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