Population Growth and Regulation Flashcards
Current world population is…
8 billion (over 200 nations).
By 2050, UN predicts global population will surpass…
9.7 billion.
j-curve
pattern of growth on graph
Infant mortality rate reduced because of…
(1) improved sanitation
(2) modern medicine
(3) higher agricultural output
Infant mortality rate has contributed to…
growing population.
Prior to IR, high birth rates were positive because…
(1) more children supported parents in old age
(2) greater labor pool for factory work
Malthus argued that…
number of people would eventually outgrow available food supply.
Predictions of Malthus and Ehrlich have…
not fully come true.
Despite quadrupling of human population, society has not collapsed because of…
(1) intensified food production
(2) slowing birth rates due to enhanced prosperity, education, and increasing gender equity
Despite improvements, population growth still…
(1) depletes resources
(2) stresses social systems
(3) degrades natural environment
carrying capacity
maximum population size of species that environment can sustain indefinitely given food/habitat/water/etc. available in environment
IPAT model
framework used to measure environmental impact
IPAT formula
I = PAT
I (IPAT)
impact on environment
P (IPAT)
population growth
A (IPAT)
affluence (consumption per capita)
T (IPAT)
technology factor
S (IPAT)
sensitivity factor (denotes vulnerability of given environment)
Modern-day China demonstrates how IPAT elements create environment impact through…
(1) erosion caused by intensive agriculture
(2) withdrawn aquifers/rivers
(3) Low air quality (equivalent to smoking 40 cigarettes)
Human population grows at rate of
88 million/year (2.8 people/sec)
Human population reached 1 billion after…
1800.
1 billion people are added to population every…
12 years.
Population growth rates…
vary from place to place.
population doubling time formula
years = 70/population growth rate
Global doubling time is…
58 years (70/1.2).
China’s doubling time prior to one-child policy was…
25 years (70/2.8).
Most of next billion added to population will come from…
emerging economies.
Emerging economies will…
(1) continue to be economically strained
(2) continue environmental degradation due to poverty
predicted population formula
predicted population = growth + current population
population growth formula
growth = current population*growth rate