ESS Study Guide
DP1 Materials Summary
Foundations of Environmental Systems and
Societies
1.1 Environmental Value Systems
a worldview or paradigm that shapes the way an individual group of people
perceive and evaluate environmental issues. This will be influenced by cultural,
religious, economic, and socio-political context.
Who is involved in the Environmental Movement?
Influential individuals: Often use media publications to raise issues and start a
debate.
Independent pressure groups: Use awareness campaigns to effect a change,
influence the public to influence the government and businesses.
Corporate businesses: They supply consumer demand, in doing so they use
resources and create environmental impact.
Governments: Make policy decisions and apply legislation, meet with other
governments to consider international agreements.
Intergovernmental bodies: Highly influential by holding Earth Summits to bring
together all of the above to consider global environmental and world development
issues
The spectrum of environmental value systems
o Different societies hold different environmental philosophies and comparing
these helps explain why societies make different choices
o The EVS we hold is influenced by cultural, religious, economic, and socio-
political contexts
o How we measure the value of the environment, or an organism is key to
understanding the value we place on the environment
o It has only been in recent times that humans have been able to control the
environment
o The Industrial Revolution heralded the arrival of technological development
when we are driven to explore, conquer and subdue the planet
o Humans may be the first species to change conditions on earth and make it
unfit for human life
Environmental Worldview
o Our view of the world is formed through experiences of life (background,
culture, education)
o This is your paradigm (pessimistic or optimistic)
Classification of different environmental philosophies
Ecocentric: puts ecology and nature as central to humanity. Emphasizes a less
materialistic approach with a more self-sufficient society. Respects the rights of
nature and the dependance if humans on nature.
Biocentric- (life centered) all life has value for its own sake, not just for
humans. Protection of
ecosystems and habitats to preserve ecological integrity. Since we are
sentient being and can alter
, our environment, it’s our duty to restore degraded ecosystems.
Deep ecologists- put more value in nature than humanity. Believe in a
decrease in consumption
and population (place the earth above humanity)
Anthropocentric: Believes humans must sustainably manage the global system.
Resolve ecological problems by influencing human behavior through law policies and
agreements.
Technocentric: Believes that technological developments can provide solutions to
environmental problems.
Environmental Managers- stewardship worldview, believe we must
compensate environmental
degradation. If we look after the planet, it looks after us.
Cornucopians- through technology and our inventiveness, we can solve any
environmental
problem and continually increase living standards. Believe in a free market
economy
EVA’s can be nurturing (ecocentrist) and intervening or manipulative
(technocentrist/anthropocentrist) but are usually somewhere along the spectrum.
1.2 Systems and Models
o Can be living or non-living
o Can be on any scale (cell, bicycle, house, etc.)
o In theory, we have open, closed, and isolated systems
o Material and energy undergo transfers and transformations in flowing from
one storage to the next
o Models, though limited, help understand systems
o Systems approach the environment is seen as a set of complex systems,
sets of components that function together and form integrated units
o Study the hydrosphere, lithosphere, pedosphere, and ecosphere (biosphere)
o Must also consider social and economic systems as they make the human
world work
o Components are studied in relation to other elements of the system
Open Systems
Presented in a diagram e.g., Pond Snails
Input Process Output
o Plants o respiration o babies &
o Oxygen o digestion movement
o Water o excretion o carbon dioxide
o Heat o reproduction o new biomass
o feaces and mucus
Open systems: exchange matter and energy with its surroundings. All have storages
(of matter of energy), flows (input or output), boundaries, and processes (transfer or
transform).
Transfers:
o movement of material through living organisms (eating other animals)
o movement of material through non-living organisms (water through streams)
o movement of energy (ocean currents transferring heat)
a substance moves without experiencing a change of state, location changes.
,Transformations:
o matter to matter (soluble glucose to insoluble starch in plants)
o energy to energy (light to heat by radiating surfaces)
o matter to energy (burning fossil fuels)
o energy to matter (photosynthesis)
When a substance is subject to chemical or physical change in its state.
e.g., Water cycle
Transformations: Transfers
o evaporation o infiltration
o condensation o precipitation
o percolation o surface outflow
Flows and Storages
Both energy and matter flow through ecosystems, but at times, they are also stored
within an ecosystem.
Closed Systems
Exchange’s energy but not matter with its environment
o extremely rare in nature
o on a global scale, the hydrological, carbon and nitrogen cycles are closed
o most closed systems are artificial (for experimental purposes)
e.g., ecosphere: doesn’t survive for long as systems become unbalanced
Isolated Systems
Exchanges neither matter nor energy with its environment
o does not exist naturally
o entire universe can be seen as an isolated system
Models of Systems
Model: a simplification, work in predictable ways and follow rules
o physical model- aquarium, wind tunnel, globe
o software model- of climate change or evolution
o mathematical equation
o data flow diagrams
Strengths Weaknesses
o easier to work with o accuracy is lost in simplification
o can predict the effect of change o wrong assumption = wrong
o can apply to similar situations model
o helps to see patterns o predictions may be inaccurate
o can visualize large or small
things
1.3 Energy and equilibria
Energy in Systems – is always subject to the laws of thermodynamics
1. First Law: energy is neither created nor destroyed, only the form of that
energy can change. The total energy in an isolated system is constant.
(Principle of conservation of energy)
2. Second Law: the entropy of an isolated system not in equilibrium will tend to
increase over time
Entropy- measure of disorder in a system, refers to dispersal of energy
(always increases)
, A system will always tend to move from and ordered to a disordered
state
3. Energy conservations are never 100% efficient, there will always be a
reduction in energy passed to the next trophic level (high entropy = high
stability, low order, vice versa)
Complexity and Stability
A high level of complexity is likely a more stable system which can better withstand
stress and change. A simple system is more vulnerable since there is no alternative
to take over.
Equilibrium
The tendency of the system to return to an original state following disturbance, at
equilibrium a state of balance exists among its components.
Steady State Equilibrium: a characteristic of an open system where there are
continuous inputs
and outputs of energy and matter. The system remains more or less constant.
Negative Feedback: stabilizes steady state equilibria by neutralizing or counteracting
any deviation from the equilibrium. It results in the self-regulation of a system. No
long-term changes, only small fluctuations in the short term.
(e.g., body temperature – we shiver and sweat to return to equilibrium)
(e.g., grazers increase due to migration, grassland is overgrazed and eroded, grazed
die lacking food)
Static Equilibrium: There is no change overtime, when disturbed, a new
equilibrium is adopted as
a result. This cannot occur in a living system.
*There are stable (return to equilibrium after disturbance) or unstable (take on a new
state) equilibria
Feedback Loops
Systems are continually affected by information inside and outside the system. A
feedback loop is when information that starts a reaction in turn many input more
information which may start another reaction.
Positive: Negative:
o Change in system to a new state o Return to its original state
o Destabilizing – increase change o Stabilizing – reduce change
Positive Feedback: results in further increase or decrease in the output that
enhances the change in the system. It destabilizes and pushes to a new equilibrium.
This process may speed up until the system collapses.
e.g., When lost in a snowy mountain, we start to shiver when body
temperature lowers to keep warm. When this stops working, the metabolic process
starts to slow down, you become sleepy and start moving less, allowing your body to
cool even further.
*Negative feedback is usually desirable whilst positive feedback in undesirable
Resilience of Systems
Measures how a system responds to disturbance. The ability for a system to return
to its initial state.
o In the case of low resistance, it will enter a new state
o generally good (e.g., in agriculture so we can predict food production)
o sometimes bad (e.g., bacterium resilience to antibiotics
Factors effecting ecosystem resilience
o diversity and complexity
