Overpopulation and development

Overpopulation The number of people in a region is greater than the ability of the land to support them Carrying capacity= no. of people a region can support with its basic resources

Optimum Population – no of people in a region with high standard of living given regions level of development and natural resources at any time Under population – no of people living in area cannot exploit fully the natural resources Inward migration improves SOL for all Ireland 1997-2007 – labour shortages

Causes of overpopulation High birth rates: demand on basic resources increase ie. The Sahel Migration: people forced to leave areas puts new areas under pressure ie. Darfur in Sudan Overuse of sources: resources that the population depend on becoming overused leading to overpopulation ie. Cod banks in the north atlantic

Factors to increase carrying capacity How these factors work 1. Decreasing population Reduces demand for basic resources 2. Fertilisers Increase food supply and feed more people 3. New farming methods Feed more people 4. Irrigation Raises crop yields, more water 5. Better crops/ animals 6. Land reclamation Provides new land for settlement and farming

Factors to decrease carrying capacity How these factors work 1. Population growth Raises demand for basic resources 2. Soil erosion Reduces food supply 3. Deforestation Reduces fuel supply/ increases soil erosion 4. Flooding Destroys living space and farmland 5. Overgrazing/ over cropping Damages soil and reduces food supply 6. Urbanisation Raises demand for resources/ reduces farmland 7. Climate change Makes land areas uninhabitable

Case study: The Sahel An area stretching across northern Africa 5,0000km long and 300km wide a semiarid zone extends from Senegal (west) through Mauritania, Mali, Burkino Faso, Niger, Northern Nigeria, Sudan to Ethopia.

Case study Focus on Sudan Same size as France Barren land 33% of population live in 7% of land Capitol city Khartoum Stage 2

Factors contributing to overpopulation and overuse of soils 1. Birth rate: birth rate = 33 per thousand death rate = 10.28 per thousand Population 43million Infant mortality rates= 81 per thousand ½ population under 18= HDR Led to a number of problems: Overgrazing: status of cattle Deforestation: need of fuel, manure often used (no natural fertilizer in the soil) over cultivation: use of cash crops to pay debt

Factors contributing to overpopulation and overuse of soils 2. Migration and conflict: Civil war and famine led to internal migration Since 2003 Darfur has become a human rights crisis region 120,000+ fled to Chad or to area at the east of Sudan Suffering brain drain Influx of 1milliion+ from Ethiopia

Factors contributing to overpopulation and overuse of soils 3. Environmental degradation: Global warming: increased temp and evaporation Droughts reduces food production Rainfall levels decreased by 30% over 20 yrs leading to drying of soil triggering erosion Wells drying up and droughts 1968-73, 1983-5, dug lower which lowers the water table Desertification caused by deforestation and drought cause the Sahara desert to spread southward by 10km a year

Unsustainable Farming Methods CAUSE EFFECT OVERGRAZING Cattle exceed carrying capacity Indication of wealth and importance GRASS CANNOT REGROW SOIL EROSION DESERTIFICTION OVERCULTIVATION. FARMERS ARE FORCED TO GROW CROPS ON POOR LAND THE CONTINUAL USE OF THE SOIL LEADS TO LOSS OF SOIL STRUCTURE. THE SOIL IS EASILY BLOWN AWAY BY DESERT WINDS DESERTIFICATION DEFORESTATION. TREES ARE REMOVED FOR FUEL AND TO CLEAR LAND FOR CROPS REDUCED TRANSPIRATION OF MOISTURE FROM PALNTS LEADS TO LESS RAINFALL ANIMAL MANURE USED AS FUEL INSTEAD OF WOOD. NO LONGER USED TO FERTILIZE THE GROUND REDUCED CROP COVER

OVERPOPULATION AND INCOME Areas with highest birth rates and highest levels of population growth poorer countries have a higher birth rate UN Development Programme: 1.3 billion live on less than .77 cent a day 800 million people do not get enough to eat 500 million are chronically malnourished

Effects of overpopulation Socio-economic Soil degradation Cash crops on valuable land Increasing population Farmers more sedentary Refugees not self reliant Environmental Change in rainfall patterns Conflict over water

Impact of Income levels on development UN development programme: 500 million + malnourished Poor people = larger families, economic asset High population density not sole indicator of poverty & population High income families – children an economic liability Education of women central to decline in birth rate

Income levels and development Kenya poor, mainly rural Stage 2 Population growing rapidly (fertility rates high) 42% of pop= 1-14age group Low incomes Women low social status Low quality education and health services Infrastructure poor Foreign investment weak Underemployment and unemployment high Low pop density but is overpopulated South Korea Successful economy, exports orientated Stage 4 Population growing slowly Economy developed per capita income improved High quality education and health Densely populated Modern lifestyle and a good standard of living Unemployment remains low High pop density but it is not overpopulated

Impact of technology on population: medical technology Improved access to family planning Vaccinations have been developed to cure/prevent infections ie. Measles etc Infant mortality rates decreased Some are cheap and administrated in primitive conditions by use of syringe better education more women starting families later Rate of increase not as rapid as a result

Impact of technology on population: agricultural technology Increase in food supply leads to longer life expectancy Advance Results 1. Improved fertilisers Increased yields 2. New strains of plants Able to grow and thrive in strained conditions 3. Chemicals New pesticides and herbicides allow food to thrive 4. Glasshouses Able to grow plants in artificial conditions all year round 5. Machinery Harvesters, planters, pickers gather more crops increasing yields 6. Selective animal breeding Increased meat and milk yields from each animal 7. Irrigation Brings formerly dry land into production

Ecological footprint and sustainability Ecological footprint Area of land required to feed, clothe, house Sustainability is based on the recognition that when a resource is consumed faster that it is produced or renewed the source runs out Technology can make a positive difference

GM foods & The Green Revolution Increase in food production, technology & research, 1960’s Modified for desired traits e.g. Salt tolerance Disadvantages: Expensive products and equipment Oil derived fertilisers- non renewable resource Genetic diversity reduced

Population growth and developed countries Developed countries are in stage 4 and 5 Agricultural and industrial revolution caused economic growth in Europe Tax revenue allowed for continued investment in health and education Increase in life expectancy and lower birth rate Today high standards of living , aging population and high GNP

Population growth and developing countries Stage 2 many countries experiencing high population growth 30% under the age of 14yrs Increase need of food, infrastructure, education and services Civil wars, corrupts leadership and MNC’s Not experiencing economic development in the same way that Europe did as due to unfair trading systems Migration to shanty towns – cities pop can double in 15yrs Low incomes cannot afford to invest in education and health Large families needed to provide economic security Very young age dependency ratio Population growth increase in rural-urban migration Brain drain: leave to find well paid work else where Loss slows down economic progress in country of origin

Over population impacts on society and culture in Bangladesh Poor country Primary economic activity: agriculture Population: 158 million+ 28% urban areas 1100 per km squared Causes of over population Risk of flooding Low lying delta Annual monsoon season, typhoons 1m of water floods 20% of Bangladesh land Sterilises agri land and contanimates water Infection: typhoid and cholera

Social Factors: Stage 3 Birth Rates declining with family planning 4 births per mother in 1990 but only 2.6 in 2011 Muslim: Marry young, desire for sons Adult literacy rate only 47%

Effects of overpopulation Bangladesh Migration Land scarce Rural to urban migration, lack skills, live in shanty towns Overcrowding Both rural and urban areas Shanty towns= high mortality rates Domestic servants- remittance