Chapter 6 Flashcards
Human Population
When did the human population reach 1 billion?
after 1800
Country’s doubling time
70/(annual percentage growth rate)
What are reasons for human population growth?
advances to technology, sanitation, agriculture, and practices that reduce death rates
Thomas Malthus
British economist who argued that the number of people would eventually outgrow the available food supply
Green Revolution
resulted in intensified food production with the increasing population
What are negative impacts of increased population size?
depletes resources, stresses social systems, degrades the natural environment
IPAT model
(I)mpact = (P)opulation x (A)ffluence x (T)echnology
Increased population (IPAT)
more individuals take up space, use resources, and generate waste
Affluence (IPAT)
greater per capita resource consumption
Technology (IPAT)
enhances ability to exploit resources/decrease impact by improving efficiency
Demography
study of statistical changes in the human population
Demographers
study characteristics of the human population: size, distribution, age structure, sex ration, birth/death/emigration/immigration rates
What population size is the global population predicted to surpass by 2050?
9.7 billion
Age structure diagrams/population pyramids
describe relative numbers of individuals of each age class in a population (lower ages at the bottom)
What is the predicted median age in 2050?
36
What is the naturally occurring sex ratio at birth?
106 males:100 females
Infant mortality rates
frequency of children dying in infancy (which has decreased)
Total fertility rate (TFR)
average number of children born per woman during her life time (decreased due to industrialization, improved women’s rights, healthcare)
Replacement fertility
TFR that keeps the population size stable (2.1)
Rate of natural increase
includes only birth and death rates
Life expectancy
average number of years a person in an age group is expected to live, increased in industrialized countries
Demographic transition
stages of economic/cultural change for industrializing countries
Pre-industrial stage
high death rates due to widespread disease, rudimentary healthcare, unreliable food supplies (people compensate for infant mortality by having many children); population growth is stable
Transitional stage
declining death rates due to improved food production and health care, but similar birth rates; high population growth
