bell, db scale is logarithmic (10 increase in db= 2x loudness)

• frequency range of humans: 20-20,000 Hz

• Noise pollution measured in loudness and frequency/pitch

• decibel A scale- logarithmic scale that measures both loudness and frequency of sound.

• noise limits- no more than 85dbA for 8 hours a day

• factories can cause noise pollution

• wealthy areas have less noise pollution than poor areas

• Noise can lead to heart disease, hormonal disruption, distraction, hearing loss

• minorities are subject to more air and noise pollution

• Noise affects bat hunting, mating and warning signals in birds and amphibians, migration routes, and sonar communication

• solution to noise pollution- make ships with quieter propellers

Unit 8- Aquatic and Terrestrial Pollution

Unit 9- Global Change