1. Environmental Science: Earth as a Living Planet
Chapter 1

2. Major Themes of Environmental Science
World Population
In A.D Million people
In Billion people
Today- 6.7 Billion people (closer to 7!)
Projected: 10 Billion by 2040
It took human population almost years to get to 3 billion, only 40+ years to add 3 billion more

3. What is the maximum number of people that Earth can support?
Problem?
The Earth has not grown any larger and the abundance of its resources has not increased
Can the Earth SUSTAIN all these people?
What is the maximum number of people that Earth can support?

4. World Population
How many people the Earth can sustain depends on science and values and is also a question about people and nature.
What quality of life are people willing to accept?
The poorer that quality, the greater the number of people that can be squeezed onto the Earth’s surface

5. Modern Population Explosion
Major factors in population:
Supply of Food
Supply of Clothing
Shelter
Decreased death rates (medical improvement)
As a result, the human population has increased greatly, threatening the environment

6. World Population

7. Consequences of Rapid Population Growth
FAMINE is one of the things that happen when a human population exceeds its environmental resources
In 1970’s, following a drought in the Sahel Region, 500,000 Africans starved to death and several million more were permanently affected by malnutrition

8. FAMINE
In 1980’s - In one year during that period, as many as 22 African nations suffered catastrophic food shortages and 150 million Africans faced starvation
There is a continuing food crisis in Southern Africa (Malawi, Zambia and Zimbabwe)

9. Reasons for Famine? Drought
Size of Population affected by drought- competing for resources
Changing climate- partly because of human activities
Poor farming practices- erosion of soil
Deforestation

10. We are forced to confront a choice
Which is more important, the survival of people alive today or conservation of the environment, on which future food production and human life depend?

11. An Urban World With economic development, comes URBANIZATION
Urbanization = people move from farms to cities and then perhaps to suburbs
Cities and towns increase in size
Cities are commonly located near rivers and coastlines

12. Destroying Wetlands
Urban sprawl often overtakes good agricultural land of river floodplains as well as coastal wetlands, which are important habitats for many rare and endangered species.
As urban areas expand, wetlands are filled in, forests are cut, and soils covered over with pavement and buildings

13. Urban Sprawl
In developed countries, 75% of the population live in urban areas, with 25% in rural areas
In developing countries, only 40% of the people are city dwellers
It is estimated that by 2025 almost two- thirds of the population (5 billion people) will live in cities

14. Largest Cities In 1999, Tokyo, Japan was the world’s largest city
In 2016, Tokyo will still be the world’s largest city with an estimated population of million
Megacities- at least 8 million people
Increased from 2 (NY and LA) to 23 in 1995
Largest Cities

15. Megacities Most Megacities- 17- are in the developing world
It is estimated that by the world will have 36 Megacities, 23 of them will be in Asia
Environmental issues have always focused on non-urban issues (wildlife, etc.) but needs to shift to urban issues

16. Sustainability What is sustainability?
Refers to resources and their environment
Sustainable Resource Harvest- the same quantity of that resource can be harvested each year for an unlimited or specified length of time without decreasing the ability of that resource to continue to produce the same harvest level

17. Sustainable Ecosystem
An ecosystem that is still able to maintain its essential functions and properties even though we are harvesting one of its resources

18. Sustainable Development
A society can continue to develop its economy and social interactions and also maintain its environment for an indefinite time

19. Carrying Capacity Related to sustainability
The maximum number of individuals of a species that can be sustained by an environment to sustain that same amount in the future
Question: What is the maximum number of people that the Earth can sustain?

20. People and Nature
People and nature are intimately integrated- each affects the other.
We depend on nature for our lives
We depend on nature for beauty and recreation
We affect nature

21. Gaia Hypothesis
Originated by British chemist James Lovelock and American biologist Lynn Margulis
Proposes that the environment at a global level has been profoundly changed by life over the history of life on Earth and that these changes have tended to improve the chances for the continuation of life.

22. Placing a Value on the Environment
How do we place a value on any aspect of our environment?
The value of the environment is based on eight justifications: aesthetic, creative, recreational, inspirational, moral, cultural, ecological, and utilitarian

23. Utilitarian Justification
Sees some aspect of the environment as valuable because it benefits individuals economically or is directly necessary to human survival
Example: Mangrove Swamps provide shrimp that are the basis of the livelihood of the fisherman

24. Ecological Justification
An ecosystem is necessary for the survival of some species of interest to us, or that the system itself provides some benefit.
Example: Mangrove Swamps provide habitat for marine fish, and although we do not eat Mangrove Trees, we may eat the fish that depend on them.

25. Aesthetic Justification
Our appreciation of the beauty of nature
Example: When people grieve following the death of a loved one, they typically seek out places with grass, trees and flowers and thus we decorate our graveyards

26. Recreational Justification
People use wilderness for recreation
Example: White water rafting, fishing, and hiking

27. Inspirational Justification
Conservation of nature can be based on its benefits to the human spirit
Example: Religious Retreats

28. Creative Justification
Nature is an aid to human creativity
Example: Artists, poets and others find a source of their creativity in their contact with nature

29. Moral Justification
Has to do with the belief that various aspects of the environment have a right to exist and that it is our moral obligation to allow them to continue or help them to persist.
Example: Species have a moral right to exist

30. Do Rocks Have Rights?
The United Nations General Assembly World Charter for Nature, signed in 1982, states that species have a moral right to exist.

31. The Big Question
DO we have a moral obligation to future generations? to leave the environment in good condition for our descendants, OR:
Are we at liberty to use environmental resources to the point of depletion within our own lifetime?