system
set of interactions, shows how it works together as a whole
transfer
change in location, not in state
transformation
change of state
model strengths
predict and simplify system
run simulations, see what happens
model weaknesses
accuracy lost because of simplifying
if assumptions are wrong, the model is wrong
brings in bias from maker of model
ex: Rachel Carson's book Silent Spring (1962)
warned about devastating effects of DDT, led to investigation and JFK banned it
ex: Bhopal disaster
Indian city where 20 000 died from release of methyl isocyanate (MIC) in 1984
ex: Chernobyl
nuclear disaster, 1986
ex: Fukushima Daiichi
nuclear accident, 2011, demonstrations worldwide and governments shutting down nuclear plants and plans
ex: Deepwater Horizon oil spill
2010 in Gulf of Mexico, largest marine oil spill
1st law of thermodynamics
energy in an isolated system can be transformed but not created or destroyed
2nd law of thermodynamics
entropy of an isolated system not in equilibrium will tend to increase overtime
entropy
amount of disorder in a system (high entropy is high disorder; randomness)
steady-state equilibrium
continuous in- and outputs of energy and matter but system remains in constant state (eg. human ability to maintain body temperature)
static equilibrium
nothing changes; non-living system
stable equilibrium
system goes back to previous equilibrium after disturbance
ecological tipping point
reached when ecosystem experiences shift to new state, with almost irreversible change (eg. receding glaciers, eutrophication)
negative feedback
stabilising; reduces change and counters deviation
positive feedback
destabilising; amplifies changes and drives system to tipping point with new equilibrium
resilience
measure of the ability of an ecosystem to respond to disturbance, measures how quickly it recovers:
either time it takes to return to stable state again
or how well it can absorb change and keep same function and structure
the more complex ecosystem (species diversity, large habitat) the more resilient
resilience can be negative with invasive species, ex.
DDT
dichlorodiphenyltrichloroethane; a persistent organochlorine insecticide, banned by WHO in 1970
independent pressure groups, NGOs
influence the public which influences governments, eg: Greenpeace, WWF
ecocentric
ecology and nature central, self-sufficiency, rights of nature, holistic view of life (deep ecologists, self-reliant soft ecologists)
anthropocentric
humans must sustainably manage the global system, environmental legislation and regulation, nature is there to benefit humankind
technocentric
technological developments can provide solutions to environmental problems (environmental managers, cornucopians)
open system
both energy and matter exchanged across boundary
closed system
energy but not matter exchanged across boundary
isolated system
hypothetical concept, neither energy not matter exchanged across boundary
efficiency
work or energy produced / energy consumed
useful output / input
can be percentage
natural capital
natural resources that can produce sustainable natural income of goods and services
environmental impact assessment (EIA)
report prepared before development project that will change use of land
ecological footprint (EF)
model used to estimate demands that human populations place on environment; accounts for area required to provide all resources needed by population
pollution
addition of substance or agent to environment by human activity, at a greater rate than it can be rendered harmless by environment
primary pollutant
active on emission (eg carbon monoxide from incomplete combustion of fossil fuels)
secondary pollutant
formed by primary pollutant undergoing physical or chemical changes (eg sulphuric acid forms when sulphur trioxide reacts with water)
non-point source pollution (NPS)
release of pollutant from numerous sources, combat by limiting all farmers or industries, eg
point source pollution (NP)
release of pollutant from single, identifiable source, usually easier to manage than NPS
persistent organic pollutants (POPs)
resistant pesticide
biodegradable pollutants
do not persist, break down quickly
pollution management strategies
changing human activity which produces it
regulating or preventing release of pollutant
working to clean up or restore damaged ecosystem