Download Environmental science

This lecture will help you understand:
• The meaning of the term
environment
• The field and interdisciplinary
nature of environmental science
• The importance of natural
resources and ecosystem services
• The scientific method and the
process of science
• Some pressures on the global
environment
• Concepts of sustainability and
sustainable development
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Our island: Earth
• Earth may seem enormous
- But it and its systems are finite and limited
- We can change the Earth and damage its systems
• Environment: all the living and non-living things
around us
- Animals, plants, forests, farms, etc.
– Continents, oceans, clouds, ice caps
– Structures, urban centers, living spaces
– Social relationships and institutions
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Humans are part of nature
• Humans depend on a healthy, functioning planet
• The fundamental insight of environmental science:
- We are part of the natural world, but we can also change it
- Our interactions with its other parts matter a great deal
• We depend completely on the environment for survival
- Increased health, longer lives, wealth, mobility, leisure
- But natural systems have been degraded by pollution, soil
erosion, species extinction, etc.
- Environmental changes threaten long-term health and
survival
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Environmental science
• Environmental science is the study of:
- How the natural world works
- How the environment affects humans and vice versa
• We need to understand our interactions with the environment
- To creatively solve environmental problems
• Global conditions are rapidly changing
- We are also rapidly gaining knowledge
- The opportunity to solve problems is still available
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We rely on natural resources
• Natural resources = substances and energy sources needed
for survival
• Renewable natural resources: can be replenished
- Perpetually renewed: sunlight, wind, wave energy
- Renew themselves over short periods: timber, water, soil
- These can be destroyed
• Nonrenewable natural resources: unavailable after depletion
- Oil, coal, minerals
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We rely on ecosystem services
• Natural resources are “goods” produced by nature
- Earth’s natural resources provide “services” to us
• Ecosystem services: arise from the normal functioning of
natural services
- Purify air and water, cycle nutrients, regulate climate
- Pollinate plants, receive and recycle wastes
• We degrade ecosystem services
- By depleting resources, destroying habitat, generating
pollution
- Increased human affluence has intensified degradation
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Human population growth amplifies impacts
• There are over 7 billion
humans
http://www.census.gov/main/ww
w/popclock.html
• Agricultural revolution
- Crops, livestock
- Stable food supplies
• Industrial revolution
- Urbanized society powered
by fossil fuels (oil, gas, coal)
- Sanitation and medicines
- Pesticides and fertilizers
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Resource consumption exerts pressures
• Exploitation and consumption of resources is also a problem
• Garret Hardin’s tragedy of the commons: unregulated
exploitation of public resources leads to depletion and damage
– Soil, air, water
• Resource users are motivated by self interest
– They increase use until the resource is gone
• Solutions to the tragedy of the commons?
– Private ownership?
– Voluntary organization to enforce responsible use?
– Governmental regulations?
© 2011 Pearson Education, Inc.
Our “ecological footprint”
• Affluence increases consumption
• Ecological footprint: the
environmental impact of a person
or population
- The area of biologically
productive land + water
- To supply raw resources and
dispose/recycle waste
• People in rich nations have much
larger ecological footprints
If everyone consumed the amount of resources the U.S.
does, we would need 4.5 Earths!
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Overshoot
Overshoot: humans have surpassed the Earth’s capacity
to support us
We are using renewable resources 30% faster than they are
being replenished
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Environmental science
• How will resource consumption and population growth
impact today’s global society?
• Civilizations have fallen after degrading the environment
- Easter Island, Greek and Roman empires
- Once lush regions (i.e. Iraq) are now barren deserts
• Civilizations succeed or fail according to how they
interact with the environment
- Along with how they respond to problems
• Environmental science can help build a better world
© 2011 Pearson Education, Inc.
The nature of environmental science
Environment  impacts  Humans
• Its applied goal: solving environmental
problems
• Solutions are applications of science
• An interdisciplinary field
- Natural sciences: examines the
natural world
- Environmental science programs
- Social sciences: examines values and
human behavior
- Environmental studies programs
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What is an “environmental problem”?
• Whether an environmental
condition is seen as a problem
- Depends on the individual and
situation
• Ex.: the pesticide DDT
- In malaria-infested Africa:
welcome because it kills
malaria-carrying mosquitoes
- In America: not welcome, due
to health risks
People also differ in their awareness of problems,
depending on who they are, where they live, what they do
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Environmental science is not environmentalism
• Environmental science
– Pursues knowledge about
the environment and our
interactions with it
– Scientists try to remain
objective and free from bias
• Environmentalism
– A social movement
– Tries to protect the natural world
from human-caused changes
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Theories and paradigm shifts
• Theory: a well-tested and widely accepted explanation
– Consolidates widely-supported, related hypotheses
• Paradigm shift – a dramatic upheaval in thought
– It changes the dominant viewpoint
• Wicked problems: are complex, with no simple solution
– i.e. environmental problems
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Sustainability and the future of our world
• Sustainability: we must live within our planet’s means
- So the Earth and its resources can sustain us and all life
for the future
• Sustainability involves conserving resources
- Developing long-term solutions
- Keeping fully functioning ecosystems
• Natural capital: Earth’s total wealth of resources
- We are withdrawing it faster that it’s being replenished
- We must live off Earth’s natural interest (replenishable
resources), not its natural capital
© 2011 Pearson Education, Inc.
Population & consumption
• Population growth amplifies all human impacts
- The growth rate has slowed, but we still add more than
200,000 people to the planet each day
• Resource consumption has risen faster than population
- Life has become more pleasant
- Rising consumption also amplifies our demands on the
environment
• The 20 wealthiest nations have 55 times the income of
the 20 poorest nations
- Three times the gap that existed 40 years ago
© 2011 Pearson Education, Inc.
Ecological footprints are not all equal
• Not everyone benefits
equally from rising affluence
• The ecological footprints of
countries vary greatly
- The U.S. footprint is much
greater than the world’s
average
• In the U.S. the richest 1%
- Have 25% of all income
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We face challenges in agriculture
• Technology expanded food production
– Leading to increased population and consumption
• It’s one of humanity’s greatest achievements, but it
comes at an enormous environmental cost
– Nearly half of the land surface is used for agriculture
– Chemical fertilizers and pesticides poison and change
natural systems
– Erosion, climate change and poor management
destroy millions of acres each year
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Humans have changed the Earth’s landscape
Agriculture, urban sprawl, and other land uses have
substantially affected most of the landscape of all nations
© 2011 Pearson Education, Inc.
We face challenges in pollution
• Waste products and artificial chemicals
– Are used in farms, industries, and households
– Contaminate land, water and air
– Kill millions of people
• Humans are affecting the Earth’s climate
– Melting glaciers
– Rising sea levels
– Impacted wildlife, forests, health and crops
– Changed rainfall and increased storms
Since the Industrial Revolution, atmospheric carbon
dioxide concentrations have risen by 39%, to the
highest level in 800,000 years
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We face challenges in biodiversity
• Biodiversity: the cumulative
number and diversity of
living things
• Human actions have driven
many species extinct
– Biodiversity is declining
dramatically
– We are setting in motion a
mass extinction event
Biodiversity loss may be our biggest problem; once
a species is extinct, it is gone forever
© 2011 Pearson Education, Inc.
The Millennium Ecosystem Assessment
•
The most comprehensive scientific assessment of the
condition of the world’s ecological systems
•
In 2005, 2000 of the world’s leading scientists from
100 nations reported :
–
Humans have drastically altered ecosystems
–
These changes have contributed to human wellbeing and economic development, but at a cost
–
Environmental degradation could get much worse
–
Degradation can be reversed, but it requires work
© 2011 Pearson Education, Inc.
Our energy choices will affect our future
• The lives we live today are due to fossil fuels
– Machines
– Chemicals
– Transportation
– Products
• Fossil fuels are a one-time bonanza
– Supplies will certainly decline
We have used up ½ of the world’s oil supplies; how
will we handle this imminent fossil fuel shortage?
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Sustainable solutions abound
We must develop solutions that
protect both our quality of life
and the environment
•
•
•
•
•
•
Renewable energy and efficiency
Organic agriculture
Legislation and technology to reduce pollution
Protect species and their habitat
Recycling, decreasing waste
Decrease greenhouse gas emissions
© 2011 Pearson Education, Inc.
Are things getting better or worse?
• Many people think environmental conditions are better
– Cornucopians: human ingenuity will solve any
problem
• Some think things are much worse
– Cassandras: predict doom and disaster
• How can you decide who is correct?
– Are the impacts limited to humans, or are other
organisms or systems involved?
– Are the proponents thinking in the long or short term?
– Are they considering all costs and benefits?
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Sustainable development
• Involves environmental protection, economic well-being
and social equity
• It does not threaten economic and social needs
- Humans cannot exist without an intact, functioning
ecosystem
• Sustainable development: the use of resources to satisfy
current needs
- Without compromising future availability of resources
© 2011 Pearson Education, Inc.
Sustainable development
• The poor suffer the most from environmental degradation
• Development: purposeful changes to improve the quality
of life
• Sustainable development: resources satisfy current
needs
- Without compromising future availability of resources
- It is not ever increasing economic gain
- It values and prioritizes environmental protection
- Human-made capital cannot substitute for natural
capital
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Will we develop in a sustainable way?
• The triple bottom line:
sustainable solutions that meet
- Environmental protection
- Economic goals
- Social equity
• Humans must apply knowledge
from the sciences to
- Limit environmental impacts
- Maintain functioning
environmental systems
We must make an ethical commitment to current and
future generations
© 2011 Pearson Education, Inc.
Conclusion
• Environmental science helps us understand our
relationship with the environment
- It informs our attempts to solve and prevent problems
• Identifying a problem is the first step in solving it
• Solving environmental problems can move us towards
health, longevity, peace and prosperity
- Environmental science can help us find balanced
solutions to environmental challenges
© 2011 Pearson Education, Inc.