3.8 Human Population Dynamics

Thomas Malthus

in 1798, he developed the theory that exceeding earth’s carrying capacity was possible and that population grows exponentially while the food supply is linear, many agreed with this

technological advancements can…

increase carrying capacity through irrigation: a positive is food production, new habitats, and money, a negative is it diverts water from native habitats, causes water shortages for humans, and costs money

birth, death, and growth rate

growth rate (r)= % increase in a population, crude birth rate+crude death rate=births and death rates/1000, calculating growth rate (CBR-CDR/10), national growth rate (CBR+immigration-CDR+emigration/10)

rule of 70

the time it takes a population to double is 70/1.00(growth rate)

future population growth

initial population x growth rate^years