How and why has the population changed?
How the Population has grown
- Until the 1800s the world's population grew slowly for thousands of years.
- In 1820 the world's population reached one billion.
- In the early 1970s, the world's population reached three billion.
- In 1999, less than 30 years later, the population doubled to six billion.
- The global rate of population growth is now one billion every 15 years.
What is the demographic transition model?
Demographic Transition Model
- Total population is low but it is balanced due to high birth rates and high death rates.
- Total population rises as death rates fall due to improvements in health care and sanitation. Birth rates remain high.
- Total population is still rising rapidly. The gap between birth and death rates narrows due to the availability of contraception and fewer children being needed to work - due to the mechanisation of farming. The natural increase is high.
Somalia Case Study
Somalia- Population Structure Or Development
Age structure: 0-14 years: 44% (male 2,293,746/female 2,298,442)
15-24 years: 18.9% (male 995,102/female 970,630)
25-54 years: 31.2% (male 1,681,705/female 1,571,586)
55-64 years: 3.6% (male 180,622/female 199,059)
65 years and over: 2.3% (male 92,707/female 144,444) (2014 est.)
Italy Case Study
Italys population structure: