Environmental Science Essay examples

Submitted By sarahx94
Words: 591
Pages: 3

Population Growth: potentially be biggest factor there is.

Earths pop is going through exponential increase. Large # of people on earth. How many peoplw will we be able t put on earth? World pop: 7.05 people. Growth rate 2.2% 94 million/year us pop size: 309 mill.

Population size(n)
Population change=births + immigration –deaths+emigration
-birth rate and death rate whenever birth rate greater, we have increase zero pop growth?
Developed contries have lowest pop growth rates, developing countries NOT because of high birth rate, death rate keeps going down. Pop stable in declining in developing countries. US declining in fertility, not neg like eaurope but lowering birth rates. Us has pop growth under control. Disproportionate amount of resources.

Factors affecting fertility rates:
Targeting problem of overpopulation:
-contraception use and availability/abortions
-economic standing and education
-child labor
-nutrition and infant child death rates
-religious beliefs
-physical ability/age of marriage –arranged marrages in india, earlier you get married, more kids you have.
-pop urban area, less of a chance for kids to be a source of income-urbanization
-education/employment opportunities for women.

Death rates: (infants)-higher in developing countries, high birth rate. Low where birth rates are low. Pop increases bc death rates go down, better medical care.

Age structure: blue is pre reproductive, yelloe reproductive, gold is post reproductive, rapid growth country, as time passes, shift these up, base of perimid gets wider,

Slow growth: us, Australia, Canada, still pyramid but less pronounced.

Zero vs. negative growth:-most deseriable (h structure diagram)
Columnar: shows a stable situation inverted pyramid: japan must have 60000 immigrants per year to fill their work force, strict immigration policies.

Population momentum: pop wont taper off in developing countries for over 100 years.

Easter iresland-pop got mysteriously wiped out 39 bc colonized by poloneasians, great soil, water, pop increase reached 30,000 people, basis of civilization around palm tree, very versatile, increased soil irrosion no more trees put big block of granite on rollers, put back to front, elaborate idols, trying to appease their god. Easter 1849, pop crush 600, warring, cannibalism, no water

1900s- all resources on earth available to a small group of people, don’t have sky rocketing birth rate death rate widens gap, pop is increasing, resources staring to dwindle, pollution relatively low, food a lot more food than there is people to eat it, pop low, death rates birth…