Chapter 1: Introduction

Environmental Problems, Their

Causes, and Sustainability

•Rachel Carson was a scientist who wrote Silent Spring in 1962.•It addressed the growing use of pesticides (DDT) and their unpredicted effects on song birds.•Original users of pesticides did not know that the poisons used to kill insects would accumulate in other living things and kill them too. BIOACCUMULATION

ThemesSustainability: A process can continue indefinitely

without depleting resources used *no sacrifice to future generations*

Stewardship: Caring for something that does not belong to you

Science: Use the scientific method and question authority

Ecosystem Capital: Essential goods and services like food, water, and fuel

Policy and Politics: Human decisions determine what happens to the natural world

Globalization: The interconnectedness of human activities, ideas, and cultures

Environmental Science

• Understand how natural world works• Understand how human systems interact with

natural system • Accurately determine environmental problems• Develop and follow a sustainable relationship

with natural world

Lessons from a Small Lessons from a Small IslandIsland

Easter IslandEaster Island

(Rapa Nui)(Rapa Nui)http://www.netaxs.com/~trance/rapa.ram

Easter Island Home Page and Music

http://www.netaxs.com/~trance/rapanui.html

Map ofEaster Island

Area - 166 km2

In the 4th century A.D there were approximately 10,000 people living here

Use of resources

Natural Resources• Fresh water • Trees• FishBrought by settlers• Chickens• Sweet potatoes• Taro• Yams

Used for:• Building houses• Food• Clothing• Technology

– Stone statues (moai)– Needed many trees to

move the statues

Moai

• There are 887 moai on Easter Island

•Average Height: 13.29 feet (4.05 meters) some are more than 20 feet (6 meters)

•Average weight: 13.78 tons

Dutch explorers arrive in 1772

• 600 people left

• Constant war

• Few of the natural resources left

What happened!

4 Global trends:

A. Population growth and economic development

B. Decline of ecosystems

C. Global atmospheric changes

D. Loss of biodiversity

A. Human population growth

• More than 6.6 billion people currently• We are adding 76 million people per year• increase pop → increase need for resources

Note: •This graph is from 1999. •These predictions are based on a faster growth rate. •Carrying capacity is higher in this graph.

Different lifestyles have different demands on the environment

Developed (industrialized) countries like America• hot running water• more than one car per family-VS-Developing countries like Tanzania• hunting/gathering• Firewood for heat and cooking• 1 billion + people live in poverty

B. Soil degradation

Demand for food destroys the soil– erosion– minerals in soil are depleted– salinization– increased use of pesticides– overuse of fresh water

C. Global Atmospheric Changes

Global Warming

– CO2 produced from fossil fuel burning acts like a blanket around the earth.

– Plants take CO2 out of the atmosphere through photosynthesis

• 6CO2 +6H2O => 602 + C6H12O6

Ozone depletion– Chemicals released from the surface of the earth

destroy our ozone shield. – No stratospheric ozone, no protection from the UV

rays of the sun.

D. Loss of Biodiversity

• Habitat destruction leads to a loss of many species starting with the plants

• exact # of species lost is unknown because not all species are identified

• strong ecosystems need biodiversity• 1959-1980 25% of all prescription drugs from natural

resources• Wild species keep domestic species vigorous• Aesthetics

A sustainable future is possible• Nutrition levels and life expectancy

are rising• Population growth rates are falling• It is cool to be “green”• YOU are taking this class

Lessons from a Small Lessons from a Small IslandIsland

Easter IslandEaster Island

(Rapa Nui)(Rapa Nui)http://www.netaxs.com/~trance/rapa.ram

http://www.netaxs.com/~trance/rapanui.html