ESS unit 1 : foundation to ess

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environmental value systems

a particular world view that shapes the way an individual or group of individuals, evaluate environmental issues

outputs of EVS

diverse perspectives, behaviour, actions, beliefs and decisions

inputs in EVS

education, religion, economic factors, socio political factors, culture

minimata 1956

release of methyl mercury into bays = contaminated food chain = birth defects

first earth summit 1972

UN conference on the human environment = action plan for human environment and the environmental fund

bhopal 1984

union carbide released 42 tonnes of toxic methyl isocyanate

Australian bushfires 2009

Black Saturday = 80 towns and communities charred and destroyed by the blaze = increased hyper-vigilance in australia about bushfire managemen

Rachel Carson

Author of silent spring. Book about the impact of DDT reducing bird of prey populations

George Perkins Marsh

author of Man and Nature, first to write that deforestation = desertification = loss of species = degradation of the ecosystem

independent pressure groups

educate the public and influence political decisions, also known as NGOs

how can corporate business begin environmental action?

They control the supply of goods in the market - can choose to be sustainable

ecocentrics

puts ecology and nature central to humanity

anthropologists

believe humans must sustainably manage the global system

technocentrics

technological developments can provide solutions to environmental problems.

what is system?

a way of visualising a complex set of interactions which may be ecological or societal

reductionist system approach

reduces the systems to their parts and each part is studied

holistic approach

system is studied as a whole, and this allows us to see how the components relate to each other - used for ecological investigations

what are components of all systems?

inputs, outputs and storages

open systems

exchange BOTH energy and matter across the boundaries

closed systems

can exchange energy across a boundary, but not matter with its environment, very rare in nature

isolated systems

DO NOT transfer energy or matter and do not exist

what is a model?

simplified view of the real world, makes a concept easier to understand

advantages of models

helps visualise small objects, highlights patterns, can predict changes, easy to understand a complex system

disadvantages of models

accuracy can be lost, models predict into the future (could be false), environmental factors are very complex

gaia hypothesis

proposes that the earth is self regulating by controlling the physical and chemical aspects of the environment

first law of thermodynamics

*energy can neither be created nor destroyed*

energy in an ecosystem

enters as light, converted into biomass, leaves as heat

second law of thermodynamics

*the entropy of an isolated system not in equilibrium will tend to increase overtime*

entropy

a measure of disorder of a system, referring to the dispersal of energy

entropy of heat

HIGH - free flowing

why are food chains so short

as more energy is lost through heat it increases in entropy

complexity makes for a…

more stable system

steady state equilibrium

despite continuous inputs and outputs of energy and matter, the system as a whole remains the same

oscillations

movement back and forth in a regular rhythm

example of a system with steady state equilibrium

predator prey relationships

stable equilibrium

when a system returns to the original equilibrium after a disturbance

unstable equilibrium

a system that moves to a new equilibrium after a disturbance

positive feedback

results in a further decrease of the output that enhances the system, a permanent change

example of positive feedback

global warming melts ice caps, leading to reduction in the earth’s Albedo

albedo

reflection from the earth’s surface

negative feedback

stabilises the steady state equilibrium through counteracting change from equilibrium

how do ecosystems remain at equilibrium

negative feedback loops

tipping points

the critical threshold where a small change can tip the equilibrium over a threshold, having a dramatic effect and causing a disproportionally large response in the overall system

what drives tipping points

positive feedback loops force systems to a new equilibrium

tipping point example

increase in CO2 levels above 450ppm would lead to increase in temperatures that will melt ice sheets and permafrost

ecological tipping point

reached when an ecosystem experiences a shift to a new state

why are tipping points difficult to predict

delays in feedback loops

resilience

system’s ability to avoid a tipping point, respond to disturbances and maintain stability

diversity

size of storages contribute to the stability of the ecosystem

relationship between resilience and diversity

the greater genetic diversity, the greater the resilience

sustainability

the use of natural resources in ways that do not reduce or degrade the resources so they are available for future generations

how do humans use resources beyond sustainable limits?

overpopulation, financial motives, ignorance, unsuitable use of soils, over grazing, over cultivation

why is society adverse to implementing sustainable practises?

inertia i.e. change is too difficult, tragedy of the commons i.e. individuals act in their own self-interest

natural capital

natural goods and services which can be used for natural resources

natural income

money derived from natural resources

millenium ecosystem assessment stats

* first report released in 2005 showed:
* 60% of world ecosystems have been degraded
* over 25% of fish stocks are over harvested
* 20% of corals have been lost in 20 years

millenium ecosystem assessment solutions

* reduce subsidies in industries that harm the environment
* protect more areas from development
* encourage the management of property to enhance the supply of ecosystem services

overshoot day

the day where all the resource have been used BEYOND a point where they can renew on their own in a year

ecological footprint

the area of land required to sustainably provide all resources for the population

environmental impact assessments (EIAs)

a report prepared before a development project to change the use of the land outlining mitigation needed to protect the environment

weaknesses of the EIA

application processes vary across countries, limited to the quality of the initial baseline study

pollution

the addition of a substance or an agent to an environment by human activity at a rate greater than that at which it can be rendered harmless by the environment

pollutants

contaminants released by *human activities*

forms of pollutants

organic & inorganic matter, energy (sound, light, heat), living organisms, invasive species,

major sources of pollution

* mining and quarrying: 27%
* Agricultural organic wastes: 20%
* industry waste: 17%
* dredging: 11%
* sewage sludge: 8%

point pollution

a source of contamination that can be represented by a single point on a map.

non-point pollution

the source is dispersed such as air pollution from cars

primary pollution

active upon emission e.g. fossil fuels

secondary pollution

formed by primary pollutants undergoing a physical or chemical change

chronic affects

occur a long time after exposure e.g. mad hatter mercury poisoning

acute affects

occur after short, intense exposure e.g. Hiroshima bombing

persistant pollutants

chemicals that cannot be broken down by living organisms and passed through the food chain

biodegradable pollutants

break down and are not stored or passed down the food chains

bioaccumulation

the retention or build up of biodegradable pollutants in the body

biomagnification

the process whereby the concentration of the chemicals increase at each trophic level

direct pollution measurement

measures the amount of pollutant in the air, soil and water

indirect pollution measurement

measures the changes in abiotic & biotic factors

pollution management strategies

modern tech, human behaviour change, education, restoration

how can human activity be changed?

invest in renewables, reuse & recycle, regulate activities

who regulates environmental activities

the EPA set environmental standards for businesses