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Transcript
CHAPTER 1
Science and the
Environment
© 2011 Pearson Education, Inc.
An introduction to environmental
science: CASE STUDY
• Easter Island is the most remote spot on the
planet. Located in the middle of the Pacific
Ocean, it is known today for the mysterious, huge
stone statues on the island. See pp. 2-4.
•
• It is also an example of how NOT to treat your
environment. Here’s that story:
© 2011 Pearson Education, Inc.
Easter Island: the past
• A handful of Polynesians arrived on the island
around 1200 A.D.
• It’s an environmentally fragile island
• Small, isolated, dry, cold, nutrient-poor
• When they arrived, it was abundantly forested
• People thrived; the population increased to 10,000+
over the next few centuries
• During those years, the inhabitants cut trees to
• Clear land for agriculture, and to provide structural
materials and firewood
• roll carved stones from quarries to edge of island
© 2011 Pearson Education, Inc.
Easter Island once had a prosperous
culture
© 2011 Pearson Education, Inc.
Easter Island catastrophe
• By 1650, almost all of the trees were gone
• With no trees, the topsoil washed into the sea,
decreasing agricultural yield
• Existence became harder
• Workers eventually revolted against the ruling elites
• Then the workers fought among themselves
• Starvation and disease became epidemic
• Without trees, no one could leave the island by boat
• The population was down to a few thousand by 1722
© 2011 Pearson Education, Inc.
The rest of the story…
• Easter Islanders (who call themselves Rapa Nui) did
not anticipate the consequences of their actions
• Unfortunately, they then suffered further from their
contacts with the “civilized” world
•
•
•
•
Visiting whalers infected them with venereal diseases
Peruvian slavers captured many for the slave trade
Smallpox killed many Rapa Nui
By 1877 only 111 Rapa Nui remained on Easter Is.
• Today, Easter Island is an annex of Chile; the Rapa
Nui live in one village, seen in the next slide…
© 2011 Pearson Education, Inc.
Hanga Roa harbor on Easter Island
© 2011 Pearson Education, Inc.
Lessons from Easter Island
• When a society does not care for its environment
and the human population increases beyond the
capacity of the land and water to provide food for
all…
• …its civilization collapses!
• Other civilizations collapsed when they failed to
recognize the constraints of their environment
• Mayans, Greeks, Incas, and Romans
• …are we next??
© 2011 Pearson Education, Inc.
The state of the planet
• Our world has, at present, four unhealthy trends:
(1) Increasing population growth (over 7 billion in 2012)
(2) A decline of available natural resources like oil
(3) Global warming and other climate changes
(4) Alarming loss of biodiversity
© 2011 Pearson Education, Inc.
Does bigger mean better?
• Today, there are more than 7 billion persons on this
planet.
• 75 million persons are added each year
• They will have to be fed, clothed, housed, and have jobs
• Most population increases will be in developing
countries
• 1 billion experience extreme poverty (live on $1 a day)
• Over 800 million are malnourished
• 6 million preschoolers die each year of hunger and
malnutrition
© 2011 Pearson Education, Inc.
The world’s population has exploded
© 2011 Pearson Education, Inc.
Global economic production
• Has doubled since 1986
• Average gross domestic product (GDP) in low-income
countries has improved
• But real income in most developing countries is
falling
• Because of the large inequalities in wealth between
them and developed countries
• Stabilizing population growth in developing countries
is essential for closing this economic gap
© 2011 Pearson Education, Inc.
The decline of ecosystems
• These vital resources are not being managed well
•
•
•
•
•
•
Groundwater, surface waters such as lakes, rivers
Soil
Fisheries
Forests
Oil reserves
Etc. (What other resources can you name?)
• Agriculture, forestry, and fishing are responsible for
50% of all jobs worldwide
© 2011 Pearson Education, Inc.
Global climate change: a serious
problem
• Global climate change is a current serious problem
• Due to the accumulation of greenhouse gases
• Carbon dioxide is a by-product of burning fossil fuels
• Carbon dioxide is a natural component of the
atmosphere
• It is required by plants for photosynthesis
• It’s important to the Earth’s atmosphere energy
system
• The greenhouse effect: carbon dioxide absorbs
infrared (heat) energy radiated from Earth’s surface,
which warms the lower atmosphere
© 2011 Pearson Education, Inc.
Global temperature and carbon dioxide
© 2011 Pearson Education, Inc.
Intergovernmental Panel on Climate
Change (IPCC)
• Established by the United Nations in 1988
• It reports its assessment of climate change every 5 years
• The Fourth Assessment Report (FAR) (2007)
• Input from thousands of scientific experts and hundreds of
authors
• This assessment produced convincing evidence that
human-induced climate change is already severely
impacting global climate and sea level
• They concluded that results could be catastrophic if
greenhouse gases emissions are not reduced.
© 2011 Pearson Education, Inc.
The Kyoto Protocol: reducing
greenhouse gas emissions
• 166 nations met in Kyoto, Japan, in December 1997
• Most industrialized nations agreed to reduce emissions
• Ratified in 2005, it is in force in most industrialized
nations (but not in developing countries).
• The United States withdrew in 2001
• Kyoto was only a first step
• Levels of greenhouse gases will continue to rise
• Short-term economic impacts conflict with the long-term
consequences of climate change
• Climate change is one of the defining environmental
issues of the 21st century
© 2011 Pearson Education, Inc.
Environmental science includes “us”!
• Human societies live in the natural world
• We use materials, converting parts of it into the built
environment (towns, factories, highways)
• We change natural ecosystems into agricultural ones
• We use the environment to dump wastes
• The term environment is an inclusive concept
• It includes the natural world
• Human societies and the human-built world
Environmental science is the most multidisciplinary of
all sciences.
© 2011 Pearson Education, Inc.
The early environmental movement
• Has its roots in the late 19th century
• Unique, wild aspects of the U.S. were disappearing
• Conservation groups were formed
• National Audubon Society, National Wildlife
Federation, Sierra Club
• President Theodore Roosevelt placed 230 million
acres under public protection
© 2011 Pearson Education, Inc.
Tilling the soil + drought produced the
Dust Bowl
© 2011 Pearson Education, Inc.
The Great Depression and World War II
• During the Great Depression, conservation provided
environmental protection and jobs
• The Civilian Conservation Corps (CCC) built trails,
planted trees, and improved national parks and
forests
• In the years after World War II environmental
problems became more obvious:
• Polluted air, fouled rivers and beaches, species
declines
© 2011 Pearson Education, Inc.
A Carteret County woman was part of
the modern environmental movement
• Rachel Carson wrote Silent Spring (1962)
• She described a future with no songbirds, along with
other consequences of pesticide pollution
• It began as a grassroots initiative
• Continues to command public interest and support
• Public outcry led to the banning of DDT use in U. S.
and the formation of the EPA (Environmental
Protection Agency)
© 2011 Pearson Education, Inc.
Environmentalism
• Wildlife advocates became active in the
environmental movement
• Environmental Defense Fund, Natural Resources
Defense Council, Greenpeace, Union of Concerned
Scientists
• Environmentalists: persons and organizations
with a strong focus on environmental concerns
• Environmentalism: the widespread development
of the environmental movement
© 2011 Pearson Education, Inc.
Environmentalism has its critics
• Polluting industries often resist regulation
• They believe regulations hurt the economy
• Some find allies in federal, state and local
governments including Congress and presidents
• Political battles surround almost every
environmental issue
•
•
•
•
Bitter conflicts arise over publicly owned resources
Special interests oppose regulations
Politics always accompanies policy
Many environmental issues are so controversial,
people are left confused
© 2011 Pearson Education, Inc.
Three unifying themes for sustainability
© 2011 Pearson Education, Inc.
Sustainability—what does that mean?
• A system is sustainable if it can continue indefinitely
without depleting material or energy resources
• The term was first applied to sustainable yields in
forestry and fisheries
• Harvest resources but stay within the capacity of the
population to grow and replace itself
• Also applies to other resources
Natural ecosystems are sustainable:
• They thrive over time by recycling nutrients; they also
maintain a diversity of species
Are we living sustainably???
© 2011 Pearson Education, Inc.
A new commitment is needed NOW.
• People everywhere recognize that “business as
usual” is not sustainable
• Current trends will lead to a point where resources
can’t support humans
• Civil order will break down
• Good news is available, too
• Fewer people are starving; life expectancy is rising
• Population growth rates are slowing
© 2011 Pearson Education, Inc.
Sustainable societies
• Many of our interactions with nature are not
sustainable
•
•
•
•
Declining biodiversity
Greenhouse gases
Human population growth
Energy and other resource consumption
• Can you think of other ways we are not in balance
with nature?
• If we don’t achieve sustainability, nature will do it for
us
© 2011 Pearson Education, Inc.
We need more stewards!
• They are people who try to stop environmental
destruction and pollution. Stewards care for
something they do not own.
• Stewards are people like…
• Rachel Carson, who wrote Silent Spring (1962)
• Pablo Mendoza and Luis Yanza of Ecuador
• demanded that Chevron pay for its petroleum contamination
• Ecuador passed stronger environmental laws
• They won the 2008 Goldman Prize
• Wangari Maathai of Kenya, who planted trees
© 2011 Pearson Education, Inc.
Pablo F. Mendoza and Luis Yanza
© 2011 Pearson Education, Inc.
Dr. Maathai: 2004 Nobel Peace Prize
winner
© 2011 Pearson Education, Inc.