The world population and it's growth

Today I am going to tell you about several different things. One of the main things I will talk about is the Human population and it's effect on the environment. I will also be telling you about the policy and practice of the human population.
In many nations, the replacement fertility is about 2.1. If a nation's total fertility rate climbs about 2.1, then the population will most likely increase over time. If it falls bellow 2.1, then the population will most likely decrease over time. 179 nations endorsed a new "Program of Action" that called on governments to provide universal access to reproductive health care by 2015 as a global growth, this program tries to contribute. Total fertility rate helps demographers predict if a population's size will increase, decrease, or stay the same. The program of action helps to ensure that men fulfill their responsibility to ensure healthy pregnancies, proper child care, promotion of women's worth and dignity, prevention of unwanted pregnancies, and prevention of the spread of AIDS and other sexually transmitted diseases.
Age structure describes the relative numbers of organisms of each age within a population and is often represented by a graph called an age structure diagram. Nations undergoing rapid growth, such as Madagascar, face different challenges as they try to provide education, roads, and other resources to support a rapidly growing population. The sex ratios for the age structure diagrams is for every 100 females born, about 106 males are born, the sex ratio is 1.06 to 1. This phenomenon may be an evolutionary adaptation because males are slightly more likely to die during any given year of life.
Demographic transitions have shown that over the past half century, worldwide average life expectancy has increased from 46 to 68 years. The demographic transition is a model that explains the change from high birthrates and death rates to a condition of low birthrates and death rates. A demographic transition is the result of economic growth that has led to social changes.