Chapter 7

The Human Population

The human population underwent exponential growth in the 1800s mostly due to increases in food production and improvements in hygiene

that came with the industrial revolution.

The 10 Most Populous Countries in the World

World 7.3bChina 1.37bIndia 1.25 bUnited States 322m- Indonesia 256mBrazil 204mPakistanNigeriaBangledeshRussiaJapan

35.89% of Global Population

4.4% of Global Population

Figure 7.2 A theoretical model of food supply and population size.

(a) In a theoretical 100-year period without significant improvements in agricultural technology, the human

population grows exponentially, while the food supply grows linearly.

Consequently, a food surplus is followed by a food deficit.

(b) In a theoretical 100-year period with significant improvements in agricultural technology, the food

supply increases suddenly. Consequently, there is a continuing

food surplus.

Malthusian prediction

Factors that Drive Human Population Growth

Demography- the study of human populations and population trends.

• Changes in Population Size

• Fertility

• Life Expectancy

• Age Structure

• Migration

Changes in Population Size

• Immigration- the movement of people into a country

• Emigration- the movement of people out of a country.

• Net migration rate- the difference between immigration and emigration in a give year per 1,000 people in the country.

Changes in Population Size

• Crude birth rate (CBR)= the number of births per 1,000 individuals per year.

• Crude death rate (CDR)= the number of deaths per 1,000 individuals per year.

• Global population growth rate = (CBR- CDR)/ 10

• National population growth rate =

(CBR+ immigration) - (CDR + emigration)/ 10

• Doubling time (in years)- 70/growth rate

Fertility

• Total fertility rate- an estimate of the average number of children that each woman in a population will bear.

• Replacement level fertility- the total fertility rate required to offset the average number of deaths in a population and for the current population size to remain stable.

US Total Fertility Rate

Adolescent Fertility Rate (per 1000) ages

15-19, from 2000-2010

World Health Organization Map Production: Public Health Information and GIS. 2011

Life ExpectancyThe average number of years that an infant born in a particular year

in a particular country can be expected to live, given the current average life span and death rate of that country.

NOTE: New Jersey “historic” population life expectancy was < 50 years at birth

Infant and Child Mortality• Infant mortality rate- the number of deaths of children under 1

year of age per 1,000 live births.

• Child mortality rate- the number of deaths of children under age 5 per 1,000 live births.

NOTE: These are deaths for < 1 year of age. The New Jersey “historic” population had fewer than 200 deaths for < 10 years of age.

The human population underwent exponential growth in the 1800s mostly due to increases in food production and improvements in hygiene

that came with the industrial revolution.

The Demographic TransitionThe theory that as a country moves from a subsistence economy to

industrialization and increased affluence, it undergoes a predictable shift in population growth.

Model of the general pattern of demographic change from high birth and death rates to low birth and death rates,

observed in the history of more-developed

countries.

Stage 1 – Preindustrial: Population rate is stable due to high br & dr

Stage 2 – Transitional: Rapid population growth; high br, but dr decline due to improvements in sanitation,

hygiene, nutrition, and health care.

Stage 3 – Industrial: Stable population growth; economy & education improves, fewer children

Stage 4 – Postindustrial: Population declines; the birth rate drops below replacement level due to affluence and economic development that encourage women to delay having children

Recap:The Stages of the Demographic Transition

• Phase 1: Slow population growth because there are high birth rates and high death rates which offset each other.

• Phase 2: Rapid population growth because birth rates remain high but death rates decline due to better sanitation, clean drinking water, increased access to food and goods, and access to health care.

• Phase 3: Stable population growth as the economy and educational system improves and people have fewer children.

• Phase 4: Declining population growth because the relatively high level of affluence and economic develop encourage women to delay having children.

Population Reference Bureau, 1990

Demography from 1775-1990, according to available information

Developing countries appear to have much larger population growth through transition

A Demographically Diverse World

Populations are still growing rapidly in less developed countries, with most of the world’s population now

within Asia.

Managing Development and Population Growth

Countries such as China, Thailand, and India have created campaigns to reduce the fertility rates of their citizens. Most demographers still predict a medium growth

rate, and a world population of 9 billion in 2040.

Age StructureVisual representations of age structure within a country for

males and females.

More Age StructureDiagrams

UNFPA is a subsidiary agency of the United Nations General Assembly

Worlds largest mulitlateral source of funding for population programs and reproductive health programs.

Guided by outcomes of a number of conferences, including

At the 1994 ICPD held in Cairo (the “Cairo Conference”), 179 nations reached consensus on actions needed to improve the quality of life of the people of the world over the next 20 years. The implementation of the recommendations contained in the Programme of Action is the sovereign right of each country, in conformity with universally recognized international human rights of the Charter of the United Nations.

ICPD Programme of ActionUN Conference on the Environmentand Development (UNCED) 19921992, “Rio conference” or “Earth Summit”, first of its kind. 109 heads of state to address urgent problems of environmental protection and socio-economic development. Resulted in climate change convention that led to the Kyoto protocol, Agenda 21, and a convention on Biological Diversity.

unfpa.org ICPD - Programme

ICPD Programme of Action (unfpa.org ICPD – Programme)

Focus on reproductive health and Education; Provided 14 recommendations for programs

1.Interrelationships between population, sustained economic growth, and sustainable development2.Gender equality, equity, and empowerment of women3.The family, its roles, rights, composition, and structure4.Population growth and structure5.Reproductive rights and reproductive health6.Health, morbidity, and mortality7.Population distribution, urbanization, and internal migration8.International migration9.Population, development, and education10.Technology, research, and development11.National action12.International cooperation13.Partnerships with the non-governmental sector14.Follow-up to the conference

September 2000 U.N. Millennium Summit, NYC

U.N. proposed eight Millennium Development Goals (MDGs), based on what member countries agreed were

the most pressing issues facing the world.

Each MDG has time-bound and quantified targets by which progress can be measured.

Member countries committed to reaching the MDGs by 2015.

Progress detailed inMillennium Development Goals Report 2015

http://www.un.org/millenniumgoals/

https://sustainabledevelopment.un.org/sdgs

2012 U.N. Conference on Sustainable Development, member states agreed to design of

Sustainable Development Goals (SDGs) as a successor of the MDGs.

Fig 7.14

To estimate the impact of human lifestyles on Earth, environmental scientists Barry

Commoner, Paul Ehrlich, and John Holdren developed the IPAT equation to estimate the

impact of human lifestyles on Earth.

Impact = Population × Affluence × Technology

Although it is written mathematically, the IPAT equation is a conceptual representation of

the three major factors that influence environmental impact.

Fig 7.15