ess unit 1

Environmental Value System (EVS)

a worldview or paradigm that shapes the way an individual approaches environmental issues (ecocentric, anthropocentric, technocentric).

environmentalism

the movement and idea that humans impact the environment, and that these impacts should be managed.

DDT

A persistent organic pollutant (POP) that negatively harms non-target organisms, specifically birds. However, it also is an insecticide which kills the malarial mosquito.

ecocentric

the approach that places value and importance on the entire environment and all life in it, not just the parts that are useful to humans.

anthropocentric

argues that humans must sustainably manage the global system. regards humans as superior to nature while other entities are resources that may be exploited for the benefit of humankind.

technocentric

the approach that solves environmental problems by developing a new technology or invention that solves the problem.

What are the five parts of a system?

1. input

2. output

3. storage

4. flow

5. boundaries

systems

a set of interrelated parts and the connection between them that unites them to form a complex whole and produces emergent properties.

storages

the part of a system where something is held or found.

processes

the part of a system that changes something.

transfers

the part of a system that relocates something from one part of the system to another, without changing it in anyway.

types of transfers

• The movement of material through living organisms

• The movement of material in a non-living process

• The movement of energy

transformation

the part of a system that relocates energy and matter, but in the process of doing so there is a change of state or form.

types of transformations

• Matter to matter

• Matter to energy

• energy to energy

• energy to matter

flows

either a process or a transfer.

open system

• A system that exchanges both matter and energy with its surrounding

closed System

• A system that exchanges energy, but not matter with its surroundings

• No inputs or outputs

isolated System

• A system that exchanges neither energy or matter with its surroundings

• Nothing in nature is completely isolated

model

A simplified version of reality that tells a story about what happens in the natural world.

pros of models

simplify complex systems, help us look at impacts, help us make predictions about future events, manageable scale

cons of models

oversimplified, can be interpreted differently, data may not be accurate, who made the model?

inputs

The energy or matter that a system needs to function.

outputs

The products produced by a system.

energy

the ability to do work or cause change.

matter

the physical material of the universe; anything that has mass and occupies space.

first law of thermodynamics (law of conservation of energy)

energy can be transferred or transformed, but not created or destroyed (e.g. food chains)

the second law of thermodynamics

The entropy of a system increases over time; the only way to avoid entropy is a continuous input of additional energy.

Equilibrium

The tendency of a system to return to its original state

Steady state equilibrium

• A type of equilibrium maintained by negative feedback that fluctuates around a mean

• Small changes over short time periods, changes occur within limits

• Inputs and outputs approximately balance over long time periods

• System is brought back to same state as before

Static equilibrium

• A type of equilibrium that does not change over time

tipping points

a part of a system that kick-starts self-perpetuating positive feedback loops that push the systems to a new state of equilibrium

tipping point characteristics

• Involve positive feedback, leads to self-perpetuating changes

• Threshold point cannot be precisely predicted

• Long-lasting changes

• Changes are difficult to reverse
  

Negative feedback

occurs when the output of a process reverses the operation of the same process in such a way as to reduce change

• Examples: predator prey relationship, human body temperature, toilet flush

Positive feedback

destabilizing and tend to amplify changes and drive the system towards a tipping point where a new equilibrium is adopted

• A small disturbance in the system causes an increase in that disturbance

• A system may find a new equilibrium and is likely to reach a tipping point

• Example: rising temperatures, deforestation

Tipping point

If disturbance moves beyond a certain value, the system will not return to the previous equilibrium

What can happen if a tipping point is reached?

• Environmental support services could collapse (eg. pollination)

• The land's food production capacity will deteriorate

• The seas' food production capacity will be compromised

• Climate may spiral into a positive feedback cycle and become unsuitable for human existence

Stable equilibrium

An equilibrium that will easily return to the same equilibrium after disturbance

Unstable equilibrium

An equilibrium that will likely reach a new equilibrium after disturbance

examples of disturbances

Fires, flooding, deforestation, pesticide

resilience

the rate at which an ecosystem returns to its original state after a disturbance (more resilient = more disturbance it can handle)

resistance

when the ecosystem continues to function during a disturbance

how does the form of energy change as it enters a system?

light - chemical - mechanical - heat

factors that determine the stability of ecosystems

climate and limiting factors, biodiversity, trophic complexity, nutrient stores, frequency and intensity of disturbances

Sustainability

The management of resources that allows full natural replacement of resources emploited & full recovery of ecosystems affected by their use

Natural Capital

• Natural resources that produce sustainable natural income of goods and services

• Goods: marketable commodities exploited by humans (eg. forests)

• Services: natural processes that provide benefits for humans (eg. clean air)

Natural Income

• The yield obtained from natural capital

• Input - Output

Sustainable Natural Income

income taken without reducing the capital (produced by renewable resources)

Environmental Impact Assessment (EIA)

A study that is undertaken to assess the likely environmental, social, and economic impacts of a project, used to inform policies.

Criticism of EIAs

Lack of standard practice, unclear definition.

Unsustainable

If EF is greater than the resources available

Sustainable

If EF is less than the resources available

EIA Steps

1. Scoping

2. Baseline study

3. Predicting and assessing effects

4. Mitigation

5. The environmental statement

Ecological Footprint

The amount of land and water required to support a human population at a given standard of living

MiIlennium Ecosystem Assessment (MA)

Used to asses the consequences of ecosystem changes for human well-being and to establish strategies to achieve sustainable use of ecosystems

Pollution

The addition of substances into the environment at a rate which is which is greater than that at which they can be rendered harmless and which cause adverse changes or harm

Point Source Pollution

Pollution that originates from one easily identifiable location

Non Point Source Pollution

Pollution that originates from diffuse sources

organic pollutant

a pollutant that is or was living (contains carbon)

inorganic pollutant

a pollutant that is non-living and does not contain carbon

Persistent pollutant

Pollution that remains in the environment for long periods of time, cannot be naturally degraded

Biodegradable pollutant

Pollution that can be processed by natural systems

Primary pollutant

A pollutant that directly impacts the environment

Secondary pollutant

A pollutant that undergoes a physical or chemical change by the environment before it has a negative impact

Persistent Organic Pollutants (POPs)

Often pesticides or herbicides, resistant to biodegredation​

Acute pollution

A single event or accident that introduces a large amount of pollution to the environment

Chronic pollution

Pollution that is emitted and exists at a relatively steady rate and exists long term

forms of pollution

matter, energy and living organisms

physical forms of pollution

air, water, land

non-physical forms of pollution

light, noise, thermal, visual

stages of pollution management

educate, legislate, remediate

preservationists

environmentalists who advocate for the preservation of land and its resources in pristine untouched condition

conservationists

people were not conserving the environment for its intrinsic value, but for the value of the goods and services it could provide

EVS inputs

Culture (includes religion) Education Experience Family

EVS outputs

Actions Answers Choices Decisions

EVS processes

Accepting or rejecting ideas

Cost benefit analysis

Emotion

the main EVS approaches (spectrum)

deep ecologist, self-reliance soft ecologists, environmental managers, cornucopians

Biosphere 2

• Ecological experiment in 1991

• Created by scientists to mirror conditions on Earth and try to create a completely closed system

• Aim: to understand Earth's systems

• Contained seven biomes

Gaia hypothesis

• James Lovelock, 1971

• Suggests that organisms co-evolved with their environment to form a self-regulating living system

• Suggests that Earth is an organism in itself

• Proposes that the evolution of life on Earth initiated significant environmental changes to make the planet more habitable

direct ways to measure pollution

recording the amount of a pollutant in the water, air or soil

indirect ways to measure pollution

recording changes in an abiotic or biotic factor which are the result of pollutants

human factors that affect approaches to pollution management

cultural values, political systems, economic systems

biosphere

Consists of all life on Earth and all parts of the Earth in which life exists, including land, water, and the atmosphere.