Topic 1 Flashcards
ENVIRONMENTAL VALUE SYSTEM (EVS)
An environmental value system (EVS) is a worldview that shapes the way an individual or group of people perceive and evaluate environmental issues. This will be influenced by cultural, religious, economic, and socio-political context.
ecocentric worldview
puts ecology and nature as central to humanity
- deep ecologists
anthropocentric worldview
believe humans must sustainably manage the global system
- humans are not dependant on nature but nature is there to benefit humankind
technocentric worldview
believe that technological developments can provide solutions to environmental problems
- cornucopians
open system+ example
An open system exchanges matter and energy with its surroundings
e.g. plants fix energy from light entering the system during photosynthesis
closed system + example
A closed system exchanges energy but not matter with its environment
e.g. carbon cycle
isolated system + example
An isolated system exchanges neither matter nor energy with its environment
e.g. (does not exist naturally but…the entire universe…)
2 examples of transfers
- water moving from a river to the sea
2. chemical energy in the form of sugars moving from a herbivore to a carnivore
2 examples of transformations
- liquid to gas
2. light to chemical energy
2 strengths and weaknesses of models
Strengths:
- easier to work with than complex reality
- can be used to predict the effect of a change in input
- help us see patterns
Weaknesses:
- accuracy is lost because the model is simplified
- if our assumptions are wrong, the model will be wrong
- predictions may be innacurate
first law of thermodynamics
is the principle of conservation of energy which states that energy in an isolated system cannot be created or destroyed
second law of thermodynamics
states that entropy of a system increases over time
entropy
is a measure of the amount of disorder in a system
equilibrium
the tendency of a system to return to an original state after a disturbance.
a steady state equilibrium
is a characteristic of open systems where there are continuous inputs and outputs of energy and matter, but the system as a whole remains in a more or less constant state (e.g. climax ecosystem)
positive feedback loop + example
are destabilising and will tend to amplify changes and drive the system towards a tipping point where a new equilibrium is adopted
e.g.
global temps rise, polar ice caps melt, dark soil exposed so more solar radiation is absorbed (as lower albedo) so global temps rise
negative feedback loop + example
is stabilising and will occur when the output of a process inhibits or reverses the operation of a process in such a way to reduce change
e.g. global temps rise, ice caps melt, more water in the atmosphere, more clouds, more solar radiation reflected, so global temps fall.
resilience of a system+ 3 factors that affect it
ability of a system to return to its initial state after a disturbance
Factors:
- more diverse and complex a system is
- species biodiversity
- larger the ecosystem
- climate (warmer climates have more resilience as faster growth rates)
ecological tipping point + example
An ecological tipping point is reached when an ecosystem experiences a shift to a new state in which there are significant changes to its biodiversity and the service it provides
- lake eutrophication
- coral reef death
- extinction of keystone species
sustainability
is the use and managment of resources that allows full natural replacement of the resources exploited and a full recovery of the ecosystems affected by their extraction and use
inertia
when changing what we do seems difficult
related to tragedy of the commons
tragedy of the commons
when many individuals act in their own self-interest to harvest a resource but destroy the long-term future of that resource
Environmental Impact Assessment (EIA)
is a report prepared before a development project to change the use of the land, e.g. to convert fields into a gold course
ecological footprint
is the area of land and water required to sustainably provide all resources at the rate which are being consumed by a given population
