Chapter 1: Introduction to Environmental Science

Major Themes of Environmental Science

• Our population has more than doubled in the last 40 years– 6.8 billion people alive today

• Continuing on this trend would lead to 9.4 billion by 2050

• How many people can the Earth sustain?– Depends on science and value– Also question of people and nature

Human Population Growth• John Eli Miller Family

– Example of family population explosion

Human Population Growth

• Miller family emphasizes a major factor in modern population explosion– Modern technology– Modern medicine – Supply of food, clothing and shelter– All decrease the death rate and increase net

growth rate

Our Rapid Population Growth

• Human population growth is the underlying issue of the environment. (What do you think???)– Damage is directly or indirectly due to

population increase. (Is this true??)

Famine and Food Crisis

• Famine occurs when human pop exceeds its environmental resources (????)

• Sahel region of Africa in 1970s– ½ million people starved to death – Millions affected by malnutrition

• Emerging global food crisis– Due to rise in fuel cost = higher food cost

Famine and Food Crisis

Food Crisis

Food riots over increasing cost of food in 2007. (left) Haiti and (right) Bangladesh

Sustainability and Carrying Capacity

• What is the maximum number of people the Earth can sustain?– Much of this book will help answer that ?

• Currently we are using resources unsustainably.– Faster than they can be replenished.

Sustainability: The Environmental Objective

• Is Earth’s very survival really in danger? The good news is that: In the long view of planetary evolution, it is certain that planet Earth will survive us– The concern is the Quality of human

environment for us today and for our children, that is at risk

Sustainability

Sustainability refers to resources and their environment.

• Sustainable resource harvest– Same quantity of that resource can be harvested

each year for an unlimited amount of time.

• Sustainable ecosystem– An ecosystem from which we are harvesting a

resource that is still able to maintain its essential functions/properties.

Sustainable Global Economy

• Population of humans living in harmony w/ natural support systems.

• An energy policy that does not pollute, cause climate change or present unacceptable risk.

• A plan for renewable resources that will not deplete the resources or damage ecosystems.

Sustainable Global Economy

• A plan for nonrenewable resources that does not damage region or global environ.– And provides a share for future generations

• A social, legal, and political system that is dedicated to sustainability.

Sustainable Global Economy

• To achieve we must– Develop an effective population-control strategy.– Completely restructure our energy programs.– Institute economic planning that will encourage

pop control and wise use of resources.– Implement social, legal, political and eductional

change.

Moving Toward Sustainability

• The new paradigm– Evolutionary rather than revolutionary.– Inclusive, not exclusive.– Proactive, not reactive.– Attracting, not attacking.– Assisting the disadvantage, not taking

advantage.

Carrying Capacity of the Earth

• Defined as – the maximum number of ind of a species that

can be sustained by an environment– w/o decreasing the capacity of the environ to

sustain that same amount in the future

A Global Perspective

• The actions of many groups of people at many locations affects the environment of the entire world.

• Gaia hypothesis

– Life affects the environment at a global level

An Urban World

• We are becoming an urban species

• In developed countries– 75% live in

urban area

• Developing countries– 40%

An Urban World

• Megacities of the World– Urban area

with at least 10 million inhabitants

People and Nature

• We depend on nature directly for– Wood– Water – Air

• And indirectly for “public services functions”– E.g. soil formation

Soil Fertility and Structure

People and Nature

• People and animals alter and change their environment.

• Dichotomy of 20th century is giving way to a new unity:– A sustainable

environment and a sustainable economy may be compatible.

Science and Values

• We must choose what we want the environment to be and to make this choice we must first know what is possible.

• Value judgment regarding the world’s human population problem– Choice between desire to have large family and

the need to limit the human population.

• The more high tech and powerful our civilization, the more knowledge is required.

Fishing for Salmon

Precautionary Principle

• 1992 - Rio Earth Summit on Sustainable Development

• Defined PP – when there is a great threat of serious environ damage we should not wait for scientific proof before taking precautionary steps to prevent potential harm.

Precautionary Principle

• PP is a proactive, rather than a reactive, tool.

• Adopted by the city of SF and the European Union

Placing a Value on the Environment

• The value of the environment based on 8 justifications– Utilitarian

– Ecological

– Aesthetic

– Recreational

– Inspirational

– Creative

– Moral

– Cultural

Placing a Value on the Environment

• Utilitarian- the environment has value because it benefits individuals economically or is necessary for human survival.

• Ecological- ecosystem is necessary for survival of some species of interest or that the system itself provides benefit.

Placing a Value on the Environment

• Aesthetic- has to do with our appreciation of the beauty of nature.– Recreational- viewing organisms in a natural

setting.– Inspirational- to benefit the inner self– Creative- aid to human creativity

Placing a Value on the Environment

• Moral- the belief that various aspects of the environment have the right to exist and it is our obligation to allow them to continue.