Unit 8 Flashcards
Crude Birth Rate (CBR)
The number of births per thousand individuals in a population, per year
Four main factors that affect population size
Birth rate, Death rate, Immigration, Emigration
Fertility rates higher than 2.0
Population increase
Fertility rates lower than 2.0
Population decrease
In order to maintain a stable population
Parents should be replaced by 2 children (not including migration)
Birth rate is expressed….
As a percentage
The high variant assumes
That CDR will fall rapidly, and CBR will fall slowly
The medium variant
Is a middle ground and a straightforward projection of the curve
Low variant
Assumes we will not find a cure to AIDS or similar big killers, resulting in a CBR fall
Until now, the global population has followed
An exponential curve - when population follows an accelerating rate of growth proportional to the population size
CBR is expressed….
Per thousand individuals
Crude death rates (CDR)
The number of deaths, per a thousand individuals in a population per year
How are CBR and CDR calculated?
By dividing the number of births or deaths by the population size, multiplying by 1000
Natural increase rate (NIR)
The rate of human growth expressed as a percentage change per year
To calculate NIR
CBR - CDR / 10 (Ignores migration)
Doubling Time (DT)
je tome in years it takes for a population to double in size (NIR of 1% will make a population double in size in 70 years)
Total fertility rate (TFR)
The average number of children each woman has, over her lifetime (this can also measure the amount of births)
Dependency Ratio (DR)
The amount of people within dependent population in comparison to the higher and lower section of the pyramid. The depended population takes care of these others in the population
Fertility Rate (FR)
The number of births per thousand women of childbearing age
Birth rate
Expressed in a percentage, birth per 1000, or 100% of the total population - (crude birth rate is more common now)
Human development index (HDI)
Measures the well being of a country combining measures of health (life expectancy), wealth (GDP per capita) and eduction into one value
LEDCs
In economic decline, least developed, potentially failed states
Newley industrialised countries (NICs)
Accelerated industrial development, increased GDP. Accompanied by massive foreign investment, population, migration to provide workforce, free trace, increased civil rights. EG: China, India, South Africa, Malaysia, Thailand, Phillipines, Turket, Mexico, Brazil
Human population causing environmental impacts are underpinned by:
- More people require more resources
- More people reduce more waste
- People usually want to improve their standard of living
- The more people there are, the greater impact they have
If we can control population increases and resource demand
Levels of sustainability should increase
Demography
The study of statistical characteristics of human populations: Total size, age, sex, composition, changes over time with varied birth / death rates
Populations are stable
When birth and death rate are qual so there is no gain or loss in population size
Factors that impact resource failure and the consequences of human population
- Size of population
- Wealth of population and demand for resource desire or need
- Assumption of everyone having the same needs
(However, resources vary in time and space)
MEDCs and LEDCs
Demonstrate contrasting use over capita. EG: Amazonian indians have a different need to Parisians, Young and elderly have different needs, urban and rural populations have different needs
20% of the world
Live in MEDCs
80% of the world
Live in LEDCs
The population is falling in MEDCs
Because of a high birth rate in LEDCs
Sometimes both rate is
Negative in MEDCs ie: Germany
An optimum population is reached when….
The population produces the highest economic return per capita, using all available resources, with some countries having a higher optimum population density than others
Richer countries tend to
Import goods and services from everywhere
Malthus and Boserup theories
Relate to population growth and food supply
Limitations of the demographic transition model:
Initially without the 5th stage, death rate not necessarily as steep as suggested, fall in birth rate makes assumption of contraception and religious practices allowing for it, deaths from diseases could affect, some countries have compressed the timescale, it is only Eurocentric and assumes all countries will become industrialised
Why do people have large families?
High child mortality rates due to malnutrition and disease, Unavailability of contraceptives (in LEDCs), Security in old age (the more children, less burden to take care of parents), children are an economic asset (working on land), Status of women (how they are deprived of many rights, considered only good for making children
Ways to reduce family size
Provide education, improve health, make contraceptives and family counselling easily available, Enhance income, improve resource management
What is the demographic transition model (DTM)?
The pattern of decline in mortality and fertility of a country as a result of social and economic transition, shown in a 5 stage population model (This also links to the sigmoid growth curve)
Stage 1: (DTM)
(Pre industrial societies) - High birth due to no birth control, high infant mortality rates, culture encouraging large families, High death rates due to disease, little medicine, famine, and poor hygiene
Stage 2: (DTM)
Early expanding (LEDCs) - Death rate drops, sanitation and food improves, disease is reduced showing lifespan improvement, birth rate still high, high population expansion, improved medicine, child mortality rates fall
Stage 3: (DTM)
Late expanding (Wealthier LEDCs) - As a country develops, birth rates fall because of improved healthcare and contraception, education, emancipation of women. Population levels off, desire for material goods and low infant death rates mean that people have smaller families
Stage 4: (DTM)
Low stationary (MEDCs) - Low birth/death rates, industrialised counties, stable population sizes
Stage 5: (DTM)
Declining (MEDCs) - population may not be replaced, fertility rate is low, ageing workforce
Something to remember with the DTM….
It explains changes in some countries but not others, China/Brazil passed through the stages very quickly, sub saharan countries or those affected by war or civil unrest do not follow the model, it has been criticised as exploiting the European model worldwide
Many countries….
Are hard to categorise into MEDCs or LEDCs
MEDC Country Examples
Most countries in Europe, North America, Israel, South Africa, and Japan
LEDC country examples
Most of sub Saharan Africa, Asia, and South America
MEDCs have:
Relatively low population growth rtes, largely due to low CBR but rising CDR. Very high carbon/ecological footprints, individuals are unlikely to starve through poverty, Population is relatively rich, relatively high resource use per capita (person), Industrial with high GDPs
LEDCs have:
Hardly any industry, lower GDP, higher poverty rates, people have very poor standards of living, high population growth rate due to falling CDR, lower carbon/ecological footprints
MEDCs have….
Falling birth rate (higher than LEDCs), which sometimes become negative (eg: Italy/Germany)
Thomas Malthus Theory
In his text “Principle of Population” in 1798, he claimed that food supply was the main limit of population growth, believing that food supply grows arithmetically, and human population grows geometrically. The growing population would eventually exhaust the world’s resources and decrease quality of life
Thomas Malthus beliefs
He believed that as population increased, there would be greater human pressure to deliver on producing more food supplies, making people farm more intensively, and cultivate poorer land.
Limitations of Malthusian Theory
Too simplistic, misses out the fact that not all food supplies are spread evenly around the world, did not consider technology, not very relevant to modern day
Esther Boserup Theory 1965,
Boserup believed that “necessity is the mother of variation” (if it is needed someone will create it) She believed in simple terms that innovation and food technology would grow with the population
Boserup’s Beliefs
Technology would be created with the motivation of starvation and the challenge of feeding more mouths. Therefore people would invent new technology and ways to improve farming and food production.
Limitations to Boserup’s theory
Also based on ‘closed’ community, migration usually occurs in areas of overpopulation, unsuitable farming practices may degrade the land, population pressure does not always lead to development
Policies which could release population growth rates….
Pay more tax for more children, increase birth control and education, policies that stimulate economic growth, pension schemes so parents are not as dependent on their children, urbanisation to reduce CBR, education of women, enabling women to have more independence
Policies which may increase population growth….
Lowering income tax, giving incentives and free education/health care, improved public health/sanitation, encouraging immigration (especially for workers), agricultural development
Neo-Malthusians
A group of people also known as the Club of Rome in the 60s who applied Malthus’ theory to resources rather than food
Trend
Time (The difference in numbers, over years) Looking at a graph of world population
Pattern
Pattern - Space (You would look at differences between countries) Population growth for different places
Why are both Malthus and Boserup right?
Malthus refers to the environmental limits, Boserup relates to cultural and technological issues
4 basic population pyramid shapes that match the DTM
Expanding, expanding, stationary, contracting
Problem with pro/anti natal policies
When a country goes back to trying to increase their population to cancel out the issues of an ageing population, they are unable to as once women gain control over their own fertility, they rarely wish to go back to having a large family
It is important to consider () when discussing population
Push and pull factors
Indents
A dramatic inwards line on a population pyramid
Natural capital
A resource which has some value to humans
Resources
Goods or services that we use
Natural income
The rate of replacement of a particular resource or natural capital
Natural resources that have value to us include:
Natural resources that have value to us, (trees, soil, water, living organisms, and ores bearing minerals)
Natural resources that provide services that support life:
Eg: flood and erosion protection provided by forests and processes (photosynthesis that provides oxygen for life form to respire), the water cycle or other process that maintain healthy ecosystems
Natural capital can also be described as….
Goods that are not manufactured but have value to humans. They can be improved or degraded and a given a monetary value.
The terms resource and natural capital
Are interchangeable
Natural capital….
Yields natural income (yield or harvest or services) - eg: factories produce objects, water cycle provides water
The measure of the true wealth of a country
Includes its natural capital. EG: how many mineral resources forests rivers it has
MEDCs add value to natural income
By manufacturing goods form it
LEDCs may have
Greater unprocessed natural capital
The world bank now calculates
The wealth of a country by including the rate of extraction of natural resources and the ecological damage caused by this (including carbon dioxide emissions)
Renewable natural capital include:
Living species and ecosystems that use solar energy and photosynthesis, not living items such as groundwater and the ozone layer
If renewable natural capital is used beyond its natural income
Then is is used unsustainably
Renewable natural capital can run out if….
The standing stock is harvested unsustainably, (more is taken than what can be replaced)
The depletion of natural resources and efforts to conserve these resources
Are often the source of conflict within and between political parties and countries
Impacts of extraction, transport and processing of renewable natural capital
May cause damage making the natural capital unsustainable
Non renewable natural capital
Resources that exist in finite amounts on earth and are not renewed or replaced after they have been used or depleted
Non renewable resources include:
Minerals, soil, water, fossil fuels, and aquifers
As the resource is used
Natural capital or stocks are depleted. New sources of stock of alternatives need to be found
Depending on your source of drinking water, where you live, and annual rainfall
Water might be considered renewable natural capital (where rain is collected and used for drinking) or nonrenewable (drier regions where aquifers refill slowly)
Some resources are both renewable and nonrenewable
EG: Iron ore - it is non renewable but the iron extracted from the ore becomes renewable
The importance of types of natural capital….
Varies heavily over time. EG: something in the past might not be use, something might not be useful in the future
Out use of natural capital depends on….
Cultural, social, economic, environmental, technological, and political factors
Examples of our use of natural capital:
Technocentrists believe new discoveries will provide new solutions to old problems, arrowheads made from flint rocks are no longer in demand, uranium is in demand for raw material fro nuclear power bu fission but may not be if we harness the energy of nuclear fusion
Examples of changing value of natural capital:
- Cork forests (Losing their value of natural capital to humans so land is used for other purposes and trees are chopped)
- Lithium (A lot more common now used in phones, cars, tablet batteries. Annual production of it is not enough to power all electric cars if they were to replace petrol cars)
Two main categories of the valuation of natural capital:
Use valuation and non use valuation
Use valuation
Natural capital that we can put a price on
Use valuation examples:
Economic price of marketable goods, ecological functions eg: water shortage / gas exchange in forests, recreational functions eg: tourism / leisure activities
Non-use valuation
Natural capital that it is almost impossible to put a price on
Non-use valuation examples:
If it has intrinsic value (the right to exist), If there are future uses for it that we are unaware of (science, medicines, potential gene pool) If it has value existing for future generations - existence value (eg: amazon rainforests)
Many people believe that the only way to make importance of non valued things
Is to place a price on them, when others believe they would just be exploited
Agriculture is only sustainable if….
Soil fertility and structure are maintained and the environment is not degraded. Biodiversity also can not be lost
Sustainable method of agriculture
Slash and burn (shifting cultivation) or sporadic logging in a Virginia forest are sustainable os long as the environment has time to recover
Adequate recovery time
Is dependent on low human population densities
Balance of global urban to rural population
50% of the population are now in cities, it is predicted that this will reach 70% by 2050
Cities are not that unsustainable because….
Transport costs a re reduced, as people live in smaller spaces, less energy to heat or cool us used
Why cities are highly unsustainable….
Mainly because cities need to remove their waste and process it, and need a large area of land to supply residents with food, they also create pollution, encroaching on and degrade natural habitats
Globalisation has been facilitated by:
New technologies
Globalisation
The concept that every society on earth is connected and unified into a single functioning entity. Connections are mostly economic but allow easy exchange of services, information, goods, and knowledge
Globalisation is not
Internationalism. It is supposed to see the world as a single unit, not recognising differences in culture/society. It is positive and negative (P: more awareness, N: awareness of what we do/don’t have)
Products are traded on a global scale
Referred to as the “global market”
Sustainability
The use and management of resources that allows for full natural replacement of the resources exploited and full recovery of ecosystems affected by their extraction and use
Four services provided by natural capital
Provisioning, regulating, cultural, supporting
Provisioning services
Providing sources which are then needed in production (food, fresh water, finer, biochemicals)
Regulating services
Regulates ecosystem processes eg: decomposing organic waste, climate/disease/water regulation, pollination, water purification
Cultural services
Giving meaning to a place eg: providing benefits of a spiritual, recreational nature, educational, cultural heritage, inspirational, aesthetic, ecotourism, sense of place
Supporting services
Regulate processes fro all other ecosystem services
Three characteristics that make an ecosystem service critical
Non substitutability, irrevocable loss (if degraded beyond a certain level, skippy could not be retained), high risk (to human well being)
Research usually
Determines which parts of natural capital are critical
Natural capital should be more controlled and used sustainable because….
The use of natural capital for the production of human artefacts is essential for our survival and well being
Destruction of natural capital is….q
A large fraction of our economic activity
Sustainable scale is exceeded for an ecosystem service….
When the rate of resource depletion reduces the capacity of natural capital
Intrinsic value
The inherent worth of something independent to fit value to anyone else
Carrying capacity
The maximum number of species of load that can be sustainable supported by a given area
To estimate carrying capacity of a specific environment or species….
Look at living requirements for specific species and compare this to the resources available
Lack of resources is a problematic case….
Of human populations for a number of reasources
Humans tend to…. (Lack of resources)
Substitute resources with something else if we run out. EG: we burn coal rather than wood, solar energy rather than oil, eat one thing if there is scarce supply of another
Humans use a wider range of….(Lack of resources)
Resources in comparison to other animals. It is not just estimating consumption, but also space for housing
Depending on lifestyle, culture, and economic situation…. (Lack of resources)
Resource use is varied from person to person or by country. This is also different with age. More money, more demand, less resources
We import resources in order to…. (Lack of resources)
Fix the problem of maybe running out. We import because we are unable to only rely on our local environment and therefore can’t measure whether we actually have enough for the population
There are constant developments…. (Lack of resources)
In technology, which leads to changes in the resources we use. Machines are becoming more efficient, so we might end up exploiting more resources if supply is produced faster
Importing resources increases….
Carrying capacity for the local population, this does not effect global carrying capacity because earth is a closed system with finite resources
Reasons why it is difficult to get an accurate estimate of a population’s carrying capacity:
Fossil fuels required for resource transportation, if the environment becomes degraded by soil erosion productivity is effected
Ways to reduce human carrying capacity (Ecocentrists)
Reduce use of non renewable resources, minimise use of renewable resources, become more self sufficient (greywater recycling, growing their own food, use of solar cells)
Ways to change human carrying capacity: Technocentrists
They might believe through technology there will always be enough of everything for everyone, using remaining oil twice as efficiently to double the time it will last, increase efficiency of technology or economically, measuring population (Limitation: not sustainable / long term)
Humans can reduce their environmental demands
Therefore, carrying capacity by reducing, reusing, reeling, and remanufacturing and absolute reductions in use of energy and materias
Reuse
When an object is used more than once (furniture, drink bottles, second hand cars)
Recycling
An object’s material used again to make a new product (plastic bags making fence posts of fleeces, melting aluminium takes a fraction of energy)
Remanufacturing
Object’s material is used to make a new object of the same type. (Plastic bottle old to new)
Absolute reduction
Using fewer resources (less energy, less paper)
Advantages of reductions of resource use
Are often eroded by population increase
Changes in birth and death rates
Do not change carrying capacity - as it is what land can provide
Limits to human carrying capacity
So far predictions have been wrong, and human carrying capacity may continue to increase, some believe famines in Africa are the sign of things to come
Ecological Footprint (EF)
An ecological footprint is the area of land and water required to support a defined human population at a given standard of living
In 1996….
Two researchers in Canada published a book on EFs and their calculation, allowing it to become more globally accepted
An Ecological footprint is a model….
That is used to determine the demands that a human population places on an environment. It takes into account land area, and water required. In addition to assimilation of all waste
When the EF is greater than available to the population
It shows how the population is exceeding carrying capacity and shows records of sustainability within the global population
EFs tend to vary….
Within each country or by person because of everyone’s different cultures, beliefs, economics, and lifestyle choices
EFs tend to include:
Lifestyle choices (EVS), productivity of food production systems, land use, industry
In 2012 the global EF was
1.5 earths, so humanity would take 18months to regenerate a year worth of resources
We have been in ecological overshoot
Since the 1970s, showing that our demand goes way beyond the natural supply
Humans exceed their carrying capacity by several means, including:
Trade and importation of resources
If we all shared equally, there would be
1.8 hectares available per person (1.3 not including productive marine areas)
EF of a country is based on several factors:
Population size, price per capita (how many people and how much land each one uses), cropland, area to grow food, graze animals, produce wood, dig up minerals, biofuels, area of land to absorb waste
Creditors (EF)
Have smaller footprints than their biopacity
Debtors (EF)
Have larger footprints by the changing sizes of countries in population
The earth is a
Closed system (there is no throwing away)
Bettors (EFs)
Could be harvesting resources in their countries which using unsustainable methods - importing goods, exporting wastes
Landfill
A site for the disposal of waste materials by burial and the oldest form of waste treatment
Landfill disadvantages
Potential to pollute surrounding soil or groundwater with toxins which build up over time, leachate is produced from the breaking down of waste forming toxic liquids, it takes many years for landfills to decompose
Landfill advantages
Cheap, out of the way of most of the population, lined with plastic liners, digest organic compost, Methane is collected and Produces renewable gas and electricity, leachate is collected in pipes, land can be reused afterwards
Incineration
The destruction of waste material through bringing, during the combustion of waste, the energy recovered is converted into gases, particles, and heat. The gases are then treated for pollutant extraction before they are emitted into the environment
Incineration advantages
Take up a lot less space, population is able to gain something from it such as electricity and heating, good for places with limited space, ash can be used for the construction of roads,
Incineration disadvantages
Flue gases produced contain residues that pollute the environment, the amount of energy produced is only limited, incinerated waste produces ash that contains toxins
Plasma gasification
An extreme thermal process in a plasma laser which reaches 25000 Fahrenheit to convert organic matter or waste into syngas or synthetic gas
Plasma gasification advantages
Clean destruction, produces “slag” which is used for construction purposes, works to produce no harmful toxins
Plasma gasification disadvantages
Costly, human health issues, operational costs high, large initial investment, frequent maintenance, less syngas production as a result of wet feedstock making higher energy consumption, little or negative net energy production
Recycling
To treat or process used or waste material to make suitable for reuse
Recycling advantages
Protects the environment, reduces consumption of energy, reduces pollution, alleviates global warming, promotes sustainable utilisation, cost efficient, the more people the recycle, company packaging costs reduce
Recycling disadvantages
Expensive, some wastes can not be recycled, technological push needed, hard to seperate what is and is not recyclable before the process begins
Ocean dumping
Deliberate disposal of hazardous wastes at sea from vessels, aircraft platforms, or other human made structures
Ocean dumping advantages
Convenient, inexpensive, source of nutrients
Ocean dumping disadvantages
Ocean overburdened, destruction of food sources, killing of plankton, desalination
Solid domestic waste
Our rubbish, garbage, and trash form residential and urban areas - combining paper, plastic, paint, textiles, electronic waste, old batteries, food, organic materials, packaging, glass, dust, and metals, collected from homes and shops
SDW creates
5% of our total waste including agricultural and industrial waste, SDW is waste that can be controlled by the population
People in LEDCs
Tend to produce less SDW than within MEDCs
Biodegradable waste
Food waste, paper, green waste
Recyclable SDW
Paper, Glass, Metals, Some plastics, clothes, batteries
Waste electrical and electronic equipment- WEEE
TVs, phones, computers, fridges
Hazardous SDW
Paint, chemicals, light bulbs
Toxic SDW
Pesticides, herbicides
Medical SDW
Needles, drugs, syringes
Inert SDW
Concrete, construction waste
Mixed SDW
Tetrapaks, plastic toys
In many LEDCs
There are entire industries to collect SDW, families live on and around the landfills so they can trawl through waste arriving from another city. People travel round residential areas going through communal bins
Types of solid waste
Industrial, household (municipal), and biomedical
The global economy is produced on the unsustainable premise of…. Linear economy
Take, make, dump. Take the raw materials, use energy to make goods, and then we dump them for replacement. This is unsustainable as we cannot rally throw things away
The circular economy model that is sustainable, aims:
- Be restorative of the environment
- use renewable energy resources
- eliminate or reduce toxic wastes
- eradicate waste through careful design
Anaerobic digestion
When biodegradable matter is broken down by microorganismo in the absence of oxygen, the methane produced can be used as fuel, and the waste is used as fertiliser or soil conditioner
Domestic organic waste
Can be composed or put into biodigesters. Can be done at home, or at large scale plants. Collects home organic waste, breaks it down to produce fuel, fertiliser, methane (biogas)
Process of pollution
Human activity producing, release into environment, impact of pollutant on ecosystem
Ways to alter human activity
Reduce packaging, reuse, compost organic matter, recycle goods
Ways to control release of pollutants
Seperate waste into different types, legislate about waste separation, educate for waste separation, tax disposal items
Clean up and restoration of damaged systems
Reclaim landfills, Incinerate SDW for energy, collect plastics (from great pacific garbage patch
Selecting the best SDW management strategy
This can be influenced by financial resources, politics, acsess ability, culture etc
