Topic 8 - ESS answers

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1 Topic 8 - ESS answers Page 352 Years Population Doubling time billion 123 years billion 47 years billion 50 years Page and 2. Region Popn 10 6 Land area km Births Deaths CBR / /year CDR / 1000/year Natural increase rate Popn density / km -2 World 6, Asia 3, India 1, Africa Tanzania Europe Switzerland N America USA Asia and India have very similar rates with CBR 25.2 and 29 respectively and CDR 8.4 and 10 respectively. Africa on the other hand has significantly higher CBR (42) but a slightly higher CDR (13.7). Generally speaking death rates have come down due to the intervention of organizations such as the WHO, UNICEF etc. Such bodies have decreased CDRs through: vaccination campaigns to wipe out the commonest killers measles, mumps etc., etc. improving sanitation condition health and hygiene education to raise awareness about the spread of disease anti-malaria campaigns improvements in water supplies. Asia and India have become aware of the pressures of large families and have started campaigns to reduce their CBRs. Africa has not followed suit and they remain very traditional in their attitudes to children. In many African countries: children are and economic asset not a cost: they work the farms they do not go to school they are a safety net for old age no pension there is no contraceptive available very traditional attitudes to women keep the women pregnant and raising children the expectation that IMR is high means couples have lots of children to make sure some survive the need for a male heir. 1

2 Page Population of the Earth number of people living worldwide since 1700 in billions world population in billions year Source: United Nations world population prospects, Deutsche Stiftung Weltbevölkerung years. 3. Date Population Doubling time (yrs) Date Population Doubling time (yrs) , Page in billions % in billions % LEDC MEDC Allow the three answers below or any other reasonable arguments. We don t know exactly how many people are alive today in all countries of the world not all have accurate censuses. Global catastrophic events wars/natural disasters/epidemics of diseases may alter predictions a lot. As we overshoot the ability of the Earth to provide resources (food, water, space) for humans, we will have to reduce population growth or reduce resource use. 3. According to Malthus the limiting factors are food. This is no longer the case as modern technology has increased agricultural production and on a global scale we have plenty of food. The green revolution, the blue revolution, hydroponics and aquaponics have all increased food production beyond what was once thought possible (Boserup s ideas). Space could be a limiting factor but again we have solved that problem with high-rise buildings increasing living densities. Though if global warming continues and sea levels rise this may become a limiting factor. Clean air and clean water may become limiting factors as humans pollute these two resources they may run out. 4. Other Asia (not including China, India or Indonesia) is approximately 15 20%. Including China, India and Indonesia it is approximately 60 65%. 2

3 Page Model diagram Malthus food required Boserup Malthusian trap quantity of food T food produced quantity of food food supply total population Main ideas Limitations Applications time Claimed that food supply was the main limit to population growth. Human population increases geometrically (i.e. 2, 4, 8, 16, 32, etc.). Food supplies can grow only arithmetically (i.e. 2, 4, 6, 8, 10, 12, etc.). Food production limited by available new land. Laws of nature dictate that a population can never increase beyond the food supplies necessary to support it. Beyond the ceiling where land is used to its fullest extent, over-cultivation and, soil erosion occurs, contributing to a general decline in food production. Population increase is limited by checks. Too simplistic food is not the only resource we have to worry about. Does not apply across the whole population only the poor go hungry! The world s community is not closed (except globally) so imports and exports distribute food. Recent evidence shows food supplies do not just grow arithmetically. On a global level the growing suffering and famine in some LEDCs today may reinforce these ideas. t 1 time Necessity is the mother of invention. She asserted that an increase in population will increase the demand for food and so act as an incentive to change agrarian technology and produce more food. Population increase drives development. Based on a closed community only applicable globally. Out-migration occurs to relieve population pressure. Overpopulation leads to unsuitable farming practices so does not lead to development. At a national scale, some governments have been motivated by increasing population to develop their resources and so meet growing demands. 3

4 2. (i) Although the food supply is increasing it is not increasing fast enough to keep pace with the increasing population so per capita food supply is decreasing. (ii) index (1989=100) Index of total and per capita food production, India population 100 per capita total (iii) This could be argued either way: population (10 9 ) Malthus as it shows that the availability of food is falling; the per capita line drops below the total amount of food. Boserup it shows that as population increases food production is increasing. This is a weak argument though as it is not increasing enough to feed the growing population. LEDC MEDC years 4. Status of women Attitudes towards family planning and contraceptives Education of women Page 362 a) Women are viewed as the homemakers, men earn the visible income and can be independent and make decisions. Fewer educational opportunities for women. Fewer opportunities for women to be part of the communal decision making. Discrimination in the job markets. b) Educate women and girls (and boys). Free contraceptives and family planning. Micro finance for women. Job opportunities for women. Anti-natalist government policies. 4

5 Taxes on large families. Reduce free education/health care for more than 2 or 3 children. Encourage rural urban move. Reduce IMR. Increase the legal age of marriage. Introduce effective pension schemes. Legalize abortions. c) Women may: understand how to control their own fertility be more able to get a job outside of the home less time for family go into further education so marry later gain independence so have more say in family planning. Page 363 Population pyramids 1. Birth rates Death rates Life expectancy (LE) Infant mortality rate Death rates at various ages Ratio of males:females and comparison of death rates Difference in LE between male and female 2. Increased birth rates Proportional drop in IMR Drop in death rates Increase in LE in women 3. male Afghanistan: Aged population (over 65) Working population (15 65) Youthful population (under 15) The dependency ratio: population (in millions) female under 15 years old are at school and dependent on the working population over 65 year olds retire and are dependent on the working population working age

6 4. Two or more of the following. China s one child policy. Availability of contraception. Urbanization. Mechanization of agriculture. Opening up of China to western influence and free market economy. High cost of raising children so parents prefer to have one only. Page 365/6 1. Stage 1. Expanding 2. Expanding 3. Stationary 4. Contracting Birth rate High High Falling Low Death rate High Falling Low Low Life expectancy Low Low but increasing Higher High Population growth rate Low Increasing High Decreasing Stage of DTM Example Primitive tribes Afghanistan Costa Rica USA 2. Amazonia India High Low in the younger age groups (up to 30) then increases Thailand Laos Malaysia Most of Europe Birth rate Death rate Life expectancy Gender differences Stage of development Reasonably good More males born than 2 maybe going some live to 89. females. in to 3 Low and falling for around 20 years Italy Very low falling for last 40 years Brazil United States High but has been falling for 30 years Pretty high but falling/ fluctuating for last 50 years Starts to increase above 50 Low: does not increase until after 80 Fairly low with small drops between age groups up to 30 Low up to 65 then increases Reasonable many in the 80+ group but no bars above that High bars go up to 100+ Reasonable many in the 80+ group but no bars above that Medium with bars up to 85+ but none above that Males have high DR in younger years (under 20) Very slight difference in BR with males higher. Better survival of females with greater numbers over 75 Very slight difference in BR with males higher. Lower DR of women between 50 and 70. More women from but none over 100 Great life expectancy for women Much better life expectancy for women (over double the number of women over 85) 3 4, maybe

7 Page 367 Go to the UN Economic and Social Affairs office website wpp/unpp/panel_ population.htm This web address has changed to and this website has changed so the questions are not possible to answer as they stand. Ask students to answer the questions changing 2050 to 2030 where appropriate. 1. Using the basic data and median variant, find the data for the following: a) 8,424,937,470 b) 1,293,904,870 c) 7,131,032,600 d) Less developed 84.6% More developed 15.3% e) Less developed 6,065,194,070/7,324,782,220 = 82.8% More developed 1,259,588,150/7,324,782,220 = 17.2% f) Population in less developed parts of the world as a proportion of total world population is slowly rising. Population in more developed is decreasing as proportion of total world population. 2. a) More =- 1.71, = 1.78 Less = 2.56, = 2.45 b) Less developed, higher number due to desire for larger families perhaps due to infant mortality/ need for offspring to look after older parents/ lower level of education of women. c) More rate about 0.2%. Less rate over 1%. Higher in less developed by about 5 times so population increases rapidly. d) Both falling due to better health care so population increases as people live longer. e) Both increased. 4. Validity depends on quality of the data possibly more accurate in more developed regions. Model basis could be flawed. Real world could change so model has to keep up with developments. Useful to help predict demand in each country for schooling, medical services, workforce etc. Help governments plan ahead. Page Low BR that has been falling for about 10 years. Medium DR with small drops between age groups. Good life expectancy with people in the 80+ age group and more women than men at that age. 2. It is going into stage three (maybe late stage 2). 3. Significant drop in the BR due to the fact that the age groups affected by AIDS are not only the workers but also the child-bearing ages. Less people in the means lower BR. Far more women above 65 years old as this is the age group ahead of the AIDS epidemic and women generally life longer than men. 7

8 More men in the working ages probably due to an influx of migrant workers to fill the jobs of the local population who dies from AIDS year-old women are low in number with the men in the family gone many women will have turned to prostitution to earn a living many will have died from AIDS. 4. By 2050 it is possible that the worst ravages of AIDS have more or less worked their way out of the population and thus the pyramid. High preponderance of women in the 80+ age group the ones not affected by AIDS. Low number of women in the age groups many lost due to AIDS spread by prostitution. Falling BR due to awareness of contraception. Page 375 Uranium s uses: Main fuel for nuclear reactors. Raw material for nuclear weapons. Powers nuclear submarines. Dense mental used as ballast in ships and counter weights in aircraft. According to Uranium-Mining-Production/ the top uranium mining countries are: 1. Kazakhstan 2. Canada 3. Australia 4. Niger 5. Namibia 6. Russia 7. Uzbekistan Uranium s use as natural capital: 8. USA 9. China 10. Malawi 11. Ukraine 12. South Africa 13. India 14. Brazil 15. Czech Republic 16. Romania 17. Pakistan 18. Germany 19. France uranium is a non-renewable resource so it can never be used sustainably it is only used in small quantities so has a long life expectancy. Page Fairtrade s vision is a world in which all producers can enjoy secure and sustainable livelihoods, fulfil their potential and decide on their future. Reduce poverty. Empower people to take control over the work and their lives. Secure access to mainstream markets. Gain widespread support for Fair Trade. 2. It is a global organization that is working to secure a better deal for farmers and workers. Fairtrade International is the organizationthat coordinates Fairtrade labelling at an international level.from our offices, in Bonn, Germany, we set international Fairtrade standards, organize support for producers around the world, developglobal Fairtrade strategy, and promote trade justice internationally. 3. A number of possible answers, of which these are three of the best known: Cadbury, Ben and Jerry s, Tate & Lyle. 8

9 4. a) They gain a minimum price that covers the costs of sustainable production. Gain the Fairtrade Premium paid on top of the price and used to improve the community. They are involved in the decisions about prices, premiums standards and strategies. Small farmers and their workers are supported. b) Shoppers can buy products that are in line with their principles. Page 391 Prices may be higher than other products. Landfill Incineration Recycling Advantages Initial cost is cheap Methane can be collected and used to generate electricity Only takes up a limited amount of space Reduces waste to a minimal amount Can be used to produce electricity Ash can be used in road construction Reduces amount of waste into landfills and incinerators Reduces the use of new raw materials Disadvantages Have to be lined to prevent leachate = expensive. Attracts pests and vermin Smells Visual pollution Running out of sites Location is very difficult very specific requirements Can be a long way from centers of population uses a lot of fossil fuels to get waste there Problems with subsidence Expensive to build and operate Requires a lot of energy to start up burning so needs to run 24/7 Must be maintained properly and regularly Visual pollution Air pollution can be toxic Can have locational restrictions Waste stream may have to be sorted and separated Waste must be washed Kerbside sorting requires several collection trucks uses a lot of fossil fuels Not all materials are recycleable Population has to be educated about the need for recycling Industries need to be in place to use/deal with the recyclables 9

10 Page 395/6 Reasons for high EF A lot of land is built on: cities transport networks factories and industry waste treatment facilities power plants Energy demands are very high Private cars Flights High electricity consumption Productive land usage Large scale extensive arable farms High calorie intake eat lots High meat intake Pollution Limited use of renewable energy sources Lack of adherence to laws controlling pollution Consumerist societies Have MANY products Technology keeps replacing old models Want new things every year Labour-saving devices Reasons for low EF Limited built land: smaller buildings lower standard of living requires less resources Energy demands are low Private cars are limited Very few people fly Electricity consumption is low Replacing fossil fuels with renewable energy Productive land Small-scale intensive subsistence farms Consume less food/subsistence agriculture Consume far less meat Pollution Reduce emissions laws Recycling, reuse of resources Technological improvements Fewer material goods Page High wheat consumption bread-/pasta-based diets High meat-based diet grain-fed cattle 2. Africa has subsistence agriculture most of the grain is produced locally on small-scale intensive farms as the per hectare amounts are high. North America has extensive commercial agriculture most grain is grown on very large-scale farms with low productivity per hectare. 3. North America is more dependent on fossil fuels because extensive farms use a lot of machinery to plant and harvest the crops and then move them to market. 4. Africa has much higher CO 2 fixation because there will be a large amount of natural vegetation around the farms, that grows all year so fixes nitrogen all year. North America will have less natural local vegetation so when the crops are harvested there will be long periods of time when there is little or no CO 2 fixation. 5. Food land CO 2 absorption Africa = = 0.03 North America _ = =

11 6. MEDC city would have a higher EF because of: greater use of electricity in homes labour-saving devices, heating / cooling appliances great energy footprint due to higher use of private transport more meat-based diets more imported products. 7. It means that Singapore is using 264 times more land than it actually has in order to provide it with resources and absorb its wastes. 8. An increase in the number of people with a vegetarian diet would reduce the EF. With a vegetarian diet we eat at lower trophic levels so less energy is lost (2nd Law of Thermodynamics) and more is available for our consumption. In commercial pastoral farming land is used to house the animals and more land is needed to grow the crops to feed them. If less people eat meat less land will be taken up = lower EF. Page 399 a) It is very difficult to define because our relationship with the resources we use is not straightforward. Carrying capacity is the maximum number of a species or load that can be sustainably supported by a given area. Humans can increase carrying capacity by [any two of the following]: Importing goods. Substituting resources. Making more efficient use of resources through technological improvements. Technology: improves agricultural yields green, blue revolution, aquaponics, hydroponics facilitates high density living enables use of renewable energy resources. b) Define and give examples of reuse, recycling and remanufacturing. How can these lead to an increase in human carrying capacity? Method Defined Example Increase in CC Reuse The object is used more than once. Reuse of soft drink bottles (after cleaning). Recycling The object s material is used The use of plastic bags to again to manufacture a make plastic fence posts for new product gardens or fleeces to wear. Remanufacturing The object s material is used to make a new object of the same type. Manufacturing of new plastic (PET) bottles from used ones. These mean you are not taking more resources but the old ones are used over and over again (to a point). BUT it can be argued that the fossil fuels for collection/ delivery and for cleaning and redistribution could also decrease CC. 11

12 c) Two possible answers. As technology develops it can: 1. Increase resource use and decrease carrying capacity. This is because of: OR agricultural technologies for irrigation/fertilisers/pesticides using up more resources; fossil fuel dependent technology increasing CO 2 waste in use/production; increasing demands for resources used in manufacture of technology; pollution produced by use/manufacture of technology requiring more waste assimilation; reducing limits to population growth thereby increasing demand for resources/ waste assimilation; promoting rapid turnover of technologies/consumer market that increase rate of resource consumption/waste production. If carrying capacity decreases so should the population because there will be higher demand for resources and Malthusian feedback may start reducing population growth. 2. Decrease resource use and increase carrying capacity. This is because of: agricultural technologies for irrigation/fertilisers/pesticides increasing productivity (per unit area); increased productivity of genetically engineered crops; technology for hydroponic agriculture requiring less resources; increased energy efficiency (reducing CO 2 waste); alternative energy sources (e.g. wind/solar/etc.) (reducing CO 2 waste); hybrid/h-fuel vehicles reducing CO 2 waste; technology to harvest energy/recycle materials from waste; technology to capture/store carbon waste. d) Many countries have anti-natalist policies in place to decrease population size China s One Child Policy is probably the most famous one. Cultural changes that cause a decrease in population: Gender equality as soon as women become educated and are given equal rights (jobs, decision making, inheritance rights) they can start to control their own fertility. Changes in attitudes about the women s place being in the home when women are no longer seen only as the home maker fertility decreases. Getting away from the idea that children are an economic asset when children become expensive the birth rates drop. Getting way from the need for a male heir. Getting away from the concept that many children somehow proves a man s virility. Quick review questions 1. A 2. C 3. D 4. C 5. B 6. C 7. C 8. B 12