topic 1

• Environmental Value Systems (EVSs)

  a particular worldview or set of paradigms that shapes the way individuals or societies perceive and evaluate environmental issues
• Environmental movement


  -influential individuals: media publications

  -independent pressure groups: awareness campaigns

  -corporate businesses: using resources such as coal

  -governments: policy decisions

  -intergovernmental bodies: influencing governments
• Environmental worldview


  -view of the world is formed from experiences

  -background, culture, education and society
• Ecocentric


  a nature-centred value system that views people as being under nature's control rather than in control of it.
• Anthropocentric


  a human-centred value system that places human as the central species and assesses the environment from an exclusively human perspective.
• Technocentric


  a technologically-based value system that believes the brain power of humans will enable us to control the environment.
• Cornucopians


  -extreme technocentrists

  -think the world has infinite resources

  -technology can solve any environmental issue
• Environmental managers


  -Earth is a garden that needs tending

  -stewardship, ethical duty to look after the earth

  -the government need to make legislations to protect the world
• Biocentric


  -all life has an inherent value, not just for humans

  -we shouldn't cause extinction of other species

  -praise small communities
• Deep ecologists


  -nature has more value than humanity

  -humans have no right to interfere with nature

  -wants a decrease in human population/ humans to consume less
• Carbon Footprint


  is the total set of greenhouse gas emissions caused directly and indirectly by an individual, organization, event or product (UK Carbon Trust 2008)
• Systems Approach


  a way of visualizing a complex set of interactions in ecology, society or another system.
• System


  is defined as an assemblage of parts and the relationships between them that enables them to work together to form a functioning whole.
• Biomes


  are groups of ecosystem with similar climates.
• Biosphere


  is the part of the Earth inhabited by organisms, and it extends from the upper atmosphere to the depths of the Earth's crust.
• Open System


  -exchanges both matter and energy within its surrounding across the boundaries of the system

  E.g.

  -plants fix energy from light

  -nitrogen is fixed by bacteria

  -forest fires expose topsoils

  
  

  -energy exchanged, matter exchanged
• Closed System


  -exchanges energy but not matter across the boundaries of the system.

  E.g.

  -nitrogen cycle

  -hydrological cycle

  -carbon cycle

  
  

  - energy exchanged, matter not exchanged
• Isolated System


  exchanges neither energy nor matter with its environment.

  
  

  -energy not exchanged, matter not exchanged
• Transfers


  involve flow through a system and involve a change in location.

  E.g.

  -water moving from a river to the sea

  -carnivores eating other animals

  -ocean currents transferring heat
• Flows and storages


  -Energy and matter flow as inputs and outputs or are stored

  
• Food chain

  
• first law of thermodynamics

  Energy can be transferred and transformed, but it cannot be created or destroyed.
• Entropy

  - a measure of the evenness of energy distribution in a system. It is also defined as a measure of the disorder of a system; the greater the disorder, the higher the level of entropy.

  
  

  Solar= efficiency is 1-2%

  Herbivores= assimilate 10%

  Carnivores= efficiency is 10%

  
• Second Law of Thermodynamics

  In isolated systems entropy tend to increase.
• Transformations

  lead to an interaction within a system and the formation of a new end product, or they may involve a change of state.

  E.g.

  -matter to matter

  -energy to energy (light to heat energy)

  -energy to matter (photosynthesis)
• Efficiency


  -useful energy, the work or output produced by the process divided by the energy consumed to the process
• Negative feedback loops


  -when output of a process inhibits or reverses the operation of the same process
• Equilibrium


  a state of balance among the components of a system.
• Steady-state Equilibrium


  (also known as dynamic equilibrium) is a stable form of equilibrium that allows a system to return to its steady state after a disturbance.

  
  

  E.g.

  - A water tank emptying at the same rate it fills

  -constant body temperature
• Static Equilibrium


  a type of equilibrium in which there are no changes over time because there are no inputs to and outputs from the system
• Stable Equilibrium


  a state of equilibrium in which a system that is disturbed returns to its former position.
• Unstable Equilibrium


  a state of equilibrium in which a small disturbance produces a large change and a new and different equilibrium.
• Feedback


  is the return of part of the output from a system as input, so as to affect succeeding outputs.
• Positive Feedback


  a feedback which results in a change in the system that leads to more and greater change. It amplifies or increases change and leads to exponential deviation away from an equilibrium and thus destabilizes the system.

  
  

  E.g.

  -getting colder and beginning to shiver, it doesn't raise the temperature enough, becomes sleepy and gets colder

  
• Negative Feedback


  a feedback which tends to damp down or counteract any deviation from any equilibrium and promotes stability. It stabilizes the system to eliminate any deviation from the preferred conditions.

  
  

  E.g.

  -getting hot and starting to sweat

  
• Feedback loops


  -information that stars a reaction in turn may input more information which starts another reaction

  
  

  Positive:

  -Changing a system to a new state

  -destabilising as they increase change

  Negative:

  - return to original state

  -stabilising as they reduce change
• Positive feedback loops


  -amplifies changes, drive system towards a tipping point where there is a new equilibrium
• Tipping Points


  the minimum amount of change within a system that will destabilize it and cause it to reach a new equilibrium or stable state.

  
  

  Characteristics

  -positive feedback

  -changes are long lasting

  -changes are hard to reverse

  
• Resilience


  -the tendency of a system to maintain stability and resist tipping points.
• Ecological overshoot


  Using resources faster than they can regenerate.