Download Chapter 22: Humans and the Environment

Chapter 22
Humans and the Environment
Table of Contents
Section 1 An Interconnected Planet
Section 2 Environmental Issues
Section 3 Environmental Solutions
Chapter 22
Section 1 An Interconnected Planet
Objectives
• Explain the importance of the study of environmental
science.
• Describe Earth’s major layers.
• Explain the natural functions of the ozone layer and
greenhouse effect.
• Summarize the ways in which biologists measure
biodiversity.
• Discuss the value of biodiversity.
Chapter 22
Section 1 An Interconnected Planet
Earth’s Layers
• Earth’s geosphere, hydrosphere, and atmosphere
are interconnected in many ways.
• Together, these parts make up the biosphere, the
part of the Earth where life exists.
Chapter 22
Section 1 An Interconnected Planet
Earth’s Layers, continued
• Atmosphere
– Important parts of the atmosphere are greenhouse
gases, which trap heat on Earth, and the ozone
layer, which shields Earth from UV radiation.
Chapter 22
Section 1 An Interconnected Planet
Earth’s Layers, continued
• Climate and Atmosphere
– The atmosphere’s ability to trap heat in this way is
called the greenhouse effect.
Chapter 22
Section 1 An Interconnected Planet
The Greenhouse Effect
Chapter 22
Section 1 An Interconnected Planet
Earth’s Layers, continued
• Hydrosphere
– A very small portion of the hydrosphere is fresh
water, and much of this fresh water is not easily
usable.
Chapter 22
Section 1 An Interconnected Planet
Earth’s Layers, continued
• Geosphere
– The geosphere exchanges materials with the
atmosphere, hydrosphere, and biosphere.
Chapter 22
Section 1 An Interconnected Planet
Earth’s Layers, continued
• Biosphere
– The biosphere includes all parts of Earth where
life exists.
Chapter 22
Section 1 An Interconnected Planet
Biodiversity
• Biodiversity refers to the variety of life found in an
area.
Chapter 22
Section 1 An Interconnected Planet
Biodiversity, continued
• Measuring Biodiversity
– Biodiversity can be measured in different ways,
including by species richness, species
evenness, and genetic diversity.
Chapter 22
Section 1 An Interconnected Planet
Biodiversity, continued
• Valuing Biodiversity
– Biodiversity is valued for various reasons.
Chapter 22
Section 2 Environmental Issues
Objectives
• Describe major consequences of air pollution.
• Relate air pollution to effects on global climate.
• Describe how chemical pollutants may undergo the process of
biological magnification.
• Identify the primary causes of modern extinctions.
• Explain why extinctions and ecosystem disruption are of
concern to humans.
• Relate human resource use to its impacts on ecosystems.
Chapter 22
Section 2 Environmental Issues
Pollution
• Over a short time period, human activities have
affected global ecosystems in ways that harm
humans and other species.
• Human impacts range from local pollution to global
change in ecosystems.
Chapter 22
Section 2 Environmental Issues
Pollution, continued
• Ozone Thinning
– Industrial chemicals called chlorofluorocarbons
(CFCs) act as catalysts in chemical reactions that
break down O3 molecules in the ozone layer.
– Most countries have banned CFCs, and the ozone
layer seems to be recovering.
Chapter 22
Section 2 Environmental Issues
Ozone “Hole” Over Antarctica
Chapter 22
Section 2 Environmental Issues
Pollution, continued
• Global Warming
– The correlation of increasing atmospheric CO2 and
rising global temperature suggests a cause-andeffect relationship.
– Considering several types of evidence, many
scientists have concluded that increased CO2
levels have caused warmer surface temperatures
on Earth.
Chapter 22
Section 2 Environmental Issues
Pollution, continued
• Acid Precipitation
– Certain air pollutants cause acid precipitation,
which harms or kills many organisms.
Chapter 22
Section 2 Environmental Issues
Pollution, continued
• Land and Water Pollution
– The release of toxic chemicals, such as DDT, into
the biosphere can impact ecosystems in many
ways, especially when chemicals undergo
biological magnification.
Chapter 22
Biological
Magnification of
DDT
Section 2 Environmental Issues
Chapter 22
Section 2 Environmental Issues
Ecosystem Disruption, continued
• Extinction
– Human impacts on the environment are causing
an increasing number of extinctions.
– Important causes of extinctions are habitat
destruction, the transfer of invasive species to new
habitats, harvesting, and hunting.
– This loss of species has both known and unknown
effects on ecosystems.
Chapter 22
Section 2 Environmental Issues
Ecosystem Disruption, continued
• Ecosystem Imbalances
– Species such as the sea otter that affect many
other species in a community are called keystone
species.
Chapter 22
Section 2 Environmental Issues
Human Resource Use
• Current levels of human resource use are probably
not sustainable.
Chapter 22
Section 2 Environmental Issues
World Population
Growth Patterns
Chapter 22
Section 3 Environmental Solutions
Objectives
• State the goals of conservation and restoration biology.
• Describe examples of efforts to protect species and their
habitats.
• Summarize international strategies for protecting entire
ecosystems.
• Discuss the roles of governments and laws in addressing
environmental problems.
• List several things that individuals can do to help solve
environmental problems.
Chapter 22
Section 3 Environmental Solutions
Conservation and Restoration Biology
• Conservation biologists are concerned with
identifying and maintaining ecosystems, while
restoration biologists are usually involved with
repairing badly damaged ecosystems.
Chapter 22
Section 3 Environmental Solutions
Conservation and Restoration Biology,
continued
• Species and Habitats
– A bioindicator is a species that is especially
sensitive to ecological change.
Chapter 22
Section 3 Environmental Solutions
Conservation and Restoration Biology,
continued
• Case Study: Saving the Whooping Crane
– Populations of many migratory birds, such as the
whooping crane, are in decline because of human
activities.
– However, some populations are recovering as a
result of legal protection, breeding programs,
habitat restoration, and international partnerships.
Chapter 22
Section 3 Environmental Solutions
Protecting Ecosystems
• Biodiversity Hotspots
– International and cooperative efforts to preserve
habitat and prevent extinctions include identifying
biodiversity hotspots, making debt-for-nature
swaps, and promoting ecotourism.
Chapter 22
Section 3 Environmental Solutions
Governments and Laws
• Environmental problems can be addressed through
the efforts of governments and laws.
Chapter 22
Section 3 Environmental Solutions
Private Efforts and Cooperation
• Environmental problems can be addressed through
the combined efforts of governments, scientists,
businesses, and individuals.
Chapter 22
Section 3 Environmental Solutions
Conservation Case Study: The Everglades
• The Everglades restoration project is the most
ambitious ecosystem-wide restoration project
attempted in the United States.
Chapter 22
Section 3 Environmental Solutions
Your Role in the Environment
• No one can predict our environment’s future, but it is
clear that individuals can make a difference in its fate.
• Thus, it is important for you, as an individual, to
understand your role in the environment and to take
responsibility for that role.