Population

Video 1
"Population Growth"

In these parts of the video the narrator says that if the

 population continue growing as it is doing now, we 

will not reach the level of living in "satisfaction" 

without risking the destruction of the environment. It 

took 123years to hit 2 billion, and only near 33 to hit 

3 billion. 

Video 2
"Population Pyramides"

 Russia having the biggest territory in the world has 

the same population as Nigeria, a country much 

smaller than Russia. But Russia's population is slowly

 declining, while Nigeria's is growing.

The population pyramide is divided in gender and ages, with males in one side and females in the other. This pyramid is separated in groups of five-year age interval, from 0 to 4 and continuing up to 100 and up:
-Pre reproductive (0-14)
-Reproductive (15-44)
-Post reproductive (45 & up)

Video 3

"7 Billion: How Did We Get So Big So Fast?"

In these two pictures we can see that in the year of 1000 there were much less people than in 2011: The population grows from 0.3 billion people (thanks for the medicine and agriculture) to 7 billion people. In both most of them lived in China, India and the rest of Asia and there were less people in North and Latin America.

Video 4
"World Population"
In this video it is said that humans depend on limited resources for our survival and we thrive in less of 17% of the earth and only a 4% to grow crops. Is also said that we are increasing the population as if these resources were infinite, and they dont't last for ever.