Module 3: Climate Change and Ecological Overshoot Flashcards
1
Q
planetary boundaries (3)
A
- estimate of the boundaries for the biophysical processes that determine the Earth’s capacity for self-regulation
- define the sustainable limits for human existence, and suggested that these boundaries must not be crossed if catastrophic environmental change is to be avoided
- concern whether we understood the Earth system enough to know the real limits to environmental degradation
2
Q
net primary productivity (NPP)
A
- estimation of how much of the biomass (living material) produced each year by vegetation is harvested and used by humans
3
Q
human appropriation of NPP (HANPP) (2)
A
- through data and modelling, found that humans are appropriating nearly 1/4 of all biomass produced each year by ecosystems
- reduces the energy amount available to other species and influences biodiversity, water flows, carbon flows between vegetation and atmosphere, energy flows within food webs, and provision of ecosystem services
4
Q
ecological footprint analysis (3)
A
- 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
- uses existing data to translate human demand on the environment into the area required for the production of food and other goods, together with the absorption of wastes
5
Q
the tragedy of the commons (2)
A
- describes an pasture open to common use where each herdsman will try to keep as many cattle as possible to maximize their gain
- gives rise to tragedy: each locked into a system that compels them to increase herd without limit, resulting in environmental degradation that negatively affects everyone
6
Q
what examples did the author of the tragedy of the commons use to relate it to real world issues (2)
A
- marine fisheries
- pollution of the environment
7
Q
what is the overall conclusion of the tragedy of the commons
A
- over-exploitation of a natural resource is an inevitable consequence of human nature
8
Q
how could the tragedy of the commons be incorrect/harmful
A
- due to a misunderstanding of the system, the author mixes up open access and common land
- as a result, companies used this information to seize the highly regulated common land by making the land private and using it for commercialization
9
Q
carbon stock
A
- quantity of carbon in a pool (reservoir containing carbon) at a specific time
10
Q
carbon flux
A
- transfer of carbon from one carbon pool to another (measured in mass per unit of area and time)
11
Q
source
A
- any process or activity that releases greenhouse gas, an aerosol or a precursor of a greenhouse gas in the atmosphere
12
Q
sink
A
- any process, activity, or mechanism that removes greenhouse has, an aerosol, or a precursor of a greenhouse gas from the atmosphere
13
Q
carbon budget
A
- balance of the exchanges of carbon between carbon pools; examination of this budget will provide info on whether it is acting as a source or a sink
14
Q
carbon sequestration
A
- process of increasing the carbon content of a carbon pool other than the atmosphere
15
Q
what are the main components of the carbon cycle, from smallest to largest (4)
A
- atmosphere
- land
- ocean
- Earth’s crust
16
Q
what determines the overall atmospheric CO2 concentration
A
- the rate of exchanges of atmosphere CO2 with the ocean and terrestrial ecosystems; exchange occurs continuously
17
Q
carbon cycling in the ocean (3)
A
- 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
18
Q
solubility pump (2)
A
- process where CO2 is transported from upper ocean to interior depending on ocean circulation and mixing where cold, dense waters sink to deep oceans
- the water dissolve and capture carbon before the water masses re-surface again after decades to centuries of years
19
Q
biological pump (2)
A
- microscopic organisms (phytoplankton) assimilate CO2 through photosynthesis
- the carbon is fixed in their biomass, 25% sinks to the deep ocean and is oxidized and added to the dissolved carbon concentration
20
Q
carbon cycling on land (natural) (2)
A
- 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)
21
Q
carbon cycling on land (human activities) (2)
A
- combustion of fossil fuels
- land cover change
22
Q
carbon cycling on land: fossil fuels (2)
A
- 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
23
Q
carbon cycling on land: land cover change
A
- 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
24
Q
how do we know fossil fuel combustion is one of the main anthropogenic sources of CO2 emissions influencing climate change
A
- it has been proven with evidence: decrease in C13/C12 ratio over time and overall decline in O2 concentration over time
- this could be determined because CO2 emissions from fossil fuel combustion is unique to natural CO2
25
how do we know land-use change is one of the main anthropogenic sources of CO2 emissions influencing climate change (3)
- CO2 emissions from land-use change is more difficult to calculate and can only be estimated through models
- estimated using book-keeping method that tracks carbon stored in vegetation and soil for each hectare of land cultivated, harvested, or reforested; based on self-reporting data
- due to difficulties calculating CO2 fluxes from land-use change, the literature shows differing total anthropogenic emissions of carbon
26
land-use change is one of the main anthropogenic sources of CO2 emissions influencing climate change: what two factors give rise to uncertainties (2)
- availability of land-use data, especially related to rate of deforestation
- availability of data on changes in carbon stocks resulting from land management, such as harvesting and burning
27
what is causing global warming/climate change/changes in Earth as a system
- humans
28
ecological overshoot (2)
- 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
29
what are the causal factors to ecological overshoot? (2)
1. species/populations have the biological disposition to expand exponentially when possible
2. humans have an unparalleled capacity for social learning
30
causal factors of ecological overshoot: expansion (2)
- 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
31
wha stabilizing feedbacks normally keep populations in check and what does it result in (2)
- 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
32
how are humans bypassing the stabilizing feedbacks that normally act on species populations (4)
- outcompeting other species by modifying the environment
- health care
- social learning
- we construct our reality (laws, politics, economy, etc)
33
is human population growth an example of a amplifying feedback loop?
- yes: the bigger the population, the more mating that occurs and the more offspring that is produced
34
causal factors of ecological overshoot: social learning (3)
- 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
35
what is the result of the population growth of humans
- we have a huge (and still growing) capacity for consumption, but Earth did not get any larger; PROBLEM
36
what fueled the exponential growth of humans
- extensive use of fossil fuels allowed more agriculture mechanization, leading to removal of stabilizing feedbacks due to food and resource abundance
37
how does technology and efficiency address ecological overshoot
- 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
38
symptoms of overshoot: atmospheric CO2 (2)
- increase in atmospheric carbon dioxide and climate change
- 45% increase above pre-industrial levels leads to a change in the chemistry of the ecosphere
39
symptoms of overshoot: surface temperature
- the average temperature per year is getting warmer
40
symptoms of overshoot: plunging biodiversity (2)
- 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
41
symptoms of overshoot: world energy (2)`
- 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
42
the boom-bust population cycle (3)
- 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
43
why can humans avoid the uncontrolled collapse of population ('bust') (4)
- high intelligence
- the ability to plan ahead
- the capacity to exercise moral judgement
- empathy/compassion for other people and species
44
how can humans avoid the uncontrolled collapse of population ('bust')
- decrease the overshoot/resource need to be under the carrying capacity of the Earth
45
project drawdown (2)
- 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)
46
product footprint
- evaluates life cycle of products and ranks actions
47
do you personal choices reduce your contribution to climate change
- yes: can be small (upgrading light bulbs, recycling) or large (one less baby, car free life)
48
why are cars bad for climate change (2)
- 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
49
why is air travel bad for climate change
- a single flight can take up ALL of the suggested yearly emissions (to avoid ecological overshoot) for an individual
50
why is a plant-based diet good for the environment
- just subbing one plant-based item for a animal-based item can achieve huge emissions reductions and free up cropland
