Dominique Aruede

p. 1-7 (9/7/16)● 24 different life stages of Pfiesteria● Pfiesteria emits toxin and burrows in fish to feed

○ Turns into carnivorous fish eaters○ Lies dormant when no nutrients are available

● Fertilizer runoff is the nutrient● Some scientists unable to replicate the life stages of Pfiesteria● Environment - the sum of all the conditions surrounding us that influence● Environmental science - the field that looks at interactions among human systems and

those found in nature● System - any set of interacting components that influence one another by exchanging

energy or materials● Ecosystem - a particular location on Earth whose interacting components include living

(biotic) and nonliving (abiotic) components● Environmentalist - a person who participates in environmentalism● Environmental scientist - follows the scientific method in laboratory research● Environmental studies - includes subjects such as environmental policy, economics,

literature, and ethics● Biotic factors interact with abiotic factors to influence the future of an ecosystem● Hunting causes extinction● Human activity can also have a positive effect on the natural world● Ecosystem services - the process by which life-supporting resources are produced● Environmental indicator - describe the current state of an environmental system● Sustainability - living on earth in a way that allows us to use its resources without

depriving future generations● Biodiversity - diversity of life forms in an environment

○ Genetic○ Species○ Ecosystem

● Genetic diversity- a measure of the genetic variation among individuals in a population● Species diversity- indicates the number of species in a region or in a particular type of

habitat● Species - a group of organisms that is distinct from other groups in its body form &

structure, behavior, or biochemical properties● Speciation - the evolution of new species

○ There's one to three new species per year● Background extinction rate - the average rate at which species go extinct over the long

term○ 2 species go extinct per year

● The number of species has been declining● Ecosystem diversity- a measure of the diversity of ecosystems or habitats that exist in a

given region● Loss of biodiversity shows that natural systems are facing strains

p. 8-15 (9/8/16)● If everyone lived like me, we’d need 4.4 planets● To support my lifestyle, I’d need 19.6 global acres of Earth’s productive area● 17.9 tons of CO2 gas emitted● Ecological footprint

○ 20% food○ 9% shelter○ 7% mobility○ 18% goods○ 45% services

● World grain production has increased fairly steadily since 1950 as a result of expanded irrigation, fertilization, new crop varieties, and other innovations

● Per person = per capita● Grain per capita decreased because grain production isn’t keeping up w/ population

growth○ soil degradation, crop diseases, and unfavorable weather condition○ demand is outpacing supply○ humans use more grain to feed livestock than they consume themselves○ Gov’t made it more profitable to not cultivate land

● Stable temps are needed to maintain presence of liquid● Greenhouse gases (CO2) trap heat which provides stable temps● Since 1800s, as global temp increases, CO2 concentrations increase which traps in the

sun’s harmful rays● Increase in CO2 most likely anthropogenic

○ CO2 combustion○ Deforestation

● Finite natural resources○ Coal, oil, and uranium

● Development - improvement in human well-being through economic advancement● 20% of the global population that lives in developed nations owns 87% of the world’s

automobiles and consumes 58% of all energy● Even though larger human population has greater environmental impacts, economic

development and consumption patterns play a role too● Recap: environmental indicators (BAHRF)

○ Biodiversity (GES)○ Food Production○ Average global surface temperature and CO2 concentrations○ Human Population○ Resource depletion

● Easter Island○ Was once a hospitable and bountiful land○ By 1870s, almost all trees cut down, soil overused, and land eroded○ The civilization collapsed

● to live sustainably:○ Environmental systems mustn't be damaged beyond ability to recover○ Renewable resources mustn’t be depleted faster than regeneration○ Nonrenewable resources must be used sparingly

● Sustainable development - development that balances current human well-being and economic advancement w/ resource management for benefit of future generations

● Living sustainably - acting in a way such that activities that are crucial to human society can continue

● Biophilia - love of life● Humans connection is a need, as well as air, water, food, and shelter● Although people in developing countries don’t consume the same amount of resources

as developed nations, they might not use environmentally friendly technologies or have the financial resources to implement environmental protections

● To assess whether we are living sustainably○ Measure the impact of a person or country on world resources

● ecological footprint - measure of how much that person consumes, expressed in area of land

○ developed in 1995 by Professor William Rees and Mathis Wackernagel○ If lifestyle demands more land than available, then you’re living unsustainably

● Human needs - means by which humans maintain sustainability

p. 16-22 (9/11/16)

● Null hypothesis - a statement or idea that can be falsified or proven wrong● Replication - taking several measurements● Sample size - the number of times a measurement is replicated● Accuracy - how close a measured value is to the true value● Precision - how close to one another the repeated measurements of the same sample

are● Uncertainty - an estimate of how much a measure or calculated value differs from the

true value● Inductive reasoning - the process of making general statements from specific facts or

examples○ This bird eats worms → all birds eat worms

● Deductive reasoning - the process of applying a general statement to specific facts or situations

○ All birds eat worms → this bird eats worms● Hypothesis is never confirmed by a single experiment● Researchers could get different results from similar measurements● This is why we repeat experiments● Critical thinking - question the source of info, consider the methods or processes used to

obtain info, & draw conclusion● Theory - a hypothesis that’s been repeatedly tested and confirmed by multiple

investigators● Natural law - a theory with no exceptions that withstood rigorous testing● To test if chlorpyrifos affects humans negatively

○ Scientist came up w/ a hypothesis and a null hypothesis (because it’s hard to prove a hypothesis conclusively)

○ Experimental group of rats was fed chlorpyrifos for 4 days and the control group wasn’t

○ Control group - a group that experiences the exact same conditions as the experimental group except for one variable

● Even low doses of chlorpyrifos damaged mouse brain● Significance: the results have helped researchers understand human health and toxic

environmental substances more● Some controlled lab experiments can’t be possible due to prohibitive costs, ethical

concerns, and the circumstances might drastically affect the results● Natural experiment - a natural event that acts as an experimental treatment in an

ecosystem● Hypothesis - a prediction that is based off of observations prior to an experiment● Variables can change in natural experiments, so you have to compare it to a system with

similar variables

● Scientists performed a natural experiment by observing people with different levels of chlorpyrifos exposure

● Those with higher exposure levels were found to have developmental abnormalities● Lack of baseline

○ No “control earth” to compare with○ Even remote parts of the planet have been affected by humans in some way

● Subjectivity○ There's no single measure of environmental quality

● Interactions○ Even if scientists find new ways to live sustainably, consumers may not want to

buy the products or participate● Human Well-Being

○ Environmental equity - fair distribution of Earth’s resources○ Poorer areas receive more pollution and environmental degradation○ Richer areas receive the luxuries that don’t allow for sustainable living○ Environmental justice - a social movement and field of study that works toward

equal enforcement of environmental laws and the elimination of disparities

p. 27-34 (9/12/16)

● Between the Great Basin and The Sierra Nevada is Mono Lake○ A terminal lake (water flows in, but not out)

● Water picks up salt and other minerals and deposits in lake● Water evaporates and salt built up until it's uninhabitable for fish● Mono brine shrimp and Mono Lake alkali fly are two of few species that live there● Shimi and fly eat algae and birds eat shrimp and fly● In 1913, LA decided to redirect water from Owens Lake and Mono Lake● Owens lake dried up and 109,000 acres (440 km2) of salt dust was left to blow around

(1930s)○ Visibility decreases in area○ Dust contains arsenic which is poisonous

● In 1941, LA extended aqueduct to Mono Lake○ Lake depth decreased to 45 ft and salinity increased to double that of ocean○ Shrimp and fly died○ Birds either stayed away or were eaten by coyotes

● National Audubon Society persuaded LA Department of Water and Power to reduce the amount of water the diverted

● Brine shrimp and birds returned● Matter - anything that occupies space● Mass - a measure of how much matter an object contains● Atom - The smallest particle that can contain the chemical properties of an element● Periodic table - lists all the elements currently known● Molecules particles containing more than one atom● Compounds - molecules that contain more than one element● Atomic number - The number of protons in the nucleus of a particular element● Mass number - The total number of protons and neutrons in an element● Isotopes - atoms of the same element that have different numbers of neutrons● Radioactive decay - The spontaneous release of material from the nucleus● Half-life - The time it takes for one half of an element to decay

● Covalent bonds - elements that form compounds by sharing electrons● Ionic bond - a chemical bond that is the attraction between oppositely charged ions● Hydrogen bond - A weak chemical bond that forms when hydrogen atoms that are

covalently bonded to one atom are attracted to another item or another molecule● Polar molecule - A molecule where one side is more positive and the other side is more

negative● Surface tension - The cohesion of water molecules at the surface of a body of water● Capillary action - when adhesion of water molecules to a surface is stronger than

cohesion between the molecules● Acid - A substance that contributes hydrogen ions to a solution● Base - A substance that contributes hydroxide ions to a solution● pH - A scale that indicates the strength of acids and bases● Chemical reaction - when atoms separate from the molecules that are a part of or

recombine with other molecules● Law of conservation of matter - The observation that no atoms are created or destroyed

in a chemical reaction

p. 25-41 (9/13/16)

● Inorganic compounds - compounds that either do not contain element carbon or do not contain carbon, but only carbon bound to elements other than hydrogen

○ NH3, NaCl, H2O● Organic compounds - compounds that have carbon-carbon and carbon-hydrogen bonds

○ C6H12O6, CH4

● Macromolecules (LPCN: pronounced “lapkin”)○ Lipids○ Proteins○ Carbohydrates○ Nucleic acids

● Carbs○ Compounds composed of carbon hydrogen, and oxygen atoms○ Glucose is a single sugar known as C6H12O6

○ Plants store energy as starch which are long chains (polysaccharides) of covalently bonded glucose molecules

○ Cellulose - A polysaccharide that can potentially replace or supplement gasoline● Proteins - made up of long chains of nitrogen-containing organic molecules called amino

acids● Nucleic acids - organic compounds found in all living cells

○ Its polysaccharides form DNA and RNA○ DNA - The genetic material organisms pass on to their offspring that contains the

code for reproducing the components of the next generation○ RNA - translates the code stored in the DNA and allows for the synthesis of

proteins● Lipids - smaller biological molecules that do not mix with water

○ Fat, waxes, steroids, Etc.● Energy - The ability to do work or transfer heat● Electromagnetic radiation- A form of energy that includes visible light, ultraviolet light,

and infrared energy

● Photons - massless packets of energy that travel at the speed of light and can move even through the vacuum of space

● Joule - The basic unit of energy in the metric system; the amount of energy used when a 1–watt bulb is turned on for one second

● Power - The rate at which work is done● Energy = power x time● Power = energy / time● Watts measure power● Potential energy - Energy that is stored but has not yet been released● Kinetic energy - The energy of motion● Chemical energy - potential energy stored in chemical bonds● Temperature - The measure of the average kinetic energy of a substance● First law of thermodynamics - Energy is neither created nor destroyed● Waste heat - the useless heat that is created when energy is converted ● Second law of thermodynamics - when energy is transformed the quantity of energy

remains the same but it's ability to do work diminishes● Energy efficiency - The ratio of the amount of work that is done to the total amount of

energy that is introduced into the system in the first place● Energy quality - The ease with which an energy source can be used for work● Entropy - all systems move toward randomness rather than toward order

p. 42-46 (9/14/16)

● All living things work against entropy by using energy to maintain order● Interactions at levels beyond the organism can also be seen as a process of converting

energy into organization● The amount of available energy determines which organisms can live in a natural

system○ Plants can't live on the sea bottom because there is no sunlight

● How do organisms convert energy from one form to another○ Plants combine water and carbon dioxide and convert them into sugars which

provides their energy○ Squids get their energy from sinking dead organisms○ Ocean floor geysers that spew out chemicals that bacteria converts into energy

are the supporters of the community● Environmental scientists study whole ecosystems rather than one individual thing

because that’s how you understand the whole system● Open system - exchanges of matter and energy occur across system boundaries

○ Ex. Water → into Mono Lake → sun provides energy for algae and plants → brine shrimp receive energy/water evaporates → birds fly in and out of lake/precipitation occurs on surface and ocean → nutrients flow into ocean and out of ocean through geological cycles

● Closed system - matter and energy exchanges across system boundaries don’t occur○ Ex. While energy can enter and leave our planet quite easily, matter circulates

within the Earth with not much input or output● Inputs - additions to a system● Outputs - losses from a system● Systems analysis - determination of inputs, outputs, and changes in the system under

various conditions

● Steady state - when inputs equal outputs, so that the system is not changing over time● To measure the properties of a system, first you must estimate the amount of energy or

matter stored in the system● People worry that is that global climate change causes systems like the ocean to no

longer be in steady state● Most natural systems are in steady state

○ the input will increase to match the output, or the output will increase to match the input, likewise for decreases

● Feedback -The result of a process feed back into the system to change the rate of that process

● Negative feedback loops - a system that responds to a change by returning to its original state or by decreasing the rate at which a change is occurring

○ Reduced surface area → less evaporation → level rises → Lake level increases → level drops

■ cycle goes back to beginning and the amount never increases● Positive feedback loop - A system that amplifies change

○ Population increase → more births → another population increase → births

■ Cycle continues to grow like this● To what extent is earth’s temp regulated by feedback loops?

○ On one hand, hot areas of the earth increase evaporation, but low-altitude clouds absorb heat from the sun which cools the earth down (negative feedback loop)

○ On the other hand, high-altitude clouds absorb terrestrial energy which heats up the earth's surface (positive feedback loop)

● The health of many environmental systems depends on the proper operation of feedback loops

● The addition of an invasive species or any anthropogenic factors could lead to a breakdown in negative feedback loop and a disrupt a system from a steady state

p. 57-65 (9/17/16)

● In Port-Au Prince, people needed charcoal to cook● 76% of Haitians lived on two dollars a day● People chopped down the forests to use for fuel and in 2006 98% was gone● When forests are cut down the land become susceptible to erosion● Rainstorms slept away the topsoil and oversaturation caused massive mudslides that

destroyed villages● The US Agency for International Development funded the planting of 60 million trees

○ People still needed the trees to cook○ Instead they planted mango trees which can provide $70-$150○ Economic incentive allowed the trees to reach maturity

● They are also developing alternative fuel sources like dried paper● The deforestation on mountains led to soil erosion and disruption of the natural cycles of

water and soil nutrients○ Also allows water to run rapidly down the mountain is leading to extreme flooding

● Ecosystem - A particular location on earth distinguished by its particular mix of interacting biotic and abiotic components

○ Ex. A forest● The more biotic components, the more biodiverse

● Abiotic components determine which organisms can live somewhere○ Sunlight, temperature, soil, water, pH, and nutrients○ A lot of water and soil can support trees but not a lot of water in soil can support

only grasses● Biotic and abiotic competence provide boundaries that distinguish one ecosystem from

another○ Some boundaries are well-defined and others are not

● Knowing the boundaries of an ecosystem makes it easier to identify the systems biotic and abiotic competence and to trace the cycling of energy and matter through the system

● Ecosystem boundaries are often subjective● Each ecosystem interact with surrounding ecosystems through the exchange of energy

and matter○ Changes in an ecosystem can have a global effect

● Plants absorb energy from the sun → herbivores spread that throughout the ecosystem → carnivores eat herbivores

● Ex. There are much less alliance then zebras in the Serengeti○ This proves the second law of thermodynamics that not all energy is transferred

to the consumer. some is lost in heat● Producers (autotrophs) - produce usable forms of energy from the sun● Photosynthesis - converting carbon dioxide and water into glucose, a form of potential

energy○ CO2 + H2O + solar energy → C6H1206 + O2

● Cellular respiration - A process that unlocks the chemical energy stored in cells of organisms

○ C6H1206 + 6 O2 → energy + 6 H2O + 6 CO2

● All organisms carry out respiration to fuel metabolism and○ Producers both produce and consume oxygen

● Consumers (heterotrophs) - are incapable of photosynthesis and obtain their energy by consuming other organisms

○ Herbivores (primary consumers)- heterotrophs that consume producers■ Zebras, grasshoppers, tadpoles

○ Carnivores (secondary consumer) - heterotrophs that eat primary consumers■ Lions, hawks, rattlesnakes

○ Tertiary consumers - eat secondary consumers■ Bald eagles, humans

● Trophic levels - successive levels of organisms consuming each other○ Algae converts sunlight into glucose → Zooplankton eats algae → Fish

eat zooplankton → Eagles eat fish● Food chain - The sequence of consumption from producers through tertiary consumers● Food webs illustrate that all species in an ecosystem are connected to one another● Omnivores operate at several trophic levels● Scavengers - carnivores that consume dead animals● Detritivores - organisms that break down dead tissues and waste products

○ Dung beetles● Decomposers - recycle nutrients from dead tissues and wastes back into ecosystem

○ Fungi and bacteria● Amount of energy in ecosystem determines amount of life● Gross primary productivity (GPP) - total amount of energy that producers in an

ecosystem capture via photosynthesis in a given timeframe

○ Used to understand where energy comes from and is transferred in an ecosystem

● Net primary productivity - the energy captured minus the energy respired by products in ecosystem

○ NPP = GPP - respiration by producers● Determining GPP can be hard because plants rarely photosynthesis without

simultaneously respiring○ You have to determine rate of photosynthesis and respiration first

● Determining rate of photosynthesis○ Measure CO2 intake and outtake

■ CO2 outtake measured in the dark because this stops the photosynthesis process

■ CO2 intake measures in sunlight ■ CO2 produced in dark + CO2 absorbed in light = CO2 absorbed in

photosynthesis● NPP allows us to compare the productivity of diff. Ecosystems● Biomass - the total mass of all living matter in a specific area

○ NPP establishes rates at which biomass is produced● Standing crop - the amount of biomass present in an ecosystem at a particular time

○ Standing crop measures the amount of energy in a system at a given time○ Productivity which measures the rate of energy production over a span of time

● Ecological efficiency - The proportion of consumed energy that can be passed from one trophic level to another

● Trophic pyramid - A representation of the distribution of biomass, numbers, or energy among trophic levels

● Biosphere - the region of our planet where life resides● Biogeochemical cycles - biological, geological, and chemical processes that deal with

the movements of matter within and between ecosystems○ Hydrologic cycle - the movement of water through the biosphere

■ Solar energy heats earth → evaporated water ■ Transpiration - when plants release water from their leaves into the

atmosphere■ Evapotranspiration - the combined amount of evaporation and

transpiration■ Runoff - Water that moves across the land surface and into streams and

rivers■ Because earth is a closed system with respect to matter, water never

leaves it■ Humans can also alter the hydraulic cycle by diverting water from one

area to another to provide water for drinking, irrigation, and industrial use● Macronutrients - key elements that organisms need

○ Nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur

The Nitrogen Cycle

● Nitrogen○ Most abundant element in the air○ Limiting nutrient

■ A nutrient required for the growth of an organism but available in a lower quantity than other nutrients

○ Used to form amino acids (proteins) and nucleic acids (DNA, RNA)

○ Most cannot be used by plants because of its natural form (N2)■ Most organisms can’t perform nitrogen fixation (converting N2 to NH3)■ Nitrogen-fixing organisms

● Cyanobacteria (blue-green algae)● Bacteria in legume roots (peas, beans, certain trees)

● Nitrogen fixation○ Biotic process: N2 → NH3 → NH4

+

■ Cyanobacteria excretes NH4+ into H2O

■ Bacteria in roots excrete NH4+ into roots

● Roots supply bacteria w/ sugars○ Abiotic process: N2 → NO3

-

■ Lightning■ Combustion in fires & burnt fossil fuels■ NO3

- precipitates back into atmosphere■ NO3

- is used by plants■ Humans use nitrogen fertilizer which fixes majority of N2

● Assimilation○ Producers eat NH4

+ or NO4-

○ Consumers eat producers○ Some fixed nitrogen is lost as waste

● Ammonification○ Decomposers break down fixed nitrogen (NH4

+ or NO3-) → NH4

+

● Nitrification○ Nitrifying bacteria converts NH4

+ → NO2- → NO3

-

○ Since most nitrates (NO3-) are negative, they repel each other and can leach

through the soil w/ H2O○ Leached NO3

- settle at the bottom of oceans, lakes, and swamps● Denitrification

○ Bacteria in hypoxic soil & stagnant H2O convert NO3- → N2O → N2

○ N2 is released into air and process begins again

The Phosphorus Cycle

● Phosphorus○ Limiting nutrient

■ A nutrient required for the growth of an organism but available in a lower quantity than other nutrients

■ Used as plant fertilizer■ The small percentage that dissolves in water is used by organisms in

freshwater and marine food webs○ Major component in DNA, RNA, & ATP○ Not very soluble in water

■ Much of it precipitates out of solution as PO43-

■ Becomes sediment on ocean floor● Major natural source of phosphorus

○ Weathering of rocks (not easily leached)○ Producers extract it and it travels through the trophic levels from there

The Carbon Cycle

● Carbon○ Most important element in living organisms

○ About 20 percent of their total body weight○ Major component in

■ Organic molecules that form the membranes and walls of cells■ Backbones of proteins■ Energy storage

● Photosynthesis○ Producers turn CO2 → sugars

■ Carbon is incorporated into plant tissue■ Some returns to the atmosphere after organism death

● Respiration○ Decomposers break down dead material○ CO2 returns to atmosphere ○ Some is respired back into atmosphere through plants

● Exchange○ CO2 is exchanged between atmosphere and ocean

■ CO2 diffuses into ocean■ Algae turn CO2 → sugars

● Carbon enters food web through algae in ocean○ Rate of CO2 diffused in ocean = rate of CO2 released from ocean

● Sedimentation and burial○ Carbon from ocean combines with calcium ions to form CaCO3

○ CaCO3 precipitates out H2O to form limestone and dolomite rock○ Some organic carbon from dead biomass is buried and sediments into fossil fuels

(after millions of years)○ Rate of carbon sedimentation = rate of carbon release through weathered rock

● Extraction○ Fossil fuels are extracted by humans for humans○ Doesn’t alter carbon cycle by itself

● Combustion○ Combusts fossil fuels or timber (forest fire)○ Releases carbon into the atmosphere as CO2 or into the soil as ash

p. 77-end (9/22/16)

● Calcium, magnesium, and potassium○ Derived primarily from rocks and decomposed vegetation○ Can be dissolved in water as positively charged ions (Ca2+, Mg2+, and K+)

● Ca2+ and Mg2+ are strongly attracted to soil particles so they’re abundant in many soils overlying these rock types

● K+ is only weakly attracted to soil particles is only weakly attracted to soil particles○ Can be leached away, leaving the soil K-deficient

● Sulfur○ Component of proteins○ Exists in rocks

■ Released when rock weathers○ Absorbed by plants as SO4

2- (sulfate ion)■ Cycles through food web

○ Volcanic eruptions → SO2 (sulfur dioxide)○ Burning of fossil fuels & mining of metals → SO2

○ SO2 → H2SO4 (sulfuric acid) naturally○ When it rains/snows, H2SO4 returns to ground○ The more SO2 added to atmosphere, the worse our terrestrial and aquatic

ecosystems will be● Disturbance - an event, caused by physical, chemical, or biological agents, resulting in

changes in population size or community composition● Instrumental value - something that has worth as an instrument or a tool that can be

used to accomplish a goal● Intrinsic value - has worth independent of any benefit it may provide to humans● Ecosystem services - the benefits that humans obtain from natural ecosystems

○ Ecosystem services were worth over $30 trillion per year (more than the entire global monetary economy at that time)

○ Provisions■ Goods that humans can use directly■ 70% of prescription drugs come from natural sources■ Our best strategy may be to preserve as much biodiversity as we can to

improve our chances of finding the next critical drug.■ Our best strategy may be to preserve as much biodiversity as we can to

improve our chances of finding the next critical drug○ Regulating services

■ Natural ecosystems help to regulate environmental conditions● Ex. humans pump out 8 gigatons of carbon per year but only 4

gigatons remain○ Support systems

■ Natural ecosystems provide numerous support services that would be extremely costly for humans to generate

● Ex. bees pollinate crops for us■ Provide habitat for animals that pollinate crops■ Ecosystems provide natural pest control services because they serve as

habitat for predators that prey on agricultural pests○ Resilience○ Cultural services

p. 207-217 (9/24/26)● Are Hybrid Electric Vehicles as Environmentally Friendly as We Think?

● Hybrid electric cars (HEVs) more efficient in their use of fuel than similarly sized internal combustion (IC) automobiles

● Even though HEV reduce use of fossil fuels…○ Construction uses scarce metals (neodymium, lithium, & lanthanum)○ Mining these elements involves pumping acids into deep boreholes & removing

the acid and mineral slurry○ The holes let air & water react w/ minerals like sulfur → forms an acidic

slurry → drainage flows over land or underground to rivers & streams → dissolves metals & other elements

○ Fragmentation and alteration of habitats○ Erosion○ Contamination of water supplies○ Fossil fuel use ↓ but other limited resources ↑

● When earth first began, heavy element sank to center of earth and lighter ones floated to top

● Core - the innermost zone of the planet

● Mantle - the layer of the earth above the core● Magma - molten rock● Asthenosphere - the semi molten layer above the mantle● lithosphere - brittle outermost layer of the earth● Crust - the chemically distinct outermost layer of the lithosphere● Hot spots - places where molten material from the mantle reaches the lithosphere● Plate tectonics - which states that Earth’s lithosphere is divided into plates, most of

which are in constant motion○ Oceanic plates - lie beneath oceans○ Continental plates - lie beneath land masses

■ Rise above oceanic plates because they contain more silicon dioxide● Seafloor spreading - where oceanic plates meet continental plates, old oceanic crust is

pulled downward, beneath the continental lithosphere○ Creates new lithosphere and brings important elements such as copper, lead,

and silver to the surface of Earth● Subduction - when one plate passes under another● Continents that straddled two plates broke apart forming smaller continents or islands● As a plate moves over a geologic hot spot, heat from the rising mantle plume melts the

crust, forming a volcano● Volcano - a vent in Earth’s surface that emits ash, gases, and molten lava

○ Natural source of atmospheric carbon dioxide, particulates, and metals● The Hawaiian Islands were formed by volcanic eruptions as the Pacific Plate traveled

over a geologic hot spot● The chain of inactive volcanoes to the northwest of Hawaii shows that those locations

used to be over the hot spot● Divergent plate boundaries - where plates move away from each other● Convergent plate boundaries - where plates move toward one another and collide

○ Want to plate will slide underneath the other do you have your plate○ Subduction of the heavier plate forms long narrow coastal mountain ranges

● Transform fault boundary - when the plates move sideways past each other● fault - a fracture in rock across which there is movement● Fault zones - large expanses of rock where movement has occurred

○ Rocks rub past each other → rocks resist movement & get stuck together

○ Eventually, mounting pressure overcomes resistance, & slip quickly, resulting in an earthquake

● Earthquake - when the rocks of the lithosphere rupture unexpectedly along a fault● Seismic activity - The frequency and intensity of earthquakes● Epicenter - the exact point on the surface of Earth directly above the location where the

rock ruptures● Volcanic eruptions happen when molten magma beneath the crust is released to the

atmosphere● Ring of Fire - where earthquake locations and volcanoes form a circle of tectonic activity

○ In the Pacific● Plate movements, volcanic eruptions, seafloor spreading, and other tectonic processes

bring molten rock from deep beneath Earth’s crust to the surface● Subduction sends surface crust deep into the mantle● Richter scale - a measure of the largest ground movement that occurs during an

earthquake○ A value increases by a factor of 10 for each unit increase

■ A magnitude 7.0 earthquake is 10x greater than a magnitude 6.0 earthquake

● Moderate earthquakes (5.0 to 5.9)= collapsed structures & buildings, fires, contaminated water supplies, ruptured dams, & deaths

● Nuclear power plants are designed to withstand significant ground movement & are programmed to shut down if movement above a certain threshold occurs

● Volcano eruption = loss of life, habitat destruction & alteration, reduction in air quality● Rock cycle - the constant formation and destruction of rock● Minerals - solid chemical substances with uniform structures that form under specific

temperatures and pressures○ I.e. Phalite, graphite, or halite (table salt)

p. 149-154 (10/13/16)● In 1620, Pilgrims found huge areas of

undisturbed temperate seasonal forest containing different tree species, like sugar maple

p. 315-322 (12/29/16)● Nonrenewable resources - once they are used

up, they cannot be replenished● Two types of nonrenewable resources: fossil

fuels and nuclear fuels● Fossil fuels - derived from biological material that

became fossilize millions of years ago (ex. coal, oil, and natural gas)

○ We harness this power through combustion

● Nuclear fuel - derived from radioactive materials that give off energy○ Harness this power by transferring heat

● An exajoule (EJ) is 1 billion (1 × 109) gigajoules

● In 2008, total world energy consumption was approximately 495 EJ per year● 70% of the world's energy is used by 20% of the world (developed countries)● United States has the greatest total energy consumption, whereas Canada has the

greatest per capita energy consumption● Tanzania has lowest average annual consumption● People in urban areas more likely to use fossil fuels● People in rural areas more likely to use fuel like wood, charcoal, or animal waste● Commercial energy sources - those that are bought and sold, such as coal, oil, and

natural gas● Subsistence energy sources - those gathered by individuals for their own immediate

needs● There is a much greater use of subsistence energy sources in developing world● As energy demand increases, societies change the types of yours to use

○ Ex. As more people on automobiles, demand for gasoline and diesel increases● What was predominant energy source for United States until about 1875 (then coal

replaced it)● In 1900s oil and natural gas join the call as primary sources of energy● Then nuclear energy and hydroelectricity became more prominent● Today oil, coal, and natural gas are the most prominent sources of energy

● The boundaries for the United States’ energy system are social, technological, and physical

○ Ex. Oil is an input from both domestic production and other countries○ Hydroelectric energy comes from within the US boundaries, but it is not an

energy input until it enters a technological system such as hydroelectric dams● Work - a major output from the system system which is the end use of the energy● Waste - a major output from the system which takes the form of heat, carbon dioxide, or

other pollutants that are released as energy● Energy varies regionally and seasonally● Midwestern and southeastern states burn coal for electricity generation● Western and northeastern states use nuclear fuels, natural gas, and hydroelectric dams

for electricity generation● The type of energy used depends on certain features of the energy

○ These features include ease of transportation and the amount of energy a given mass of your contains

● For transportation, we use gasoline or diesel because liquid energy sources are relatively compact and they have a high energy-to-mass ratio

○ They also provide and cut off energy supply quickly○ Ever, it produces a lot of pollution

● To determine the best source of energy, consider energy efficiency● Energy efficiency - both the efficiency of the process of obtaining the fuel and the

efficiency of the process that converts it into the work that is needed● To determine energy efficiency, quantify the energy expended to obtain a fuel and how

efficient you use it● The second law of thermodynamics states that when energy is transformed its ability to

do work diminishes and some energy is lost● To calculate the energy required to produce an energy source, calculate the energy

returned on energy investment (EROEI)

● EROEI=Energy obtained¿ t h e fuel ¿Energy invested ¿

obtaint he fuel ¿EROEI=Energy

obtained from the fuel/Energy invested to obtain the fuel● Natural gas water heater can actually be more efficient overall compared to an electric

water heater if a coal-fired power plant is the source of the electricity that fuels electric water heater

● Nearly 30% of energy use in US is for transportation● Transportation - The movement of people and goods● Transportation is the chief primarily through the use of vehicles feel by petroleum

products, such as gasoline and diesel, and by electricity○ This drastically contributes to air pollution and greenhouse gas emissions

Energy Expended for Different Modes of Transportation in the US Mode MJ per passenger-kilometer

Air 2.1

Passenger car (driver alone) 3.6

Motorcycle 1.1

Train (Amtrak) 1.1

Bus 1.7

● In the US light trucks account for one half of automobile sales, while hybrid electric vehicles account for between two and 3 percent of total sales

● Electric cars and plug-in hybrid electric cars obtain better fuel efficiency● 20 mpg = 8.5 km/L● 1 mpg = 0.43 km/L● How many people drive vehicles that yield relatively low fuel efficiencies● 2005 people chose light trucks and SUVs over cars● Efficiency was predicted to reach 15 km (35 mpg) per liter by 2016

p. 325-330 (1/5/16)● Energy carrier - something that can move and deliver energy and a convenient, usable

form to end users● Turbine - a large device that resembles a fan or a jet engine● Electrical grid - A network of interconnected transmission lines that electricity is

transported along● Combined cycle - has two turbines and generators● Capacity - The maximum electrical output● Capacity factor - used to measure the amount of time a plant actually operates in a year● Cogeneration - the use of fuel to generate electricity and produce heat

p. 330-332 (1/8/17)● Oil sands - slow flowing, viscous deposits of bitumen mixed with sand, water, and clay● Bitumen - a degraded type of petroleum that forms when a petroleum deposit is not

capped with nonporous rock (aka, tar or pitch)● The mining of bitumen is much more energy-intensive than conventional drilling for

crude oil● Extraction of the bitumen from the other material contaminates roughly 2 to 3 L of water

for every liter of bitumen obtained● The system efficient energy of bitumen is lower due to the amount of energy it takes to

refine● Resulting CO2 released is greater● CTL - (“coal to liquid”) the process that converts solid coal into a liquid fuel● Producing liquefied coal is expensive● CTL could eliminate US dependence on foreign oil● Greenhouse gas emissions from liquefied coal are more than twice those from

conventionally produced oil● Energy intensity - The energy used per unit of gross domestic product (GDP)● Even though we're using energy more efficiently, since the world population has

increased, our overall energy use has also increased● Any use of fossil fuels is not sustainable because there is no way to limit our

consumption to the rate at which they are being formed● The Hubbert curve - A graph created by M. King Hubbert that projected the point at

which world oil production would reach a maximum and the point at which we would run out of oil

○ Hubbert used an upper estimate and the lower estimate● Peak oil - The point at which half the total known oil supply is used up

● Oil usage slows down are 50% because it doesn't come out of the ground as easily when it is tapped anymore

● Hubbard predicted that 80% of the world's total oil supply would be used up roughly around 2029

● Rising oil prices create a powerful incentive to invest in alternative energy resources and conservation

● Wind energy, hydroelectricity, and solar Energy are examples of alternative energy sources

● Higher prices of oil mix formerly unproductive mining and extraction methods cost-competitive, and may result in greater total production of fossil fuels

● Uranium is a conventional, nonrenewable fuel that does not contribute significantly to the addition of greenhouse gases

p. 346-350 (1/12/17)● Brownout - a reduction in or restriction on the availability of electrical power in a

particular area● Energy conservation - finding ways to use less energy

○ Ex. lowering the household thermostat during cold months, consolidating errands in order to drive fewer miles, or turning off a computer when it is not being used

● Government can facilitate energy conservation on a wider scale by taxing electricity, oil, and natural gas, since higher taxes discourage their use

● Tiered rate system - customers pay a low rate for the first increment of electricity they use and pay higher rates as their use goes up

● Energy efficiency - doing the same amount of work for less energy● One can increase energy efficiency by switching to Energy Star appliances, products

that meet the efficiency standards of the U.S. Environmental Protection Agency’s Energy Star program

○ If implemented by the whole town, could save them 20MW of a typical power plant output

● Brownouts/blackouts occur when electricity-generating plants are unable to handle the high energy demand

● Peak demand -the greatest quantity of energy used at any one time● Electric companies produce enough energy to satisfy peak demand even though the

actual demand is much lower● To live sustainably, peak demand must be lowered● One way to do this is to allow consumers to pay less for when they use it when ⚡

demand is lowest● In a typical thermal fossil fuel or nuclear power plant, only about 1/3 of energy consumed

goes to intended purpose (the rest is lost as heat)● The amount of energy we save is the sum of the energy we did not use and the energy

that would have been lost in converting that energy into the form we would’ve used it● Building houses close to where residents work reduces reliance on fossil fuels for

transportation, which in turn reduces the amount of pollution and carbon dioxide released into the atmosphere

● An energy-efficient home could consist of○ High efficiency heating/cooling systems○ Insulated basement walls & floors○ Efficient windows

● Passive solar design - a technique that takes advantage of solar radiation to maintain a comfortable temperature in the buildings

● Thermal inertia - the ability of a material to retain heat or cold; materials with high thermal inertia stay hot once they have been heated and cool once they have been cooled.

○ Stone and concrete have high thermal inertia, whereas wood and glass do not

p. 367-371 (1/18/16)

● Fuel Cell - operates like a battery except the reactants are continuously added to the cell so that it can supply electricity for as long as it has food

● Electricity is formed by the reaction of hydrogen with oxygen which forms water: 2 H2 + O2 → energy +2 H2O

● Electrolysis - when electricity is applied to a substance to split apart the molecules

p. 242-245 (1/24/17)

● Water distribution methods○ Levees

■ When nutrient-rich rivers overflowed their banks, created floodplains with very rich soil

■ Humans created levees to block flooding so that we can use the rich soil for agriculture

■ Levee - and enlarged bank build up on each side of the river

■ Problems● Floodwaters can't add fertility to floodplains after they're blocked● Because the sediments don't leave the river, they are carried

further downstream and settle in the ocean● The forest floodwater farther downstream where it can cause

flooding in that city or town● Levees can collapse when floodwaters are high

○ New Orleans 2005 - Hurricane Katrina caused one of the biggest levee failures

○ Dikes■ Event ocean waters from flooding adjacent land■ They often protect farmland below sea level■ Famous one is in the Netherlands■ Combine with pumps that send water back into the ocean

○ Dams■ A barrier that runs across a river or stream to control the flow of water■ Water stored behind dam in reservoir■ Used for human consumption, electricity, flood protection, or recreation■ Hydroelectric dams are only 3% of dams■ Three Gorges Dam

● Largest dam in the world● On the Yangtze River in Hubei Province of China

○ Caused people near the river base to relocate due to rising water levels

■ flooded 13 cities, 140 towns, and 1,350 villages○ Stops flooding downstream and generates huge amounts

of electricity■ Dams block fish from migrating upstream to breed

● Also affects other organisms like bears who depend on migrating fish

■ Fish ladders - migrating fish can swim up the fish ladders and reach their traditional breeding grounds

■ Some organisms depend on seasonal flooding that’s blocked by dam● Managers have started releasing large amounts of water to mimic

seasonal flooding○ Super effective

○ Aqueducts■ Canals or ditches used to carry water from one location to another■ Modern aqueducts include concrete canals and pressurized steel pipes

laid above or under the ground● Super efficient

■ The Catskill Aqueduct brings clean, fresh water over 120 miles from Catskill Mountains to NYC

■ Construction of aqueducts is expensive and fragments natural habitats■ Diverting water from a natural river means that there is less water flowing

where water has flowed for millennia● Rivers like these often go dry before they reach the ocean

■ Puts fish populations and river navigability for commerce at risk■ Bangladeshi dam project may reduce flow of fresh water into

estuaries → ocean water moves farther up into the river → raises salinity of estuary → harms aquatic life

■ When Soviet Union diverted two rivers that fed the Aral Sea in Central Asia in 1950s

● Diversion of rivers decreased freshwater input and increase salinity

● Destroyed fish populations● Summers are now much hotter because of loss of body of water● They’re tryna save North Aral Sea, but South Aral Sea too

expensive to save● South Aral Sea predicted to be completely dry in 10 years

○ Desalination■ Removes salt from saltwater■ Countries of Middle East produce 50% of world’s desalinated water■ Two main types

● Distillation○ Salt water is boiled and evaporates, leaving salt behind○ Steam is captured and condensed to form pure water○ Very expensive

● Reverse osmosis○ Water is forced through thin semipermeable membrane at

high pressure○ Water can pass through, but salt can’t○ More efficient, less costly than distillation○ The leftover salty liquid (brine) is usually dumped back in

sea which causes harm to ecosystem

p. 246-450 (1/26/17)

● Irrigation○ Furrow irrigation

■ Easy and inexpensive■ Digs trenches, or furrows, along the crop rows and fills them with water■ 65% efficient

○ Flood irrigation■

○ Spray irrigation○ Drip irrigation

(1/27/17) these notes are from presentations, so you may not find it in the textbook

● Mekong River○ Controlled by monsoons○ Rain bearing monsoons arrive in the summer or something○ Temperatures vary around 89 degrees○ Home to one of the most diverse species in the world○ Accounts for 25% of freshwater for 60 mil people○ The drought in Thailand is making it hard to produce major crops

1/30/17

● Riparian zone - an area situated by a river

p. 437-452 (2/20/17)

● Polystyrene - A plastic polymer that has a high insulation value○ Harmful to the environment because it does not decompose in landfills

● Many companies eliminated the use of poly styrene and replace them with disposable paper cups

● But paper cups don't insulate well and hot drinks could burn your hand○ So the Cubs are often wrapped in cardboard which creates additional waste

● Twice as much energy is needed to make a paper cup rather than a polystyrene cup● Plastic cups can leach harmful chemicals into drinks● Bleach and other chemicals used to make plastic cups can harm fish when discharged

into rivers and streams● A paper cup will decompose and produce methane gas while a plastic cup will remain in

a landfill for a long time● There is no definitive answer to whether paper cups or polystyrene cops cause more

harm● Outputs - anything not useful or consumed● Waste - non-useful products generated within a system● The waste of one organism can sometimes become a source of energy for another● Humans are the only organisms that produce waste others can't use● Back in the day everything that lost its original purpose was reused as something else,

which generated little waste● After World War II, industrialization and wealth made it possible for household items to

be used and thrown away● Planned obsolescence - The design of a product so that it will need to be replaced within

a few years● Municipal solid waste (MSW) - refuse collected from households, small businesses, and

institutions● Environmental protection agency (EPA) estimates that approximately 60% of MSW

comes from residencies and 40% from commercial and institutional facilities● Source reduction - reduces waste by reducing, in the early stages of design and

manufacture, the use of materials -- toxic or otherwise -- destined to become MSW○ Ex. Printed gn double sided or less wrapping on CDs or avoiding purchase of

CDs● Car manufacturer Subaru of America utilizes all aspects of Reduce, Reuse, Recycle● Optimally, no energy is needed for a material to be reused

○ By covering the first mailing address on a used envelope and labeling a new address over it, we increase the residence time of the envelope and reduce waste disposal rate

● Sometimes reuse might involve repairing an object which costs time, labor, energy, and materials

● Energy is also required to prepare and transport objects for reuse from someone other than the original user

● Reuse was commonplace before we became a “throw-away society”● Recycling - the process by which materials destined to become MSW are collected and

converted into raw materials that are then used to produce new objects○ Closed-loop recycling

■ The recycling of a product into the same product

■ Ex. Aluminum cans are brought into an aluminum plant, melted down, and made into new aluminum cans

■ Like a closed system, you can keep making new aluminum cans indefinitely out of old cans

○ Open-loop recycling■ The recycling of a product into a different product■ Ex. Plastic soda bottles are made into a tacky polar fleece jacket■ In this case, there's still a demand for raw materials like petroleum to

make the plastic bottles○ Today we recycle roughly ⅓ of MSW○ zero-sort recycling program - allows residents to mix all types of recyclables

which are then sorted at a sorting facility● Sometimes, recycling requires more energy than reusing and reducing due to the sheer

amount of time, processing, cleaning, transporting, and possible modifications● Absence of O2 in landfills cause organic material to decompose anaerobically

○ Produces methane gas and other harmful greenhouse gasses● Compost - organic matter that has decomposed under controlled conditions to produce

an organic-rich material that enhances soil structure, cation, exchange capacity, and fertility

● Marat and dairy aren't composted cuz they don't decompress easily, emit bad smells, and might attract rats, raccoons, and skunks

● The carbon to nitrogen ratio must be as close to 30:1 to support microbial activity○ Alternate layers of dry stuff and wet stuff

● Good compost should not smell bad○ Proper aeration and water (if it gets too dry) will keep the smell away○ If it’s too wet, it might produce methane gas

● Sanitary landfills - hold MSW with as little contamination of the surrounding environment as possible

○ They have clay or plastic lining the bottom○ Clay can impede water flow and retain positively charged ions like metals○ Pipes below the landfill collect leachate - which is sometimes recycled back into

landfill○ A cover of clay or soil called a cap is installed once landfill reaches capacity○ They try to stop extra water from coming in because water→anaerobic

decomposition→methane release● Aluminum and other metals could leach and should never go in landfills

○ They are also valuable recyclables ● Glass and plastic are chemically inert and can go in landfills when not recycled● A landfill must always be closed off when full to reduce the amount of water input and

output to avoid odors● Closed landfills can be reclaimed

○ When they plant herbaceous, shallow-rooted plants on the topsoil layer for aesthetic reasons and to reduce soil erosion

● A municipality or private enterprise constructs a landfill at a tremendous cost so they make up for the loss by charging a tipping fee

○ $35 per ton in US for solid waste landfills○ Twice as much in the northeast○ Creates incentive to reduce amount of waste going into landfills

● Recycling is free● Some areas mandate that recyclables be separated from waste stream

● If tipping fees get to high and laws to strict, people could start illegally dumping waste in places other than landfills and recycling centers

● Where should a landfill be constructed?○ A place with soil rich in clay○ Away from bodies water and drinking water supplies○ Far away from population○ Not too far away so that energy isn't wasted transporting it

■ Regional landfills - A single location where all waste is sent for greatest economic advantage

○ Siting - designation of the location■ Rich people adopt a “not-in-my-backyard” (NIMBY) attitude towards

landfill siting and send landfills to neighbor places that lack the resources to oppose

● Ex. In Fort Wayne, Indiana, the Adams Center Landfill was located in a densely populated, low income, and predominantly minority neighborhood

● Problems with landfills○ Locating landfills near populations that do not have the resources to object is a

global problem○ There's always the possibility that leachate from landfills will contaminate

underlying and adjacent waterways■ Risk of leachate is uncertain

● Methane and CO2 created from anaerobic decomposition causes combustion so vents are installed in landfills

● Sometimes, the methane is collected to make heat or energy● It's best to keep organic material out of landfills and use it to make compost● Decomposition takes place only in those areas of a landfill where the correct mixtures of

air, mustard, and organic material or present● Incineration - the process of burning waste materials to reduce their volume and mass

and sometimes to generate electricity or heat● Efficient incinerator operating under ideal conditions may reduce the volume of solid

waste by up to 90 percent and the weight of the waste by approximately 75 percent● Heat is released as combustion rapidly converts much of the waste into carbon dioxide

and water, which are released into the atmosphere● Ash - residual inorganic material that does not combust during incineration● Bottom ash - residue collected underneath the furnace● Fly ash - residue collected beyond the furnace● Ash is typically ¼ of volume of precombustion material● Ash with low levels of contaminants can be released into landfill

○ If the ash is toxic, it goes to a special landfill for toxic material● Exhaust gases from the combustion process, such as sulfur dioxide and nitrogen oxides,

move through collectors and other devices that reduce their emission to the atmosphere● Acidic gases like HCL are neutralized and sometimes treated further before being

released in landfills● Waste-to-energy - When heat generated by incineration is used rather than released to

the atmosphere● In order to cover the costs of construction and operation of an incinerator, tipping fees

are charged○ $70 per U.S. ton

● The siting of an incinerator raises NIMBY and environmental justice issues similar to those of landfill siting

● Incinerators require large quantities of MSW daily to burn efficiently and be profitable● Hazardous waste - liquid, solid, gaseous, or sludge waste material that is harmful to

humans or ecosystems○ Ex. Oven cleaner, oil-based paints, motor oil, or chemical cleaners○ Only 5% of hazardous waste recycled each year

p. 452-455 (3/1/17)

● Every aspect of the treatment and disposal of hazardous waste is more expensive and more difficult than the disposition of ordinary MSW

● RCRA - (1976) protects human health and the natural environment by reducing or eliminating the generation of hazardous waste

○ Those who improperly dispose of hazardous waste get punished○ EPA maintains lists of hazardous wastes and works with businesses and state

and local authorities to make sure it’s thrown out properly● CERCLA - (1980) aka Superfund

○ imposes a tax on the chemical and petroleum industries○ tax funds cleanup of abandoned hazardous waste sites where a responsible

party cannot be established○ EPA maintains the National Priorities List (NPL) of contaminated sites that are

eligible for cleanup funds○ There’s at least one site in every state except North Dakota

● Love Canal○ A landfill that was covered and then use as a site for housing and schools○ Cancer causing chemicals found in basements of homes (1978-1980)○ Deemed a Superfund site and all inhabitants relocated (1983)○ Taken off NPL after cleanup finished in 1994

● CERCLA May not receive enough funding to clean up all Superfund sites○ Superfund sites only include top priority sites

● Brownfields program allows state and local gov’t to clean up less prioritized hazards● Brownfields - are contaminated industrial or commercial sites that may require

environmental cleanup before they can be redeveloped or expanded○ Seattle’s Gasworks Park- a famous brownfield that was a coal and oil gasification

plant, but is now a park○ criticized as an inadequate solution because

■ Management varies from region to region■ Lack authority to make polluters clean up their properties

● Sometimes US garbage and ash barges cross the seas looking for third-world countries that would accept their hazardous waste in exchange for money

○ Cargo vessel Khian Sea left Philadelphia with almost 13,000 metric tons of hazardous ash (1986)

○ Some was dumped in Haiti and some straight into ocean○ Haiti ash was brought back to US in ‘96 and placed in landfill after being deemed

non-hazardous● Sometimes hazardous waste is generated by other countries and sent to US● Tamil Nadu, India sent 270 metric tons of mercury to a mercury recovery plant in

Pennsylvania○ Mercury was concentrated, purified, and then sold to industrial users

● Life-cycle analysis - looks at the materials used and released throughout the lifetime of a product

○ This can be useful in determining whether trash should go in the incinerator or landfill

● Sometimes it's not possible to determine this○ Ex. It's hard to decide whether it's better for food waste to produce nitrogen

oxides in an incinerator, or produce methane in a landfill● The best choice for disposing of food waste might be to compost it● Life-cycle analysis is more useful for economic and energy impact than environmental

impact● Considering all the competing factors in life-cycle analysis is very challenging and the

ultimate decisions based on such analyses are often debatable

p. 456-457 (3/2/17)

● Integrated Waste Management - employs several waste reduction, management, and disposal strategies in order to reduce the environmental impact of MSW

○ Includes source reduction and any combination of recycling, composting, use of landfills, incineration, and more

● If a region makes a large investment in an incinerator, for example, there is a risk that it would then need to attract large quantities of waste to pay for that incinerator, thereby reducing the incentive to recycle or use a landfill

● University of Virginia dean William McDonough and co-author, Michael Braungart, argue that

○ It is first necessary to assess existing practices in order to minimize waste generation before, during, and after manufacturing

○ Manufacturers of durable goods like automobiles and furniture should consider designing their products such that they can be taken apart and recycled easily after use

■ Volkswagen, for example, manufactures some of its cars so that they can be easily taken apart and materials of different composition easily separated to allow recycling

● Humans should take a note from turtles because they produce hard shells without creating any toxic waste

● Recycling E-Waste in Chile○ Electronics contain a large fraction of the hazardous waste that ends up in

landfills○ In Switzerland more than 80% of electronics are recycled, but in the US it's only

about 20%○ Chili recycle less than 1% of e-waste○ Recycla Chile of Santiago was established in 2005 and allowed its workers to

separate e-waste parts safely○ Some materials are sold to dealers in Chile, while others are compacted to

minimize shipping and energy costs and sent to environmentally certified metal smelters around the globe

p. 463-467 (3/2/17)● Norco Louisiana located between a chemical plant and an oil refinery● In 1973, a pipeline explosion blue house off its foundation and killed two residents● Times more people were killed from toxic chemicals in the air● Local resident, Margie Richard, organized the Concerned Citizens of Norco

○ She wanted Shell to by the citizens’ properties so they could move away

○ She tested the air and found that shell was releasing 2,000,000 pounds of toxic chemicals into the air annually

● In 2002, Shell agreed to purchase the homes of the Old Diamond neighborhood● They got hella money from it● Three major categories that harm human health

○ Physical■ Natural disaster■ UV radiation exposure

○ Biological■ Disease - any impaired function of the body with a characteristic set of

symptoms○ Chemical

■ Exposure to chemicals● Biological risks cause the most human deaths● Infectious disease - diseases caused by pathogens

○ Pneumonia and STDs● Only six types of illnesses account for 94% of all deaths caused by infectious disease● Chronic disease

○ Slowly impairs the functioning of a person's body○ Ex. Heart disease and cancer

● Acute disease○ Rapidly impairs the functioning of a person's body○ Ex. Ebola hemorrhagic fever

● Epidemic - when a pathogen causes a rapid increase in disease● Pandemic - when an epidemic occurs over a large geographical region● Plague - caused by an infection from a bacterium carried by fleas

○ Fleas carried by rats which comeni. Contact with humans○ Symptoms

■ Swollen glands, black spots on skin, extreme pain○ Killed ¼ of Europe in 1300s

● Malaria - caused by an infection from any one of several species of protists in genus Plasmodium

○ Carried by mosquitoes which transfer disease to humans○ Widespread spraying of DDT eradicated mosquitoes, but not effectively

● Tuberculosis - caused by bacterium the primarily and fix the lungs○ If someone coughs, the bacteria persists in the air until someone breathes it in○ Symptoms

■ Weakness, night sweats, coughing up blood○ Taking antibiotics for a year should cure you○ Two things could happen if you don't take the medicine for the full duration of

time■ The pathogen rebuilds inside the body■ Because the last few bacteria are generally the most drug resistant, this

could produce drug-resistant strains● New drugs are required to treat this strain, which could cost 100

times more than the regular drug

p. 471-475 (3/3/2017)● Neurotoxins

○ chemicals that disrupt the nervous systems of animals

○ Ex. lead and mercury

○ Insects are really sensitive to these and can become paralyzed and die

○ Damaging to human kidneys, brain, and nervous system

○ Gov’t required elimination of lead in gas and paint → lead exposure lowered in US

● Carcinogens○ Chemicals that cause cancer○ Two ways it damages cells

■ Tampering with normal metabolic processes of cell■ Damaging genetic material of cell

○ Mutagens - Carcinogens that cause damage to the genetic material■ Ex. asbestos, radon, formaldehyde, and tobacco chemicals

● Teratogens○ Chemicals that interfere with the normal development of embryos or fetuses

■ Ex. thalidomide was prescribed to pregnant women during the late 1950s and early 1960s to combat morning sickness and caused their kids to have birth defects

○ Ex. alcohol reduces the growth of the fetus and damages the brain and nervous system

● Allergens○ Chemicals that cause allergic reactions○ Abnormal response from immune system causes breathing difficulties and even

death○ Ex. chemicals in peanuts and milk and several drugs including penicillin and

codeine● Endocrine disruptors

○ Chemicals that interfere with the normal functioning of hormones in an animal’s body

○ Hormones released into bloodstream bind to cells that regulates bodily functions

○ The hormones in wastewater from animal-rearing facilities, pesticides, and birth control pills ends up in waterways and feminizes male fish and amphibians!

■ Testes would produce low sperm count or both eggs and sperm● Endocrine disruptors disrupts the conversion of estrogen into

testosterone● Dose-response studies - expose animals or plants to different amounts of a chemical

and then observe a variety of possible responses including mortality or changes in behavior or reproduction

○ Chemical amount is either measured as concentration or dose○ Lasts for 1 to 4 days○ An acute study - a short study○ Measures mortality as a response

■ When # of mortalities per dose is graphed, S-shaped curve appears■ Rats and mice represent all mammals ■ Pigeons and quails represent all birds■ Trout represent all fish■ Water fleas represent all invertebrates

● Threshold - the dose at which an effect can be detected● LD50 - lethal dose that kills 50 percent of the individuals

○ Assesses relative toxicity of a chemical○ Helps to determine whether a new chemical is more or less lethal in comparison

to other chemicals● Sublethal effects - the effects of chemicals acting as a teratogen, carcinogen, or

neurotoxin that could alter the behavior of an individual● ED50- effective dose that causes 50 percent of the individuals to display the harmful, but

nonlethal, effect● Toxic Substances Control Act - gives EPA the authority to regulate many chemicals,

excluding food, cosmetics, and pesticides (1976)● Federal Insecticide, Fungicide, and Rodenticide Act- pesticide manufacturers must state

how their product "will not generally cause unreasonable adverse effects on the environment" (1996)

● Scientists test on the most sensitive species of animal groups to create a more inclusive treatment for chemicals

● Amphibians or reptiles because standards for testing chemicals were set up before there was much interest in protecting them

● A safe concentration is obtained by taking the LD50 value and dividing it by 10● Since it’s unethical to test on humans, chemicals are tested on mice and the

extrapolated to humans○ LD50 or ED50 values are divided by 10 to determine safe concentrations for

mice and rats○ Divided by 10 two more times to ensure safety for humans (Divide by 1,000)

● Chronic studies - experiments of longer duration○ Last from the time an organism is very young to when it is old enough to

reproduce○ Used for examining the long-term effects of chemicals

p. 476-478 (3/6/17)● Epidemiology - a field of science that strives to understand the causes of illness

and disease in human and wildlife populations○ Retrospective studies

■ Monitor people who have been exposed to a chemical at some time in the past

■ Compare health problems of exposed group w/ and unexposed group over years

■ When 80,000 lbs of hazardous methyl isocyanate gas was released in Bhopal, retrospective studies found that 100,000 people are still suffering 20 yrs later

○ Prospective studies■ Monitor people who might become exposed to harmful chemicals in the

future■ Scientists ask 1,000 participants to keep track of diet, tobacco use, and

the alcohol they drink for the next 40 years■ Challenging because a participant’s habits, such as tobacco use, can also

be associated with many other risk factors including socioeconomic status■ Synergistic interactions, in which two risks together cause more harm

than one would expect based on their individual risks● Ex. A tobacco user who is also exposed to asbestos is more at

risk■ 276 kids from Rochester, NY were put in a prospective study and those

who consumed lead had lower IQs● Routes of exposure - ways in which an individual might come into contact with a

chemical ○ Ex. bisphenol A is a chemical used in the manufacturing of hard plastic items

such as toys, food containers, and baby bottles■ Responsible for early puberty and increased rates of cancer

● Solubility - how well a chemical can dissolve in a liquid○ Water-soluble chemicals pervasive in groundwater and surface waters○ Fats/oils-soluble chemicals found in soils

● Bioaccumulation - increased concentration of a chemical within an organism over time○ An animal incorporates small amount of chemical into fats and tissues and it

accumulates over time○ Rate of accumulation depends on concentration in environment, rate of

consumption, rate of chemical breakdown in body, and rate of excretion○ EX. fish drink in water-soluble chemicals, breathe it in, and eat food that has it

● Biomagnification - the increase in chemical concentration in animal tissues as the chemical moves up the food chain

○ Primary consumer incorporates chemical○ Secondary consumer eats primary consumer and bioaccumulates chemical○ Ex. DDT sprayed on water → zooplankton eat bacteria →

bioaccumulates → fish eat zooplankton → bioaccumulates → large fish eat small fish → bioaccumulates → birds eat fish → bioaccumulates -> birds produce thin-shelled eggs that break when incubated by mother

● Persistence - how long a chemical remains in the environment○ Depends on temp, pH, whether the chemical is in water or soil, whether the

chemical can be degraded by sunlight, and whether the chemical can be broken down by microbes

○ Measured by calculating half-life○ Modern chemicals are designed to break down much more rapidly so that any

unintended effects will be short-lived● Environmental hazard - anything in our environment that can potentially cause harm● Risk assessment

○ Qualitative of risk assessment■ Categorize as low, medium, or high risks

● Ex. choosing to slow down on a wet highway ■ Because our personal risk assessments are not quantitative, they often

do not match the actual risk■ Because catastrophic events like nuclear meltdown or plane crash are

heavily covered by media, perception is that these have greater risk than heart disease and secondhand smoke

○ Quantitative risk assessment■ Risk = probability of being exposed to hazard x probability of being

harmed by hazard■ Bring together tremendous amounts of data. The estimates of harm can

come from acute and chronic dose-response experiments, retrospective studies, and prospective studies

■ PCBs = damage in animals and impaired learning in human infants● Scientists found

○ Which concentration causes cancer○ Which concentration humans are exposed to daily

■ Calculate risk● Calculate how much risk is acceptable

○ Varies● Risk management

○ integrates the scientific data on risk assessment and the analysis of acceptable levels of risk with a number of additional factors including economic, social, ethical, and political issues

○ Ex. regulation of arsenic in drinking water■ Acceptable concentration of arsenic was 50 μg/L

● This amount can still cause cancer● EPA tried to lower it to 10 μg/L, but cost a lot of tax and miners

were burdened● Acceptable concentration returned to 50 μg/L● New risk assessment found balance between scientific data and

economic interests● Innocent-until-proven-guilty

principle - based on the philosophy that a potential hazard should not be considered a hazard until the scientific data can definitively demonstrate that a potential hazard actually causes harm

○ Pro: allows beneficial chemicals to be discovered more quickly

○ Con: harmful chemicals can affect humans or wildlife for decades before sufficient scientific evidence accumulates to confirm that they are harmful

● Precautionary principle - based on the philosophy that when a hazard is plausible but not yet certain, we should take actions to reduce or remove the hazard

○ Pro: fewer harmful chemicals will enter the environment; saves lives and money in damages/cleanup

○ Con: the slower pace of approval can reduce financial motivation of manufacturers to invest in research for new chemicals

● Use of precautionary principle has been growing everywhere except US● Stockholm Convention - an agreement that produced a list of 12 chemicals to be

banned, phased out, or reduced○ Twelve chemicals = “the dirty dozen”

● REACH - registration, evaluation, authorisation, and restriction of chemicals; an agreement on how chemicals should be regulated within the European Union

● Case study: Working Toward Sustainability○ Bill Gates was a philanthropist○ He saw that people were trying to eradicate malaria

■ It was eradicated in US due to widespread spraying of DDT, but it caused thinning eggshells, so method is not sound

○ Malaria is hard to eliminate because■ Mosquitoes rebound easily■ Mosquitoes can rapidly evolve resistance to insecticides such as DDT■ Malaria pathogen can rapidly evolve resistance to antimalarial drugs■ Eradicating malaria is expensive

○ Scientists came out w/ new drug that pairs with longer-lasting mosquito net to reduce malaria cases

○ Bill Gates increased malaria funding from $50 million to $1.1 billion○ Biggest problem: organizing distribution systems to hand out the drugs and

millions of mosquito tents○ Drug is sold for less than cost of manufacturing, which is a huge loss for

company, but save 550,000 lives

p. 409-413 (3/14/17)● Chattanooga, Tennessee had highest level of polluted air in US

○ Gov’t poured $40 mil into cleanup○ Ozone levels continued to rise because of cars

● Good ozone○ O3 that makes up the ozone layer in the stratosphere○ Protects earth from harmful UV rays from the sun

● Bad ozone○ O3 that appears in the troposphere

● Mountain inversions○ Warm air is closer to the ground and cold air is up above○ Particles supposed to rise and clear out, but mountains stop them○ Also, warm air acts as a lid and traps pollutants inside

p. 517-525 (3/27/17)● Polar bears eat seals● Seals live under ice, but ice is getting smaller● Scientists found that there was 25 to 39% less ice each year● Bear consumes the blubber of the seals and other animals such as the arctic fox

consumes the carcass● Indigenous people depend on polar bear for food and clothing● temperatures in the Arctic have risen much faster than in other parts of the world,

causing ice caps to melt● Polar bears have less time to hunt● Polar bears near Hudson Bay in Canada currently weigh 67 kg (150 pounds) less than

they weighed 30 years ago● Polar bears could go extinct● Seal population would increase, arctic fox population would decrease● While acknowledging that pollution and hunting contributed to the bears’ bleak future,

the nations agreed that the effect of global warming on the ice cap posed the greatest threat to polar bears

● Volcanic eruptions○ The sheer amount of ash that erupts can reflect sunlight back out into space,

causing earth to cool○ 1991: Mount Pinatubo in the Philippines erupted and spewed millions of tons of

ash into atmosphere■ 0.9°F decline in the temperature on the surface of the planet

● Methane○ Occurs in wetlands where decomposition is anaerobic○ Wetlands largest natural source of methane○ Animals that consume significant quantities of wood or grass, including termites

and grazing antelopes, require anaerobic gut bacteria to digest the plant material which produces methane instead of carbon dioxide

○ Second largest natural source of methane● Nitrous oxide

○ (N2O) produced through denitrification○ Occurs in the low-oxygen environments of wet soils and at the bottoms of

wetlands, lakes, and oceans● Water vapor

○ The most abundant greenhouse gas○ Greatest natural contributor to global warming○ Produced when liquid water from land and water bodies evaporates and by the

evapotranspiration process of plants● Fossil fuels

○ Organisms buried underground tens of millions of years ago without first decomposing into CO2

○ Organisms break down into carbon and become fossil fuels○ Since rate of burning fossil fuels into CO2 is faster than rate of atmosphere taking

CO2 out of air, pollution occurs○ Each type of fossil fuel produces different amounts of carbon dioxide

■ Coal produces most CO2, then oil, then natural gas○ Combustion of fossil fuels can release methane and nitrous oxides as well○ Particulate matter may be responsible for up to one-quarter of observed global

warming during the past century○ PM lands on ice and snow in high altitudes and absorbs radiation which

lowers albedo, causing ice to melt → PM concentration increases on earth’s surface → more radiation is absorbed → more ice melts

■ Positive feedback loop● Agricultural practices

○ Overirrigated fields produce methane○ Synthetic fertilizers, manures, and crops that naturally fix atmospheric nitrogen

produce nitrous oxide○ Cattle eats grass and gut bacteria anaerobically breaks it down

■ Feces releases methane

■ Decomposition taking place in an area with high amounts of oxygen would simply release CO2

● Deforestation○ When forests are destroyed by burning or decomposition and not replaced, net

destruction of vegetation will contribute to the increase in atmospheric CO2

○ Clearing forests and burning crops = major source of both particulates and a number of greenhouse gases, including CO2, methane, and nitrous oxide

● Landfills○ If landfills become too wet, methane is released

● Industrial production of new greenhouse chemicals○ CFCs are the chemicals used in refrigerants

■ Damage protective ozone layer○ Very high greenhouse warming potentials○ Montreal Protocol phased out production and use of CFCs by 1996○ Alternative refrigerants, like hydrochlorofluorocarbons (HCFCs), still have very

high greenhouse warming potentials○ Developed countries will phase out the use of HCFCs by 2030

● Major contributors of methane in atmosphere ○ Digestive processes of livestock○ Landfills○ Production of natural gas and petroleum products.

● Major contributor of nitrous oxide○ Agricultural soil that receives nitrogen from synthetic fertilizers○ Applications of manure as an organic fertilizer○ Nitrogen-fixing crops such as alfalfa

● Carbon dioxide in atmosphere○ 94% of all CO2 emissions come from the burning of fossil fuels

● In 1988 the United Nations and the World Meteorological Organization created the Intergovernmental Panel on Climate Change (IPCC)

○ Scientists that assess climate change○ Mission: to understand the details of the global warming system, the effects of

climate change on biodiversity and energy fluxes in ecosystems, and the economic and social effects of climate change

3/30/17● Thin Ice Video

○ Climate is just average temperature○ Must record temperature daily○ Dig into ice cores to find layers

■ Harvest snow that’s fallen over past few decades■ Measures chemistry and record how climate and weather is preserved in

snow■ Melt ice cores and measure composition of greenhouse gases

○ To understand the surface temperature of the planet, you must first understand the rate at which energy goes in and out of the atmosphere

○ The only way a planet can lose energy is it loses light energy○ Temperature correlates directly with CO2

○ Temperature all over the world is recorded over many decades and converted into a graph

■ It was found that the world has shown significant warming in the recent decade compared to past data

○ Sites on the ocean are visited multiple times every year to record depth of ocean and surface temperature

○ Algae is found in ice core, indicating climate was three to four degrees warmer than today