Population Demographics is the study of human population distribution and migration. Key Issues of Demographics are: Food Supply Health and life expectancy Status of women People are NOT distributed evenly across the Earth. Population is clustered in the mid latitude climates and relatively sparse in the dry and polar climates or the highlands. Distribution- of the worlds population lives on only 5% of the land. Very uneven distribution was intensified in the 20 th cent. as population soared. 2/3 of the pop. lives near an ocean or river. Carrying capacity-the number of people that can be supported in an area given the technology of production. Density-the measure of the number of people per square mile/kilometer, etc. Arithmetic density-total number of people divided by the total land area. It is the most common statistic given. Physiologic density-is the number of people per unit of arable (farmable) land. World Population Cartogram Countries named have at least 50 million Major Population Concentrations East Asia 1.5 billion people South Asia 1.7 billion people SE Asia 0.6 billion people Population Growth From Dawn of History to 1820 to reach 1 billion to reach 2 billion 1970s only 12 years to add another billion. Then a decade for another billion. 80 million people added to the world pop. each year. Doubling time-the number of years needed to double a population-divide 70 by the growth rate % of to get doubling time in years. For example, the growth rate of the USA is /0.78 = years for the population of the USA to double in size. Burundi has a growth rate of /3.27 = 21.41 World Birth Rate number of births in a year per 1,000 people. World Mortality Rate number of deaths in a year per 1,000 people. World Population Growth Rate of natural increase (does not take into account immigration and emigration). Total Fertility Rate (TFR) of 2.1 to 2.5 children per woman is considered replacement level. Crude death rate-the number of deaths per 1,000 each year. Crude birth rate-the number of births per 1,000 each year. Natural increase (NIR)rate-the % by which a population grows in a year. Computed by subtracting the % of CBR-CDR. Total Fertility Rate (TFR) the number of children born to women of childbearing age-usually reported as a percentage. Dependency ratio-the number of people who are too young or too old to work compared to the number of people old enough to work. In poorer countries, Infant Mortality Rates are usually high, which is reflected in the pyramid shape. Maternal mortality ratio is the greatest health disparity between the developed and developing countries. The World Health Organization reports that 600,000 women die each year from complications of pregnancy. Social, cultural and economic barriers prevent women in the developing countries from receiving proper health care. In 1798 he published An Essay on the Principle of Population Malthus was the first to sound the alarm that the worlds population was expanding more rapidly than food production. He was the first to recognize exponential or geometric population growth. Today those who share his concerns are Neo- Malthusians Rev. Thomas Malthus Demographic cycles of population growth Stage 1 High Stationary Growth with high birth rates 40/1000 or higher and high death rates. Stage 2 Early Expanding with high birth rates and declining death rates (birth 40s/death 20/1000) = rapid growth in pop. Stage 3 Late Expanding with declining birth rates (30s) and low death rates (10) = still significant growth Stage 4 Low Stationary has low birth rates and low death rates (birth 15 and death 10 or lower) SPL Stationary Population Level Second Agricultural Revolution and Industrial Revolution Industrial Revolution in agricultural production: Mechanization of agriculture Crop yields improved with better farming methods Medical Revolution was also a factor: Improved sanitation Improved medical care Disease prevention from vaccines Long Term Effects and the Unintended Consequences of Government Policies Population Policies Restrictive or Anti-Natalist Policies discourage births. Policies vary- e.g. despite Vatican policies, most Catholic Italians practice artificial birth control-Philippines (only Asian Catholic country) a different case-govt. restricts birth control. Some countries have learned that industrialization & urbanization do as much as government policy in controlling births. Geography of Demography Recognized minorities (3%) of pop. were exempt Many rural Chinese defied rule, hid pregnant women, failed to register births, prevented inspectors from visiting rural villages. Government took drastic action: Violators were fired Land was confiscated Lost all benefits Pregnant women were arrested & forced to have abortions Geography of Demography First 6 years 70 million abortions 1980s about 20 million sterilizations a year-3X as many women as men. Party Members were birth control police-got cash and promotion for enforcing the laws One Child Policy was relaxed in the countryside-a couple with a daughter-2 nd child after 4 years. Geography of Demography Chinas One-Child Policy created a generation of 90 million 119 boys for every 100 girls 30 million unmarried men by % of Chinese women said they dont intend to wed. 3/10 families have grandparents living with them Biggest demographic revolution in history-Number of Elderly is rising-by 2050 about 30% of the population will be over 60-no pensions or social security. Epidemiological Transition