1. Human Population and its Challenges

2. First a Review: Resources
What is the difference between a Renewable Resource and a Nonrenewable resource?
Make a list of examples from each:

3. What are some resources that humans need?
Lets make a list:

4. Limiting Factors What is a Limiting Factor?
Any factor/force that slow/stop the growth of a population.
Density-Dependent Limiting Factors: Effect a population more strongly as the population grows. (ie: competition, etc)
Density-Independent Limiting Factors: Effect the same percentage of a population regardless of its size. (ie: natural disasters, etc)
*See next slide for examples.

6. Carrying Capacity
Carrying Capacity is the maximum number of organisms the environment is able to support for a given population. (It is an average)
What causes the Carrying Capacity?

7. Carrying Capacity: Variations that can occur:

8. History of Human Population Numbers
Have we reached our carrying capacity yet?

9. Brainstorm
What are some events or developments that can change the human population? (Either help to increase or decrease)

10. Human Population Changes
Factors Increasing Growth Rate:
Agriculture
Improved Agriculture leads to crops that yield more food.
Industry and Technology
Greater availability of many goods.
Safer work environments.
Etc…
Health Care
What discovery in the 1800’s helped to boost Health Care far ahead and lead to our modern medicine?
Factors Decreasing Growth Rate:
Plague
The Bubonic Plague killed around 25% of Europe and Asia’s populations.
Do you think cities, suburbs, or rural areas are most effected by diseases?
Famine
Irish Potato Famine in 1840’s killed over a million people.
War
Rapid decrease in population.
WWII killed over 61 million people.

11. Demographics and Changing Population Needs
Demography is the science of the changing vital statistics in a human population.
What factors are looked at in Demography?
Why are populations for ages of particular importance?

12. Demographics and Changing Population Needs
As population growth occurs their needs change:
More food, water, and living space needed.
More energy needed.
Changes in technology, lifestyle, and standards of living all affect the needs and consumption rates of a population.
Do small or large populations require more resources?
Do underdeveloped or industrialized/modernized societies use more resources?
As a nation becomes more industrialized, what might be some of its concerns?

13. Overpopulation and its Challenges
The current human population is a little over 7 Billion people on earth.
What portion of the carrying capacity curve are we on? What does this mean for our growth rate?
Has the human population reached its
carrying capacity?
How long before we reach our

14. Overpopulation and its Challenges
What are some challenges to having a high population?
Using more and more living space (earth’s land).
Greater demand for food and water.
Greater demand for other resources such as minerals, wood, fuels.
Increased need for energy.
Increased pollution.
Spread of disease due to crowding.
More need for proper hygiene systems and medical facilities.
More need for infrastructure (roads, bridges, etc)
Impact on other species (Conserving wildlife preserves, etc)
Remember that no country is an “island” – the choices of countries effect other countries.
Can you think of any others?

15. Solutions to Overpopulation
Positive Solutions
Increasing resources through smart technologies.
Renewable energy
Better agriculture
Better crops (genetic engineering)
Better mining systems
Etc…
More efficient production
Encouraging birth control to families (what are the challenges to this one?)
Wrong Solutions
Forcing people to limit the size of their families.
Genocide Attitudes or Actions
Questions:
Do you think that overpopulation is a real problem? Is this something we have to worry about? Why or why not?
If you think not, Is it something we will have to worry about in the future?
Are there enough resources on earth?
What role does greed and vice play in reducing resources?
Do you think technology can solve the problems?

16. Gaia Hypothesis
“Earth functions like a single, living organism that regulates itself to maintain life”
Developed in 1972 by James Lovelock.
Think of it as earth-wide homeostasis.
Looks are large scale connections and chaos theory.
Changes in one system can cause changes in another.
Some controversy over mechanisms, details, and implications.

17. A Tour Through History: Hunter Gatherers
Nomadic People Groups that gather food and hunt.
Usually do not plant crops.
Their population size and densities are usually low and therefore have a small impact on the environment.

18. A Tour Through History: Agricultural Societies
Societies that survive through farming.
People settle in one are and build cities nearby.
Not all people need to farm, and some can do other jobs for society.
Large amount of food allows the population to grow.
Survives within the limit of its environment, and can last indefinitely.
Smart agriculture allows for minimal environmental impact (ie: rotating crops, high yield crop technology, etc)
Early societies sometimes negatively impacted through poor farming, overgrazing, and logging.

19. A Tour Through History: Industrial Societies
A society where food and goods are produced by machines.
(Farming and goods used to be done by human
hand or made by craftsmen)
Increased agricultural technology and medicine.
These societies require a greater amount of energy and resources.
Pollution becomes a much greater issue to deal with.
While technology can cause some environmental issues, it also can be used to help solve these problems.

20. Frontier vs. Sustainable Development Ethics
Frontier Ethic (Early Industrial Europe): An older concept that humans are separate from nature.
Resources are unlimited are completely meant for human consumption.
Humans are separate from nature and not subject to natural law.
Human success is measured in the level of control we have over nature.
Sustainable Development Ethic: A modern view
Resources are limited and are not all meant for human consumption.
Humans are part of nature and are subject to natural laws.
Human success is living in harmony with the natural world.
Thinking whether a resource is renewable or non-renewable; and considering how quickly it can regenerate is very important in this ethic.
Remember that it is ok for humans to use their environment as that is its purpose… the key is using it smartly.

21. Chapter 14: Food and Nutrients