2. Human population growth
Section 5.3

3. How many people live on Earth?
7.4 billion!
Human population tends to increase
Very large increase over time!

4. Earth’s population increase
Why the sudden increase?

5. Malthus’ prediction
200 years ago, English economist predicted that Earth’s population growth was unsustainable
Only ways to stop population was
War (competition)
Famine (limited resources)
Disease
All density dependent factors!

6. Is Human growth rate exponential?
It was, but not anymore…
Peaked in 1960s
Rate of growth is now slowing down – why?

7. Why do population growths differ among countries?
Demography – study of human populations
Look at Birth Rate, Death Rate and age structure of a country to understand what is going on….

8. Demographic Transition model
In which country is population size increasing the most?

9. The future By 2050 – Earth’s population is expected to reach 9 billion
Will the human population level out on a logistic growth curve?
This require all countries to go through the stages of demographic transition