Module 3: Finals Version

Question 1

ecological footprint analysis (3)

Answer 1

• standard measure that can be used to related demand for natural resources to the planet’s ability to replenish resources
• results presented as the amount of land and sea area needed to support human populations

Question 2

what are the main components of the carbon cycle, from smallest to largest (4)

Answer 2

• atmosphere
• land
• ocean
• Earth’s crust

Question 3

what determines the overall atmospheric CO2 concentration

Answer 3

• the rate of exchanges of atmosphere CO2 with the ocean and terrestrial ecosystems; exchange occurs continuously

Question 4

carbon cycling in the ocean (3)

Answer 4

• atmospheric CO2 exchanges with oceanic CO2 at the surface through diffusion
• oceanic CO2 reacts to form bicarbonate, allowing oceans to uptake more CO2, but is limited by mineral cation supply from coastal sediment weathering
• concentration of CO2 increases in ocean interior due to two processes: solubility pump ad biological pump

Question 5

carbon cycling on land (natural) (2)

Answer 5

• CO2 removed from the atmosphere by photosynthesis of plants and stored in organic matter (can be for a long time); about half is released back through respiration
• remainder joins pool of organic matter in soil and eventually returns to atmosphere through soil decomposition (can also take a long time)

Question 6

carbon cycling on land (human activities) (2)

Answer 6

• combustion of fossil fuels
• land cover change

Question 7

carbon cycling on land: fossil fuels (2)

Answer 7

• combustion of fossil fuels (coal, oil, natural gas) from million year old organisms as primary energy source
• releases large amounts of CO2 into the atmosphere and alters the natural carbon cycle

Question 8

carbon cycling on land: land cover change

Answer 8

• land cover change, mainly deforestation, from human population increase and expansion of human settlements
• large areas of native forests cleared and converted into agricultural and urban areas
• as terrestrial carbon storage occurs in forests, land cover changes resulted in net flux of carbon to the atmosphere

Question 9

what is causing global warming/climate change/changes in Earth as a system

Answer 9

• humans

Question 10

ecological overshoot (2)

Answer 10

• the phenomenon which occurs when the demands made on a natural ecosystem exceed its regenerative capacity
• occurring right now because of human; our needs surpass the regenerative capacity and resources of a single earth

Question 11

what are the causal factors to ecological overshoot? (2)

Answer 11

1. species/populations have the biological disposition to expand exponentially when possible
2. humans have an unparalleled capacity for social learning

Question 12

causal factors of ecological overshoot: expansion (2)

Answer 12

• species/populations have the biological disposition to expand to fill all accessible habitats AND to use all available resources for continued growth and reproduction
• stock will grow unless a stabilizing feedback mechanism keeps it in check

Question 13

wha stabilizing feedbacks normally keep populations in check and what does it result in (2)

Answer 13

• population reaches a threshold where it is too big and resource depletion occurs(no more food, space, etc)
• results in loss of infinite growth/ a crash before stabilization of the population size

Question 14

how are humans bypassing the stabilizing feedbacks that normally act on species populations (4)

Answer 14

• outcompeting other species by modifying the environment
• health care
• social learning
• we construct our reality (laws, politics, economy, etc)

Question 15

is human population growth an example of a amplifying feedback loop?

Answer 15

• yes: the bigger the population, the more mating that occurs and the more offspring that is produced

Question 16

causal factors of ecological overshoot: social learning (3)

Answer 16

• we learn from others (both genetically and non-genetically related to us), thus bypassing costly trial-by-error learning
• supports cumulative culture and innovation
• we socially construct our realities and the way we perceive those realities

Question 17

what is the result of the population growth of humans

Answer 17

• we have a huge (and still growing) capacity for consumption, but Earth did not get any larger; PROBLEM

Question 18

what fueled the exponential growth of humans

Answer 18

• extensive use of fossil fuels allowed more agriculture mechanization, leading to removal of stabilizing feedbacks due to food and resource abundance

Question 19

how does technology and efficiency address ecological overshoot

Answer 19

• the though that we can support the growth with efficiency is incorrect; more efficiency will lead to increased consumption due to faster inflow into the stock

Question 20

symptoms of overshoot: atmospheric CO2 (2)

Answer 20

• increase in atmospheric carbon dioxide and climate change
• 45% increase above pre-industrial levels leads to a change in the chemistry of the ecosphere

Question 21

symptoms of overshoot: surface temperature

Answer 21

• the average temperature per year is getting warmer

Question 22

symptoms of overshoot: plunging biodiversity (2)

Answer 22

• human population and economic growth are competitively displacing wild species from their habitats and food sources
• results in extinction and displacement; replacement of wild species with livestock to support humans and room for humans to live

Question 23

symptoms of overshoot: world energy (2)`

Answer 23

• increase in consumption of all energy types
• positive: renewable energy use is increasing, but this is not the solution if overall energy consumption continues to grow as this will still increase carbon emissions

Question 24

the boom-bust population cycle (3)

Answer 24

• populations will experience a ‘boom’ when favourable growth conditions occur (humans here right now)
• when nutrients are depleted (unavoidable as we are confined to a finite number of resources on Earth), stabilizing feedbacks will cause the population to go through a ‘bust’
• pattern common to non-human species introduced to a resource-rich system

Question 25

why can humans avoid the uncontrolled collapse of population ('bust') (4)

Answer 25

- high intelligence - the ability to plan ahead - the capacity to exercise moral judgement - empathy/compassion for other people and species

Question 26

how can humans avoid the uncontrolled collapse of population ('bust')

Answer 26

- decrease the overshoot/resource need to be under the carrying capacity of the Earth

Question 27

project drawdown (2)

Answer 27

- global initiative to rank hundreds of solutions to current climate projections - aim to show which climate issues are most important to achieve a future point in time when levels of greenhouse gases in the atmosphere stop climbing and start to steadily decline (inflow < outflow)

Question 28

product footprint

Answer 28

- evaluates life cycle of products and ranks actions

Question 29

do you personal choices reduce your contribution to climate change

Answer 29

- yes: can be small (upgrading light bulbs, recycling) or large (one less baby, car free life)

Question 30

why are cars bad for climate change (2)

Answer 30

- the cost to manufacture, refine fuel, run the vehicle, and for maintenance are high; lots of emissions - more car users take up more space, creating need for more space for roads/parking, creating an increased need to own a car to get to further away places; amplifying feedback loop that requires even more emissions

Question 31

why is air travel bad for climate change

Answer 31

- a single flight can take up ALL of the suggested yearly emissions (to avoid ecological overshoot) for an individual

Question 32

why is a plant-based diet good for the environment

Answer 32

- just subbing one plant-based item for a animal-based item can achieve huge emissions reductions and free up cropland