Natr 2050: Human Population

what is today’s world human population?

8.2 billion

what is the projected human population in 2050?

9.6 billion

What are the 3 periods of human growth?

pre-agricultural

agricultural

industrial

characteristic of the pre-agricultural period

advancement of TOOL MAKING & passing down skills

what was the human population at at the end of the pre-ag period?

5-10 mil

The rate of global population growth depended on __________

the speed humans spread into new regions

How did the agricultural period begin?

~10,000 years ago with the DOMESTICATION OF PLANTS & ANIMALS & FARMING

what tech was invented in the agricultural period?

irrigation & plowing

what was the human population at at the end of the agricultural period?

more than 500 mil

When did the industrial period begin?

~1800

What was the tech powered by in the industrial period?

fossil fuels

in the industrial period, agriculture ws able to expand onto land that was previously unfit for farming because of tech

demography

where you are, where you’re located, where you’re from

what can change population amount?

women’s empowerment, leading to lower fertility rates

education for girls

in poor countries, ________ birth rate

high

in wealthy countries, _________ birth rate

low

pretransition (stage 1)

death rate high

birth rate high

Mortality transition (stage 2)

death rate lower

birth rate high

rapid population growth

fertility transition (stage 3)

death rate low

birth rate low

population slows

Stability transition (stage 4)

low birth rate

low death rate

birth & death rates equal

zero population growth or decline

Pre-transition stage

prior to economic development human populations are limited by a low availability of food and a high prevalence of disease High death rates and high birth rates High death rate among the young Families compensate for high death rates by having many children . birth and death rates even out = zero population growth

Mortality Transition Stage

Improved economic conditions relieve food shortages , produce better living conditions and health care , and expand access to education death rate decreases while the birth rate stays high / increases result : rapid , sustained population growth (Nigeria/Afghanistan)

fertility transition stage

Continued economic development produces social and cultural changes that lead to lower birth rates . People delay starting families , which lowers total fertility rates families may limit # of children through using contraceptives or other family planning death rate remains low and birth rate decreases so population growth slows

stability transition stage

Characterized by low birth rate and a low death rate birth rate and death rate nearly equal almost zero population growth or even a decline in population (Japan, some western European-Italy/Spain)

what does the age structure show?

present populatrion growth rates

future growth rates

balanced age structure pyramids show a ________ population size/growth

stable

inverted pyramids show ___________

declining populations

broad-based pyramid show __________

high birth rate & low survivorship

what did china do to reduce overpopulation?

1 child policy

what did india do to reduce overpopulation?

Department of Family Planning (education & voluntary)

ecological footprint

the amount of LAND needed to keep the demand for ecological GOODS & SERVICES

biocapacity

measure of area and land QUALITY avaiable to supply a population with resources

a population exceeds its biocapacity when it draws a portion of its _________________________________________

ecosystem goods & services from outside its geographical boundaries

carrying capacity

how much of population that the environment can support

when the population approaches the carrying capacity,

death rates INCREASE & birth rates DECREASE

humans must stay below the carrying capacity to keep being sustainable