Midterm 1 Flashcards
Describe earth as a system
- earth is a system within which there are many substances
- energy enters and leaves
- matter is here to stay but cycles through subsystems
What are the layers of the earth’s atmosphere? Where do we experience weather and climate?
- troposphere: weather and climate, planes fly + tropospheric ozone
- stratosphere : atmospheric ozone
- mesosphere
- thermosphere
- exosphere
What are the temperatures of each layer of the atmosphere?
- troposphere: warm to cold
- stratosphere : cold to warm
- mesosphere: warm to cold
- thermosphere : cold to warm
- exosphere
What are the two forms of ozone? Where are they found?
- stratospheric ozone is ‘good ozone’
- tropospheric ozone: ‘bad ozone’
Describe the electromagnetic spectrum?
- different forms of radiation define the temperature of the object
- the sun emits mostly visible and near infrared light (it is 5500 C / 5800K)
- solar radiation comes in various EMR wavelengths
- 43% visible, 49% near infrared, 7% UV
Is all the energy from the sun the same EMR wavelength?
- no! Energy from the sun comes in various wavelengths: UV, near infrared, visible
Describe the peak forms of EMR energy from the earth and the sun + what is the earth’s effective temperature? What does this mean?
- the sun’s surface temperature is 5500 C, and its peak radiation is in visible wavelengths of light
- the earth’s effective temperature (it’s temp without an atmosphere) is -20 C, and its peak radiation is in thermal infrared wavelengths
Which has shorter wavelengths : the sun or the earth?
- the sun has far shorter wavelengths! - earth reflects longer, less energetic wavelengths back to space
Describe the normal ozone breakdown and formation?
- the shorter the wavelengths he more harmful UV radiation is to living organisms
- ozone naturally forms and breaks down as they absorb UV radiation
- typically ~10% of UV-B radiation gets to earth’s surface
Why is UV radiation harmful?
- UV harms the DNA molecules of living things in different ways
- one common form: UV causes the nucleotides to bind with each other rather than across the chain : causes a bulge and the DNA molecule doesn’t function properly
- UV is also damaging to shallow water marine organisms: urchin embryo has bulge
What other processes in the biosphere are impacted by UV radiation?
- photosynthesis: plants and phytoplankton
Describe the process of ozone formation and breakdown in the atmosphere?
- Oxygen + UV-C breaks down into two Oxygen molecules
–> Oxygen and Oxygen molecule forms Ozone O3 - hit with UV-B and breaks down into O and O2 - O + O3 forms 2 new oxygen molecules
What is the trend seen between CFCs and ozone?
- increase CFCS = decrease ozone
What are CFCs?
- chlorofluorocarbons: CF2Cl2
- ‘freon’ first synthesized in 1930’s
- used as coolants in fridges and air conditioners, used as propellants for spray cans, used to make foam cups and plates, non-toxic, combustible, volatile
How do CFCs break down?
- in CFC driven ozone breakdown:
- CFCs are released into the atmosphere
- UV-B breaks down and releases chlorine atom
- chlorine breaks down ozone into ClO and O2
- without ozone in stratosphere, more UV-B radiation reaches surface of the earth
Where is the largest area of ozone depletion in the atmosphere? Why?
- above Antarctica in the spine (September/October)
- 3 conditions met:
- cold: polar vortex and polar stratospheric clouds
- Chlorine in the atmosphere (due to CFCs)
- increased sunlight from springtime
What unit of measurement is used for ozone?
- the density of ozone is measured in Dobson units
What about polar stratospheric clouds is ideal for ozone breakdown?
- the frozen crystals making up polar stratospheric clouds provide a surface for the reactions that free chlorine atoms into the antarctic atmosphere
What molecule indicates ozone depletion?
the presence of CLO’s is a good indicator: is it a product of the breakdown of CFCs and ozone and is not formed naturally
How do PSCs impact the breakdown of CFCs?
- typically the breakdown of CFCs would occur very slowly and release more stable compounds
- the presence of PSCs allows for heterogenous reactions to occur: gaseous molecules stick to the solid particles (frozen water) and accelerates the rate of ozone depletion
- in the polar spring increase UV breaks down ozone
What is the key takeaway considering PSCs and heterogenous reactions
- heterogeneous reactions are critical to polar stratospheric chemistry
- allows slow/impossible reactions to occur efficiently and drives seasonal ozone depletion
What are the different ways to measure ozone?
- light sensors: uses Dobson spectrophotometer to measure how much light comes in from space
- satellites: measures ozone levels from space based on how much light is reflected
- ozonesondes: a sensor that provides ozone profile by sending it via weather balloon into different levels of the atmosphere: sensor has a source of potassium iodide which acts with ozone and provides a proportional amount of electricity
What is the Montreal protocol?
- addressed ozone depletion: 1987 180 countries agreed to reduce their CFC production by half
- depended cuts, addressed other prove,s, advanced time tables: by 2009 it was ratified by all countries of the world
- today production has decreased by 95%
- ozone is healing; set to mend by 2050
challenges: CFCs remain in atmosphere a long time, replacements are potent greenhouse gases that are now also being phased out
What did the MP do correctly to help it be so successful?
- used cautionary Principle
- policy makers and industry worked together to develop replacement chemicals
- used adaptive management as new s scientific data was procured
What are air pollutants?
- gases and particular matter added to the atmosphere naturally o anthropogenically that can affect climate or harm organisms
- have recently decreased due to government policy and improved technology in developed countries, still an issue in developing nations and urban areas
What are some types of air pollutants?
point source and non point source, transboundary, primary and secondary sources,
What are primary air pollutants? Secondary pollutants?
- primary: remain as they are
- secondary: pollutant formed in the lower atmosphere by chemical reactions (ozone, sulfuric acid, nitric acid)
Describe outdoor air pollution
- outdoor air pollution includes chemicals and small particle in the atmosphere that can be natural in origin or from humans
What is acid deposition?
- increased acid in the atmosphere leads to acid rain, etc
- not harmful to humans but threatens terrestrial and marine ecosystems, and infrastructure
- leads to acidified water, soil, acidified fog
What is the critical load for acidification? What is the critical load for lakes in NS?
the most amount of acid precipitation an ecosystem can endure before long term harmful effects occur
- in NS critical load is 8kg of sulphate / hectare/ year
Why is size important for particulate matter?
- smaller particles are more harmful because they can be more easily taken up by tissue
What is the Canadian Environmental Protection Act 1999?
- lists air pollutant subjected to legislative control and monitoring by categories:
- criteria air contaminants
- toxic air pollinates
- heavy metals
- persistent organic pollutants
Has air pollution deceased at all?
- monitoring shows that air pollutants have decreased in concentration
Is CO2 considered a toxic pollutant?
- it was added the the CEPA list in 2005
- EP CONSDIERS it toxic so regulated in states too
What are the challenges with preventing the release of air pollutants?
- a simple solution but industry needs a reason to pursue ways to decrease air pollution
- policies often needed to encourage less pollution
- technology (smoke stack scrubbers) + policies: subsidies/grants, market driven initiatives (cap and trade), penalties, green taxes
What is the premise behind a cap and trade program that controls air pollution?
- an upper limit is set for pollution, but if one produces less they can sell part of their allotment to another factory who produced too much
What are some examples of air pollution?
the great smog in London (industrial smog) Ontario photochemical smog
What are the main components of industrial smog?
- soot (carbon), sulfuneic acid, ammonium sulphate
- burning coal also releases mercury and sulphur
What is photochemical smog?
- ground level ozone is a secondary pollutant
- ground level ozone + PM2.5 + SO2 + NOX = photochemical smog
describe ozone formation and scavenging
- ozone formation: O2 + VOC + NO2 + sun = O3
- ozone scavenging (night) : O3 +NO –> O2 + NO2
How does ozone and photochemical smog impact human health?
- irritates respiratory tract and eyes, chest tightness, coughing, wheezing, children active on hot summer days at risk, linked to hospitalization and premature death
-
Why is southern Ontario most at risk for ozone and smog illness?
- southern Ontario has the highest recoding for ozone and PM2.5 In Canada
- due thigh density industrial/transportation emissions, transboundary pollution from American midwest, weather conditions: hot summer exacerbate ozone formation
How has southern Ontario dealt with/reduced pollution?
- Ontario has comprehensive air monitoring system: 39 monitoring sites
- created ambient air quality criteria: sets goals for acceptable concentration of air pollutants with targets to remain below these levels
- regulation, covid, etc etc etc omg
What keeps the earth warm?
- the sun: provides the radiant heat energy
- the atmosphere: absorbs and emit radiant energy, transports heat around the globe, latent head and conviction
- the oceans: shaped climate by storing and transporting heat/moisture
Describe temperature, internal temperature, heat, and the forms of heat transfer
- temperature is the average speed of molecules of an object (kinetic energy = always moving)
- heat is the transfer of energy from different temperature objects
- internal temperature : the energy stored within a group of molecules
- forms of heat transfer:
radiation, convection, conduction, latent heat
What is latent heat?
- energy required to change a substance from one state to another
- latent means hidden
- latent heat is an important source of atmospheric energy
Provide an example of latent heat
- every time a cloud forms it warms the atmosphere
- warm tropical water evaporates and blows to the poles, where it condenses and loses heat energy (convection)
what is conduction? what is convection ?
- conduction: energy transferred from one molecule to another within a substance
- convection: transfer of heat by mass movement of a fluid (water or air eg)
Describe the relationship between the temperature of objects and wavelength
- objects at high temperatures (greater than 500C) emit waves with many lengths
- the sun emits many wavelengths but because it is so hot most are short wavelengths (look at all and we obtain the sun’s EMR spectrum)
What is some evidence that the type of energy corresponds to the temperature to the object?
- the sun’s peak energy is in visible and near infrared while the earth’s (15C) is thermal infrared
Why is the atmosphere a selective absorber? What does this lead to?
- the atmosphere does not act like a blackbody as the earth does: instead, it absorbs certain wavelengths and is invisible to others
- objects that selectively absorb and emit radiation are known as selective absorbers
- the atmosphere is a selective absorber which leads to the greenhouse effect
What is a selective absorber?
- objects that selectively absorb and emit radiation
describe the first step of energy entering the earth system from the sun
- energy enters, 70% reaches the surface and 30% bounces off of dust particles, clouds, etc.
- the energy that does make it to the ground is absorbed by other things
What is albedo? What has a high and low albedo on earth?
- albedo is the amount of light reflected off a surface
- snow has a high albedo, while the ocean has a low albedo absorbs 90% of the energy
Do cold or warm objects emit more energy?
- warm objects: as the earth reflects energy back into space it Is less than incoming from sun, and longer wavelengths
What happens to most energy that is reflected off of the earth’s surface?
- most is caught in the atmosphere by clouds and gases : only small windows allow for direct escape
- the energy that is caught is reflected in all directions, some of which further warms the earth (greenhouse effect)
Which processes balance the surface energy budget of the earth?
- thermals and evaporation
- all forms of incoming/outgoing radiation has led to the perfect conditions for us here on earth
Describe how the greenhouse effect is warming the planet
- earth’s energy balance = equilibrium, where energy in = energy out, and the temperature stays constant
- increases gases in the atmosphere capture more energy going out and warms the planet
What are climate forcers?
- factors that can affect the climate and alter the energy balance
- positive climate forcers: things that warm the planet (eg; burning fossil fuels)
- negative climate forcers: things that cool the climate
What is thought to be responsible for glacial cycles?
- systematic changes of the distance/orientation of the earth relative to the sun
- right now, the earth is at a 23.4 degree tilt
What are climate feedbacks?
- our climate does not change in a linear fashion
- positive feedbacks (self perpetuating) and negative feedbacks (self regulating)
- our climate is full of climate feedbacks!!
What are some examples of climate feedbacks on our planet?
- ice melt: increased temperature leads to ice melt leads to more water to absorb heat rather than reflect it
- cloud formation: warmer temperatures = more evaporation = more cloud formation = more reflection = cooling = back to warmer temperatures: positive feedback
What are the greenhouse gases?
- water vapour, methane, ground level ozone, NOx, CO2, CFCs/HFCs
What makes a greenhouse gas a greenhouse gas?
- a gas that can absorb and emit infrared radiation and trap heat in the atmosphere
- molecules which vibrate in response to certain wavelengths (selective absorption)
- present in the atmosphere
- partial polarity, asymmetrical bonds
What are criteria air pollutants?
- pollutants regulated by national environmental agencies as they pose a threat to human and environmental health at the concentrations they are released at
- have regulatory standards based on health and environmental criteria
- monitored for compliance to ambient air quality standards
What ARE the criteria air pollutants?
- lead, NOx, PM2.5, SO2, CO
What are the 3 natural climate forcers?
- the sun, the proximity of the earth to the sun, anthropogenic climate forcers: deforestation, land use, burning of fossil fuels, agriculture, waste management, CFCs/HFCs, etc.
What is climate?
- Refers to time and space pattern of temperature, precipitation, and wind
What is climate change?
a change in the pattern over space and time
Why should we be interested in climate change?
- climate determines where we can do agriculture, the quantity and quality of freshwater we can use, the weathering of rock and the type of soil formed + the rate, the severity of storms droughts and floods, determines biomes and species distributions, etc
How much has the average global temperature risen by?
- it has risen by 1.1 degrees C over the last century
- rising much faster than pre-industrial times (~0.02 C per year)
How do we study climate?
- historical temperature records using thermometers date back to 1850
- prior to that, the paleoclimate is studied through paleoclimatology: the study of ancient climate before the period of instrumental measurements
- uses proxy indicators: indirect measurements to replace direct ones
what is one very good indicator of the paleoclimate?
- ice sheets: atmospheric air bubbles trapped deep in the ice from when it formed
What is thought to be the reason for period glacial periods of the earth?
- ## the orientation and proximity of the earth to the sun
What are the rates of temperature of the earth now and in the past?
- today, global temperature rise of 0.02 C per year
- ancient levels recovering from glacial periods are 0.0013 C per year
Is the addition of GHG to the atmosphere a positive or negative climate enforcer? Which is the greatest contributor to climate change?
- positive: warms the climate !
- CO2 is not the only GHG but it has the greatest impact
What are some anthropogenic sources of CO2?
humans have shifted the balance between carbon cycles: moving more between sinks
- deforestation, burning fossil fuels, moves carbon into atmosphere ,ocean absorbs
- because of land use change, cement production, electricity generation, transportation emissions
As average temperatures rise what do we expect to see more of?
- more severe storms, sea level rise, ice melt, higher average temperature, higher peak temperatures, warming ocean, impacts on biodiversity, increased precipitation in coastal areas
Describe the risks of melting ice and snow
- normally snow accumulates in winter and is released slowly through the summer
- many communities rely on snow melt for freshwater
- more than 1/6 of the world’s population lives in region supplied by snow melt
- melting increases risk of sudden flooding if ice dam breaks
- uncertainty with how melting permafrost will change in arctic
- but we know that it will release carbon dioxide and methane and threaten infrastructure
What is a glacier?
- a large accumulation of ice that moves down slope with gravity
- found in arctic, antarctic, and even high altitudes of tropical regions
What is an ice sheet?
- a large glacier that expands beyond 50,000 km squared: Antarctic ice sheet and Greenland ice sheet
What is sea ice?
- ice that covers the ocean
How can we interpret glacial retreat?
- by observing pictures decades apart at the same location
Which part of the world is experiencing intense impacts of climate change?
- Arctic is warming four times faster than the rest of the globe since 1979
What are the impacts of warming of arctic sea ice?
- decreases albedo = increased thermal absorption
What are the impacts of warming in Antarctica?
- more intense
- between 2000-2020 21 ice shelves have broken apart
- ice shelves acts as a ‘bookend’ for ice sheets and glaciers : a collapsed ice shelf means that ice sheets move faster towards the ocean leading to sea level rise : CONTRIBUTES TO 3% OF SEA LEVEL RISE
what are some reasons that coastal communities might be impacted by climate change?
- rising sea levels (ice melting and thermal expansion) and increased frequency/severity of storms
- eg; Maldives and Tuvalu at risk
Have scientists decided which factors are responsible for climate change?
- scientists model both natural and humans factors to determine which best explains observed climate changes
- they have attributed climate change to both natural and human factors
- the last 3 decades temperatures have increased rapidly due to human impacts
What are some impacts climate change on biodiversity?
- pests are destroying forests worldwide as the summers are no longer cold enough to kill beetles
- coral reefs are experiencing coral bleaching due to warming waters
- some species expanding their range further north
- penguin breeding failure, 17,000 trees at risk from climate change
What are some of the impacts of the changing climate on humans? How can we address them?
- crop loss, biodiversity loss, fires, increased storms droughts, fires, rising sea levels/coastal erosion
- mitigation is needed to limit change but adaptation will be required
Why might adaptation be required if mitigating climate change is implemented?
- change is already here. The effects of climate change are in motion and irreversible.
- adaptation and mitigation will be needed
What does the IPCC report provide to address climate change?
- they suggest mitigation strategies to keep temperature warming below 1.5-2.0 degrees celsius
- carbon dioxide budget: how much more we can put into the atmosphere and how much we must capture
What is the wedge approach?
- any 8 of the 15 methods can stabilize CO2 in the atmosphere
- time is of the essence: the longer we wait the more wedges are required
What is project drawdown?
- Drawdown is the point at which CO2 levels stop increasing and begin to steadily decline
- game over or game on!
- created list of activities: applied, hands-on practices, technologically and commonly available and scientifically valid
- almost all processes lead to economic regenerative outcomes
Why is project drawdown good even if it DIDN’T reduce emissions ?
- almost all proposed processes have regenerative economic outcomes: support society regardless
- BUT drawdown is good for the planet and the people!
What were some major themes of project drawdown?
- improve efficiency: less food waste, heat pumps, improve mass transit
- generate electricity from renewable sources: not carbon based
- electricity energy including transportation
- social changes - behavioural changes: change our diets, consumption patterns, transportation decisions, EDUCATION
- target solutions where they will be most effective to start: fighting climate change is good for the planet and people
What are milankovitch cycles?
these refer to the position of the earth relative to the sun
- the angle of the earth, its position relative to the sun, and the shape of its orbit are thought to be responsible for the glacial periods on earth (natural climate change)
How many earths are required to sustain our current lifestyles?
1.5 planets
- overshoot day is the day in the year when we exceed the annual resource allowance
What is an ecological footprint? what is biocapacity?
- ecological footprint is a measurement of how much land (ha) we need to produce resources and absorb waste
- biocapacity is the amount of biologically productive area available to produce resources and absorb waste
What is an ecological creditor? An ecological debtor?
- ecological creditor is an area that has a lot of resources and can sustain itself: eg, Canada and the Congo have enough resources to sustain the entire nation
- ecological debtor, like the US, does not have enough land to support the lifestyle
What percentage of the world uses the most resources?
- 17% of the global population uses 80% of global resources
- consumption is inefficient and uneven
What is the triple bottom line?
- people, planet, profit
- environment > society > economy
What are some solutions suggested by project drawdown (top 10)?
- plant rich diet, reduce food waste, family planning and education, clean cooking, tropical forest restoration, etc
What was it that interface carpets just didn’t get ?
- why was it no enough, from an environmental point of view, to just follow the law
What is economics?
- the social science that deals with the production, consumption and distribution of goods and services
- more than just money, also concerned with ecological services provided by the environment
What big ideas are missing from our current economic system?
- sustainability
- our economy is tied to the natural environment
What is sustainability?
- using a resource / action that can be continued without degrading the environment
What are some assumptions of mainstream economics?
- human and natural resources are infinite, or easily replaceable
- value current good higher than those of the future
- only internal costs are considered
- economic growth can go on forever
- there is an “away”, we can operate in a linear sequence
What are the realities of the earth’s ecosystems as contrasted to the mainstream economic assumptions?
- resources are not always infinite or easily substitutable
- sustainability relies on future resources
- there are many external costs
- ecosystems function in a steady state
Describe why natural and Human Resources being infinite or easily substitutable is a misconception?
- some certainly can be replaced - others are non-renewable
- can we depend on the replacement once exhausted
- many natural processes are costly to replace with artificial technology
Describe why long term effects being discounted is a problem
- decisions are made that maximize short term benefits despite having long term costs
Are costs and benefits only internal to the transaction at hand ?
- assumptions that costs/benefits do not impact other members of society
- internal pricing ignores the environmental / social costs of business
Is the growth paradigm good for us?
- the dramatic rise in per person consumption has dramatic consequences
- critics fear that economic growth will destroy the economic system on which we all depend
- resources are not infinite so how can growth be infinite
Do all forms of economic growth require the use of finite resources?
- there are some forms of economic pursuit that has the capacity to keep growing without using more resources
- like ecotourism, and a service economy: providing services rather than goods
What does it mean for our economy to be based on a linear system?
- energy and resources extracted –> social and business economy –> waste
- no regard for how resources will be replenished
What are ecological economics?
- considers the long term impacts on the well being of humans and the environment
- closed loop system, efficient, reduction, valuing resources, reduction non renewable, no product focused economy
What are ecosystem services?
- ## essential processes that make life on earth possible
What is natural capital and natural interest?
- capital: how much we had to begin
- interest : how much it changes
What is the impact equation?
I = PAT (with efficient tech can become I = PA/T)
What are internal costs? External costs?
- costs included in the pricing of the item ; materials, labour, extraction costs, taxes, utilities, etc
- external costs: costs not considered in pricing of item; cleanup, environmental stress, health problems
- cost of external is passed on to a third party who does not benefit from the transaction
What are true costs?
- accounts for both internal and external costs
provide an example of external costs in NS?
- Boat harbour pulp mill NS: shut down, effluent discharged into harbour
- left to government to clean up, ~300 million
- did not consider external costs!
What is a circular economy?
- a production in which the product is returned to the resource stream when consumes finished with it or it is disposed in a way that can be decomposed by nature
- No landfill!
What does cradle to cradle mean?
- refers to management of a resource during its use at every stage, from raw material to disposal/recycling
What is a service economy?
- business whose focus is on leasing/caring for a product in the customers possession rather than the product itself: sells the service not the product
How did interface change to better fit an ecological economy?
- became a service economy based company, reused carpets, bought back
What is an ecological economist? What are they primarily interested in?
- they study the environmental and resource impacts of human activity/our choices : keen interest due to limited information that economic analysis provides
- less interested in what people pay and more interested in what the energetic / environmental inputs to create those products are
What is a finite ecosphere? What is out growing economic subsystem based on?
- finite ecosphere means energy enters and waste energy leaves, all else (matter) is finite and stays
- growing economic subsystem is based on energy in, matter in, energy out, matter out (acts as if resources are infinite)
How would an environmental economist suggest we better understand limiting energy and matter waste?
- Life Cycle Assessments!
What are lifecycle assessments?
- came about within the last 25 years
- based on the 50 year history to understand impact and extend of material and energy flows to sustain human activity
- LCA follows production (energy and resource requirements) from point of extraction, processing, transport, packaging, selling, waste/recycling
- follows from cradle to grave
What period of the life cycle makes up the majority of the LCA?
- prior to packaging!
Describe the LCA of salmon?
- salmon shows that life cycle impacts are greatly: transportation and how it is raised really do matter: frozen is better unless buying fresh, then buy local (speed kills, must transport fish via air travel)
- further, food: not the type of food but the AMOUNT of food
Describe the major impacts of lobster from an LCA perspective
- high fuel consumption for transportation (high air travel, low truck: same distance, drastically different energy use)
- fuel use
Describe the fundamentals of energy and its elimination from Micheal Metzger’s lecture
- 1kWh = 1000 W / hour = 100 ml of gasoline (high energy density)
- several countries state 100% electric 2030-2035: must move electricity/heating away from fossil fuels: requires renewable energies on a massive scale
- must also move transportation and energy production away from fossil fuels
Why are coal and oil so significant In energy production? Where is the majority of loss?
- oil and coal are by far the greatest energy producers
- Lankey Diagram shows that most energy loss comes from transportation and electricity sectors: from inefficiency/heat loss
Is it possible to satisfy all the energy needs with PV?
- yes! We would need 6 300x300 km^2 PV facilities
- plenty of solar energy but need to be able to store energy for nights and times of high energy demand
What are the two challenges associated with providing energy through PVs ?
- need a method to store solar energy for night/times of high demand
- must compete with prices of coal/oil: electricity would be cheaper overall if we used renewables (reduces inefficiency)
What is one major economic benefit from switching to renewables?
- to produce energy, renewables are overall cheaper because they reduce inefficiency
What are peak and base loads? What does it mean to “shave the peak”?
- base load is the energy required all of the time (~30% of total energy demand), peak is energy needed during times of high demand (weekdays morning, lunch, evening, and overall less on weekends)
- shave the peak means storing energy during times when demand is low and using it when demand is high: make energy production requirements lower
How does energy storage impact the energy grid?
- makes the grid more stable! (less stress during times of high demand)
What is hydroelectricity in terms of energy storage?
- suitable for energy storage: high energy conversion efficiency
- only two places that have enough height between water reservoirs : sites are rare
What is a gravity energy storage system?
- towers with cranes lift bricks up, store energy as kinetic energy: drop and become electrical energy
- not very efficient, not a very high energy density
Why do renewable energies have a ‘lifespan’?
technologies and infrastructure are not indefinite: eg dams are generational, nuclear power plants must be updated and maintained
What other forms of energy storage are there?
- lithium ion batteries: can store energy for mobile (eliminates gas) and stationary (Wind and solar) purposes
- graphite, electrolyte (lithium salt), and positive electrode crystals: make lithium ions travel back and forth rapidly as many times as possible
- ‘the million mile battery’
- affordable!
What are the non renewable sources of energy?
- coal: stationary, natural gas :stationary, oil: mobile: fossil fuels
- nuclear: stationary
Describe coal formation?
-plants decompose: under anaerobic conditions + slow decomposition and pressure = coal
- burning fossil fuels break covalent bonds and forms energy: high energy density : small amount = high yield
- coal contains carbon, mercury, sulphur, hydrogen
What is EROEI?
Energy return of energy input
- describes the efficiency of extraction, how much energy is put in
Rank the EROEI of stationary source of electricity
hydroelectric > PV > Wind > Coal > nuclear > Geothermal > Natural Gas
Describe the methods of mining for coal
- strip mining: in strips, replaces it and regenerates area
- subsurface mining: underground: hazardous for people working/living in area - increased cost from health hazards (disasters and health issues like black lung)
- mountain top removal
Describe mountain top removal
- 7 tonnes of overburden removed for 1 tonne of coal
- increases PM2.5 for workers/residents in those states
What is acid mine drainage?
- surface water and oxygen combines newly exposed rock (from overburden) containing sulphur contains minerals to form sulphuric acid
- sulphuric acid dissolves heavy metals leaching from rock from exposure to the acid
- sulphuric acid lowers pH and increase concentrations of heavy metal
- heavy metals dissolve in water and flow down streams: harms freshwater systems and ecosystems (fish, plants, etc)
What is one example of an acid mine drainage spill?
- dike holding sludge in a holding pond broke, releasing 300 million gallons of toxic sludge into the big sandy river in Martin Country, Kentucky
- the sludge killed all life in smaller streams and made it 20 miles down to the Ohio River
What are the benefits of coal?
- high energy density
- easy to transport: rail
- accessible: found in many places around the world
Describe the coal fired power plant
- coal burns, heats water which creates steam and drives the turbines
- releases methane, carbon dioxide, sulphur, mercury, and PM2.5, arsenic
- also, fly ash released
Describe carbon capture and storage
- small scale and costly
- a part of the climate solution
- requires energy: Lowers the EROEI: carbon dioxide captured with a solvent –> separated from solvent, some CO2 used for industry, remaining buried
What are some other forms of carbon storage technology?
- clean coal: remove mercury and sulphur before it is burned
- smokestack scrubber: catch sulphur
- electrostatic precipitator: catches 99% of fly emissions
- low NOx combustion systems
Describe the current status of coal usage?
- Developing nations (china and India) whose economies are growing are increasing use of coal
- developed nations beginning to phase out coal
- in 2016 Canada announced its goal to phase out unabated coal power plants: between 2005 and 2021 Canada has reduced power generation from coal by 66%
How is oil and gas formed?
- formed from dead marine organisms which sank to ocean floor: time and heat forms oil!
- much deeper underground, harder to access than coal
- requires more drilling + more spread out
How is most conventional oil obtained? How is most unconventional oil obtained?
- conventional: drilling
- unconventional: through fracking
Describe oil and gas
- world’s most useful fuel
- modern extraction started I 1850s
- oil forms in a narrow window: 3000-9000m down
Describe the process of oil discovery and extraction
- geologists predict where oil is using seismic testing (CAT scan of ocean floor)
- oil companies drill an exploratory well to see if prediction is correct
- then drill a primary/secondary well
- if the oil is valuable enough, tertiary extraction occurs: uses the same injection well but oil is forced out with water, CO2, or natural gas (can extract 75% this way!)
Is natural gas often harvested when drilling for oil?
- natural gas is often flared (burned) and not collected for logistic reasons
Where does drilling for oil take place?
- on land or on the sea floor on the continental shelf
- offshore sites: strong fixed platforms or floating platforms
How is oil used and how is it transported?
- oil is transported via trucks, pipeline, ship, or rail
- petrochemical industry: chemicals used as raw material for pesticides, plastics, and synthetic fibres
- oil used for heating oil, gasoline transportation, and asphalt
Describe natural gas as a source for energy + how is it extracted?
- more ‘recently’ been widely used
- primarily methane CH4
- first extraction 1821: used locally, too dangerous to transport
- 1st commercial export in 1908
- 1950s-60s: hundreds of km of pipeline built in Canada
- extracted in a similar way to oil: drilling and flows freely or pump it out
- natural gas can be burned to heat spaces/water, propel vehicles, generate electricity
- use expected to increase as it is fairly abundant
- transportation difficult: uses pipelines
- releases much less CO2 (30-40% less than coal)
- called the transition ga or bridge fossil fuel
How much cleaner is natural gas compared to coal?
- natural gas releases 30-40% less CO2 than coal because it has less impurities
What kind of damage can occur from fossil fuels?
- explosions, oil spills, habitat loss, habitat fragmentation, wildlife disruption, air pollution, etc etc.
Describe unconventional oil reserves
- some oil is in places harder to access that cannot be accessed with typical oil extraction methods : may be accessed through other methods
-tight oil (shale oil), shale gas, tar/oil sands - as oil prices get higher unconventional oil sources become economically viable
Describe Alberta oil sands
- covers 140,000 km2 of boreal forest
- contains 16 billion barrels of economically feasible oil
- the 4th largest oil reserve in the world (after Venezuela, Saudi Arabia, Iran)
What are oil sands?
- each grain of sand surrounded by a layer of water and a film of bitumen
- 2 tonnes of sand must be extracted for every 1 barrel of oil
- 3:1 energy ratio: 30% of energy goes to extraction (heating, mining, hot water - waste water also produced)
Describe the steps of oil sand extraction and purification
- hot water/mechanical energy –> or preparation: hot/warm water –> bitumen extraction/: gravity separated –> froth treatment
Where is water stored once used?
- water is reused/recycled until it can’t be anymore: then it is stored in a tailing pond
- tailing ponds larger than Vancouver and Toronto combined
where does most of the crude (unrefined) oil produced in Canada go?
- 80% is exported, majority of that goes to the US
What are the trade-offs of oil sands?
- high energy yield
- not very clean
- threatens indigenous land rights
- high water/energy inputs
- habitat destruction/loss
- highest carbon footprint of any fossil fuel extraction method
- difficult to transport: pipelines must be heated
Why is oil and gas difficult to transport?
- uses pipelines which must be heated!
What does all nuclear power go towards?
- 100% of nuclear power goes towards generating electricity
What is nuclear power?
- atoms undergo nuclear fission and create power which heats water producing steam and spinning turbine
what are atoms?
the simplest form of an element that still maintains the characteristic of the element
- elements are composed of all the same atoms
- atoms are made up of subatomic particles: protons, neutrons, and electrons
- protons define the type of element (all forms of one elements have the same number of protons)
What are isotopes?
- there are atoms with different numbers of neutrons
- eg; uranium (commonly used in nuclear power) has 92 protons, but U-235 is more unstable and more energetic : placed in fuel rods
- most isotopes are stable but some emit subatomic particles and heat energy as radioactive decay
What is the half life of U-235? Does it ever fully go away?
- half life of U-235 is 700 million years
- technically it never goes away, always present in a fractional amount but eventually the radioactive part will become negligible for practical purposes
How is uranium sourced? Once sourced, how is it used?
- it is mined (decays into radon which is harmful)
- placed into fuel rods
- control rods made up material that absorb neutrons in order to control the fission chain reactions
- 10million times more energy than fossil fuels!
What is the nuclear chain reaction?
- bombarding U-235 with neutrons triggers fission, released more neutrons which hit other atoms causing them to split and trigger more fission reactions!
What are the two forms of nuclear fission reactors?
- pressurized water reactor: heats other water, leak is not harmful and more common method
- boiling water reactor: radioactive water creates steam to run turbines: entire generator is radioactive (Fukushima)
boiling water reactor: entire thing
pressurized water reactor:
Why is radioactive waste dangerous?
- emits 3 forms of radiation : alpha (not through paper, can be ingested), beta (not through lead or thick clothes), gamma : harmful, shorter EMR waves than the sun emits!: causes damage to many organs leading to radiation sickness, and can cause mutations!,
How is low radioactive waste disposed?
- short half life: thrown away in regular trash
- longer half life: clothing and spent filters buried deep underground!
How is high level radioactive waste managed?
- spent fuel rods stored in steel lined pools and then moved to dry cask storage
- no long term solution yet
What is waste management by geographic isolation?
- many potential sites for deep waste storage have been identified
- Nuclear Waste Management Organization identified Wabigoon Lake and the township of Ignace as future sites of Canada’s deep geological repository for used nuclear fuel: announced November 28, 2024.
What are the trade-offs of nuclear power?
- benefits: efficient energy, low air pollution (no PM2.5, CO2, methane, etc)
- negatives: costly start ups, difficult to deal with radioactive waste, radon/radiation harmful
What is latent heat? Why is it an important part of atmospheric energy?
- latent heat is the heat required to change a substance from one state to another
- important for atmospheric energy because of evapotranspiration events + every time a cloud forms it warms the atmosphere (cloud can form in tropical regions and be sent to polar regions where it condenses and releases heat)
