population and environment final

population definition

amount of people in a defined area

what is distribution

how populations spread globally/regionally

what is density in terms of population

measurement of popualtion per unit area

how can technological advancements affect population distribution

improves quality of life so acts as a pull factor

what are examples of societal advancements

ends of wars

hygiene improvements

medical discoveries

how has the global population changed since 1960

it has increased

what type of areas are the most densely populated

urbanised

by how much has food production increased globally in the last 50 years

tripled

which continent consumes the least number of calories

africa

which continent has seen the most rapid increase in food consumption

asia

what is a physical input in an agricultural system

give examples

Any condition or factor that influences the system

• climate factors (sun/rain)

• soil (mineral content/saturation)

• location (altitude, relief)

• pollution

examples of human inputs into agricultural systems

farming machinery

fertilisers and pesticides

seeds and livestock

labour

examples of useful outputs from agriculture

foods crops

other crops (silk, cotton)

animal produce

excess products to sell/trade

examples of losses/other outputs from agriculture

unused wasted food

losses in natural disasters (eg droughts, floods)

examples of reusable outputs and products from agriculture

profits from selling goods

manure as a fertiliser

what are the two main variables in population (demographics)

age and sex

what is the dependency ratio

the proportion of dependant people to economically active

(typically under 18 and 65+)

what is the demographic dividend

The economic growth potential when a country has a larger working population (18-64)

than dependent populations - children/elderly

what is the replacement level

the level which states the number of births needed to replace the number of deaths

what is sub replacement fertility

when birth rates fall and dont meet the replacement level

what is societal population control

creating policies to artificially alter the population

Example of societal population control

China’s 3 child policy 2021 to cope with ageing population

contraception and education

emancipation of women

societal/cultural norms

what occurs in stage 1 of the DTM and why explain

High fluctuating birth and death rates

Due to high levels of disease and famine

The population remains low as birth rates don’t exceed death rates

what occurs in stage 2 of the DTM and why explain

Death rates decrease and birth rates are high

Due to advancements in healthcare, hygiene and general living standards

There’s a rapid increase in population due to high birth rates

what occurs in stage 3 of the DTM and why explain

Birth rates fall due to social change (emancipation of women, contraception, less need for large families)

Death rates continue to fall

what occurs in stage 4 of the DTM and why explain

Birth rates and death rates are low

So population growth is slow

what occurs in stage 5 of the DTM and why explain

a proposed future stage

birth rates fall below death rates causing decline in population

what are mortality rates

number of deaths over time

what are morbidity rates

the number of disease incidences/prevalence over time

where is health usually better and why

HICs as people have more money to spend on healthcare so die at an older age

what is the global distribution of communicable and non communicable diseases

NC usually higher in HICs due to lifestyle choices (smoking, poor air quality)

C usually higher in LICs due to poor healthcare available

what does the epidemiological transition model show

how the main causes of death change as a country develops

To start deaths are mostly due to high CD

As development progresses CDs decrease due to improved sanitation, medicine

Whilst NCDs increase as populations live longer - old people are more vulnerable and urbanisation causes pollution which causes lung diseases etc

what occurs in stage 1 of the epidemiological transition and why

high C diseases and low NC diseases - many pandemics and high mortality due to disease

what occurs in stage 2 of the epidemiological transition and why

NCD increases - as populations live longer old people are more vulnerable / urbanisation causes pollution which causes lung diseases

CD decrease due to advances in technology and medicine, hygiene

what occurs in stage 3 of the epidemiological transition and why

NC disease is high

C disease is low

what is the double burden of disease

CD are still common (due to poor sanitation, healthcare etc)

At the same time NCD are increasing due to lifestyle changes eg poor diet, less exercise

Usually occurs in NEEs - going through socioeconomic changes but haven’t fully solved basic health problems yet eg India

whats the definition of demographic transition

the societal change in health and morbidity causing changes in population due to changes in birth and death rates

what does it mean to have food security

having accessible, safe and nutritious food so that many people may live a healthy lifestyle

examples of strategies used to increase access to food and thus ensure food security

importing more food from foreign markets

joining trade agreements to lower costs

getting aid and relief to help when foods seriously limited

examples of strategies used to increase the amount of food available and thus ensure food security

tech advancements to produce more food or make food healthier (eg. GM crops, hydroponics)

managing farms better with training

better farming equipment

increased yield variety

how can increased efficiency of food production ensure food security

food may be more affordable for consumers if the farms expenditures are lower due to increased efficiency - they can decrease waste by harvesting natural resources and having better storage

examples of techniques used to help farming

hydroponics creating healthier and more sustainable crops (eg thanet earth - kent)

GM crops

what is an case study showing advancement in farming technology failing

The green revolution in India 1960s

agrochemicals increased the Punjab rice yield by 6x

but these contaminated the crops causing 34,000 deaths

what is the malthusian perspective

the negative view that population cant be sustained due to the earth having insufficient resources for no of people (especially as it increases) and will decline as a result

describe the malthusian model

population increases exponentially but resources only increase linearly and so malthusian catastrophe will occur

whats the projected population-environment relationship

what might need to be done to help with this

as countries grow socio-economically so will consumption of resources

eg fossil fuels are finite and so expected to run out in future so the population may need to consider investing in more renewable energy sources

whats the negative effect of technology on projected population-environment relationships

can be used to exploit the earths resources

who are the two people with positive perspective on population vs resources and what is their theory

Boserup and Simon

no matter how a large a population grows they’ll always discover new ways to sustain food supplies

(eg new tech and supplies - eg hydroponics)

what is the cause of ozone depletion

pollution which thin/create a hole in it

what is the main impact of ozone depletion on humans

more UV radiation is able to enter the atmosphere which can cause more diseases caused by UV exposure

eg skin cancer

how many skin cancer cases are linked to ozone layer depletion

90% cases are linked to UV exposure

which has increased in the 21st century

examples of conditions linked to heat stress

(strain on body when exposed to high temps - which are worsening with global warming)

heat exhaustion

hypothermia

heat strokes

what type of diseases can increase due to increased global temps

vector born diseases

the season people are at risk of contraction has also lengthened

how can an increase in global temps effect farming

and thus humans

changing conditions can cause lower yields due to poor nutrition standards - so available food may be of lower quality

low availability may also cause higher food prices - causing a lack of food for poorer people

whats the projected 2100 population

and according to who

10.2b - the UN

whats risk does mass migration’s pose for population densities of host/home countries

over population in host countries

under population in home counties

what can economic migration cause in host and home countries

a demographic dividend in host country

brain drain and large dependency ratio in home country

which sex is more likely to migrate then the other and what does this often cause in home countries

men

often causing women to do ‘male’ jobs in home country (eg manual labour)

how can migration effect the age composition of a home country

as younger people migrate an ageing population may occur

what is population ecology

the study of how the environment effects population factors eg

• size

• distribution

• density

• age-sex composition

what is population dynamic

the concept that population is constantly changing

what is meant by the optimum population

the ideal no of people for the environment and its resources to support

what is overpopulation

when there are too many people to be supported by the environment and its resources

what is underpopulation

when there’s too little people to fully utilise the environment and its resources

what is meant by carrying capacity

the max population that can be supported in an environment without the it being severely degraded

what is an ecological footprint

the impact of a person/community on the environment expressed as the amount of land needed to sustain their use of the earth’s resources

eg if everyone lived like me we would need 30 earths

what is the positive feedback loop of population and resources

as population increases, resource demand increases

so more resources are created/collected to support the increased demand

which increases the population

what is the negative feedback loop of population, resources and pollution

as population increases, resource demand increases

so pollution increases causing environmental degradation OR resources decline as a result of environment

reducing the no of resources available, so population decreases/stabilises

what are refugees

people forced to leave their home country and travel to another

often to flee conflict, avoid political/religious prosecution

they have been granted temp/permanent residence by the host country or the UN refugee agency

what are asylum seekers

people who’ve left their home country and are seeking asylum in another

they’re waiting to be granted residency and become a refugee

push factors

reasons migrants want to leave their country (pushing them away)

pull factors

reasons migrants wish to move to a country (pulling them towards it)

list examples of social impacts of migration on the host countries

increased multiculturalism

migrant workers often take unwanted jobs

overpopulation causing pressure on services

conflicts between natives and migrants due to negative effects of migration

list examples of environmental impacts of migration on host countries

larger workforce for environmental protection

higher demand for environmentally unsustainable resources (eg need for housing / waste / fuel)

list examples of economic impacts of migration on host countries

migrants may pay taxes

they may become dependant on the increased economy migrant workers contribute to which could cause issues if they stop coming

lack of jobs for natives if taken by migrants

list examples of political impacts of migration on host countries

host countries that accepts lots of migrants usually have strong ties created with home countries so decreased likelihood for conflict

possible political disagreements due to overpopulation causing international disputes (eg brexit to avoid free movement of migrants)

laws/policies may be introduced to limit population

list examples of social impacts of migration on home countries

relaxed pressure on services as population decreases - possible better quality of life

or more pressure on services due to less workers

people may be vulnerable to exploitation (when in host country) as theyre desperate for work

list examples of environmental impacts of migration on home countries

possibly reduce waste, fuel usage, emissions etc as they’re less people

smaller workforce for env protection and conservation (eg less waste removal workers)

list examples of economic impacts of migration on home countries

remittances sent back to home country help their economy grow - but may become dependent on them so if they stop it can be detrimental for the economy

brain drain - unskilled people are left to run the economy

list examples of political impacts of migration on home countries

relaxed pressures on services and resources can reduce criticism on the gov for doing a poor job

policies/laws may be put in place to get workforce to grow (eg encouraging migration)

what is meant by agricultural productivity

the amount of useful output (yield) in proportion to the amount of inputs

shows the efficiency of a farm

what is agricultural productivity effected by

the type of agricultural system (eg. management strategies using low inputs to maximise outputs)

climate (precipitation, temperature, humidity, winds)

quality and type of soils (some crops can only grow in certain soils)

examples of issues which can effect soils for agricultural use

over farming (eg ploughing)

erosion

water logging

desertification

low nutrients

salinisation

how does climate change effect agriculture

conditions will become unproductive causing declines in yield

• increase in extreme weather events (eg flood, drought, tropical storms, wildfires)

• rising sea levels = increased risk of floods, tropical storms

what is water erosion - soil

soils can be degraded due to water causing soil to ware away

(eg sheet erosion, rills/gullies, river bank erosion)

what can cause water erosion - soil

poor farming irrigation (controlled use of water) can cause soil to erode causing nutrients to be leached

what is wind erosion - soil

the displacement and removal of top soil due to high winds and unstable soils

what is meant by the structural deterioration of soil

loss of soils structure

what is water logging

over saturation of soil (by water) causing leaching of nutrients and minerals

what can cause waterlogging of soil to occur

too much irrigation causing too much water for roots to handle so plants cant grow properly

what is salinisation

when water tables rise the soils salts are brought to the surface

then when water evaporates concentrated salt is left at the top of the soil

what can cause salinisation to occur and what is it’s effect - soils

poor irrigation (water logging) and fertilisers

can cause decrease yield as its toxic to plants and reduces fertility

what is desertification

when fertile land becomes dry, cracked and desert like

what can cause desertification

long term salinisation

overgrazing (the protective plant cover on the soil is lost)

over cultivation (eg ploughing - causes water and minerals to be over exploited)

how can wind erosion of soil be managed

planting trees/hedges to block the wind

adding mulch to reduce dry particles

how can soil problems caused by water be managed

using terraces (hill cut into a flat steps) to redirect surface runoff

contour ploughing and diversion channels to redirect water

how can structural soil issues be reduced

moving livestock regularly to avoid trampling

what 3 things are water important for to ensure a healthy lifestyle

health

sanitation

hygiene

what can poor water quality cause

water borne diseases (eg. cholera)

caused by pathogens contaminating water supplies

ultimately leading to death

what can happen if toxins enter water supplies

they can become poisonous and kill