1. Human Demographics

2. Demography
The study of the growth rate, age structure and other characteristics of human populations
Since industrial revolution, birth rates have remained fairly stable, but death rates have decreased dramatically  why?
Growth rate is 1.6%
96 million people per year
Doubling time of 43 years

3. This graph shows one factor affecting population growth. What is it?
Predict how this factor will affect the population in each country between now and 2050.
Brainstorm list of factors, events or conditions that might affect population growth in these countries.

4. Population Pyramids Shows age structures of populations
Stable populations have an even distribution across most age classes
A large number of young people indicates a growing population
Growth momentum – the inherent future growth in a population that results form a disproportionately large fraction of the population being of younger age

5. Majority of people are in their pre-reproductive years
Therefore, there will be a lot of births in the years to come
Less industrialized countries ex. Kenya

6. Stable population
Relatively equal number of individuals in each age groups (except for elderly since they naturally have a higher mortality rate than any other age group)
Industrialized countries ex. United States

7. Few young people to reproduce in the future
Majority of population is in post-reproductive years
Low fertility rates and high mortality rates
Ex. Japan, E. Europe

8. Demographic Transition Model
Four-stage model describing relationship between economic development and changes in population patterns
Preindustrial – harsh living conditions, high birth and death rates, slow population growth
Transition – industrialization decreases death rates, birth rates still high, high population growth
Industrial – birth rates decline, population begins to stabilize
Postindustrial – birth and death rates balance, zero population growth

10. Trends in Human Population Growth
Increased food supply due to improved agricultural methods and domestication of animals
Breakthroughs in medicine enabled people to be treated for once-fatal illnesses
Better shelter
Improvements in storage capacity of food

11. Earth’s Carrying Capacity
Humans have been able to increase the carrying capacity of Earth
Population continues to grow exponentially
Great disparity among countries in the amount of resources that are used per person
Wealthiest 20% of population consumes 86% of world’s resources and produces 53% of world’s CO2 emissions
People in poorest countries use 1.3% of world’s resources and produce 3% of CO2 emissions

12. Ecological Footprint
The amount of productive land that is required for each person in a defined area for food, water, transportation, housing, waste management and other requirements
6 major categories: cropland, grazing land, fishing grounds, forest land, carbon absorption land, building area (available biocapacity)
Estimated average per person globally is 2 hectares of land (1ha = m2)

13. Ecological Footprints from Around the World

14. Available Biocapacity
Earth’s carrying capacity for the human population
Approx. ¼ of Earth’s surface
Does not include arid regions, open oceans, etc.