ESS - Unit 1.1

Environmental Value System

A particular worldview that shapes the way an individual or group of people perceives and evaluates environmental issues. It is influenced by culture, economics, religion, and socio-political contexts.

Tipping Point

A critical threshold when a small change to a system leads to dramatic effects and a disproportionally larger change in their system.

An ecosystem that has enough change leading to a new state in which there are significant changes to biodiversity due to positive feedback.

Resilience

Ability to withstand a change

What would make ecosystems more resilient?

• Higher biodiversity  

• Greater genetic diversity within individual species 

• Species with larger geographical range  

• Larger ecosystem 

• Steady climate

• High species reproduction rate 

• Human involvement  

Negative Feedback

Process which reverses a change
Stabilises steady-state equilibria

Positive Feedback

Process which increases a change

amplifies changes —> driving to tipping point —> destabilising

Properties of Tipping Point

• Positive feedback: Process which increases a change (bad) --> self-perpetuating  

  • Negative feedback: Process which reverses a change (good) 

  • e.g. Antarctica reflects, sea absorbs (melting ice caps) 

• Fast shifts of ecological states occur (extreme weather events) 

• Cannot precisely predict threshold point 

• Long lasting changes 

• Hard to reverse changes 

• Significant time-lag between pressures driving change and impacts appearing (make it hard to manage and prevent) 

State the what Silent Spring by Rachel Carson talked about and its influences.

1. Raised awareness of the threat of the bioaccumulation of pesticide DDT to organisms higher up food chains.

2. With JFK’s evidence, DDT was banned in the US and other countries.

3. Inspired people to be more environmentally active

4. BUT may have caused more harm than good due to malaria!

State what Chernobyl is and its influences

1. 1986 accident due to flawed soviet-era reactor design which caused huge amounts of radiation.

2. Hundreds of people suffer from illnesses due to living on contaminated land (cancer)

3. Biodiversity suffered negative impacts, however some has adapted and became a unique sanctuary for wildlife (no industrial activities

4. Reinforced negative perceptions of nuclear power in society.

5. Made people question the safety of nuclear power

6. Countries shut down nuclear power reactors and used safer energy resources

State what the Inconvenient Truth is and its influences.

1. A documentary that talked about the effects of global warming.

2. Publicised global warming

3. Mainstream political figure (former US Vice President) championed environmental issues for the first time

4. Changed people’s attitudes and raised awareness about climate change

Ecosystem

A community and the physical environment with which it interacts

Social system

People, groups and institutions that work together, forming distinct patterns and relationships that define the society.

Explain Ecocentrism

• nature-centred EVS

• Sees nature as having an inherent value

• “Humans are dependent on nature”

• Aims for sustainability for the whole Earth

• “Nature is the most important thing

Explain Anthropocentrism

• people-centred EVS

• Everyone in society should participate in environmental decision making

• People act as the managers of sustainable global systems

• taxes, regulations, legislations

• Educate people about environmental issues

• Debate to reach a consensual pragmatic approach to solving environmental problems

What is the middle EVS

• Self-reliant, soft ecologists

• more conservative about environmental problem solving than deep ecologists

• Believe that materialism for its own sake is wrong

• No faith in technology

• Environmental managers

• believe that economic growth and resource exploitation can continue only if it is managed

• laws and regulations can manage natural resources

• preserving biodiversity can have economic ecological advantages

Explain Technocentrics

• technology-centred EVS

• sees technology as providing solutions to environmental problems even when human effects are pushing natural systems beyond their normal boundaries

• “We can use technology to benefit nature”

• Emphasis should be on scientific research, economic growth

Intrinsic value

A characteristic of a natural system that has an inherent worth, irrespective of economic considerations

the belief that all life on Earth has a right to exist

System

A set of interrelated parts working together to make a complex whole

a way of visualising complex sets of interactions

Environment

a series of complex system which interacts and transfers energy and materials

State the components of a system

Storages, flows, inputs, outputs, boundaries, and processes

Transfers

processes that involve a change in location within the system but no change in state

e.g. water flowing from groundwater to river

Transformation

lead to the formation of new products

e.g. photosynthesis converting sunlight to glucose

Models

A simplified version of a system

used to understand how a system works and predict how it will respond to change

Open system

A system that can exchange both energy and matter across a system boundary

e.g. rainforest, any ecosystem

Closed system

A system that can only exchange energy and not matter across a system boundary

e.g. the Earth

Isolated system

A system that does not exchange either matter or energy with its surroundings

Gaia Theory

a model of earth that argues that Earth is a living organism which regulates itself through negative feedback

3 Evidence of Gaia theory

1. Constant temperature of Earth despite the sun giving 30% more energy

2. Composition of atmosphere is stable even when oxygen should go down (attach to rocks more)

3. Ocean salinity is 3.4% entering via rivers should increase

Entropy

A measure of the amount of disorder, chaos, or randomness in a system

Greater disorder, higher the entropy

First Law of thermodynamics

Energy cannot be created or destroyed but only transferred from one form to another

Second Law of thermodynamics

Entropy of a system not in equilibria will increase over time

Equilibrium

A state of balance among the components of a system

Steady-state equilibrium

condition of an open system in which there are no changes over the longer term but may be oscillating in the very short term

Stable equilibrium (equilibria)

Tendency in a system for it to return to the original equilibrium after the disturbance

System

A set of interrelated parts working together to make a complex whole

3 systems of the biosphere

Atmosphere, Lithosphere, Hydrosphere

Unstable equilibrium

System tends to return to a new equilibrium after the disturbance

Static equilibrium

No change over time