ENVIRONMENTAL SCIENCE - chpt. 8

6.7

Approximation of humans living in the planet today.

human population growth

Is occurring in developing countries whee economic hardships exist and the governments are ill-equipped to deal with increasing citizens requiring services.

IPAT model

Impact x Affluence x Technology.

IPATS model

Impact x Affluence x Technology x Sensitivity factor. The sensitivity factor can be added to the equation to denote how sensitive a given environment is to human pressures.

percentage difference

number/number - 1 (100)

demography

Is the science & study of human population.

population size

The absolute number of individuals.

age structure diagrams

Show the relative sizes of each age group in a population and are especially valuable to demographers in predicting future dynamics of a population.

total fertility rate (TFR)

Average number of children born per female member of a population during her lifetime.

replacement fertility

Is the TFR that keeps the size of a population stable; for humans it is 2.1.

natural rate of population change

Is the change due to birth and death rates alone, excluding migration.

life expectancy

The average number of years that an individual in a particular age group is likely to continue to live.

demographic transition

A theoretical model of economic and cultural change that explains the trend of declining death rates and birth rates that occurs when nations become industrialized.

pre-industrial stage

First stage.Characterized by conditions in which both death rates and birth rates are high.

transitional stage

Second stage.Death rates decline and birth rates remain high.

industrial stage

Third stage.Creates employment opportunities, particularly for women, causing the birth rate to fall.

post-industrial stage

Final stage. Both birth rates and death rates remain low and populations stabilize or decline slightly.

India

First country to implement population control measures.