Lesson 8: Human population

What is current human population

8.1 billion

What is current human population

347 million

What does the us demographic period look like

Onion dome

What are the 5 most populated countries 

India, china, United States, indonesia, pakistan 

What is the malthusian crisis

Predicted the rat of population growth (exponential) in great britian would exceed he rate in the growth of the cultivation of arable lands and food production (linear)

WHat were the changes in uk agricultural force like from 1800-2000

Peak agricultural labor force in 1900 but it has been steep decrease since then

Decreases of UK agricultural labor force reflects increased mechanization and efficieny of agricultural production (and also social, economic, and landownerhship changes)

When did agricultural yields increased 

in 2nd half of the 20th cenutry

What drove increased productivity of agriculture

mechanizarion, plant breeding, and chemical fertilizers

How was the post war popuation boom supported

y industrial N-fixation

baby boomers were fed on left voers from WWII

What does that mean for malthusian crisis

has been postponed bc industrial N fixation (haber process)

What is the big picture 

Growth rates in populations are declining while total populations still increase 

What is the replacement level fertility

The average number of children bron per woman at which a population exactly replaces itself from one generation to the next, without migration. This rate is roughly 2.1 children per woman, for most countries although it may vary with mortality rates

What are some reasons for the decline it fecundity

• increases in development/affluence

• increasing access to health care and employement for women

• Increasing female literacy

The demographic trasition model 

many countried are in the phase 2 lag (developing in phase) so birthrate is dlightly decreasing, death is also decreasing, growth rate is increasing 

What is death rate doing

going down globally resulting in greater life expectancy

What will our generation inherit

an old urban planet

the population of older persons is increasing in amount and total share of population due to incereasing life expectancy and decreasing fecundcity

What are us trends in life expectancy drien by 

more rich, live longer 

wWhat are general trends for mortalisty doing

less for urban, especially for men

What are big conclusions

Growth rates are declining, but not everywhere. THey are declining bc political empowernment, education, increased access to health care and education for disanfranchised people 

higher country affluence means more emissionsBut higher education and affluence leads to greater resource consumption 

What us happening to population and agricultural lands 

Human population and consumption continues to increase as avaaible agricultural lands plateau