When you study all the growth characteristics of a human population, what are you studying?

Population studies cover many issues, such as total population, population growth, population density, average (median) age, aged vs. young people, doubling time, crude birth rate, total fertility rate, crude death rate, age structure, etc.

The starting point in a population estimate (projection) is the current (today's) age structure and mortality data which could be taken fromlife tables. A life table is developed by applying a real population's age-specific death rates to hypothetical stable and stationary populations having 100,000 live births per year, evenly distributed through the year, with no migration. As the 100,000 people added each year aged, their ranks are thinned in accordance with the age-specific death rates.

Population studies provide details necessary for city planning, water supply, waste need to be collected, numbers of dwellings, roads, parking space, green areas (public parks), infrastructure, etc. By the way today's total (human) population is nearly 7,416,100,000 and we consume the resources and pollute the environment badly.