Environmental Science Flashcards
(188 cards)
1
Q
What is the difference between applied science and empirical science?
A
Empirical science investigates the world through experimental and observational analysis to learn
Applied science seeks to answer
2
Q
Describe the case study of the Greenland vikings. How did they adapt and why did they go extinct?
A
Colony (led by Erik the red) left Iceland fro Greenland in search of walrus’ to hunt (tusks were their currency)
- In Greenland, they overused resources and put too much pressure on the ecosystem. Due to the cold and slow growing ecosystem, could not recover.
- Also existed during the “little ice age”
- As resources depleted, they resorted to hunting seals (dangerous) and irrigating and fertilizing fields with manure
- Europe else interested in trade
3
Q
What is the difference between the Iceland and Greenland viking colonies?
A
- Icelandic vikings adopted sustainable development: they used their land responsibly and adapted to fishing etc to meet their needs without impacting future generations.
- Greenland viking may have better survived if they matched their lifestyle to their environment
4
Q
What is sustainable development?
A
The act of meeting current human needs without impacting future generations
5
Q
Do the Greenland vikings meet the criteria of the demise of a society? How?
A
…
6
Q
What are the Jared Diamond’s 5 factors the lead to the demise of a society?
A
- Natural climate change
- Failure to respond to environmental changes
- Self inflicted environmental damage
- hostile neighbours
- loss of friendly neighbours
7
Q
Do the Greenland Viking’s experience mirror human interactions on earth today?
A
yes, we are experiencing a change in climate but are beginning to adapt
- overusing resources
- hostile neighbours based on different responses/acknowledgement, political challenges
8
Q
What are the take home messages from the Greenland Vikings?
A
- the natural environment and how we interact with it affects what happens to humans at any time
- we must work to understand and live sustainably
- Adaptive management
9
Q
What is adaptive management?
A
- tale science we know and put policies in place, adapt these policies as new information is learned that informs scientific processes
10
Q
Why is science is our scope referred to as ‘Western Science’?
A
All cultures around the world have science - there is no single way to interpret or do things. Different experiences and responses .
- western science is a rational, culturally based empirically sound way of knowing nature that yields descriptions and explanations
11
Q
Describe White Nose Syndrome in Little Brown Bats.
A
- Thousands of bats found dead with white fuzz on most. Visibly suffered (emaciated)
- Fungus determined to wake up bats more often in the winter, causing them to use up energy and starve to death
12
Q
What is science?
A
- culturally based process that leads to a body of knowledge about the natural world
- constantly changing
13
Q
Is science a constant ?
A
No, it is always changing as fact, figures, and understandings are revised
14
Q
What is the ‘process’ of science?
A
- a series of standard methods that enable scientists to test ideas
- gather evidence, evaluate quality of evidence, share results
15
Q
is the scientific method the only approach?
A
- there are many: data driven, theory driven, data rich, dat poor, experimental, observational, qualitative, quantitative
- diversity influences methods/aproaches to answer research questions
16
Q
What is a theoretical scientist?
A
- studies things we cannot measure directly ie: how did the universe begin
17
Q
What is an empirical scientist?
A
Gather data through experiments
18
Q
What is applied science?
A
- findings guide actions
19
Q
Why might some methods be different in Eurocentric science?
A
- eurocentric science shares common scientific values but methods may change between disciplines
- variable controlled, parameters of study defined, peer reviewed, then shared
- should be replicable
20
Q
How do scientists collect empirical evidence?
A
- Only phenomena that can be objectively observed are fair game for science
21
Q
What are observational evidence and empirical evidence?
A
Observational: information detected with the senses or with equipment that extends our senses
Empirical: info gathered via observation of physical phenomena
22
Q
What is the process of science?
A
- curiosity, investigation, sharing of information
23
Q
What is the scale of proof, and when is a theory certain?
A
- theories occur after enough evidence is collected from all angles to suggest an explanation
- no theory has absolute proof. Hypotheses may be rejected but never proved right.
24
Q
What were the two forms of empirical evidence in research studies? Use bats for examples.
A
- observational: observe bats in wild without manipulation using body temp. sensors.
- Experimental: bats used in experiments where they control environmental factors: bring bats into labs
25
What does a higher body temperature in a bat mean?
- they are awake.
26
What might observational and experimental studies be useful when answering research questions?
- observational is less invasive/harmful
27
What are the rules of ethics in animal studies?
- animal studies of any type raise ethical concerns
- ethical reviews in order to ensure no undue pain/distress
- must weigh ethics of placing animal in pain over benefits of that research
28
What is correlation vs. causation?
Correlation: two things occurring together but not a cause-and-effect relationship
Causation: one variable is a result of another
29
Why does correlation not prove causality?
Just because two things are happening at once does not mean they are a product of each other
- lab experiments on bats helps to confirm that WNS and bat deaths are actually related and not just occurring simultaneously
30
What are some other potential causes of bat death?
- temperature changes, population threshold, lack of insects, etc.
31
How is Dr.Max Liborion's research lab different from conventional western science?
- inclusive, accessible, open access science.
- asks communities what they would like to know, answers those questions
- data from land belongs to Indigenous, is given back
- minorities, not just white old men
32
What is a logical fallacy?
Arguments used to confuse or sway someone to accept a claim or position in the absence of evidence
33
What are the logical fallacies?
Hasty generalization
Red hering
Ad hominem
Appeal to authority
appeal to complexity
false dichotomy
(defined later + ensure familiarity using practice questions)
34
What are some things to consider when reading news?
- sources, accuracy, personal bias, author bias, corroboration from another source, reasonability
35
What is environmental science?
How we interact with environment, how it's changing, how our actions impact the environment, considering solutions
36
Is environmental science interdisciplinary?
yes. It seeks to understand interactions between earth systems and how we effect/can address these issues
37
What is empirical science?
- investigating the world through observation and experimentation
38
What is applied science?
- use findings to inform actions and bring positive change ( can be from specific research or uses empirical science)
39
Why should we study environmental science?
- the state of the environment is linked to human health
- environmental problems are wicked problems : multiple causes, multiples solutions, requires tradeoffs
40
What do wicked problems always require?
Tradeoffs
41
what is the triple bottom line?
The 3 P's : profit, people, planet
- solutions to wicked problems must confront and promote all 3 economic social and environmental factors
42
What are the revolutions?
Agricultural, industrial (fossil fuels - begins and grows negative impact) , environmental
43
What is sustainable development?
Meeting present human needs without compromising the future - must occur everywhere, renewable energy key
44
What are the primary components of the planet?
Geosphere, hydrosphere, biosphere, atmosphere
: all systems interconnected, impact each other
45
What are the 3 biomes of the biosphere?
- marine, terrestrial, freshwater
46
What are the two abiotic factors that influence what type of biome is found where?
- temperature and precipitation
- determines which plants live in an area that determines which animals live there
47
Which biome is nova Scotia?
Temperate boreal forest
48
What do ecosystem ecologists study?
- how ecosystems work in relation to their abiotic components such as air, water, and soil and their biotic components
- additionally how humans changed these ecosystems and how changes will impact ecosystems and way of life
49
What are the 3 kinds of ecology study?
- community ecology, ecosystem ecology, population ecology
50
What is a community?
all the populations (plants, animals, and other species) living and interacting in an area
51
What does a community ecologist do?
- investigate the factors that influence biodiversity, community structure, and the distribution and abundance of species in a given area
52
What is a population?
- all the individuals of a species that live in the same geographic area and are able to interact and interbreed
53
What do population ecologists study?
- investigate how populations of a single, interacting species change over time (how they grow and change etc)
54
What are the peatlands? Why are they important?
- a type of ecosystem
- has abiotic and biotic characteristics
- an important sink: covers 3% of the world but stores 1/3 of carbon found in soil worldwide
55
What are the biotic and abiotic components of peatlands?
- cold air, organic matter (peat), soil/water pH, mineral component of soil (phosphorus and nitrogen)
- acidic soil trees (spruce), moss, microbes
56
What are the two fundamental processes that link species with each other and their environment ?
- energy flows through ecosystem
- matter cycles - recycles
57
Why are the fundamental processes in certain directions?
- energy from sun is renewable, flows through and is lost as heat
- matter is non-renewable, must be reused again and again
58
What is a sink?
- abiotic or biotic components of the environment that serve as storage place for cycling nutrients
59
What is matter?
- the stuff of life
- earth's elements come down to elements and compounds
- elements combine through chemical reactions to form countless compounds
60
-What is matter? What is the law of conservation of matter?
Matter: all material in the universe that has mass and occupies space
- law of conservation of matter: matter cannot be destroyed or created - recycled by nutrient cycles in ecosystems
61
What is energy?
- underlies every process in environmental science
- energy is the ability to do work, to move matter
- can change position, composition, or temperature of matter
62
What is the 1st and 2nd law of thermodynamics?
1st law: energy can be neither created or destroyed, only altered in form
2nd law: when we take energy and convert it from one form to another we lose some useful energy as heat
63
What is the difference between a biome and an anthrome?
Biome: a region where temperature and precipitation determine which plants live there and thus which animals live there
Anthrome: human altered biome
64
What 5 categories are anthromes grouped into?
1. Dense settlement
2. villages
3. croplands
4. rangelands
5. forestlands
65
What limits species distribution?
limiting factors and range of tolerance
66
What are limiting factors?
- the critical resource whose supply determines the populations of a given species in a given ecosystem
ie: excess CO2 don't mean shit when there aint enough phosphorus and nitrogen in the soil
67
What is the range of tolerance?
- the range, within upper and lower limits, of a limiting factor that allows a species to survive and reproduce
68
What are the limiting factors of the peatlands?
- Phosphorus and Nitrogen
69
What happens in the SPRUCE experiment when temperatures increase inside the experimental enclosure ?
- soil microbes may work faster, decompose peat further releasing nitrogen and phosphorus into soil: shrubs grow more while moss lose sunlight and grows less = less acidic soil means microbes do better job and release stored carbon into the atmosphere
70
Are the SPRUCE experiments experimental or observational?
- experimental
71
What happens when CO2 is increased in the SPRUCE pods?
- plants are able to grow faster with more CO2 readily available, trees store more carbon but grow more
72
What happens when both CO2 and temperatures are increased?
- - increased growth which is eventually capped due to limiting factors of [phosphorus nitrogen and water
- becomes too hot, exceeds range of tolerance
73
Would a species with a greater or smaller range of tolerance be able to adapt to changing conditions better?
(each individual has specific range it prefers, genetic diversity within population)
- overall species with greater range of tolerance would do better because it could evolve more easily into the extremes
whereas a species with a small range might be wiped out immediately
74
The SPRUCE project studies the reactions of plants to changes in temperature and atmospheric:
Carbon Dioxide
75
If you are an ecologist studying how populations in an area live together and interact, you would be focusing on the organizational level of:
Community
76
What are residence times?
Nutrients are stored in sinks, residence time is how long the nutrients will remain in that sink
77
What are the nutrient cycles?
Nutrients (carbon, nitrogen, and phosphorus) transfer though biotic and abiotic components of the ecosystem
--> go from sink, through food chain, into another sink
78
What are 4 ways carbon might return to the atmosphere from a plant?
Decay, burned, cellular respiration (animals eat), breathing?
79
how does carbon go from plants to atmosphere?
Cellular respiration
80
How does the slow cycle return carbon to the atmosphere?
volcanic eruptions!
81
What are the 3 relevant nutrients?
Nitrogen, Carbon and phosphorus
82
Describe carbon as a nutrient?
- Essential component of organic molecules such as DNA, proteins, fats, carbohydrates
- bonds are a source of chemical energy both through respiration but also fossil fuels
- the amount of carbon dioxide in the atmosphere influences the temperature on earth
- stored in sinks
83
What are some of the major sinks carbon can be found in?
- fossil fuels, plants and animals (cell resp), ocean, atmosphere, soil
84
Describe the fast carbon cycle?
1. carbon is removed from the atmosphere during photosynthesis and incorporated into plants via photosynthesis
2. Carbon compounds enter the soil, decomposers/ consumers and producers (who eat others with carbon) all undergo cellular respiration, CO2 goes back into atmosphere
85
What are the two processes used in the fast carbon cycle?
- cellular respiration (sugar broken down to release energy: O2 used, co2 released)
- photosynthesis (co2 taken and turned into sugar, releases O2) - energy from sun
86
What are the 4 ways that carbon can move from a plant back to the atmosphere?
- cellular respiration
- decomposition
- wild fires / burning
- one more???
87
Describe the steps of the slow carbon cycle
1. Rain is slightly acidic and rains down on rocks - causes chemical weathering: important ions released (calcium, potassium, magnesium, sodium)
2. Carbon dioxide and water combine to form bicarbonate ions - when calcium meets it forms calcium carbonate
- calcium carbonate is used by coral and phytoplankton to produce shells
3. animals die and fall to cone floor: sediment and shells are packed over time to become rock and stored in sink (residence time = thousands / millions of years)
4. Carbon returns to the atmosphere via volcanic eruption
88
What is the ion in the ocean that bond with calcium?
bicarbonate - originates when carbon dioxide combines with water
89
Which organisms most commonly use calcium carbonate for their function?
- coral and phytoplankton
(coccolithophores and foraminifera)
90
Where is most of the carbon stored in the ocean found?
80% is found in the sediment, 20% found in fossil fuel reserves
91
Describe how a hummingbird might contain a carbon molecule after drinking nectar of a flower above where a pig has died and was buried
- fast carbon cycle: pig dies, consumers (fungi and decomposers) eat pig (inc. carbon) then respire releasing co2 into atmosphere
- through photosynthesis, CO2 taken up to produce sugars in flower (nectar)
- hummingbird comes to drink nectar, sugar contain carbon molecules of the pig!
THE CIRCLE OF LIFE
92
How are humans altering the carbon cycle?
- burning fossil fuels, wildfires, deforestation
93
How does the carbon cycle try to balance the excess carbon dioxide in the atmosphere? (ie: how is the balance of exchange between carbon sinks altered?)
- extra co2 leads to rise in temperature = more rain = more chemical weathering and more carbon stored in sediment in the ocean BUT this is the slow carbon cycle and takes a long time: cannot keep up with the demands so the environment must adapt before excess carbon is stored
94
What does the Mauna Loa observatory graph present about global CO2 levels?
CO2 levels are increasing - has spikes up and down, the downward spikes represent the seasons: more plant growth and PP leads to more CO2 uptake in summer months
95
How will earth systems adapt to higher CO2 levels?
- land plants will draw more CO2 - 25% of excess CO2
- oceans will absorb 25% leading to ocean becoming more acidic (more energy required to makes shells = weaker shells)
- excess co2 leads to warming temp and precipitation changes and severe weather events
- overall impacts how successful species are in the future
96
Why might a higher ocean pH affect the coral reef and phytoplankton?
- higher pH from excess CO2 means fewer carbonate ions: more energy to form calcium bicarbonate and weaker shells
97
Describe nitrogen as an element
- 6th most abundant element on earth
- make sup 78% of our atmosphere
- essential ingredient in proteins, DNA, RNA that build our bodies
- essential for plant growth and often a limiting factor for plant growth (abundant but in the wrong form)
98
Why is nitrogen often a limiting factor of plant growth? what is used to accommodate?
- because it is in the wrong form (gas)
- nitrogen fixation!
99
What are the steps of the nitrogen cycle?
1. Nitrogen fixation
- intense lighting strike or nitrogen fixing bacteria
- N2 (atmosphere) + hydrogen = NH3 (ammonia)
2. Ammonification: organic matter is converted into NH4
3. Nitrification: NH4 into NO3-
4. Denitrification: NO3- into N2 (cycle begins again!)
100
Why is nitrogen fixation important?
N2 gas must be turned into NH3 (ammonia) because ammonia is a form that plants can use
101
What is the relationship between species richness and diversity when it comes to resilience?
- the more even and rich a community is, the greater its complexity and resiliency
- ensures that one dominant population will not 'take over' any others
102
What is the two step process of net secondary production?
- individual growth creates new population biomass - some of that biomass is transferred to heterotrophs who eat the initial individual
103
Describe energy
- underlies every process
- can move, change the temperature, or change the composition of matter
104
How have humans impacted the phosphorus cycle?
- increased use of fertilizers and mining has put excess phosphorus into the environment
105
Why is there a minimum viable population number?
- minimum number required for certain behaviour like hunting, courtship rituals, interactions, flocking, etc
- also risk interbreeding and decreased genetic diversity (less ability to adapt)
106
Why is population density important?
- too low: not enough genetic variation, in breeding, population behaviours
- too high: density dependant factors such as disease, predation, competition
107
What is biological evolution?
Genetic changes in populations across generations that change appearance, behaviour, or functioning
108
What is selective pressure?
- a non random influence which effects who survives and reproduces
109
What is a common form of selective pressure?
- predation: slower and weaker get killed = selective pressure
110
Differential reproductive success ?
- individuals with varying traits may be better able to survive and reproduce
111
What is a good definition for natural selection?
- individuals with better adaptations have greater success breeding and surviving
112
Are all salmon identical?
- No! variation in salmon translates into variations In survival and reproduction
113
What are some beneficial traits in salmon (that may have arose from variation)?
- hooked jaw, change colours before entering the sea, strong swimmers, lots of babies, lay eggs in gravel of stream,
114
How does genetic variation come about?
- mutations and genetic recombination : parents alleles combine to form new combinations of genotypes that may be neutral, beneficial, or detrimental
115
What are the steps of natural selection?
1. overproduction
2. inheritable variation
3. differential (or unequal) reproductive success
116
Can selective pressure change over time?
YES! and it can reverse direction
- selective pressure can change within a generation, evolution occurs across. multiple generations
117
Describe the tungara frogs distribution
initially phenotypic distribution of mating calls is stabilized between complex and simple
- mates are attracted to complex calls increasing reproduction, but also these calls attract bat predators = selection acts in opposing directions = stabilized
118
Can multiple selective forces act on the same trait at once?
- yes, and they can act on the same trait in different directions ie: tungara frogs
119
What was the causing factor of moth colour distributions going from directional to the other directional?
- Industrial Revolution coal air pollution made the background dark - causes selection of light to dark directional selection
120
Is the pace of evolution constant or the same for all species?
no - rate of evolution is impacted by factors such as generation time, strength of selective pressures and genetic divesity
121
How do random events influence the evolution of a population?
- along with natural selection, random genetic drift, the founder effect and the bottleneck effect can impact variation within a population
122
What are the two methods of genetic variation?
- allele recombination and genetic mutations
123
What is genetic drift?
- change in gene frequencies over time due tor random events - results in loss of gene variants die to lack of breeding or death of those carrying certain alleles
- genetic drift occurs due to random events OR random mating
124
What is the bottleneck effect?
Some events causes population size to decrease leading to the loss of some genetic variants and decreasing diversity
125
What are 3 ways that genetic diversity might reduce in a population?
- founder effect, genetic drift, bottleneck effect all reduce allelic frequencies
126
Describe palm oil plantations and how they are a problem
- half of us products and food use palm oil - demand has increased 6x since 2000
- 25% of palm oil comes from Malaysia and Sumatra: lead the world in deforestation rates while housing an incredible array of biodiversity which is threatened
127
what are the stupid tenants of stupid critical thinking?
- assess the evidence, be sceptical, open minded, author biases
128
What is biodiversity? What are its components?
biodiversity is the variety of life on earth
- composed of genetic, species, and ecological diversity
129
What is genetic diversity?
- variations present in DNA of individuals within species an populations
-provides raw material for adaptation to local changes = enables species to adapt to ecological changes
130
What is species diversity?
- species richness = the number of species
- species abundance = the abundance of those species (rare or abundant)
131
What is ecological diversity?
- multiple habitats, niches, and ecological communities within an ecosystem
132
What are the principles of biodiversity? (3 statements)
1. higher ecological diversity, the more species (more niches and transfers of energy)
2. The greater the species diversity the more resilient the communities
3. The greater the genetic diversity the greater chances a population can adapt and change
133
How many species are there?
1.5 million identified, 3-11 million estimated, >150 billion with bacteria
134
What are the environmental costs of the palm oil business?
- indonesia lost 25 million acres of forested land in 20 years most of which as for oil palm plantations
- the rainforest has the greatest diversity of species so loss means:
- loss of carbon sink : accelerated climate change
- polluted air and water: health impacts on locals
- more flooding and soil erosion: loss of natural resources and services
- loss of biodiversity from death of native species
135
What is intrinsic and instrumental value?
intrinsic: has value in and of itself
instrumental: useful for humans to use
136
What is an endemic species?
- a species native to that region and not found anywhere else naturally
eg; Indonesian orangutan
137
What are ecosystem services?
Any positive benefit that ecosystems provide to people
- without the species that keep ecosystems functioning use of resources and enjoyment would be reduced
138
What are the ecosystem services ?
- provisioning (human use), regulation (natural processes that keep environment functioning), cultural (enjoyment, education, spiritual)
139
What is the relationship between population size and density?
- need a minimum population size to do certain things and to ensure there is no inbreeding and enough variation for adaptations to occur if the environment changes
BUT
- if the population is too dense there are density dependant factors such as competition, disease, and predation which may cause harm
140
How can we distinguish between empirical science and applied science?
- applied science seeks to study something in order to find a solution
- empirical science simply gathers information experimentally or observationally
141
What is the difference between ecocentrism and biocentrism?
Ecocentrism: values entire ecosystems protection
Biocentrism: more focused on living things (biodiversity)
142
What is the equation to determine growth rate?
(P2-P1 / P1) x 100
143
What is conservation biology? Classify the threats to biodiversity
- conservation biology is the science of preserving biodiversity - focus is on protecting individual species and maintaining/restoring ecosystems
- human threats: habitat destruction/fragmentation, invasive species, pollution, climate change, overexploitation
144
What is SARA?
- Canadian species at risk act passed in 2002 protects species endangered or at risk of extinction
- extinction, extirpation, threatened, species of special concern
a legal requirement to assess species at risk
- once passed the law includes:
- probihibiton to kill, capture, harm
- protection of habitat
- recovery plan/action plan
- emergency authority to protect species in imminent danger (including stopping Development of habitat area)
- makes available funding and compensation
145
What are some species in Nova Scotia that have gone extinct or extirpated?
extinct: passenger pigeon, great auk, Labrador duck
extirpated: grey whale, wolves, caribou, walrus
146
What percentage of species to have ever existed have gone extinct?
- 99%
147
What is the IUCN red list?
- 28% of species assessed threatened with extinction
brings attention to problems of threatened and at risk species
- added to the list when at risk of endangerment, taken off when recovered
- assigning status allows conservation biologists to prioritize
- extinct, extinct in the wild - critically endangered, endangered, vulnerable - near threatened, least concern, no data
148
Which species types are more threatened?
- those with:
- narrow habitat ranges
- extreme specialization or co-evolved dependancy
- rarity of species
- low reproduction rate
- large area requirements
149
What is single species conservation? landscape suite species? Flagship species?
- single species: strategy focuses on one species conservation: understand biology of the species and then develop conservation plans
- landscape suite species: protect species which use large colonially diverse areas- protect them will protect ecosystem and other species
- flagship: species that are infesting or charismatic to raise conservation interest
150
What is COSEWIC?
Committee on status of endangered Wildlife In Canada
- biologists, indigenous, uni academics classify species and determine the status report
- assessment of wildlife species at risk of extinction and extirpation
- provides advice regarding status of wildlife species
151
What are the 3 core sciences involved in environmental science?
- humanities and arts, social sciences, natural sciences all used to understand the environment and our relationship with it
152
What are some examples of wicked problems today?
- climate change, feeding an ever growing world, air and water pollution, etc
- all complex, require tradeoffs to solve (must be good for environment, society, and affordability : people, profit, planet)
153
What is a social trap?
Decisions that seem good in the short term but harmful in the long term making the problem worse
ie: a cheap pipe that bursts later
154
What are the best ways to address a social trap?
- education, privitization, regulation
155
What is the difference between a biome and an ecosystem?
Ecosystem combines living things that are interacting with each other - often found within a biome
- biome is a region defined by precipitation and temperature
156
What is the rule of 70?
- 70 / growth rate (in percent) = doubling time
157
What is biotic potential ?
- the maximum growth a population can reach under optimal conditions
158
what is symbiosis?
- a long term close relationship between two members of separate species
eg; clown fish and anemone
159
What is the difference between detrivores and decomposers?
Decomposer: breaks down material back to original components so plants can take it up
detrivores: eat dead materials (cellular respiration occurs)
160
what is a surrogate species?
- a species whose needs represent the entire ecosystem
161
What is I = P x A x T ?
I = Impact
P = Population size
A = affluence - rich generally have more impact, consume more, more space
T = technology - can exacerbate or decrease impacts
Our individual human impact
162
What is demography?
- the application of ecology principles to the study of statistical change in humans populations
- it is a social science
163
What is the formula for population growth? Growth rate ?
P2 = P1 + (Births - Death) + (immigration - emmigaration)
growth rate (%) = (number added/pi)x100
164
how many growth spurts has the human population had? What is the population on track for in 2100?
- 2 growth spurts (agricultural revolution and Industrial Revolution)
- 21 billion by 2100
165
What is zero-population growth ?
- the absence of population growth ; occurs when birth rates = death rates
- will result in population stabilization
166
What growth curve is the human population? at what percentage is it increasing? What is the doubling time?
- exponential (1.12%)
- 70/1.12 = 63 years we will be at 15,200,000,000
167
What would the growth rate need to be to have no population growth?
Zero
- even if there is a decline in growth rates, the population is still growing but more slowly than it did before
168
Is the distribution of the population even?
no, wildly uneven (clumped)
-59.5 % in Asia alone
- populations are located close to the ocean or major rivers
169
What percentage of the population are in 10 nations?
60% in just 10 nations
- china and india most populous, in 2023 India passed china as the most populous country
170
What are some factors that determine human population size?
- birth, death, emigration, immigration
170
What are demographic factors?
population characteristics such as birth rate the influences changes in population size and composition
- population growth factors and population RESISTANCE factors
171
What is desired fertility? TFR? What is their relationship?
- Desired fertility: the ideal number of children an individual indicates he or she would like to have (influenced by health, education, economic conditions, culture, and religion)
TFR: total fertility rate: the number of children the average woman has in her lifetime (2019 TFR=2.5)
- TFRs are highly variable place to place
- relationship: generally as desired fertility increases so does TFR
172
What are pronatalist pressures?
- factors that influence population growth
- high infant mortality rates, lack of education or job opportunities for women, valuing children (labour, religion, cultural), unmet needs for contraception
173
What are some relationships between pronatalist factors and social justice?
- childhood mortality and TFR - closely related to poverty, more death = more children
- education of women and TFR: fertility declines as educational opportunities for girls and women increase
- contraceptive use and TFR: access to contraceptives and family planning have been effective in many areas of the world
--> however, in countries with high desired fertility such as niger providing contraceptives may have little impact on TFR
174
Describe the demographic transition graph
--
175
How does age structure help predict growth?
- we can see that births and deaths that predict whether a population will have high birth rates
eg; madagascar has a lot of children, they keep reproducing, die earlier
176
Is the demographic transition a universal process?
- Canada, Japan, US have followed this model
- why might industrialization not lead to a demographic transition in all countries? -No contraception, religious beliefs, fewer rights for women, disease in countries keeps death rates high,
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What is an ecological footprint?
- a measure of one's consumption and waste production expressed in land required per person
(I = P x A x T)
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When did the human population exceed earth's carrying capacity?
in 1970 we began to use more resources than earth could replace long term - not sustainable, cannot continue indefinitely
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What might increase our footprint?
- wealth produces severe and far-reaching environmental impacts ( buy more stuff, drive, take up more space, create more garbage, more emissions, etc, etc)
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What are some methods to reduce the population growth?
- population and carrying capacity is complex
- to be truly sustainable: must address key components address components such as poverty, education, improving basic human rights
- those with greater affluence must reconsider their lifestyles and impacts
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What are invasive species?
- a species which has been introduced intentionally or accidentally from one place to another
- most organisms introduced to new environments perish but few survive and do well
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What are some characteristics of invasive species ? Provide one example of invasive species and why they were successful
- lacks predators, spreads widely, and becomes dominant in communities outcompeting native species
- exotic or alien, not native
- asian carp fish: introduced from china to remove algae in ponds - soon escaped: very adaptable, big problem
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What primarily powers the water cycle? What is the secondary driver of the water cycle?
- the sun! - evaporation and other processes including wind
- gravity
184
How much freshwater is on earth?
- 97.5% salt water, 2.5% freshwater and only 1.2% accessible
185
What are pools and fluxes? Provide some examples
pools: where water is stored
- ice sheets, glaciers, lakes, oceans, wetlands, permafrost, atmosphere, soil, rivers, groundwater
The way water moves between pools are known as fluxes
- evaporation, precipitation, transpiration: evapotranspiration, runoff, ocean circulation, groundwater runoff
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What drives the water cycle?
- natural and human controlled processes
- natural: energy from the sun and gravity
--> Gravity allows water flows, sun dries evapotranspiration and wind patterns
--> Human processes:
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How do humans alter the
