ESS Grade 11 Exam

DDT

DDT A persistent insecticide, banned by the WHO (world health organisation) in 1970, used in some countries to kill malarial mosquitoes in houses. (killed many birds, etc.)

Describe stage 2 of DTM

Early expanding, death rate drops as sanitation/food improves, lifespan increases as disease reduced, child mortality falls due to improved medicine, birth rate still high so population expands rapidly

Blue Planet

Earth's name due to the fact that 70% of Earth is covered with water

Factors that lead to LOSS of Biodiversity

-natural disasters -habitat degradation/fragmentation -agricultural practices -invasive species -pollution -hunting, collecting, harvesting

What are the main disadvantages of renewables?

1. They are not as cheap as fossil fuels currently 2. Non - renewable is currently favoured amount MEDC's and LEDC's 3. People do not like putting renewables like wind turbines in locations near residences as they 'spoil the surrounding environment'

What are the main advantages of renewables?

1. They do not release pollutants such as greenhouse gases or chemicals that contribute to acid rain.

What are 5 strategies for waste disposal?

1. landfill 2. incineration 3. anerobic digestion 4. composting 5. anaerobic bio-digesters

4 ways to reduce family size

1. provide education 2. improve health 3. make contraceptives and family planning more available 4. enhance income by small scale projects

4 reasons why people have large families

1. security in old age 2. children are an economic asset 3. status of women 4. unavailability of contraceptives

Negative Feedback

A self-regulating method of control leading to the maintenance of a steady-state equilibrium.

Synergy

A state in which two or more things work together to perform a particular function.

Closed System

A system which exchanges energy but not matter with its environment.

Open System

A system which exchanges matter and energy with its surrounding.

Isolated System

A system which exchanges neither matter nor energy with its surroundings.

What shows a pattern of decline in mortality and fertility of a country, as a result of social and economic development

5-stage demographic transition model

Pollution

Addition of a substance or an agent in an environment by human activity, at a greater rate that the rate the environment can render it harmless by the environment, and has an appreciable effect on the organisms in it.

Succession

A process where organisms occupy a site & gradually change environmental conditions by creating soil, shelter, and increasing humidity.

environmental value system

Particular world view or set of paradigms which shape the way an individual or group of people perceive and evaluate environmental issues.

CITES

The Convention on International Trade in Endangered Species

water budget

a quantative estimate of the amount of water in different storages - the distribution of water on Earth - 97% salt, 3% fresh - mostly in ice caps and glaciers (68.7%)

Millenium Ecosystem Assesment

a report created by the UN that shows the impacts we are having and have had on ecosystems. It shows us different statistics on how our ecosystems are being degraded.

Natural capital

a resource which has some value to humans

system

a set of inter-related parts working together to make a complex whole

System

a set of inter-related parts working together to make a complex whole. With inputs, outputs/feedback and processes. A system consists of a number of parts that interact with each other and the surrounding environment. The interaction produces the emergent properties of the system.; the whole is more than its constituent parts and possesses characteristics that the individual elements do not.

A model

a simplified version of reality that tells a story about what happens in the natural world. Makes it easier to understand, visualise or define in order to make predictions about what could happen in a similar situation, or if x, y or z were to change. E.g. in a climate model the scientist might theoretically alter the amount of CO2 in the various stored to see what happens to the climate. They are the foundation of the scientific method. Most common in ESS are simulations and systems. "All models are wrong, but some are useful." - George Box

flash flood

a sudden rush of water caused when rainwater or snowmelt cannot infiltrate the soil and runsoff on the surface

rice - fish farming

a system whereby fish are reared in rice paddies - the fish eat insect larva and algae and produce waste which the rice uses as fertiliser

Natural capital

a term used for natural resources that can produce a sustainable natural income of goods and services. global stock of natural resources that can be used for the long-term supply of goods and services Natural capital is the amount of natural resources in a particular environment and if it's managed sustainably it will continue to generate natural income in the future.

Environmental value system (EVS)

a worldview or paradigm that shapes the way an individual group of people perceive and evaluate environmental issues. This will be influenced by cultural, religious, economic and socio-political context.

Resilience

ability of a system to recover after a disturbance

Processes

act on the inputs and transform them into outputs

primary pollutants

active on emission (carbon monoxide from incomplete combustion of fossil fuels)

Primary pollutants

active on emission e.g. carbon monoxide from the incomplete combustion of fossil fuels, which causes headaches and fatigue and can kill.

Preservationists

advocates of the preservation of something, especially of historic buildings and artifacts.

deep water currents

aka thermohaline currents - caused by difference in temperature and salt concentration hot water rises (less dense) - cold water sinks water with a high salt concentration sinks (is more dense) - lower concentrations rise

Intergovernmental bodies/organizations

an organization composed primarily of sovereign states (referred to as member states), or of other intergovernmental organizations.

NGOs

an organization that is neither a part of a government nor a conventional for-profit business. Usually set up by ordinary citizens, NGOs may be funded by governments, foundations, businesses, or private persons

La Nina (ENSO)

an overdrive of the neutral phase - the trade winds blow harder - the temperature difference between east and west increases more evaporation and therefore rain in the west

ecological footprint

area of land and water required to provide resources at the rate they're consumed

renewable water storages

atmospheric water and rivers - quickly replenished

How do techno centrists view non-renewable resources

believe that new discoveries will provide new solutions to old problems o Hydrogen fuel cells replacing hydrocarbon-based fuel o Harvesting algae as a food source

anthropocentric worldview

believes humans must sustainably manage the global system

Matter

cycles through systems again and again, moving from one place to another and eventually back again. Matter in the universe is finite, it was created as a big band and there is no more being created so instead it is used and reused. In the carbon cycle e.g. there is a fixed amount of carbon in our global system - the proportions in the stores change, global warming is happening because the atmosphere store of CO2 is increasing. E.g. the carbon atom atmosphere -> plant -> cow -> atmosphere

DOM

dead organic matter waste created by living organisms as they grow and die

Positive feedback loops

destabilising and will tend to amplify changes and drive the system toward a tipping point where a new equilibrium is adopted. Some beneficial, while others are not. E.g. Deforestation

sustainable development

development that meets the needs of the present without compromising the ability of future generations

Sustainable development

development that meets the needs of the present without compromising the ability of future generations to meet their own needs.

biodegradable pollutants

do not persist in the environment and break down quickly

Biodegradable pollutants

do not persist in the environment and break down quickly. They must be broken down by decomposer organisms or physical processes, e.g. light or heat. E.g. soap, domestic sewage, etc.

Biodegradable Pollutants

do not persist in the environment. Breaks down quickly by microorganisms or by light or heat etc.

the hydrological cycle

energy from solar radiation and the force of gravity drive the water cycle - which drives the world's weather systems

The second law of thermodynamics

energy is transformed through energy transfers. Entropy is the measure of the amount of disorder in a system. An increase in entropy arising from energy transformations reduces the energy available to do work. the entropy of a system increases overt time; the only way to avoid entropy is continuous input of additional energy.

transformations

energy or matter flows and changes its state (chemical nature, state, or energy)

transfer processes

energy or matter flows and changes location, but does not change state

second law of thermodynamics

entropy of an isolated system not in equilibrium will tend to increase over time; energy is transformed through energy transfers

open system

exchanges both energy and matter across its boundary (ecosystems are open systems)

Closed system

exchanges energy but no matter with its surroundings e.g. the nitrogen cycle.

Open system

exchanges matter and energy with its surroundings, e.g. a pond or lake

Isolated system

exchanges neither energy nor matter with its surroundings. An imaginary construct, since nothing in nature is completely isolated. The only example given is the universe.

benefits of fish

high in protein, contains important lipds (fats and oils), low in bad fats, provides on average, people eat 20 kg of fish and only 8 kg of meat

turnover times

how long it takes for a molecule of water to enter and leave that part of the hydrological system (e.g. 37,000 years in the ocean; 16,000 years in ice caps; 300 years in groundwater; 12-20 days in rivers; 9 days in the atmosphere)

water scarcity

how much water we have and how we use it there may be enough water in an area, but then it is diverted for non-domestic use

Land pollution

human misuse of land resources. Often caused by poor disposal of waste, use of chemicals such as insecticide, pesticides and fertilisers for agriculture that wash into the soil and damage it. -> smell pollution. Exploitation of minerals also pollutes land.

isolated system

hypothetical concept in which neither energy nor matter is exchanged (the universe)

Efficiency

the useful energy, the work or output produced by a process divided by the amount of energy consumed being the input to the process: efficiency = work or energy produced/energy consumed or efficiency = useful output/input You can express efficiency as a percentage if you multiply by 100.

evapotranspiration

the water lost by plants (especially trees in rainforests) through their leaves

climate

the weather patterns experienced by different locations

the Walker Circulation

the winds which travel west across the Pacific, rise in the west (eastern coast of Australia), travel east again, and sink in the east (Western coast of the Americas)

Natural income

the yield obtained from natural resources

Light pollution

less considered types and cause by poor use of lighting in towns and cities. Caused by street lamps and general high usage of lighting in homes. - timing of biological activities (mating) - disrupt animal navigation - sleep cycles, e.g. humans

evaporation

liquid water changing state to gaseous water (water vapour)

diverting flow (a human effect on water systems)

many rivers are led way from important/urbanised areas some are led to dams to increase storage

Goods

marketable commodities that can be exploited by humans, e.g. forests, fisheries, fertile soil and mineral deposits.

20 litres of 40 litres?

the WHO (World Health Organisation) and Agenda 21 state that every human should have/needs access to this much water per day (on average) much of the world has far less - other considerably more

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, and which has an appreciable effect in the organisms within it.

pollution

the addition of a substance to an environment by human activity, at a greater rate than what it considered harmless to the environment

discharges (a human effect on water systems)

the addition of pollutants to water e.g. chemicals from agriculture, fertilisers, sewage.

Doubling time

the time in years that it takes for a population to double in size. A NIR of 1% will make a population double in size in 70 years. o 70 / NIR

Sustainability

the use and management of resources that allows full natural replacement of the resources exploited and full recovery of the ecosystems affected by their extraction and use. indicators such as biodiversity, pollution and climate change.

Sustainability

the use and management of the resources that allow full natural replacement of the exploited ones and full recovery of the ecosystems affected by their extraction and use

sustainability

the use of resources that allow full natural replacement of the resources exploited and full recovery of the ecosystems

Major sources of pollutants

- Combustion of fossil fuels - Domestic waste - Industrial waste - Agricultural waste

water crisis

the UN's term to describe the situation we are in today where up to 40% of humans alive do not have access to sufficient clean water

Unstable equilibrium

the system returns to a new equilibrium after disturbance.

Stable equilibrium

the system tends to return to the same equilibrium after a disturbance

stable equilibria

the system tends to return to the same equilibrium after a disturbance

Sustainable Yield = ???

(Total Biomass at T + 1) - (Total Biomass at T)

Pollution management strategies

- Altering human activity (EDUCATE) - Controlling release of pollutant (LEGISLATE) - Clean-up and restoration of damaged systems (REMEDIATE)

Factors accounting for different ecosystems' stability

- Climate and limiting factors e.g. desert (hostile climate) - Biodiversity e.g. Tropical rainforests (high biodiversity) - Trophic complexity e.g. (ocean) less biodiversity = less complexity - Nutrient stores e.g. trees hold large percentage of the nutrients - Frequency and intensity of disturbances

steady state equilibrium

- Continuous inputs and outputs of energy and matter, but systems remains in more or less common state. - Living Systems (e.g. Human, Tropical Rainforest)

Who is involved in the environmental movement?

- Influential individuals e.g. Rachel Carson's Silent Spring - Independent pressure groups e.g. Greenpeace or World Wildlife Fund (WWF) - Corporate businesses e.g. MNCs & TNCs - Governments e.g. UNEP - Intergovernmental bodies e.g. United Nations

2 examples of how individual use is a dynamic principle

- MEDCS and LEDCS demonstrate contrasting resource use per capita - Urban and rural populations demonstrate varying resource use profiles - Young people have different resource uses to the elderly - Amazonian Indians have different resource needs than Parisians.

feedback

- Positive: results in a further decrease of output and the system is destabilized and pushed into a new state of equilibrium (e.g a poverty cycle; global warming) - Negative: tends to neutralize or counteract any deviation from an equilibrium and tends to stabilize systems (e.g sweating on a hot day)

Value on the environment may be

- The goods and services the environment provides - Intrinsic value

Categories of EVS

- ecocentrists - anthropocentrists - technocentrists

The goods and services the environment provides

- its aesthetic importance - the recreational provision it offers - resource it supplies

resilience

- tendency to avoid tipping point and maintain a stable equilibrium - diversity and size and storage of systems can contribute to its resilience - human activity can affect this resilience - delay in feedback loops can make it difficult to predict tipping points

Give 3 examples of the circular economy practises

-Recycle plastics/metals -Build for connections and reuse of components -Shift taxation from labour to non-renewable energy -Increase effectiveness and interconnectedness in manufacturing.

give 3 criticisms of the DTM

-Some countries do not adhere, such as China which passed through stages very quickly. -fall in death rate not as severe -Assumes that all countries will become industrialised

What are the 3 estimates in population growth?

1. The high variant - assumes that CDR will continue to fall rapidly but CBR will continue to fall slowly 2. The medium variant - straightforward projection of the curve 3. The low variant - assumes that CBR will fall and that we will not find cures to 'big killers' e.g. AIDS

List 8 types of SDW with example

1. Biodegradable: Food waste 2. Recyclable: Paper 3. Waste electrical: TVs 4. Hazardous: paints 5. Toxic: Pesticides 6. Medical: Needles 7. Inert: Concrete 8. Mixed: plastic toys

What are the 2 main disadvantages of fossil fuels?

1. Contribution to climate change. 2. Unsustainable source of energy.

If tipping points are reached in the natural environment:

1. Environmental support services could collapse - water cycle regulation, clear air, pollination, soil conservation - etc. 2. The lands food production capacity will deteriorate 3. The seas' food production capacity will be compromised 4. Climate may spiral into a positive feedback cycle and become unsuitable for human existence.

What are the advantages of fossil fuels?

1. Fossil fuels are relatively cheap and plentiful. 2. Large amounts of energy are generated. 3. Oil can be delivered over a long distance by pipeline.

Name 4 types of renewable energy sources:

1. Hydroelectric Power 2. Tidal Power 3. Solar Energy 4. Wind Power 5. Biofuel 6. Geothermal Energy

Name five energy sources

1. Oil 2. Coal 3. gas 4. Nuclear 5. Renewables

Steps of the EIA

1. Scoping 2. Baseline Study 3. Predicting and Assessing Effects - Temporary (seen during development phase) - Permanent (result of finished project) 4. Mitigation 5. The Environmental Statement

DDT

1970, WHO banned DDT because it accumulated in people's fatty tissues, causing risks of cancer, but mosquitoes survived and spread malaria

laws of thermodynamics

1st law: energy is neither created nor destroy, but can only be changed from one form to another 2nd law: the entropy of an isolated system will increase over time

China's production of farmed fish

62% of all farmed fish - mostly carp or catfish - often grown in rice paddies (DOM and waste provides nutrients for the rcie)

environmentalism

A broad philosophy and social movement regarding concerns for environmental conservation and improvement of the environment

dynamic equilibrium

A continuous move from one point to another with the same magnitude, so no net change. - Pendulum of a clock

Sustainable developement

A developement that meets the needs of the present without compromising the ability of future generation to meet their own needs

Direct Measurements

A form of monitoring pollution in which the amount of a pollutant in water/air/soil is recorded. It includes measuring the acidity of rainwater, the amount of gases (CO2, etc.) in the atmosphere, the amount of pesticides emitted by a diesel engine, and the amount of lead in the atmosphere.

Indirect Measurements

A form of monitoring pollution that records changes in an abiotic or biotic factor, which are the result of pollutants. It includes measuring abiotic factors that change as a result of the pollutant (oxygen content in water) and recording the presence/absence of indicator species (species only found if the conditions are either polluted (rat-tailed maggot in water) or unpolluted (leafy lichens on trees).

Species

A group of organisms that interbreed and produce fertile offspring

Positive Feedback

A method that leads to increasing change in a system—it accelerates deviation.

Survival of the Fittest

A natural process resulting in the evolution of organisms best adapted to the environment

Describe stage 3 of DTM

Birth rates fall due to contraceptive access, improved healthcare and education

Describe the process of anaerobic bio-digesters

Break the waste and produce methane biogas) which can be used as a fuel

Bioaccumulation

Build up of persistent or non-biodegradable pollutants within an organism or trophic level because they cannot be broken down (eg mercury in the sea consumed by fishes)

Altering Human Activity

Changing human behaviour in order to affect and therefore reduce pollution. this is done by promoting alternative technologies, lifestyles and values: campaigns education community groups government legislation economic incentives/ MOST DESIRABLE, MOST DIFFICULT

Example of the changing value of natural capital

Cork forests previously high in demand for cork bottle lids but now plastic lids used. Lithium was previously unknown but is now used in lithium carbonate batteries in many electronics.

Describe stage 5 of DTM

Declining, population might not be replaced as fertility rate is low and suffering problems of an ageing population

3 ways in which natural capital can be USE valued

Economic price of marketable goods Ecological functions Recreational functions

Primary Succession

Ecosystems coming from Bare rock 1. Pioneer Species 2. Growth in plants 3. Growth of roots 4. Disturbances

Conservationists

End of 19th century early 20th century people were not conserving the environment for its intrinsic value but for the value of goods and services it could provide. Emphasis on sustainable use of the environment and the management of its resources to allow for future development.

Preservationists

End of the 19th century environmentalists focused on preservation. They advocated for the preservation of lands and its resources in pristine untouched condition. Insisted that the land has intrinsic value - its natural beauty has value to us simply by its existence.

FAO

Food and Agriculture Organisation: - more than 70% of world fisheries are fully exploited, in decline, seriously depleted or too low to allow recovery

What is maximum sustainable yield?

MSY is the largest yield that can be taken from the stock of species over an indefinite period of time. MSY aims to maintain the population size at the point of maximum growth rate by harvesting the individuals that would normally be added to the population.

What can high ecological footprint be a result of?

Greater reliance on fossil fuels; more frequent use High levels of imported resources (transportation) High carbon waste (heating, energy, fossil fuels

Secondary Succession

Happens with existing soil

4 main life processes leading to a dissipation of energy as it is passed along the food chain.

Heat, excretion, respiration, digestion

Describe stage 1 of DTM

High stationary; high fertility; high death rates

Example of a non-renewable resource

Iron ore as ore mined and processed is not replaced in our lifetimes, but iron extracted IS renewable

Biomagnification

Increase in concentration of persistent or non-biodegradable pollutants along a food chain. (eg penguin eats fishes which accumulated mercury, penguin had loads of mercury in it now)

Carbon fertilisation effect

Increased levels of CO2 in the atmosphere lead to increased levels of photosynthesis and plant growth. Increased plant biomass and productivity reduces atmosphere concentrations of CO2. Example of negative feedback as the increased rates of photosynthesis and plant growth counteract deviation from the equilibrium by reducing the amount of CO2 in the atmosphere.

3 divisions between an MEDC and LEDC

MEDC: Industrialised with high GDPs Population relatively rich Relatively high level of resource use per capita LEDC: Less industrialised (hardly any industry) May have raw materials but these are exported and processed in MEDCs Lower GDP and higher poverty rates

Environmental Impact Assessments

Is a report before the development of a project that change the use of land. The reports outlines the pros and cons of the development, in order to predict how the biotic and abiotic environment would be impacted. ... originated from the National Environmental Policy Act which was passed in the United States in 1969. ... are used to predict the scale of impacts and mitigate the effects to acceptable limits. They are thus used as a planning process by governments, as infrastructure such as road networks are built.

State the isolation that can lead to different species being produced that are unable to interbreed to yield fertile offspring

Isolation of populations can lead to behavioral differences that do not allow for reproduction and the ability of producing fertile offspring, leading to speciation.

Outline the mechanism of natural selection as a possible driving force of speciation

Isolation: Geographic Isolation + Reproductive Isolation

3 ways in which natural capital can be NON-USE valued

It has intrinsic value (the right to exist) If there are future uses that we do not yet know If it has value by existing for future generations

Describe stage 4 of DTM

Low birth and death rates in industrialised countries with stable population sizes

Environmental managers

Mainly anthropocentric but with some technocentric elements. Natural resources and human population need to be managed. see Earth as a garden that needs tending - the stewardship worldview. We have an ethical duty to protect and nurture the Earth. There are problems and we need governments to legislate to protect the environment and resources from overexploitation and to make sustainable economies. We may need to compensate those who suffer from environmental degradation and the state has a duty to intervene. If we looks after the planet, it looks after us.

Self-reliant/ce soft ecologists

Mainly ecocentric but with some anthropocentric elements. Small scale development. Community identity that keeps development in check.

Speciation

Making species with mechanisms over time + generation -cross breeding -genetic manipulation -changing habitat -isolation

What are the two population growth theories?

Malthusian and Boserup

How would technocentrists change carrying capacity?

May argue that human carrying capacity can be expanded through technological innovation and development

Simpsons Div Index

N(N-1) D = ------------- ∑n (n-1)

What is renewable natural capital?

Natural capital that can be generated and/or replaced as fast as it is being used

What is the relationship between natural capital and natural income?

Natural capital yields natural income

Domestic Waste

Non-decomposable waste which is combustible (carboard, plastics, wood , etc.) which comes from a household of four living units or less.

Describe the process of composting

On a small scale or large scale, material is broken down by natural decomposers.

A plant

Open system. Energy inputs: light Energy output: heat Matter input: Water, minerals, CO2 Matter output: Organic plant material

Secondary Pollutants

Pollutants produced by primary pollutants in the environment undergoing physical or chemical change. (eg. sulphuric acid is produced when sulphuric trioxide reacts with water.)

Agricultural Waste

Pollution produced by crops and other agricultural infrastructures

What can a low ecological footprint be a result of?

Reducing amounts of resources Recycling Less reliance on fossil fuels; public transportation, less frequent use Improving technology to increase carrying capacity

Inertia

Resistance to being altered

Persistent Organic Pollutants (POPs)

Resistant to break down, remain in the environment for a long time. Can bioaccumulate + biomagnify

equilibrium

the tendency of the system to return to an original state following disturbance

Chronic Pollution

Result of a long term release of pollutants released in a broader location. Greater scale and takes time to clean it up.

Solid domestic waste (SDW) or municipal solid waste (MSW)

Rubbish from residential and urban areas

What is sustainable yield?

SY is calculated as the rate of increase in natural capital that can be exploited without depleting the original stock or its potential for replenishment

TCN's (third country nationals)

a person who is employed by an international organization and who comes neither from the country where the organization has its main base, nor from the country where they are working

system scale

Small scale local ecosystem Large ecosystem e.g. Biome Global ecosystem e.g. Gaia

Feedback

Sometime part of the output re-enters the system as feedback and become a new input. The system responds to a change (internal or external) and the feedback moves the system in the same direction (positive) or the opposite (negative).

Instrumental value

Sth is valued because it is a means to an end, it gives you sth tangible. Natural resources such as gold, diamonds and fossil fuel are worth millions of dollars so they can be sold to get sth else.

UNCLOS

The UN Convention on the Laws of the Sea - in 1982 they designated the continental shelf as belonging to the country from which they extend

Biodiversity

The amount of biological or living diversity per unit area (species diversity, habitat diversity, and genetic diversity)

Ecological Footprint

The area of productive land and water needed to sustain a specific population at a given standard and assimilate their waste.

What does the Antarctic Treaty of 1959 agree?

The area will be: • Free of nuclear tests and nuclear waste • Peaceful purposes • Preserved environment • Undisputed as a territory There will be: • Prevention of marine pollution • Clean up sites • No commercial mineral extraction

Point Source Pollutant

a pollution done in a specific clearly identifiable site eg. (oil spillage)

Describe the linear economy/model

The model is unsustainable - 1. We find the raw materials or natural capital (take) 2. Use energy to produce goods (make) 3. Often goods become redundant or break down (dump)

ecocentric worldview

The moral view that organisms and ecosystems have values

Fertility rate

The number of births per thousand women of child bearing age

system

comprised of storages and flows

System

The product of individual component parts that work together to perform a particular function.

Habitat Diversity

The range of different habitats or number of ecological niches per unit area in an ecosystem, community, or biome. Eg, woodland = river, soil, trees Eg, desert = sand + occasional vegetation

Genetic Diversity

The range of genetic material in the gene pool of a population of a species (sections of DNA , large gene pool helps species adapt to changes in environment)

Industrial Revolution

The rapid development of industry brought about by the introduction of machinery. It was characterized by the use of steam power, the growth of factories, and the mass production of manufactured goods.

Industrial revolution

The rapid development of industry that occurred in Britain in the late 18th and 19th centuries, brought about by the introduction of machinery. It was characterized by the use of steam power, the growth of factories, and the mass production of manufactured goods

Equilibrium Stability

The tendency of the system to return to the original equilibrium following disturbance, rather than adopting a new one.

homeostasis

The tendency toward a relatively stable equilibrium between interdependent elements, especially as maintained by physiological processes.

Energy

The ultimate source of all energy in any system is solar radiation from the sun. The energy is converted into chemical bonds during the process of photosynthesis and then it flows through the system. These bonds are broken down during respiration to release energy that can be used for life processes or to be lost as heat. Once lost as heat it is of no use to the system or anything in it, it can not be reused. E.g. solar energy -> chemical energy -> heat energy

Species Diversity

The variety of species per unit area

Stewardship

The view that humankind is responsible for caring for the environment

technocentric worldview

The view that humans are the dominant species and that other species only have value if they are useful to us

Ecosystem Services

They are the benefits provided by different ecosystems that contribute to making both human and animal life possible and worth to live.

Pollution Management

Three different ways to reduced / control pollution (Altering Human Activity, Controlling Release of Pollutant, Clean-Up and Restoration of Damaged Systems)

Example of the dynamic nature of natural capital

Uranium is in demand as raw material for nuclear power but might not be if we could harness the energy of nuclear fusion (the hydrogen economy)

Industrial Waste

Usually chemical waste create by cooperate facilities (EG, Factories)

Ecocentists vs. Technocentrists

View on fossil fuels

Rachel Carson's "Silent Spring"

Warns of effects of pesticides because it passes along food chain and kills others, criticized for scaremongering, influenced Al Gore

Describe the process of incineration

Waste is pre-sorted to remove incombustible materials and heat is produced to generate steam to drive a turbine

Describe the process of landfill

Waste is taken to a suitable site and buried and is lined with a special plastic liner to prevent leachate.

static equilibrium

When a static equilibrium is disturbed, it will adopt a new equilibrium as a result of the disturbance. - Non—living only

Describe the process of anaerobic digestion

When biodegradable matter is broken down by micro-organisms in the absence of oxygen. The methane produced can be used as a fuel and the waste as fertiliser.

Controlling Release of Pollutant

Where the activity/production (release of pollutants isn't completely stopped, but adhered, regulated, or prevented. legislating and regulating standards of emissions developing/applying technologies for extracting pollutants from emissions.

Steady-state equilibrium

a characteristic of open systems where there are continuous inputs and outputs of energy and matter, but the system as a whole remains in a more-or-less constant state (e.g. a climax ecosystem). many small changes over shorter periods of time and the changes occur within limits. The small changes will be countered by negative feedback.

Modern environmental movement

a diverse scientific, social, and political movement for addressing environmental issues.

Pressure groups

a group that tries to influence public policy in the interest of a particular cause.

static equilibrium

a kind of equilibrium in which there is no change over time

Green revolution

a large increase in crop production in developing countries achieved by the use of fertilizers, pesticides, and high-yield crop varieties.

aquifer

a layer of porous rock sandwiched between two layers of impermeable rock refills where the porous rock meets the surface as water infiltrates (flow can be as little as 1-10m per centrury - therefore refilling is extremely slow)

Entropy

a measure of the amount of disorder (chaos)/randomness in a system.

The Human Development Index

a measure of the well being of a country that measures health, wealth and education

Anthropocentrism

believes humans must sustainably manage the global system. Might be through the use of taxes, environmental regulation and legislation, etc. Human/people-centred, in which people manage their environment and themselves with the help of independent regulatory authorities. Population control and resource management are given equal importance.

Technocentrism

believes that technological developments can provide solutions to environmental problems. Emphasis on the use of scientific analysis and prediction in order to understand and control natural processes. Technology will keep pace with and provide solutions to all problems. Science will find alternative resources and the market economy can continue unheeded.

4 factors that affect population sizes

birth rate; death rate; immigration; emigration

changing the flow (a human effect on water systems)

building roads and channeling water rivers underground or in concreted areas canalising - straightening large sections of rivers use of dams, barrages and dykes; making reservoirs

Fossil Fuel Combustion

burning of coal, oil or other fossil fuels in order to create energy, the heat released is transferred into kinetic energy, which is turned into the electricity that the use as the human race

Renewable resources

can be replaced as fast as they are used e.g. crops grow quickly and timber from the trees (grows)

transfer

change in location

transform

change in the chemical nature, in state, or in energy (requires more energy than transfer) - Matter to matter (glucose converted to starch in a plant) - Energy to energy (light converted to heat by radiating surface) - Matter to energy (burning fossil fuels) - Energy to matter (photosynthesis)

Thermal pollution

changes the temperature in an area, usually rise in temperature of water or air. Higher temperatures, decrease the oxygen content of the water, which impacts flora and fauna.

steady-state equilibrium

characteristic of open systems where there are inputs and outputs of energy and matter, but the system as a whole remains in a more-or-less constant state

The carbon cycle

closed system - solar energy drives the cycle and heat escapes into space. Storages: Atmosphere, Plants, Fossil fuel rocks, Animals & Soil Flows: Photosynthesis, Combustion, Extraction, Sedimentation, Decay & Respiration

over-exploitation of fisheries

fishing at an unsustainable level - over-fishing (we are too good at catching fish) - commercial fishing has high technology to aid in catching efficiency - fishing fleeting are larger with modern refrigeration (to stay out longer) - within a fishing fleet there are now also processing ships - indiscriminate fishing gear catches all organisms whether they are the target species or not (by-catch) - trawlers drag huge nets along the seabed destroying the benthic ecosystems

secondary pollutants

formed by primary pollutants undergoing physical or chemical changes

Secondary pollutants

formed by primary pollutants undergoing physical or chemical changes e.g. sulphuric acid forms when sulphur trioxide reacts with water Photochemical smog is a mixture of primary and secondary pollutants

Millennium Ecosystem Assessment

founded 2001 to focus on how ecosystems have changed over time and predict changes (60% of world ecosystems have been degraded, 35% of mangroves destroyed, 20% of corals lost and 20% degraded)

Millennium Ecosystem Assessment (MEA)

funded by the UN and started in 2001, is a research programme that focuses on how ecosystems have changed over the last decades and predicts changes that will happen. Gave a scientific appraisal of the condition and trends in the world's ecosystems and the services they provide using environmental indicators, as well as the scientific basis for action to conserve and use them sustainably.

condensation

gaseous water (water vapour) which turns to liquid - especially in clouds causing rain

Resources

goods or services that humans use ('RESOURCES' / 'NATURAL CAPITAL' = INTERCHANGEABLE)

aquifer

groundwater - the water which is stored in permeable rocks between layers of impermeable bedrock - often drilled down into to create wells

middle ground (neither renewable or non-renewable) water storages

groundwater aquifers - take a long time to replenish (currently used unsustainably)

Primary Pollutants

harmful substances that are released directly and are active on emission. (EG. incomplete combustion resulting in carbon monoxide, causing death and damage)

Environmental Impact Assessments (EIAs)

incorporate baseline studies before a development project is undertaken. They assess the environmental, social and economic impacts of the project predicting and evaluating possible impacts and suggesting mitigation strategies for the project. Usually followed by an audit and continued monitoring. Each country or region has a different guidance on the use of EIAs. As projects requiring an EIA usually concern local habitats and populations, it's the local authorities that fund the carrying out of such an assessment.

flow

inputs and outputs of energy and matter

Non-renewable resources

irreplaceable except over geological timescales e.g. coal takes millions of years to form so we are using it faster than it is forming. (e.g. gold and gemstones)

the tragedy of the commons

is an economic theory of a situation within a shared-resource system where individual users acting independently according to their own self-interest behave contrary to the common good of all users by depleting that resource through their collective action e.g. individual countries using the ocean as a resource, and so over-exploitation is occuring

Non-renewable natural capital

is either irreplaceable or only replaced over geological timescales e.g. fossil fuels, soils and minerals

Stability

is the ability of an ecosystem to remain in balance. Two components: Resistance and Resilience.

Resilience

is the ability of the ecosystem to recover after a disturbance.

Natural income

is the annual yield obtained from natural resources trees provide timber, fisheries yield fish, fertile soil gives us food to eat and minerals keep our industries going We are only interested in sustainable income, the income that can be taken without reducing capital. (only renewable resources)

Resistance

is when the ecosystem continues to function during a disturbance.

What would an ecological footprint of 2.4 mean?

land would actually need to be 2.4 times larger than the actual size of the country to fully support its population

Disturbances

may be natural (flooding, fires or volcanic eruptions) or human induced (deforestation, pesticides or introduced species). If the disturbance occurs over and extended time, over large areas or is of sufficient severity then any ecosystem may reach a tipping point. If so, then it becomes unstable and normal patterns cannot be maintained. Such disturbances are often a result of human activity, loss of biodiversity, pollution and climate change are all putting a strain on ecosystem resilience and the resultant ecosystems are often degraded and lack stability and resilience.

entropy

measure of disorder in a system

ocean currents

movements in the sea both vertically and horizontally - move in specific directions, and some have names

Services

natural processes that provide benefits for humans such as water replenishment, clean air and protection against erosion. - Supporting - Provisioning - Regulating - Cultural

natural capital

natural resources that can produce a sustainable natural income of goods or services

neutral equilibrium

no tipping point

The Kalahari Bushmen as ecocentrists

nomadic people living in the Kalahari Desert in Botswana and Namibia.

Inorganic pollutant

non-living and generally doesn't contain carbon. E.g. nitrates and phosphates from artificial fertilisers

Transformation

occur when energy or matter flows and changes its state - a change in the chemical nature, a change in state or a change in energy. So, move energy and matter but in the process of doing so there is a change of state or form. E.g. water changes state from solid, to liquid to gas (matter) and energy is converted into matter during photosynthesis.

Transfers

occur when energy or matter flows and changes location but does not change its state. So, simply move energy or matter from one place to another without changing it in anyway. E.g. water flows in rivers moving across the land and matter moves through a system.

non-renewable water storages

oceans and icecaps - they would take 100s of years to replenish if used

marine ecosystems

oceans, mangroves, estuaries, lagoons, coral reefs, deep ocean floor very diverse and have high stability and resiliene

Persistent organic pollutants (POPs)

often manufactured as pesticides in the past. They are resistant to breaking down and remain active in the environment for a long time. They can bioaccumulate in animal and human tissues and biomagnify in food chains and can cause significant harm. E.g. DDT Similar properties: - high molecular weight - not very soluble in water - highly soluble in fats and lipids - which means they can pass through cell membranes - halogenated molecules, often with chlorine

What does the circular economy rely on?

on manufacturers and producers retaining ownership of their products and so being responsible for recycling them or disposing of them

closed system

only exchanges energy across its boundary (only exist experimentally, although the global geochemical cycles approximate to closed systems)

Visual pollution

only issue to humans - anything intrusive and ugly that detracts from the natural beauty of an area.

benthic

organisms living on or in the sea bed

pelagic

organisms living surrounded by water from above the sea bed to the surface

Conservationists

people who advocate for the protection and preservation of the environment and wildlife

Water pollution

pollutants introduced into a body of water without having the harmful substances removed. Sometimes direct e.g. with oil tankers illegally washing out their tanks at seas and dumping waste straight into the ocean. Indirect as with the excess fertilisers from agricultural fields. Can destroy entire ecosystems, disrupt food chains, spread diseases and poison humans.

Non-Point Source Pollutant

pollution produced in an area, not necessarily in one isolated source (factories exhaust gases, vehicles)

Noise pollution

presence of loud sounds that can be harmful or just plain annoying. Can disrupt marine mammals ability to navigate, upset nesting birds, damage hearing and cause general stress.

first law of thermodynamics

principle of conservation of energy; energy cannot be created or destroyed

1 pro and 1 con of landfill

pro: cheap con: chemicals pollute soil and water

1 pro and 1 con of incineration

pro: disposes of clinical and hazardous waste effectively con: air pollution

1 pro and 1 con of composting

pro: returns valuable nutrients to soil con: smells

Deep ecologists (extreme ecocentrists)

put more value on nature than humanity. Believe in bio rights - universal rights where all species and ecosystems have an inherent value and humans have no right to interfere with this. Decrease human population and consume less. Nature has intrinsic values in and of itself. No development. Do not condone the use of fossil fuels.

Ecocentrism

puts ecology and nature as central to humanity and emphasises a less materialistic approach to life with greater self-reliance, self-sufficiency of societies, self-restraint and minimal disturbance of the natural processes to achieve sustainability for the whole earth. Nature-centred, which respects the rights of nature and the dependence of humans on nature so has a holistic view of life which is earth-centred, in which environmental, social and spiritual aspects are integrated. We do not even know what species are alive on Earth at the moment and certainly do not know how they interact so it's arrogant of us to think that we can manage it all.

precipitation

rain

How would an ecocentrist change carrying capacity?

reduce use of non-renewable resources and even renewable ones. May become self-sufficient.

Point source (PS) pollutants

release from a single, clearly identifiable site, e.g. a factory chimney. Easier to identify polluter and manage as it can be found more easily.

Non-point source (NPS) pollutants

release of numerous, widely dispersed origins, e.g. gases from the exhaust systems of vehicles, chemicals spread on fields.

desalination plants

removing salt from saline water to create potable (drinking) water requires a lot of energy - extra salty water is often released back into the ocean damaging sea-bottom ecosystems (the salt water sinks)

Acute Pollution

result of large amount of pollution is released in one spot. Easier to clean up than chronic pollution. (Deepwater Horizon and other oil spills)

Chronic pollution

results from a long-term release of a pollutant but in small amounts. It is serious because: - often it goes undetected for a long time - it's usually more difficult to clean up - often spreads widely E.g. air pollution causing non-specific respiratory diseases like in Beijing.

saline

salt water - this is the majority of Earth's water

Cornucopians (extreme technocentrists)

see the world as having infinite resources to benefit humanity. They think that through technology and our inventiveness, we can solve any environmental problem and continually improve our living standards. Free-market economy - capitalism with minimal government control or interference - as the best way to mange markets and the planet. The Earth is a spaceship and we are its captain and crew. If we understand the machine, we can steer it. We can carry on with development because technology will solve any problems that arise.

Biosphere

self-regulating, closed system, which includes all organisms and the spheres in which they live - atmosphere (air), hydrosphere (water) and lithosphere (rocks and soil). As with ecosystems the living sphere interacts with the non-living elements and drives the biochemical cycles (carbon and nitrogen).

Explain how Plate Activity has influenced evolution and biodiversity

separation of gene pools, formation of physical barriers and land bridges = generation of new and diverse habitats = greater biodiversity. Plate activity has isolated populations causing them to interbreed and live under different environmental conditions. Eg. Caribou + Reindeer Similarities in East Indies and Australia

black water

sewage - the water containing human waste - may carry disease-causing bacteria or parasites

A systems diagram

shows the stores as boxes and the flows as arrows pointing in the direction of flow. The size of the boxes and the width of the arrows can be varied to show the proportional size of the stores and flows. e.g. the carbon cycle or a plant

Environmental Indicators

simple measures that tell us what is happening in the environment

models

simplified models can help predict the future strength: predict the effects of a change to an input to the system weakness: omit some of the complexities of the real system

model

simplified version of reality and can be used to understand how a system works and predict how it will respond to change inevitably involves some approximation and loss of accuracy

advantages

simplifies interactions but may provide a more holistic view than reducing issues to single processes

zooplankton

single-celled animals which feed off of phytplankton and their waste - crucial in supporting oceanic food webs

phytoplankton

single-celled organisms that can photosynthesis and are the most important producer in in the oceans, producing 99% of primary productivty - crucial in supporting oceanic food webs

vegetarian farmed fish

solution to sustainable aquaculture - the United States Department of Agriculture has proven that there are eight species of carnivorous fish which can gain enough nutrients on a diet excluding other fish

Negative feedback loops

stabilising and occur when the output of a process inhibits or reverses the operation of the same process in such a way to reduce change - it counteracts deviation. E.g. predator prey relationship and human body temperature

negative feedback loops

stabilizing and reduces change

The first law of thermodynamics (Principle of conservation of energy)

states that energy in an isolated system can be transformed but cannot be created or destroyed.

Organic pollutant

sth that is or was living. E.g. human sewage. They are carbon based and they may or may not be toxic. The organic compounds that are dangerous to the environment are man-made.

system diagrams

storage: box flow: according to arrows

Pollutants

substances or agents released during a wide range of human activities. These include: matter (organic or inorganic) energy (light sound heat) living organisms

sources of freshwater

surface freshwater - rivers, streams, reservoirs and lakes underground aquifers

unstable equilibrium

system returns to a new equilibrium after a disturbance

stable equilibrium

system tends to return to the same equilibrium after a disturbance

positive feedback loop

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

Ecological footprint (EF)

the area of land and water required to sustainably provide all resources at the rate at which they are being consumed by a given population. support a human population at a given standard of living - providing all the resources and assimilating all the waste. Gives indication of the demand people place on the earth's natural capital and ecosystems it comes from. Units: number of planets that would be required to supply the humanities needs and as a global hectare per person (Gha/pers), which is then compared to the biocapacity of the area.

Total fertility rate

the average no of children a woman has over a lifetime

water wars

the conflict caused by dispute over water sources - often when sources are shared e.g. Israel, Gaza and Egypt

Input

the elements (flows) that go into the system in order for there to be processes, outputs and feedback.

continental shelf

the extension of the continents under the seas and oceans - creates shallow water important because: - 50% of productivity in only 15% of its area - upwellings bring nutirent-rich water to continental shelf - higher light penetration/insolation - countries can claim it as theirs to exploit and harvest

aquaculture

the farming of aquatic organisms in both coastal and inland areas involving human intervention in the rearing process to enhance production (FAO)

Outputs

the flows of matter and energy that leave the system.

the great oceanic conveyer belt

the huge oceanic currents which circulate the globe

Ecological footprints

the hypothetical area of land required by a society, group or individual to fulfil all their resource needs and assimilate all wastes.

Intrinsic value

the idea that sth can be of value in and of itself and not because it is of any use to humanity. Of value just because it is there, you can not sell it to get anything else.

aquitard

the impermeable rock above (upper) and below (lower) the permeable rock forming an aquifer

maximum sustainable yield (MSY)

the increase in natural capital that can be exploited each year without depleting the original stock or its potential to replenish itself - use of this leads to sustainability SY = annual growth and recruitment - annual death and emigration may lead to depletion of a population in bad breeding (recruitment) years

Air pollution

the introduction of harmful materials into the atmosphere. May be gases, particulates or biological elements. Much of the gas and particulate matter is from the combustion of fossil fuels and the biological elements include viruses and pollen. Can cause respiratory problems and damage vegetation.

carrying capacity

the maximum number of a species or load that can be sustainably supported by a given area

surface currents

the movement of the ocean in the upper 400m - movement is due to wind

Natural capital

the natural resources that can sustainably produce goods and services.

Diversity

the number and proportions of species present Eg. Rainforest has high diversity and inertia but if undergoes catastrophe it has low resilience.

Crude birth rate

the number of births per thousand individuals in a population per year o (Number of births/population size) x1000

Crude death rate

the number of deaths per thousand individuals in a population per year o (Number of deaths/population size) x1000

Natural increase rate

the rate of human growth expressed as a percentage of change per year o (Crude birth rate - crude death rate) / 10

Natural income

the rate of replacement of a particular resource or natural capital

entropy

the spreading out or dispersal of energy over time there will always be a reduction in the amount of energy passed on to the next trophic level - Because of entropy, we need a constant replenishment of energy in a system, otherwise life couldn't exist.

Demographics/ demography

the study of the dynamics of population change (e.g. total size, age, sex composition, changes in birth/death rates)

unstable equilibria

the system establishes a new after a disturbance

Static equilibrium

there is no change over time. When disturbed it will adopt a new equilibrium as a result of the disturbance. (Most non-living systems). They do not change their position or state for long periods of time. This cannot occur in living systems as life involves exchange of energy and matter with the environment. It can be disturbed.

Neutral phase (ENSO)

trade winds blow warm air and water from the east to the west Pacific cold water is drawn up from the deep on the western coasts of the americas (carrying nutrient rich waters = fertile waters - many fish) air rises in the western Pacific and circulate back to the eastern Pacific

El Nino Southern Oscilations (ENSO)

trade winds weaken allowing warm waters to spread to the east this causes warm are to rise in the middle of the Pacific cold mineral rich water is pushed up in the middle of the Pacific causing fish to be found too far off shore for fishermen in small boats

efficiency

useful energy divided by input energy

systems approach

visualizing a complex set of interactions which maybe ecological or societal.

withdrawals (a human effect on water systems)

water is used for domestic use, irrigation in agriculture and in industry

infiltration

water sinking below the surface into the soil

domestic water use

water used for drinking, washing and cleaning at home

agricultural water use

water used for irrigation (water for crops) and for animals to drink

industrial water use

water used for processes such as machine cooling, manufacturing and mining

grey water

water used in the home for cleaning, brushing teeth, showering etc often is not really dirty, but drains the same way as sewage

surface run-off

water which does not infiltrate the soil, bu flows along the surface

Ecological tipping point

when an ecosystem experiences a shift to a new state in which there are significant changes to its biodiversity and the services it provides e.g. lake eutrophication, extinction of a keystone species or coral reef death The problem in large systems is that feedback loops may be slow and the impact of a particular action will not be seen immediately.

fishery

when fish are harvested in some way - includes capture of wild fish and aquaculture (fish farming) 90% is marine - 10% is freshwater

feedback loop

when information that starts a reaction in turn may input more information that may start another reaction

Feedback loop

when information that starts a reaction in turn may input more information which may start another reaction.

Acute pollution

when large amounts of pollutants are released, causing a lot of harm. E.g. the Bhopal Disaster of 1984 in India.

Clean-Up and Restoration of Damaged Systems

when the two other pollution management systems have failed, strategies to recover the damaged ecosystem by extracting and removing pollutant from ecosystem replanting/restocking lost or depleted populations and communities

advection

wind-blown movement

Describe the aims of the circular economy

• Be restorative of the environment • Use renewable energy sources • Eliminate or reduce toxic wastes • Eradicate waste through careful design

Describe the Malthusian theory

• Believed that human population increases geometrically WHEREAS food supply can only grow arithmetically (being limited by available new land) • 'Laws of nature' dictate that a population cannot increase beyond the food supplies necessary to support it • Population increase is limited by certain 'checks', which prevent numbers of people increasing past the optimum population which the available resources cannot support. • As long as fertile land is available, Malthus believed that there would be more than enough food to feed a growing population. As population and the demands for food increases there is a greater pressure to farm intensively and cultivate poorer, more marginal land. • Food production can only increase to a certain level determined by the productive capacity of the land and existing levels of technology. • Beyond the ceiling when land is used to its fullest extent soil erosion occurs, leading to a general decline in food production.

3 difficulties in measuring carrying capacity

• Humans use a far greater range of resources than any other animal • We substitute resources with others if they run out • Resource use varies between individuals // countries depending on lifestyle, culture, economy • We import resources from outside our local environment so cannot establish local c.capacity • Developments in technology lead to changes in the resources we use

Give 3 limitations to the Malthusian theory

• Ignores the reality that only the poor go hungry, as poverty results from the poor distribution of resources, not physical limits on production • Except on a global scale, the worlds community is not 'closed' and so does not enjoy a fair and even distribution of food supplies • Malthus could not predict technological advances which contradicts the Malthusian notion of food supply increasing only arithmetically

2 policies that may reduce population growth rates

• Introduction of pension schemes • Policies directed towards the education of women, enabling women to have greater personal and economic independence.

2 limitations of Boserup's theory:

• Like Malthus, based on the assumption of a 'closed' community, and therefore it is difficult to test Boserups ideas o Migration usually occurs in areas of over-population, to relieve population pressure, which, according to Boserup, leads to technological innovation • Fragile environments cannot support excessive loads and so population pressure does not always lead to technological innovation

2 policies that may increase population growth rates

• Lowering income tax or giving incentives-free health care and education e.g. Australia baby bonus • Encouraging immigration, particularly of works

What does capital include?

• Natural resources that have value to us E.G. trees, soil, water, living organisms and ores bearing minerals • Natural resources that provide services that support life E.G. flood and erosion protection provided by forests • Processes that maintain healthy ecosystems and thus support life E.G. Photosynthesis that provides oxygen for life forms to respire

Describe Boserup's theory

• Suggested that any rise in population will increase the demand for food and so act as an incentive to change agrarian technology and produce more food. • Her theory suggests that as population increases, agriculture moves into higher stages of intensity through innovation and the introduction of farming methods.

Explain the relationships among ecosystem stability, diversity, succession, and habitat.

•Diversity changes THRU succession •Greater Habitat Div = greater species and Genetic Div •Complex ecosystems provide stability thru nutrients and energy •Human activities modify succession (logging, grazing, burning) pathways •Ecosystem's capacity to survive change may depend on diversity, resilience and inertia