Exam 3 Flashcards
Identify the biological impacts resulting from fossil fuel CO2 emissions.
What are criticisms of using lab rats to set sage limits to human exposure?
Explain how burning wood for heat (wood -> CO2 + heat) does not produce a net increase in the amount of CO2 in the atmosphere.
?
What does EROI stand for?
Energy Return on Investment
EROI =
Energy acquired / energy spent
Which energy source has the highest EROI and what is it?
Hydro; 100
What are the physical changes of burning fossil fuels?
- Temperature increasing
- Greater frequency of extreme weather events
- Sea level rising (glacier melt (50%) + thermal expansion (50%))
- Acidification
Acidification
CO2 + H2o –> 2H+ + CO2-/3
What are the biological changes of burning fossil fuels?
Northward shifts in distribution
“Feed-need” disjunction
Shifts in phenology
What are the fates of trees in the changing climate?
- Migrate to track “temperature window”
- Adapt to altered conditions (in place)
- Disappearance (extirpation)
phenology
study of environmental conditions that trigger important life events (e.g., loss of leaves in the fall)
timing of cyclic and seasonal natural phenomena (usually in relation to climate)
Phenology shifts
Herbivores 6 days earlier, upper trophic levels > 3 days earlier
- decoupling between predator and prey
- elevated temps:
- predators don’t concur with prey
- some bit of overlap
Green sea turtle sex is determined by
Temperature they are incubated at
What is the “pivotal temperature” for sex determination of green sea turtles?
29°C
What are the unexpected consequences of seawalls holding back rising tides?
seawalls holding back rising tides + sea level rise = no beach to lay eggs for turtles
How has the climate change discussion has changed direction?
From “is it happening?” and “do humans’ actions contribute?” to “what do we have to do to reduce eventual severity and adapt to changes”
What are approaches to dealing with with global change?
- Reduce energy use
- Shift from fossil fuels to alternative energy (electrification)
- Carbon capture and storage
- Geoengineering
- Birth control?
What are ways of reducing energy use?
- More efficient vehicles —> less vehicle use
- More efficient buildings
- “Smart growth”: build and renovate in ways that make things accessible
Which law regards efficiency of buildings?
Local Law 97
The Local Law 97 states:
By 2030, carbon emissions have to be reduced by a certain amount to avoid
How does carbon capture and storage work?
Suck CO2 out of atmosphere and make it solid, then bury it somewhere
What are the functions of geoengineering?
- CO2 removal
- Pull CO2 out of atmosphere
- Reforesting/replanting: as trees grow, they remove more CO2 from water - Solar radiation management
What is the difference between carbon capture and geoengineering?
Geoengineering uses nature
Hydropower “cons”
Climate change risk (drought)
Dams vs. fish (increase temperature)
Methane emissions
How do reservoirs create methane emissions?
Plants in reservoir die and settle in bottom
—> creates layer of organic debris
—> bacteria start to work on breaking down material
—> consume oxygen as they do this
—> no oxygen present
—> bacteria generate methane
—> methane diffuses out of water into atmosphere
“…our children will enjoy in their homes electrical energy too cheap to meter” was said by who?
Lewis Strauss
Lewis Strauss was the head of…
AEC (atomic energy comissions)
Determinants of price for electricity:
Capital cost - cost of constructing nuclear power plant (nuclear»_space; fossil fuel)
Operating costs (nuclear < fossil fuel)
What type of emissions is the life cycle analysis comparing and how is it being measured?
CO2 g/kW-hr
What do stack emissions represent in the life cycle analysis?
CO2 emissions
What does the life cycle analysis show?
- Nuclear generates the least amount of CO2
- Coal generates 278g/kW-hr of CO2
The life cycle analysis of CO2 compares the CO2 emissions of…
fossil fuel, traditional renewables, and new renewables
Describe the inside of a nuclear reactor.
- Heat —> steam (volume expands)
- Steam is used to vaporize water
- Generates pressure that pushes through and turns it turbine
- Turbine generates electricity
Which film was released 12 days before the Three Mile Island accident?
The China Syndrome
Price-Anderson Act (1957)
- liability limit for nuclear industry = $10 billion
- above that number -> US government pays
What health effects rose from the Chernobyl accident?
- birth defects sky rocketed
- thyroid cancers rose by a factor of 5 immediately after
Which isotope was used for nuclear waste disposal but was no longer efficient in splitting atoms to produce heat?
235U
Yucca mountain site
Take all nuclear waste and bury it deep underground far from people
Geologically stable
Examples of new renewables
Biomass, wind, solar energy, geothermal energy
New renewables make up ___% of global energy
7
List the organic substances produced by recent photosynthesis.
- methane
- ethanol
- biodiesel
Methane (gas)
anaerobic fermentation of biomass
Ethanol (liquid)
- anaerobic fermentation of biomass
- reduces net automotive emissions
What is biodiesel (liquid) derived from?
Vegetable oils (including used cooking grease, animal fat)
Pros of biomass
- no net carbon release
- renewable… in theory
- waste —> energy
Cons of biomass
- monoculture agriculture
- fossil fuel, fertilizer, pesticides
- loss of nature and food crop production
- low EROI (2-3)
- rate of energy capture < demand
Which type of solar (passive or active) utilizes a building design?
Passive solar
What is the purpose of passive solar?
- maximize heat capture in winter
- maximize heat capture in summer
through
- orientation & window placement
- thermally absorbent materials (absorb, store, release heat)
Which type of solar (passive or active) uses technology to focus & convert solar energy?
Active solar
Photovoltaic (PV) cells
converts energy DIRECTLY to electrcity
Constraints of solar power
Geography
Weather
Efficiency
Wind power converts _____ energy to _______ energy
mechanical; electrical
How much of the US’s electricity generation comes from wind power?
4%
How much of South Dakota’s electricity generation comes from wind power?
26%
How much of Texas’ electricity generation comes from wind power?
29%
How much of Iowa’s electricity generation comes from wind power?
31%
Constraints of wind power
Geography
Weather
What is geothermal energy?
Radioactive decay in Earth’s core
Geothermal energy uses geothermal heating of what?
Subterranean water
Describe geothermal reservoir
Production well sucks up heat
Re-injection well ejects heat
Active volcanoes and quakes emit ______ heat
shallow
Constraints of geothermal power
Geography
Ocean energy sources
Tidal power and wave power
Describe the steps of how wave power produces energy.
- incoming waves enter chamber
- rise and fall of water level within chamber compresses column of air above it
- Air flow in both directions drive turbine, generating power
T or F: Hydrogen is an energy source
F: Hydrogen is not an energy source, it is a fuel
What is the simplest and most abundant element in the universe?
Hydrogen
Electrolysis
Split water: 2 H2O + NRG —> 2 H2 + O2
Fuel cell
Uses hydrogen gas to produce electricity
Fuel cell equation
2 H2 + O2 -> 2 H2O + energy
“Green-ness” of H2 production?
Energy for electrolysis
Bioelectrolysis is performed by what?
Chlamydomonas
How would hydrogen be used to serve as basis for clean energy system?
- electricity from (intermittent) renewable sources produce H2 gas
- fuel cells: H2 -> electricity
What are advantages of epidemiological studies?
realistic
What are disadvantages of epidemiological studies?
- only correlational; establish link, cannot prove mechanism
- time required
Cohort studies
Two groups: exposed and unexposed
Example of a cohort study
Does disease develop? - Inference of cancer based on exposed group vs unexposed group
Case-control studies
cases have disease, controls do not
What is the purpose of case-control studies?
Distinguish what could have caused the difference between the groups (e.g., were patients with disorder exposed?)
What does threshold mean in reference to the dose-response curve?
dose at which response begins
What does LD50 mean ins reference to dose-response curve?
does lethal to 50% of test animals
How does the real world go against the dose-response curve?
- individuals differ in sensitivity to the toxin (e.g., lead)
- threshold: hard to say
- three degrees of cognitive impairment
What are tough questions regarding the dose-response curve?
- What is the threshold?
- Acute vs. chronic exposure?
- How long are exposures?
- Rats = humans?
- Are all people equal? - No. Individuals differ in susceptibility
- What should be the allowable exposure?
What is a type I error? What are the consequences in regards to contention that the abundance of migratory birds is declining?
Type I error concludes differences exist when really they do not
Consequences:
What is a type II error? What are the consequences in regards to contention that the abundance of migratory birds is declining?
Type II error concludes differences do not exist when really they do
Risk
An adverse event that could occur; predictable what might happen
Examples of risk
Car accident, global warming, bird extinction
Uncertainty
Probability not exactly known
What are sources of uncertainty?
- Uncertainty from info (theory and data)
- Uncertainty from different paradigms
- Uncertainty from semantics
What is a paradigm and how do different paradigms relate to uncertainty?
- Paradigm - “world view”
- The way you view the world and interpret that information
- Not everyone is going to interpret the information the same way
- People have different world views that affect interpretation
- Who you work for influences your interpretation
Semantics
“study of word meaning”
Which is statement is true about uncertainty from semantics?
- synonyms do NOT always mean the same thing
- source of uncertainty
The answer to “How acceptable is a risk?” depends on what?
- Degree of control - less fear of what we feel we have control over
- Degree of familiarity/understanding - less fear of what we feel we understand
- Degree of “voluntary-ness” - more likely to accept the risk voluntarily; less fear of what we do voluntarily
- Whether consequence is catastrophic - less fear of what we feel is not likely to he catastrophic
Why did cities originate?
- Sacred places
- Projection of power (=security)
- Commerce (& opportunity)
Megacity
Conglomeration of more than 10,000,000 people
Describe the urban development of Los Angeles from 1770-1900.
1770: First settlement (Franciscan Mission San Gabriel Arcangel in S.G. valley)
Series of religious missions
Goal: convert native to Christianity
1847: US control
Population in LA:
- Railroads arrived: contributed to tremendous population growth (1880)
Sprawl
spread of low-density development outward from an urban center
What were the consequences of sprawl?
Inefficient use of ground
Traffic became a problem
What are the characteristics of sprawl?
- No center community
- Businesses arrayed in long strip along a roadway
- requires a car to where you want to go - Low-density single-use development
- you live there but can’t shop there
- places were spread out
- detached homes
- large lots
- far from commerce - Scattered (leap-frog) development
What were the impacts of sprawl?
- transportation
- sprawl led to more driving - Pollution impacts of driving
- Land use change drive ecological impacts
- Sprawl promotes physical inactivity
- Funnel tax $$ into infrastructure, health impacts
What is the commonality of the most sprawling American urban areas?
- Most on Southern East Coast
- All after WWII
What is the commonality of the least sprawling American urban areas?
- Most on coast lines
- Old/original/historic cities (e.g., New York)
Who was Frederick Law Olmsted?
- Landscape architect
- Gave landscape design of: Trinity college, Yale university, UC Berkeley, Prospect park, Niagara park, Central park
Who did Frederick Law Olmsted partner with on his projects?
Calvert Vaux
Central Park (1857-1976)
- City around park is quite warm
- Park represents a place of relative coolness in the city
Why does urban heat island exist? Why are there higher temperatures in the city than outside?
- Dark colors that soak up sun
- Lots of asphalt and concrete
- Absorbs a lot of sunlight
- When sun goes down, asphalt and concrete release absorbed heat
When and how intense is the urban effect on temperature? When is the effect of urban temperature strongest?
- 11:00pm-3:00am
- difference is about rate of cooling
- during daytime, rural and urban are not that different
- differences appear during night time
(delta T u-r) night =
up to 10 C
(delta T u-r) day =
0-2 C
Why is UHI not the same as climate change?
UHI: smaller scale; city/regional scale
Climate change: global scale
What is UHI magnitude determined by?
- Time of day (greatest UHI in night/early am)
- Degree of conversion
- Building height & concentration
- Season (–> weather): wind & cloud cover (UHI greatest when calm, clear)
- City characteristics
How do city characteristics determine UHI magnitude?
- How a city is built will determine how hot it gets
- Population: larger city = greater population = hotter
What is the result of sea levels rising in Tuvalu?
Saltwater intrusion (drinking water, agr.)
Erosion —> land area loss (land area shrinks as sea level rises
What is causing “feed-need” disjunction?
Shifts in phenology
Most global warming US skeptics are…
Motivated by religion, politics, economics
Facilitated by ignorance of data
Facilitated by misunderstanding of science
What word to skeptics like to hold on to?
“Uncertain”
What behavioral and lifestyle choices increases risk of radiation exposure after Chernobyl accident?
Food consumer (forest products, wild game, fish, locally produced milk and meat)
Time outdoors
Use shallow wells (for drinking water)
House heating/cooking with firewood
When 235U is longer efficient in splitting atoms to produce heat, is it called?
“Spent” nuclear fuel
There are how many sites of “temporary” nuclear waste storage in how many states?
125 sites in 39 states
Epidemiological studies
Incidence, distribution, and possible control of diseases
Long-term, large-scale non-experimental comparisons of different groups
Why are epidemiological studies more advantageous than experimental studies?
Often non feasible because of high costs and ethical issues
What is the best way to answer, “which error is worse?” when comparing type I error and type II error?
Consequences
Apply type I and II error to the question: “bird abundance declining?”
Type I error: mistakenly conclude bird abundance is dropping
Type II error: mistakenly conclude that bird abundance is not declining
What was the social hierarchy of sacred places?
priest class, middle class, entrepreneurs
Examples of projection of power/security?
System of laws (Babylonian Hammurabi)
Walls
What were the commerce and opportunities provided in city origins?
Opportunities for economic improvement
Entrepreneurship (—> class (economic) mobility)
Western countries urbanized before or after non-Western countries?
Before
What was the history of urbanization-transportation store: railroad suburbs
Late 1800s-early 1900s:
- railroad suburbs in Garden city, bronxville ny, and brookline ma
What was the history of auto suburbs prior to WWII?
1920-1945:
- e.g., radburn (fairlawn, nj)
- development of automobile suburbs
- streets size determined by traffic load
- cul-de-sac (bottom of the bag)
How did auto suburbs advance post-1945/WWII?
FHA & VA loan programs
- returning veterans purchases houses
Cheaper autos
Federal interstate highway program + subsidies for road improvements (e.g., Levittoawn (1952))
Mass transit de-emphasized
- tearing out LA streetcar tracks to add other lanes to road
What are the pollution impacts of driving as a result of sprawl?
Smog
Ultrafine particular matter (PM2.5)
Metals (e.g., zinc)
What were the outcomes of land use change driving ecological impacts
Edges allow influx of organisms we don’t want
Nonnative species in city (e.g., poison ivy)
