ESSP 200 – Sustainability Science
Assignment #5
Socio-economic Impacts on Environmental Conditions
Due Wednesday, December 8th
In class, we discussed about the IPAT equation used for estimating environmental impact. By
conducting this assignment, you will gain experience in using quantitative methods to
calculate a projection of atmospheric CO2 levels from which you are asked to compare with
other data in order to draw inferences on potential future conditions. You are also asked
to analyze graphical data and draw a reasoned conclusion based on the information
presented. These objectives fall within the Essential Studies goals of Quantitative
Reasoning.
The information below on current world population, the estimated world human affluence
represented in the number of cars per person, and the amount of CO2 output per car per year, is to
be used calculate and answer the following questions.
Current:
Population: 7.4 billion
Affluence: 0.1 cars/person
Technology: 5.4 tons CO2 per car per year
1) Calculate if the global population rises to 10 billion by 2050 and Affluence is likely to
more than quadruple as China, India, Brazil, and many other middle, low-income
countries become wealthier, how much CO2 emission would rise if we hold technology
constant? How many more times greater is this increase as compared to the current CO2
emissions? Given that current atmospheric CO2 levels are just over 400 parts per million
(ppm) what would this increase mean for the future atmospheric CO2 levels? How does
this future level compare with the graph of the geologic record of CO2 levels over the last
800,000 years determined from the Antarctic ice cores (discussed during Lecture 17 –
Environmental Quality Part 2)? Finally, what can you infer about potential future
temperature changes from these results?
2) Given the population and affluence level in 2050, calculate if we want to keep CO2
emissions constant, how much technology would have to advance to reduce emission
levels?
3) Discuss the different focuses for developing and developed countries to design
environmental policies based on the IPAT equation.
4) Discuss the hypothetical relationship between economic growth and environmental
quality in developing countries and the possible reasons that could explain the
Environmental Kuznets Curve.
Sustainability Science
Economics and Sustainable Development
Rivalry
• When a good or service loses value upon
consumption
• Once it is consumed by one person, it cannot be
consumed by another; a rivalrous good
• Example: food
• Non-rival good
• A good or service that can be consumed multiple
times by many consumers
• Example: air
Excludable
• When it is possible to prevent people from
consuming or enjoying a good or service
• Someone might place a form of payment on the
good or service
• Example: a car, most private goods
• Non-excludable
• A good or service which cannot be purchased or
enforced through payment
• Example: air, rain
Categories of Goods
De Vries 2013
Common Pool Resources vs. Market
• Competitive market
• Pursuing self interest is “efficient”
• Only concerned about making a profit
• “sustainability” of the economic condition is
individualistic and short lived
• Therefore, not actually “sustainable”
• Incorporating the concept of Common Pool
Resources
• Self-interest can mean too little resources for everyone
• Not efficient for the greater system
Open Access Problem
• Open-access resources
• Lack any system of rules governing its use
• Weighing private benefits against private costs
• Overexploitation of resources will occur
• “Tragedy of the Commons”
“Tragedy of the Commons”
• Garrett Hardin (1968)
• Example of the cattle herder
• One additional cattle brings large private
gain, but also a large public loss
•
“ The only sensible course for him to pursue is to add another
animal to his herd. And another, and another…Therein is the
tragedy. Each man is locked in to a system that compels him
to increase his herd without limit —in a world that is limited.
Ruin is the destination toward which all men rush, each
pursuing his own best interest in a society that believes in the
freedom of the commons.”
-Garrett Hardin (1968)
The cost of the environment
• Externality
• Cost of a transaction not borne by the buyer or seller
• Example: noise, pollution, etc.
• Negative externality
• Example: public transportation
• Positive externality
• Market Failure: Product or service does not accurately
reflect true costs and benefits
• Negative externality: factory pollution
• Failure occurs due to over production and lack of true
cost (environmental and social)
• Positive externality: public transportation
• Cost in supplying public transportation
• Needs to be paid for as more people use it
How do we solve this issue?
• Theoretically
• If we all were aware of our impacts on the systems and
other humans, we would be more sustainable
• Pragmatically
• The moral approach does not typically work
• Cannot rely on a “moral awakening”
• Moral development is important, but…
• Build mechanisms that lead to the right objectives
Approaches to externality problems
• Private negotiation between affected
parties
• Legal approach: Liability
• Government Action
• Direct regulation
• Tax/subsidy
• Standards: limit on amount of pollution
• Marketable pollution permit
Sustainability Science
Resource Rent
Is GDP a good measure of sustainability?
• GDP (Gross Domestic Product)
• Value of all goods and services produced and consumed in a
year
• Missing the value of non-market production
• Missing the costs of growth
• Missing the depreciation of natural capital
• A measure of the “average” person, but not the “typical” person
Net National Welfare
• GDP + non-market output
•
•
•
•
Externality costs
Pollution abatement and cleanup costs
Depreciation of created capital
Depreciation of natural capital
• Resource Rent
• What future generations are losing by exploitation of natural
capital
• The amount needed to be saved and invested if resource
depletion is to be sustainable
Internalizing Environmental Costs
• Resource extraction produces vast quantities of waste and damages
to land and water
• Should consider both direct and indirect environmental costs during
extraction
• If environmental costs are internalized into the price, theoretically
less resource will be extracted and consumed
• Two theories as resource depletion occurs
• Shift money to stocks which are “healthy”
• Weak sustainability
• Use current stock values and internalized costs to invest in substitutes
of current resources (e.g. energy, metals, etc.)
• Strong sustainability
Ted Talk: Doughnut Economics
• https://www.youtube.com/watch?v=1BHOflzxPjI
Beginning of
Semester
End of
Semester
Sustainability Science
Sustainable Development
IPAT Equation
• Ehrlich and Holdron (1971)
• Argued that three main factors impact the
environment since WWII
• Environmental Impact =
Population * Affluence * Technology
• Main drivers of environmental problems
• Population growth
• Growth in consumption per person
• Damage per unit of consumption inflicted by available
technology
CO2 and the IPAT Equation
• Automobile CO2 emissions:
• Population: 6 billion
• Affluence: 0.1 cars/person
• Technology: 5.4 tons CO2 per car per year
• CO2 emissions / year = (6 billion) * (0.1 cars /
person) * (5.4 tons CO2 / car / year) =
3.45 billion tons CO2 / year
Poverty and the Environment
• Many environmental problems are problems of poverty
• Poor people cannot afford to conserve resources
• Population growth slows with increased income
• Environmental Kuznets Curve
• Relationship between Pollution and Economic Growth
Why do we see this?
• Political demand for
pollution control
• Rising Education
• Shift in industrial
composition
In Reality…
Natural Resource Curse
• Low and middle-income countries
• Abundant natural resources
• Strongly resource dependent economically
• However, low GDP, low GDP per capita, and low
GDP growth rate
• Why is development so poor?
• Less labor and capital in manufacturing
• Expensive input prices
• Less innovation and unwise reinvestment
• Lack of diversity in economy
• External factors
• Colonial history, undemocratic government, etc.
Assignment #5
• IPAT Equation
• Assignment found on Blackboard
• Answer questions based on the IPAT
equation
• Some of the questions require you to look
back at old lecture notes
• Due Wednesday, December 8th at class time
Sustainability Science
Future Scenarios
Why should we care?
• All of our advancements today were built
from those before us
• Are we the end product?
Calvin and Hobbes, by Bill Watterson
Why should we care?
• No, we are not the end product!
• Others will (likely) come after us
• We have a duty to advance upon past success
• This is why sustainability is important!
Calvin and Hobbes, by Bill Watterson
Rates of change in Human Activity
The increasing rates of
change in human activity
since the beginning of
the Industrial Revolution
to 2000.
Significant increases
in rates of change occur
around the 1950s in each
case and illustrate
how the past 50 years
have been a period of
dramatic and
unprecedented change
in human history
(Steffen et al. 2004, and
references therein).
Global Scale
Changes in the
Earth System
Planetary Boundaries
The inner green
shading represents
the proposed safe
operating
space for nine
planetary systems.
The red wedges
represent an
estimate of the
current position for
each variable. The
boundaries in
three systems (rate
of biodiversity loss,
climate change and
human
interference with the
nitrogen cycle) have
already been
exceeded
(Rockström et al.
2009a)
Sustainable Futures
• The world is a crowded place
• Finiteness of the planet is in sight
• Possible pathways for the world have to be
explored
• Need to explore scenarios as
combinations of stories and models to
prepare for alternate futures
Scenarios take into consideration both quantitative (i.e. modeling)
and qualitative (e.g. human reactions) to construct and explore
different possible futures.
Branch
Points
Branch
Points
Sources of Uncertainty
•Ignorance
•Surprise
•Volition
SCENARIOS
Elements of a Typical Scenario
• Description of step-wise changes in the future state of society and
the environment
• Examples: change in temperature, change in economic conditions
• Driving forces. The main factors or determinants that influence the
step-wise changes in a scenario
• population and economic growth
• Base year. Beginning year of the scenario – often determined by
adequacy of data
• Time horizon and time steps. Most distant future year covered.
• Steps usually kept to a minimum due to high analytical cost per step
• Storyline. A narrative description of a scenario including the main
features and relationships of these to driving forces.
How can Scenarios Be Useful in
Sustainability Assessments
•
Provide a picture of future alternative states of the environment
•
Raise awareness of future connection between different problems
•
Illustrate alternative policy pathways
•
Combine qualitative and quantitative information
•
Identify robustness of policies under different future conditions
•
Help stakeholders and policymakers “think big” about sustainability
issues
•
Raise awareness of emergence of new intensifying sustainability
problems
Energy in the Future: Trends and Unknown
Renewable Energy
• Energy from the Sun: Direct – Solar
• Energy from the Sun: Indirect – Hydropower, Wind
Biomass,
• Ocean Energy: Tidal, Waves and Current
Renewable Energy
◼
Solar Energy
◼
Wind Energy
◼
Biomass
◼
Energy from the Tidal & Ocean
❑
Tidal energy
❑
Wave Energy
❑
Current
Energy Needs
• Energy Services
• Energy Forms
– Buildings
– Electricity
– Transportation
– Fuels
– Industry
– Heat
Understanding the extend of future energy needs requires understanding of system
Disparity
Transitions
Constraints
Tidal Energy
• The only energy of Earth’s energy flow that originates as
mechanical energy
• Due to the gravitational interaction between the Earth
and the Moon
• The world highest tides, Nova Scotia’s Bay of Fundy,
range to 17 meters (≈ 56 ft)
• Yield tidal energy rate ≈ 3 TW (≈ 20% total world energy
consumption rate); However, only 1 TW could be
available to be harnessed
• Harvesting tidal energy:
– tidal must be several meters or more
– In bays, estuary and narrow inlets where tidal flows is
concentrated
• Only 10% of 1 TW is actually available to human use
≈ 100 GW or 100 large fossil or nuclear power plants
http://picasaweb.google.com/112341
759435121900017
http://picasaweb.google.com/11
2341759435121900017
Harnessing Tidal Energy
http://www.bigelow.org/virtual/handson/water_level.html
Tidal barrages: environmental impact
Tidal Fence: bi-directional less environmental impact
• 20th century, resurgence of interest in tidal power, using what are
essentially underwater version of wind turbines.
• Capture the energy of tidal currents without the need for dams.
• Individual tidal turbine have power outputs ≈ 300kW.
• Exist plan calls for large-scale turbine farms generating as much as 100 MW.
Waves and Current
It is important to distinguish between tidal energy and the energy of waves
Usually, waves are caused by the action of the wind over water, in turn wind is the results of the
differential solar heating of air over land and sea
Waves
• Mainly indirect manifestation of solar energy: ocean waves are generated by the wind passing over long
stretches of water
• Began early 2000s, Peak output ≈ 1MW
• Very modest contribution to electrical energy supply because wave energy is limited
• Total wave power delivered to all world’s coasts = 3 TW. But only a minuscule portion can be harnessed
• The power economically extractable with current wave-conversion technology is estimated at 0.01 to
0.1 TW. Tiny fraction of world 16 TW primary energy consumption
Onshore Systems
• Oscillating column devices – the in-and-out
motion of waves enter the column, compress
air that activate a turbine
• Tapered channel (Tapchan) – Channel-mounted
structure that concentrate and direct waves in
an elevated reservoirs. Water flowing out of the
reservoir activate a turbine.
Offshore Systems
• Floating devices, float or buoys systems, use rise
and fall of the ocean swells to drive hydraulic
pumps
• Movement “strokes” an electrical generator
and makes electricity that is then shipped
ashore by under water cables
Current
• Ocean currents are even less developed for energy. It is at an early stage of development
• Ocean current are large “rivers” that flow within the oceans
• Estimate suggest may be able to capture as much as 450 GW of power worldwide. Significant ≈ 1/4
world’s electric power consumption
• High capital costs of producing equipment that can operate for years on ocean floor
• As with geothermal wave & current energy – limited
locations
• This will be a long time before ocean currents contribute
to our energy supply
• Realistically, ocean energy is unlikely to make a
substantial contribution to the global energy supply
Environmental Impacts Tidal and Wave Energy
• Tidal:
– Clean, quiet, nonpolluting process, Intermittent
– Tidal barrages:
• reduce tidal flow and water’s salinity
• Impede movement of large marine organisms
• Shifting sediment and alter water clarity
– Newer tidal turbines are more environmentally friendly, but in farm group they will also reduce tidal flow and
therefore the balance of fresh and salt water
• Wave: Maybe among the most environmentally benign of energy technologies.
• Clean, quiet, nonpolluting process, Intermittent
• Little potential for chemical pollution
• Little visual impact and Low noise generation likely
• Small (though not insignificant) hazard to shipping
• Low emissions: 11 g CO2, 0.03 g SO2, & 0.05 g NOx by kWh of electricity generated. Thus, wave energy can
make a significant contribution in meeting climate change and acid rain target
Solar Energy
• Solar energy systems use technologies converting solar energy into other from of energy: heat or
electricity
• The only viable long-term energy that can clearly and sustainably meet our energy needs. This is the
most abundant renewable energy source in the world
• Some of the Sun’s energy is diffuse, and some is direct
A proportion of this
scattered light comes to
Earth as diffuse radiation
Diffuse radiation provides
most of the ‘daylight’ in
buildings
The portion of light that
appears to come straight from
the Sun, ‘sunshine’, is known
as direct solar radiation
Electricity: Direct radiation
are concentrated to generate
very high temperatures
Heat: can be used without
such concentration in active
solar heating systems
Solar Resource Availability
• Snnual insolation = incoming solar energy per square meter of Earth’s surface per year
• Near the equator, it can reach 2000 kWh.m-2 per year, and more in some sunny desert areas
Solar radi ation in the U.S.
• The amount of insolation available at
various locations is based on factors such
as:
✓ Region (latitude altitude), Season
(time of the year), Time of the day,
Climate (humidity cloud cover) , Air
quality (pollution)
✓ The angle of sunlight as it strikes a
location is also an important
consideration for overall insolation
levels
In kW
h/m2
Source: U.S. Department of Energy Photovoltaics Program
Solar Energy Systems
• Systems that convert solar energy into other forms of energy – heat & electricity
• Solar thermal- use heat energy from the sun for heat and electricity generation
• Heat: systems referred as passive or active
o Passive Solar Systems: Direct use of solar energy through architectural design without the need for any
mechanical power
o Active Solar Energy Systems: Direct use of solar energy requiring mechanical power; usually consists of pumps
and other machinery to circulate air, water, or other fluids from solar collectors to heat sink where the heat may
be stored
• Electricity: High temperature solar thermal Power systems
o Concentrating Solar Power (CSP): Combination of concentrators, heat engine, and electrical generator to
produce electricity
• Solar Photovoltaic- convert sunlight into direct current electricity by using semiconductors
• Photovoltaic : Systems use photovoltaic cells, made of thin layers of semiconductors and solid-state
electronic components with few or no moving parts to produce direct current electricity
Passive solar system
• No moving part, rely on design structure to enhance the ability to
capture & use sun radiation – solar oven, greenhouse
o Keeping the sun out & Letting the sun in
o Storing the sun’s energy
Absorbed nearly all incident solar energy and convert into low-quality
heat
© 2005 John Wiley and Sons Publishers
Direct gain system
o South-facing windows act as solar collectors
o High summer sun-light is blocked by overhang
o Moveable insulation used to cover windows at night to reduce heat loss
o Massive concrete floor acts as a storage device & prevents overheating
Indirect gain system
o Feature designed to facilitate the storage & circulation of passive solar
heat
Trombe wall:
Heat a Sun-facing
thermal mass so th
at natural
convection carries
energy throughout
the house.
Active Solar Thermal Systems
Active solar heating systems: collectors, a distribution system, & a storage device
Solar energy heats a fluid (liquid or air) that transferres the heat directly to the interior space or
to a storage system for later use
To most people, ‘solar heating’ – rooftop solar water heater
• a collector panel: glazing, an absorber plate, & insulation
• an insulated hot water storage tank, with hot water
circulating through a heat exchanger situated at the bottom
• a pumped circulation system containing an anti-freeze
(needed in northern regions) transferring the heat from the
panel to the storage tank
High Temperature Solar Thermal: Concentrated Solar Power
Concentrated Solar Thermal
• Due to low level of insolation reaching the Earth, it is useful to
collect sunlight from a wider area and focus it (concentrate) to make
conversion to electricity easier
Through system
Linear Fresnel System
• Use solar collectors to concentrate solar energy on a central
receiver/absorber. It produces temperature high enough to
produce steam. Steam turns a turbine that will drive a generator to
generate electricity
• Categorized based on the types of solar collectors used or the
method of concentration
• Often need to be angled directly at sun, don’t pick up diffuse
radiation Tracking mechanisms:
o Single-axis tracking, move device to west along the sky
o Two-axis tracking, move collectors in two dimension – constant
perpendicular orientation to incoming sunlight
Dish system
https://www.volker-quaschning.de
Heliostat Solar Field
CSP vs. Large PV options
Optimal latitude to operate CSP or large PV:
• CSP work only with direct sun radiation. This limits CSP
sites almost exclusively to arid desert or semiarid regions
at lower latitudes near the equator
• Outside those zones, large PV will likely be the optimal
choice
Other considerations may alter the economic within this
general parameters
• Geography
• Land use
• Water requirement to cool down the system
• Operation & Management
• Environmental considerations
• Access to transmission: grid
Photovoltaic Systems
The conversion of solar energy directly into direct current electricity by using semiconductors
• Almost the ideal conversion energy system:
✓
✓
It harnesses solar energy, by fare the most abundant of energy sources available on earth;
PV cell cells made almost entirely from silicon, the second most abundant element in the earth’s crust
✓
No moving part – in theory can be run for an
indefinite period of time without wearing out
✓
Electricity is the output: the highest quality,
most versatile of all energy forms
• How does it work? When the sun hits a PV
cell, electrons are freed and formed an
electric current
• That electric current can power electric
devices
Environmental Impacts of Solar Energy
• Environmental impacts
o Generally low impact
o Land use:
✓ No real problem when can be combined with existing structure
✓ Greater impact on land use for highly centralized and technological structures
o Water: to dispose of (cool down) heat waste like any other electric power system
o No emissions, except during development processes
o Question about possible effect on climate effects: can it changes Earth’s net energy balance?
• Advantages
o Renewable, No emissions
• Other considerations
o High-power density when concentrated, Intermittent availability, access to the grid
PV system: Environmental Impact and Safety
• … of PV systems
o
o
o
o
o
o
Probably lower than any other renewable or non-renewable electricity generating system
No gaseous or liquid pollutant emission, no radioactive substance
PV modules have no moving part: safe on mechanical part, and no noise
Risk of electric shock as with other electrical equipment: potential fire hazard
PV have a visual impact
Large multi-megawatt PV arrays will require land
• … of PV production
o Unlikely to be significant – except in the event of major accident of manufacturing plant
Sierra Nevada, CA
o However,
small amounts of toxic material are used such as cadmium
o Array disposal? preferable recycled
o Manufacture and eventual disposal: Semi-conductor processing
▪ Large use of metal, glass, plastic may cause environmental problems through production and accidental
realize of toxic material
Energy from the Sun Indirect
Water
23% incident solar energy goes into
water evapotranspiration, which
condenses to fall as rain, some on
continents where it returns via rivers to
the oceans
Wind
1% goes into kinetic energy of
atmosphere and oceans: winds and
ocean currents
Biomass
0.08% is captured by photosynthetic
plants, which store the energy
chemically and provide the energy
supply for nearly all life on Earth
➢
Today just under 10% of human’s energy is provided by those indirect form of solar energy
Hydropower Resources
• Conversion of the energy of flowing water into electricity
• In the early 20th century hydropower supplies 40% of U.S. electricity
• By mid-century competition with fossil fuels electricity generation: share drops one-third.
• Today about 7.5% of U.S. electricity comes from Hydropower (eia)
• Worldwide provide about 17% of electricity demand, equivalent to about 4% of total energy demand
• Largest hydroelectricity plant in the world:
Three Gorges Dam (China) on the Yangtze
river
o 22,500 MW capacity, output 20 times
greater than a large coal-fired or nuclear
electrical plant
o 2.3 km (1.4 miles) wide & 185 m (607 ft)
high. Creates a reservoir 625 km (373
miles) long. 1.3 people relocated
• Room to increase electrical energy generation from
hydropower, especially in developing countries
Wolfson, 2012 Energy, environment, and climate
• Potentially United Nation estimates world’s technically
exploitable hydroelectric resources ≈ today’s global electrical
energy production
• Thus, hydropower could produce energy demand in some
regions (almost)
• Hydropower has greater potential in developing countries,
much less in developed countries
• Hydropower Systems:
• Micro-hydropower systems power output
Purchase answer to see full
attachment
Assignment #5
Socio-economic Impacts on Environmental Conditions
Due Wednesday, December 8th
In class, we discussed about the IPAT equation used for estimating environmental impact. By
conducting this assignment, you will gain experience in using quantitative methods to
calculate a projection of atmospheric CO2 levels from which you are asked to compare with
other data in order to draw inferences on potential future conditions. You are also asked
to analyze graphical data and draw a reasoned conclusion based on the information
presented. These objectives fall within the Essential Studies goals of Quantitative
Reasoning.
The information below on current world population, the estimated world human affluence
represented in the number of cars per person, and the amount of CO2 output per car per year, is to
be used calculate and answer the following questions.
Current:
Population: 7.4 billion
Affluence: 0.1 cars/person
Technology: 5.4 tons CO2 per car per year
1) Calculate if the global population rises to 10 billion by 2050 and Affluence is likely to
more than quadruple as China, India, Brazil, and many other middle, low-income
countries become wealthier, how much CO2 emission would rise if we hold technology
constant? How many more times greater is this increase as compared to the current CO2
emissions? Given that current atmospheric CO2 levels are just over 400 parts per million
(ppm) what would this increase mean for the future atmospheric CO2 levels? How does
this future level compare with the graph of the geologic record of CO2 levels over the last
800,000 years determined from the Antarctic ice cores (discussed during Lecture 17 –
Environmental Quality Part 2)? Finally, what can you infer about potential future
temperature changes from these results?
2) Given the population and affluence level in 2050, calculate if we want to keep CO2
emissions constant, how much technology would have to advance to reduce emission
levels?
3) Discuss the different focuses for developing and developed countries to design
environmental policies based on the IPAT equation.
4) Discuss the hypothetical relationship between economic growth and environmental
quality in developing countries and the possible reasons that could explain the
Environmental Kuznets Curve.
Sustainability Science
Economics and Sustainable Development
Rivalry
• When a good or service loses value upon
consumption
• Once it is consumed by one person, it cannot be
consumed by another; a rivalrous good
• Example: food
• Non-rival good
• A good or service that can be consumed multiple
times by many consumers
• Example: air
Excludable
• When it is possible to prevent people from
consuming or enjoying a good or service
• Someone might place a form of payment on the
good or service
• Example: a car, most private goods
• Non-excludable
• A good or service which cannot be purchased or
enforced through payment
• Example: air, rain
Categories of Goods
De Vries 2013
Common Pool Resources vs. Market
• Competitive market
• Pursuing self interest is “efficient”
• Only concerned about making a profit
• “sustainability” of the economic condition is
individualistic and short lived
• Therefore, not actually “sustainable”
• Incorporating the concept of Common Pool
Resources
• Self-interest can mean too little resources for everyone
• Not efficient for the greater system
Open Access Problem
• Open-access resources
• Lack any system of rules governing its use
• Weighing private benefits against private costs
• Overexploitation of resources will occur
• “Tragedy of the Commons”
“Tragedy of the Commons”
• Garrett Hardin (1968)
• Example of the cattle herder
• One additional cattle brings large private
gain, but also a large public loss
•
“ The only sensible course for him to pursue is to add another
animal to his herd. And another, and another…Therein is the
tragedy. Each man is locked in to a system that compels him
to increase his herd without limit —in a world that is limited.
Ruin is the destination toward which all men rush, each
pursuing his own best interest in a society that believes in the
freedom of the commons.”
-Garrett Hardin (1968)
The cost of the environment
• Externality
• Cost of a transaction not borne by the buyer or seller
• Example: noise, pollution, etc.
• Negative externality
• Example: public transportation
• Positive externality
• Market Failure: Product or service does not accurately
reflect true costs and benefits
• Negative externality: factory pollution
• Failure occurs due to over production and lack of true
cost (environmental and social)
• Positive externality: public transportation
• Cost in supplying public transportation
• Needs to be paid for as more people use it
How do we solve this issue?
• Theoretically
• If we all were aware of our impacts on the systems and
other humans, we would be more sustainable
• Pragmatically
• The moral approach does not typically work
• Cannot rely on a “moral awakening”
• Moral development is important, but…
• Build mechanisms that lead to the right objectives
Approaches to externality problems
• Private negotiation between affected
parties
• Legal approach: Liability
• Government Action
• Direct regulation
• Tax/subsidy
• Standards: limit on amount of pollution
• Marketable pollution permit
Sustainability Science
Resource Rent
Is GDP a good measure of sustainability?
• GDP (Gross Domestic Product)
• Value of all goods and services produced and consumed in a
year
• Missing the value of non-market production
• Missing the costs of growth
• Missing the depreciation of natural capital
• A measure of the “average” person, but not the “typical” person
Net National Welfare
• GDP + non-market output
•
•
•
•
Externality costs
Pollution abatement and cleanup costs
Depreciation of created capital
Depreciation of natural capital
• Resource Rent
• What future generations are losing by exploitation of natural
capital
• The amount needed to be saved and invested if resource
depletion is to be sustainable
Internalizing Environmental Costs
• Resource extraction produces vast quantities of waste and damages
to land and water
• Should consider both direct and indirect environmental costs during
extraction
• If environmental costs are internalized into the price, theoretically
less resource will be extracted and consumed
• Two theories as resource depletion occurs
• Shift money to stocks which are “healthy”
• Weak sustainability
• Use current stock values and internalized costs to invest in substitutes
of current resources (e.g. energy, metals, etc.)
• Strong sustainability
Ted Talk: Doughnut Economics
• https://www.youtube.com/watch?v=1BHOflzxPjI
Beginning of
Semester
End of
Semester
Sustainability Science
Sustainable Development
IPAT Equation
• Ehrlich and Holdron (1971)
• Argued that three main factors impact the
environment since WWII
• Environmental Impact =
Population * Affluence * Technology
• Main drivers of environmental problems
• Population growth
• Growth in consumption per person
• Damage per unit of consumption inflicted by available
technology
CO2 and the IPAT Equation
• Automobile CO2 emissions:
• Population: 6 billion
• Affluence: 0.1 cars/person
• Technology: 5.4 tons CO2 per car per year
• CO2 emissions / year = (6 billion) * (0.1 cars /
person) * (5.4 tons CO2 / car / year) =
3.45 billion tons CO2 / year
Poverty and the Environment
• Many environmental problems are problems of poverty
• Poor people cannot afford to conserve resources
• Population growth slows with increased income
• Environmental Kuznets Curve
• Relationship between Pollution and Economic Growth
Why do we see this?
• Political demand for
pollution control
• Rising Education
• Shift in industrial
composition
In Reality…
Natural Resource Curse
• Low and middle-income countries
• Abundant natural resources
• Strongly resource dependent economically
• However, low GDP, low GDP per capita, and low
GDP growth rate
• Why is development so poor?
• Less labor and capital in manufacturing
• Expensive input prices
• Less innovation and unwise reinvestment
• Lack of diversity in economy
• External factors
• Colonial history, undemocratic government, etc.
Assignment #5
• IPAT Equation
• Assignment found on Blackboard
• Answer questions based on the IPAT
equation
• Some of the questions require you to look
back at old lecture notes
• Due Wednesday, December 8th at class time
Sustainability Science
Future Scenarios
Why should we care?
• All of our advancements today were built
from those before us
• Are we the end product?
Calvin and Hobbes, by Bill Watterson
Why should we care?
• No, we are not the end product!
• Others will (likely) come after us
• We have a duty to advance upon past success
• This is why sustainability is important!
Calvin and Hobbes, by Bill Watterson
Rates of change in Human Activity
The increasing rates of
change in human activity
since the beginning of
the Industrial Revolution
to 2000.
Significant increases
in rates of change occur
around the 1950s in each
case and illustrate
how the past 50 years
have been a period of
dramatic and
unprecedented change
in human history
(Steffen et al. 2004, and
references therein).
Global Scale
Changes in the
Earth System
Planetary Boundaries
The inner green
shading represents
the proposed safe
operating
space for nine
planetary systems.
The red wedges
represent an
estimate of the
current position for
each variable. The
boundaries in
three systems (rate
of biodiversity loss,
climate change and
human
interference with the
nitrogen cycle) have
already been
exceeded
(Rockström et al.
2009a)
Sustainable Futures
• The world is a crowded place
• Finiteness of the planet is in sight
• Possible pathways for the world have to be
explored
• Need to explore scenarios as
combinations of stories and models to
prepare for alternate futures
Scenarios take into consideration both quantitative (i.e. modeling)
and qualitative (e.g. human reactions) to construct and explore
different possible futures.
Branch
Points
Branch
Points
Sources of Uncertainty
•Ignorance
•Surprise
•Volition
SCENARIOS
Elements of a Typical Scenario
• Description of step-wise changes in the future state of society and
the environment
• Examples: change in temperature, change in economic conditions
• Driving forces. The main factors or determinants that influence the
step-wise changes in a scenario
• population and economic growth
• Base year. Beginning year of the scenario – often determined by
adequacy of data
• Time horizon and time steps. Most distant future year covered.
• Steps usually kept to a minimum due to high analytical cost per step
• Storyline. A narrative description of a scenario including the main
features and relationships of these to driving forces.
How can Scenarios Be Useful in
Sustainability Assessments
•
Provide a picture of future alternative states of the environment
•
Raise awareness of future connection between different problems
•
Illustrate alternative policy pathways
•
Combine qualitative and quantitative information
•
Identify robustness of policies under different future conditions
•
Help stakeholders and policymakers “think big” about sustainability
issues
•
Raise awareness of emergence of new intensifying sustainability
problems
Energy in the Future: Trends and Unknown
Renewable Energy
• Energy from the Sun: Direct – Solar
• Energy from the Sun: Indirect – Hydropower, Wind
Biomass,
• Ocean Energy: Tidal, Waves and Current
Renewable Energy
◼
Solar Energy
◼
Wind Energy
◼
Biomass
◼
Energy from the Tidal & Ocean
❑
Tidal energy
❑
Wave Energy
❑
Current
Energy Needs
• Energy Services
• Energy Forms
– Buildings
– Electricity
– Transportation
– Fuels
– Industry
– Heat
Understanding the extend of future energy needs requires understanding of system
Disparity
Transitions
Constraints
Tidal Energy
• The only energy of Earth’s energy flow that originates as
mechanical energy
• Due to the gravitational interaction between the Earth
and the Moon
• The world highest tides, Nova Scotia’s Bay of Fundy,
range to 17 meters (≈ 56 ft)
• Yield tidal energy rate ≈ 3 TW (≈ 20% total world energy
consumption rate); However, only 1 TW could be
available to be harnessed
• Harvesting tidal energy:
– tidal must be several meters or more
– In bays, estuary and narrow inlets where tidal flows is
concentrated
• Only 10% of 1 TW is actually available to human use
≈ 100 GW or 100 large fossil or nuclear power plants
http://picasaweb.google.com/112341
759435121900017
http://picasaweb.google.com/11
2341759435121900017
Harnessing Tidal Energy
http://www.bigelow.org/virtual/handson/water_level.html
Tidal barrages: environmental impact
Tidal Fence: bi-directional less environmental impact
• 20th century, resurgence of interest in tidal power, using what are
essentially underwater version of wind turbines.
• Capture the energy of tidal currents without the need for dams.
• Individual tidal turbine have power outputs ≈ 300kW.
• Exist plan calls for large-scale turbine farms generating as much as 100 MW.
Waves and Current
It is important to distinguish between tidal energy and the energy of waves
Usually, waves are caused by the action of the wind over water, in turn wind is the results of the
differential solar heating of air over land and sea
Waves
• Mainly indirect manifestation of solar energy: ocean waves are generated by the wind passing over long
stretches of water
• Began early 2000s, Peak output ≈ 1MW
• Very modest contribution to electrical energy supply because wave energy is limited
• Total wave power delivered to all world’s coasts = 3 TW. But only a minuscule portion can be harnessed
• The power economically extractable with current wave-conversion technology is estimated at 0.01 to
0.1 TW. Tiny fraction of world 16 TW primary energy consumption
Onshore Systems
• Oscillating column devices – the in-and-out
motion of waves enter the column, compress
air that activate a turbine
• Tapered channel (Tapchan) – Channel-mounted
structure that concentrate and direct waves in
an elevated reservoirs. Water flowing out of the
reservoir activate a turbine.
Offshore Systems
• Floating devices, float or buoys systems, use rise
and fall of the ocean swells to drive hydraulic
pumps
• Movement “strokes” an electrical generator
and makes electricity that is then shipped
ashore by under water cables
Current
• Ocean currents are even less developed for energy. It is at an early stage of development
• Ocean current are large “rivers” that flow within the oceans
• Estimate suggest may be able to capture as much as 450 GW of power worldwide. Significant ≈ 1/4
world’s electric power consumption
• High capital costs of producing equipment that can operate for years on ocean floor
• As with geothermal wave & current energy – limited
locations
• This will be a long time before ocean currents contribute
to our energy supply
• Realistically, ocean energy is unlikely to make a
substantial contribution to the global energy supply
Environmental Impacts Tidal and Wave Energy
• Tidal:
– Clean, quiet, nonpolluting process, Intermittent
– Tidal barrages:
• reduce tidal flow and water’s salinity
• Impede movement of large marine organisms
• Shifting sediment and alter water clarity
– Newer tidal turbines are more environmentally friendly, but in farm group they will also reduce tidal flow and
therefore the balance of fresh and salt water
• Wave: Maybe among the most environmentally benign of energy technologies.
• Clean, quiet, nonpolluting process, Intermittent
• Little potential for chemical pollution
• Little visual impact and Low noise generation likely
• Small (though not insignificant) hazard to shipping
• Low emissions: 11 g CO2, 0.03 g SO2, & 0.05 g NOx by kWh of electricity generated. Thus, wave energy can
make a significant contribution in meeting climate change and acid rain target
Solar Energy
• Solar energy systems use technologies converting solar energy into other from of energy: heat or
electricity
• The only viable long-term energy that can clearly and sustainably meet our energy needs. This is the
most abundant renewable energy source in the world
• Some of the Sun’s energy is diffuse, and some is direct
A proportion of this
scattered light comes to
Earth as diffuse radiation
Diffuse radiation provides
most of the ‘daylight’ in
buildings
The portion of light that
appears to come straight from
the Sun, ‘sunshine’, is known
as direct solar radiation
Electricity: Direct radiation
are concentrated to generate
very high temperatures
Heat: can be used without
such concentration in active
solar heating systems
Solar Resource Availability
• Snnual insolation = incoming solar energy per square meter of Earth’s surface per year
• Near the equator, it can reach 2000 kWh.m-2 per year, and more in some sunny desert areas
Solar radi ation in the U.S.
• The amount of insolation available at
various locations is based on factors such
as:
✓ Region (latitude altitude), Season
(time of the year), Time of the day,
Climate (humidity cloud cover) , Air
quality (pollution)
✓ The angle of sunlight as it strikes a
location is also an important
consideration for overall insolation
levels
In kW
h/m2
Source: U.S. Department of Energy Photovoltaics Program
Solar Energy Systems
• Systems that convert solar energy into other forms of energy – heat & electricity
• Solar thermal- use heat energy from the sun for heat and electricity generation
• Heat: systems referred as passive or active
o Passive Solar Systems: Direct use of solar energy through architectural design without the need for any
mechanical power
o Active Solar Energy Systems: Direct use of solar energy requiring mechanical power; usually consists of pumps
and other machinery to circulate air, water, or other fluids from solar collectors to heat sink where the heat may
be stored
• Electricity: High temperature solar thermal Power systems
o Concentrating Solar Power (CSP): Combination of concentrators, heat engine, and electrical generator to
produce electricity
• Solar Photovoltaic- convert sunlight into direct current electricity by using semiconductors
• Photovoltaic : Systems use photovoltaic cells, made of thin layers of semiconductors and solid-state
electronic components with few or no moving parts to produce direct current electricity
Passive solar system
• No moving part, rely on design structure to enhance the ability to
capture & use sun radiation – solar oven, greenhouse
o Keeping the sun out & Letting the sun in
o Storing the sun’s energy
Absorbed nearly all incident solar energy and convert into low-quality
heat
© 2005 John Wiley and Sons Publishers
Direct gain system
o South-facing windows act as solar collectors
o High summer sun-light is blocked by overhang
o Moveable insulation used to cover windows at night to reduce heat loss
o Massive concrete floor acts as a storage device & prevents overheating
Indirect gain system
o Feature designed to facilitate the storage & circulation of passive solar
heat
Trombe wall:
Heat a Sun-facing
thermal mass so th
at natural
convection carries
energy throughout
the house.
Active Solar Thermal Systems
Active solar heating systems: collectors, a distribution system, & a storage device
Solar energy heats a fluid (liquid or air) that transferres the heat directly to the interior space or
to a storage system for later use
To most people, ‘solar heating’ – rooftop solar water heater
• a collector panel: glazing, an absorber plate, & insulation
• an insulated hot water storage tank, with hot water
circulating through a heat exchanger situated at the bottom
• a pumped circulation system containing an anti-freeze
(needed in northern regions) transferring the heat from the
panel to the storage tank
High Temperature Solar Thermal: Concentrated Solar Power
Concentrated Solar Thermal
• Due to low level of insolation reaching the Earth, it is useful to
collect sunlight from a wider area and focus it (concentrate) to make
conversion to electricity easier
Through system
Linear Fresnel System
• Use solar collectors to concentrate solar energy on a central
receiver/absorber. It produces temperature high enough to
produce steam. Steam turns a turbine that will drive a generator to
generate electricity
• Categorized based on the types of solar collectors used or the
method of concentration
• Often need to be angled directly at sun, don’t pick up diffuse
radiation Tracking mechanisms:
o Single-axis tracking, move device to west along the sky
o Two-axis tracking, move collectors in two dimension – constant
perpendicular orientation to incoming sunlight
Dish system
https://www.volker-quaschning.de
Heliostat Solar Field
CSP vs. Large PV options
Optimal latitude to operate CSP or large PV:
• CSP work only with direct sun radiation. This limits CSP
sites almost exclusively to arid desert or semiarid regions
at lower latitudes near the equator
• Outside those zones, large PV will likely be the optimal
choice
Other considerations may alter the economic within this
general parameters
• Geography
• Land use
• Water requirement to cool down the system
• Operation & Management
• Environmental considerations
• Access to transmission: grid
Photovoltaic Systems
The conversion of solar energy directly into direct current electricity by using semiconductors
• Almost the ideal conversion energy system:
✓
✓
It harnesses solar energy, by fare the most abundant of energy sources available on earth;
PV cell cells made almost entirely from silicon, the second most abundant element in the earth’s crust
✓
No moving part – in theory can be run for an
indefinite period of time without wearing out
✓
Electricity is the output: the highest quality,
most versatile of all energy forms
• How does it work? When the sun hits a PV
cell, electrons are freed and formed an
electric current
• That electric current can power electric
devices
Environmental Impacts of Solar Energy
• Environmental impacts
o Generally low impact
o Land use:
✓ No real problem when can be combined with existing structure
✓ Greater impact on land use for highly centralized and technological structures
o Water: to dispose of (cool down) heat waste like any other electric power system
o No emissions, except during development processes
o Question about possible effect on climate effects: can it changes Earth’s net energy balance?
• Advantages
o Renewable, No emissions
• Other considerations
o High-power density when concentrated, Intermittent availability, access to the grid
PV system: Environmental Impact and Safety
• … of PV systems
o
o
o
o
o
o
Probably lower than any other renewable or non-renewable electricity generating system
No gaseous or liquid pollutant emission, no radioactive substance
PV modules have no moving part: safe on mechanical part, and no noise
Risk of electric shock as with other electrical equipment: potential fire hazard
PV have a visual impact
Large multi-megawatt PV arrays will require land
• … of PV production
o Unlikely to be significant – except in the event of major accident of manufacturing plant
Sierra Nevada, CA
o However,
small amounts of toxic material are used such as cadmium
o Array disposal? preferable recycled
o Manufacture and eventual disposal: Semi-conductor processing
▪ Large use of metal, glass, plastic may cause environmental problems through production and accidental
realize of toxic material
Energy from the Sun Indirect
Water
23% incident solar energy goes into
water evapotranspiration, which
condenses to fall as rain, some on
continents where it returns via rivers to
the oceans
Wind
1% goes into kinetic energy of
atmosphere and oceans: winds and
ocean currents
Biomass
0.08% is captured by photosynthetic
plants, which store the energy
chemically and provide the energy
supply for nearly all life on Earth
➢
Today just under 10% of human’s energy is provided by those indirect form of solar energy
Hydropower Resources
• Conversion of the energy of flowing water into electricity
• In the early 20th century hydropower supplies 40% of U.S. electricity
• By mid-century competition with fossil fuels electricity generation: share drops one-third.
• Today about 7.5% of U.S. electricity comes from Hydropower (eia)
• Worldwide provide about 17% of electricity demand, equivalent to about 4% of total energy demand
• Largest hydroelectricity plant in the world:
Three Gorges Dam (China) on the Yangtze
river
o 22,500 MW capacity, output 20 times
greater than a large coal-fired or nuclear
electrical plant
o 2.3 km (1.4 miles) wide & 185 m (607 ft)
high. Creates a reservoir 625 km (373
miles) long. 1.3 people relocated
• Room to increase electrical energy generation from
hydropower, especially in developing countries
Wolfson, 2012 Energy, environment, and climate
• Potentially United Nation estimates world’s technically
exploitable hydroelectric resources ≈ today’s global electrical
energy production
• Thus, hydropower could produce energy demand in some
regions (almost)
• Hydropower has greater potential in developing countries,
much less in developed countries
• Hydropower Systems:
• Micro-hydropower systems power output
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