Dynamics of Population growth Dr. Ayesha Babar Kawish Al-shifa School of Public Health

why the population is rapidly growing There are about 7.6 billion people in the world and over 95 million babies are born per year – that is an average of three babies per second!

Population of the World

Identifying Overpopulation According to WHO, at present: 1 billion people: living in poverty 10 million people: die each year from malnutrition, starvation, and diseases from drinking contaminated water Premature deaths: 27,400 people per day Natural resources: under increasing pressure (depleting) Deterioration of the environment Are we overpopulated?

Exponential growth The human population is said to be growing exponentially. This means that the larger the population, the faster it grows. An increase in average life expectancy is largely responsible for the rapid increase in population. Why do people live longer than they did hundreds of years ago? better healthcare (hospitals, medicines, vaccines) more and better food cleaner water better sanitation The biggest increase in population is in developing nations, rather than developed nations. Why do you think is the case?

Predicting future growth rate Computer models can be used to make predictions about population growth by using assumptions about birth rate. Most analysts assume that birth rates will fall within the next 50 years. Why do you think this might happen? decreased fertility lack of resources disease war How important do you think predictions about climate change and unsustainable development are in the analysts’ calculations?

The Population “Explosion” In 2005, there was an estimated 6.4 billion people in the world according to the U.S. Census Bureau. Where 1 person stood 12,000 years ago, there are now 1067 people. Statistical projections suggest that by 2100, there will be about 1700 people.

Three main factors responsible for population rise : 1.High birth rate : child marriages, gender inequality ,ignorance, illiteracy, lack of family planning coverage, social believes 2. low death rate : modern scientific development, disease control, health care awareness, better ability to face natural calamities, conscious effort to avoid accidents, research to increase ,clean atmosphere 3.Increse life span : In 1850 census lifespan was 38 years which now has increased up to 65 years

Contributing factors : Better provision of food : Improved agricultural practices leading to few famines Better machinery Improved fertilizers Better pesticide control Health care standards : Advances in health care technology Provision of health care services

Contributing factors : Sanitation : improved control of communicable diseases Vaccination : better immunization services Standard of living Increase Immigration Decrease in Emigration Illiteracy

Is population explosion a boom or a curse? Its Boon for a developed country But, its Curse for developing country

The effect of population growth on land and resources

Air Pollution Increase in 2O C in air temperatures will be enough to decrease the rice yield by 0.75 ton/hectare. It is also estimated that a drastic increase in greenhouse gases like carbon dioxide may cause wheat production to fall as much as 68%. Additionally, the changing climatic conditions have the potential to significantly increase tropical disturbances like cyclones and storms in coastal regions

Increase in Industries & Vehicles

why indicator species are useful for assessing pollution

More people means more Air pollution In order to provide enough energy needed for all the people on Earth more fuels need to be burned to create electricity and heat. This will produce more air pollution The most common source of air pollution is the burning of gas, oil and coal. This usually happens in vehicle engines and power stations. Indicator Species can show how polluted the air is. Some species will only survive in very clear air, some can survive in polluted air. If very sensitive species such as lichen are found in an area the air is very clean, if there are no lichens on trees this suggests the air is more polluted.

Water Pollution There is no life without water. One might think that 70% of the earth is covered with water, so, why worry about the water problem? In fact, 3 sides of the Indian subcontinent is surrounded by water. And there are several rivers, lakes, and other sources of water within the country as well However the fact is that less than 3 percent of that water we see can be used for human consumption and industrial uses.

More people means more water pollution Waste chemicals are being dumped into rivers and seas. Sewage, fertilizers and toxic chemicals end up in rivers/lakes etc. Toxic chemicals such as pesticides and herbicides may be washed from land to water. Indicator Species can show how polluted the water is. If you find mayfly larva this means the water is very clean, if you can only find water snails or worms then the water is more polluted. If no water life is to be found the water is VERY polluted.

Raw sewage and industrial waste flows directed to main River or Sea

Effect of pollution Petroleum products required for automobiles, cooking, and other such human activities. Pesticides and herbicides used for agriculture by the Indian farmers. Heavy metals from industries, automobiles’ exhausts and mines. Hazardous wastes. Excessive organic matter like fertilizers and other organic matter used by farmers. Sediments caused by soil erosion produced by strip mines, agriculture and roads. Thermal pollution caused by deforestation.

Effect of pollution Over use of natural resources Increase in Food Demand Increase in waste generation Other effects like Unemployment Poverty Increase in crime rate Energy crisis Over crowding of cities Illiteracy in 1972-73, unemployment rates in rural areas were 1.2 for males and 0.5 for females, and in urban areas, it was 4.8 for males and 6.0 for females. This unemployment rate rose to 2.3 for males and 1.5 for females in rural areas and 4.9 for males and 8.2 for females in urban areas in 1998-99.

Increase in Deforestation For occupying land for day by day increase in population . For Agriculture For Urbanization

Using resources and producing pollution minerals buildings, farms, quarries and dumps Humans use land for Building Quarrying Farming Dumping We pollute the WATER – with sewage, fertiliser, toxic chemicals AIR – with gas such as sulfur dioxide and smoke LAND – with pesticides and herbicides (these can be washed into the water) use more raw materials fossil fuels use more land use more energy more people produce more waste and pollution pesticides and herbicides sewage, fertilizer and toxic waste CO2, SO2, CO and smoke

Consequences of Rapid Population Growth Economic Consequence Social Effects Political Effects Consequences for Education Health, Welfare and Child Development Environmental Deterioration Security Problem Rapid Population Growth

More People = Less Land Available More people require extra housing and amenities this uses up more land. Mining and quarrying uses up large areas of land in order to access the resources such as gravel, metal ores and diamonds. Large populations of people require large quantities of food. We use billions of acres of land in order to grow enough food and crops for human use. Large populations produce large quantities of waste which is stored in landfill sites. These large quantities of waste contribute to pollution of land, air and water.

More People = More Resources Used Up With increasing population the demand for resources is and raw materials is rapidly rising. As raw materials are only in a limited supply eventually they will run out and cannot be replaced. Fossil Fuels including oil, natural gas & coal Metal Ores Building Materials As people use more resources, more waste is produced. All this waste is polluting the Earth: House hold waste piles up in landfill

Overall View: In the 20th century, human population has grown much faster than before. Between 1950-1990---population crossed 5 billion mark i.e., 92 million every year In 2000 the world population was 6.3 billion and predicted to grow 4 times in next 100 years 2016: 7.4 billion 10 billion: 2060

Important Views On Population Growth Malthusian theory: Human populations tend to grow at an exponentential rate where as food production tend to very slow growth. Starvation, poverty, disease, crime & misery expected For stabilizing the population growth we need “positive checks” – famines, disease outbreak and violence “preventive checks” – birth control systems

Rapid Population Growth “There is a natural urge for people to reproduce and that population has a constant tendency to increase.” Thomas Malthus, was an English cleric and scholar, influential in the fields of political economy and demography. Malthus himself used only his middle name Robert. Rapid Population Growth

Marxian theory –karl Marx Population growth – a symptom rather than cause of poverty, resource depletion ,population and other problems Social exploitation and oppression of the less privileged people leads to poverty, unemployment, environmental degradation and in turn cause over population.

Migration happens because of push and pull factors Push factors are the things about a persons place of origin that make them decide to move. Pull factors are things about a persons destination that attracts them to it. Example Push factors Example Pull factors Not being able to find a job. Poor living conditions. Natural disasters Job opportunities Better standards of living

Migration has positive and negative impacts Positive impacts Negative impacts Source country Reduced demand on services e.g. schools and hospitals Money is sent back to the source country by emigrants Labour shortage- its mostly people of working age that emigrate. Skills shortage – sometimes it’s the more highly educated people that emigrate. Ageing population- there's a high proportion of older people left Receiving country Increased labour force- young people immigrate to find work. Migrant workers pay taxes that help to fund services Locals and immigrants compete for jobs- this can lead to tension and conflict. Increased demand for services e.g overcrowding in schools and hospitals Not all the money by immigrants is spent in the destination country- some is sent to their country of origin.