Environmental value system (EVS): a worldview that shapes the way an individual or group perceive and evaluate environmental issues
Who is included in the environmental movement?
Categories of EVS:
Cornucopians: people who see the world as having infinite resources to benefit humanity. They think that technology can solve any problem
Environmental managers: believe that we have an ethical duty to protect and nurture the earth
Biocentric: thinkers see all life as shaving value for its own sake, not just for humans. Humans should not cause premature extinction of any species
Deep ecologists: put more value on nature than humanity. They believe in biologists, universal rights where all species and ecosystems have value and humans cannot interfere with it
System: set of interrelated parts working together to make a complex whole, can be living or nonliving. Systems are all more than the sum of their parts
Systems can be closed, open, or isolated
Biome: can be seen as an ecosystem. It helps if the ecosystem has clear boundaries
Biosphere: is a fragile skin on planet earth. Includes atmosphere (air), lithosphere (rocks), hydrosphere (water)
All systems have:
Matter (material) and energy flow through ecosystems as:
Transformations: when energy or matter flow and changes its state, a change in the chemical nature, a change in state or energy
Transfers require less energy → more efficient than transformations
An open system exchanges matter and energy with their environments; all ecosystems are open systems
A closed system exchanges energy (not matter) with its environment. They are extremely rare in nature
An isolated system neither exchanges matter nor energy with its environment. They do not naturally exist; the entire universe is an isolated system.
Models are simplified versions of systems, it could be:
Advantages of Models:
Disadvantages of models:
Sustainability is achieved only when economy, society, and the environment overlap
Steady-state equilibrium: a characteristic of an open system where there are continents inputs and outputs of energy and matter, the system remains in constant state
No long-term changes, however, small fluctuations occur in the short term
Static equilibrium: no change occurs over time. Most non-living systems are in a state of static equilibrium
This cannot occur in a living system, it can only occur in an isolated system
Stable equilibrium: the system tends to return to the same equilibrium after a disturbance
Unstable equilibrium: the system will return to a new equilibrium after a disturbance
Feedback loop: when information that starts as a reaction in turn may input more information which may start another reaction
Negative feedback loop: stabilises steady state equilibria, occur when the output of a process inhibits or reverses the operation of the same process in such a way to reduce change, counteracts deviation.
Positive feedback loop: will amplify changes and bring the system towards a new tipping point where a new equilibrium is adopted
Resilience: the ability of a system to return to its initial state after a disturbance
Factors affecting ecosystem resilience:
An ecological tipping point: is a reached when an ecosystem experiences a shift to a new state
Lake eutrophication: nutrients added to a lake may not change much until enough nutrients are added to change its state
Extinction of a keystone species: A keystone species within an ecosystem is fundamental to keeping the ecosystem stable and supported
Coral reef death: if ocean acidity rises enough the reef coral dies and cannot regenerate
Sustainability: the use of resources that allows full natural replacement of the resources used and full recovery of the ecosystems affected by their extraction
Ecological overshoot: when a sustainable resource is exploited to its maximum
Natural capital: natural resources that can produce a sustainable natural income of goods or services
Environmental impact assessments (EIA): is a report prepared before a development project changes the use of lans. It weighs up the advantages and disadvantages of the development
Baseline study: an analysis of a current situation to identify the starting points for a project
Ecological footprint (EF): the area of land and water required to sustainability provide all resources at the rate which they are being consumed by a given population
A model used to estimate the demands that human populations place on the environmental
Pollution: the introduction/addition of a substance to the environment by human activity. This addition is considered harmful to the environment
Primary pollutants: are active on emission (carbon monoxide) from the incomplete combustion of fossil fuels
Secondary pollutants: are formed by primary pollutants undergoing physical or chemical changes
Point source and nonpoint source pollutants:
Persistent organic pollutant (POPs): a toxic environmental contaminant which requires special handling and disposal
Biodegradable pollutants: do not persist in the environment and break down quickly. May be broken down by decomposer organisms or physical processes. Example: Light, heat
Acute pollution: when large amounts of pollutants are released causing a lot of harm
Chronic pollution: long term release of a pollutant but in small amounts
Pollution:
How can pollution be managed?