Essential Environment 4e Chapter 1 PowerPoints

© 2012 Pearson Education, Inc.

Lecture Presentations prepared by Heidi Marcum

Essential Environment:The Science Behind the Stories 4th Edition

Withgott/Laposata

Chapter 1

Science and Sustainability: An

Introduction to Environmental

Science


This lecture will help you understand:

• The term environment and the field of environmental science

• Natural resources and ecosystem services

• Population growth and resource consumption

• The scientific method and the process of science

• Environmental ethics• Global environmental pressures• Concepts of sustainability and

sustainable development


Our island, Earth

• The Earth may seem enormous to us– But Earth and its systems are finite and limited

– We can change Earth and damage its systems

• Environment: all the living and nonliving things around us– Continents, oceans, clouds, ice caps

– Animals, plants, forests, farms, etc.

– Structures, urban centers, living spaces

– Social relationships and institutions


People exist within the environment

• Humans depend on a healthy, functioning planet• The fundamental insights 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 our long-term well-being

and survival


Environmental science explores our interactions with the world

• 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

– We still have the opportunity to solve problems


We rely on natural resources

• Natural resources: substances and energy sources we need for survival

• Renewable natural resources: replenished over short periods– Perpetually renewed: sunlight, wind, wave energy– Renewed over short periods and can be depleted: timber, water,

soil• Nonrenewable natural resources: unavailable after depletion

– Oil, coal, minerals


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 and allow us to survive– 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 and population have intensified

degradation


Human population growth amplifies impacts

• There are now over 7 billion humans

• Agricultural revolution: 10,000 years ago

– Growing crops and livestock led to sedentary lives

– Stable food supplies increased survival and children

• Industrial revolution: mid 1700s

– Urbanized society powered by fossil fuels (oil, gas, coal)

– Sanitation and medicines

– Pesticides, fertilizers


Resource consumption exerts pressures

• Growth in resource consumption is also a problem• Garrett Hardin’s tragedy of the commons: unregulated

exploitation of public resources leads to depletion and damage

– Grazing land, forests, 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?


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 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!


Overshoot

We are using renewable resources 50% faster than they are being replenished

Overshoot: humans have surpassed Earth’s capacity to sustainably support us


Environmental science helps us avoid past mistakes

• How will resource consumption and population growth impact today’s global society?

• Civilizations have fallen when population growth and consumption overwhelm resource availability

– Easter Island; Greek, Roman and Mayan empires– Once lush regions (e.g., Iraq) are now barren deserts

• Civilizations succeed or fail according to how they interact with the environment and respond to problems

• Environmental science can help build a better world


The nature of environmental science

Environment impacts Humans

• Its applied goal: solving environmental problems– Solutions are applications of

science• It is a broad, interdisciplinary

field• Natural sciences: examine the

natural world– Environmental science programs

• Social sciences: examine human interactions and institutions– Environmental studies programs


Environmental science: an integrated approach

• An integrated approach to addressing environmental problems can solve problems

• Example: leaded gasoline makes car engines run smoothly– But emissions cause brain damage and death

– Multiple professions worked together and banned the largest source of atmospheric lead emissions in the U.S.


Environmental science is not environmentalism

• Environmental science: the pursuit of knowledge about the environment and our interactions with it– Scientists try to remain objective and free from bias,

personal values, preconceptions

• Environmentalism: a social movement – Tries to protect the natural world from human-caused

changes


The nature of science

• Science: a systematic process for learning about the world and testing our understanding of it– The body of knowledge arising from the dynamic process

of questioning, observation, testing, discovery

• Knowledge gained from science can solve society’s needs– Develop technology – Inform policy and management decisions

• Scientists are motivated to:– Develop useful applications– Understand how the world works


Applications of science

Prescribed burning restores healthy forests

Engineering and technology

Energy-efficient electric car

Policy and management


Science tests ideas by examining evidence

• Science asks and answers questions• Scientists do not simply accept conventional wisdom

– They judge ideas by the strength of their evidence

• Observational (descriptive) science: information is gathered about organisms, systems, processes, etc.– Cannot be manipulated by experiments– Phenomena are observed and measured– Used in astronomy, paleontology, taxonomy, genomics

• Hypothesis-driven science: targeted, structured research – Experiments test hypotheses using the scientific method


The scientific method: a traditional approach

• It tests ideas with observations• A scientist makes an

observation and asks questions about some phenomenon

• Hypothesis: a statement that tries to answer the question

• The hypothesis generates predictions: specific statements that can be directly tested


The scientific method tests hypotheses

• Experiment: tests the validity of a prediction or hypothesis

• Variables: conditions that can change or be manipulated

• The data (information) are analyzed and interpreted– By statistical tests

• The experiment either supports or rejects the hypothesis


Experiments manipulate variables

• Independent variable: can be manipulated

• Dependent variable: depends on the independent variable

• Controlled experiment: the effects of all variables are controlled

– Except the independent variable whose effect is being tested

• Control: an unmanipulated point of comparison

• Treatment: a manipulated point of comparison

• Quantitative data: information expressed by numbers


Hypotheses are tested in different ways

• Manipulative experiments: reveal causal relationships– The independent variable is manipulated

– Yields the strongest evidence

– Long-term, large-scale processes can’t be manipulated

• Natural tests: search for correlations among variables

– Compare how dependent variables are expressed in different contexts

– Weaker evidence, but shows real-world complexity

– Results are not neat-and-clean, or black-and-white

– Addresses immense-scale questions (i.e., ecosystems)


The scientific process: part of the scientific community

• Peer review: other scientists judge the work

• Conferences: scientists interact with others

• Grants and funding: from private or government sources

– Intense competition

• Repeatability: others try to reproduce the results


Experimental design

Animation: Spontaneous Generation 1Right-click slide / Select “Play”


Experimental results, 8-year study



Control group and experimental group



Theories and paradigm shifts

• Theory: a well-tested and widely accepted explanation– Extensively validated by great amounts of research

– Consolidates widely supported, related hypotheses

– It is not “just a theory” (speculation)

– Example: Darwin’s theory of evolution by natural selection

• With more data, scientific interpretations can change• Paradigm shift: a new dominant view replaces the old

– Example: Earth, not the sun, is the center of the universe

– Example: plate tectonics move continents


Ethics

• Ethics: the study of good and bad, right and wrong

– The set of moral principles or values held by a person or society that tell us how we ought to behave

– People use criteria, standards or rules when making judgments of right or wrong

– Different cultures or worldviews lead to different values, leading to different “right or wrong” actions

• Relativists: ethics varies with social context

• Universalists: notions of right and wrong remain the same across cultures and situations


Ethical standards

• Ethical standards: criteria that help differentiate right from wrong

– Categorical imperative: the “Golden Rule,” which tells us to treat others as we want to be treated

• Utility: principle holding that the right action is the one that produces the most benefits for the most people


Environmental ethics

• Environmental ethics: application of ethical standards to relationships between human and nonhuman entities

• Hard to resolve: it depends on the person’s ethical standards and domain of ethical concern

Should we conserve resources for future generations?

Is it OK for some communities to be exposed to excess pollution?

Should we drive other species to extinction?

Is it OK to destroy a forest to create jobs for people?


Three ethical perspectives

• Anthropocentrism: only humans have rights– Costs and benefits are measured only by their impact on

people– Anything not providing benefit to people has no value

• Biocentrism: certain living things have value– All life – human and nonhuman – has ethical standing– Opposes development that destroys life – even if it creates

jobs

• Ecocentrism: whole ecological systems have value– Values the well-being of species, communities,

ecosystems– Holistic – it preserves connections between entities


Expanding ethical consideration


The preservation ethic

• Nature deserves protection for its own inherent value

– We should protect our environment in a pristine, unaltered state

John Muir’s (right, with President Roosevelt) ecocentric viewpoint advocated for the preservation of wilderness


The conservation ethic

• Use natural resources wisely

– A utilitarian standard that calls for using resources for the greatest good for the most people for the longest time

Gifford Pinchot’s anthropocentric viewpoint promoted prudent, efficient, sustainable use of resources


The land ethic

• Healthy ecological systems depend on protecting all parts– We are obligated to treat the

land ethically– The land ethic will help guide

decision making– A thing is right when it

preserves the biotic community

Aldo Leopold’s ecocentric ethical outlook calls for people to view themselves and the land as members of the same community


Environmental justice (EJ)

• Involves the fair treatment of all people with respect to the environment, regardless of race, income, or ethnicity

• The poor and minorities are exposed to more pollution, hazards, and environmental degradation

– Despite progress, they still suffer substandard conditions


Sustainability and our future

• A guiding principle of environmental science• Sustainability: living within our planet’s means

– Earth can sustain humans AND all life for the future

– Leaving our descendants with a rich, full world

– Conserving resources for future generations

– Developing solutions that work in the long term

– Requires keeping fully functioning ecological systems

• We cannot sustain human civilization without sustaining Earth’s natural systems


Earth’s resources are like a bank account

• If we deplete resources, we draw down the account• Natural capital: the accumulated wealth of Earth’s

resources– We are withdrawing our planet’s natural capital 50%

faster than it is being produced

• We must live off nature’s interest – its replenishable resources – to be sustainable

• Drawing down resources faster than they are replaced eats into nature’s capital– We cannot do this for long


We are increasing our burden on the planet

• Human population growth amplifies all environmental impacts– We add over 200,000 people to the planet each day

• Our consumption of resources has risen even faster – Life has become more pleasant for us

– But rising consumption increases the demands we make on our environment

• Increased affluence has not been equal– The gap between rich and poor countries has tripled in the

past 40 years


Ecological footprints are not all equal

• The ecological footprints of countries vary greatly

– The U.S. footprint is much greater than those developing countries


Increased population and consumption cause:

• Erosion from agriculture• Deforestation• Toxic substances• Mineral extraction and mining• Depletion of fresh water • Air and water pollution• Global climate change• Loss of Earth’s biodiversity


Humans have heavily influenced the U.S.


The 2005 Millennium Ecosystem Assessment

• The most comprehensive scientific assessment of the condition of the world’s ecological systems– And their capacity to continue supporting us

• 2,000 leading environmental scientists found:– Our degradation of environmental systems is having

negative impacts on all of us

– With care and diligence we can still turn many of these trends around


Sustainable solutions abound

• Sustainable solutions must:– Enhance quality of life– Protect and restore the environment that supports us

• Many solutions exist:– Renewable energy

sources– Improved agricultural

practices– Habitat and species

protection– Reduced emissions

of greenhouse gases


Sustainable development

• We must use resources to satisfy our needs– But leave enough resources for the future

• Satisfies the triple bottom line – environmental, economic, and social goals are all met

• We must limit our environmental impact while promoting economic development and social justice– Make an ethical commitment to current and future

generations– Apply science to solve problems

The single most important question we face is: “How can we develop sustainably?”


Conclusion

• Finding ways to live sustainably on Earth requires:– A solid ethical grounding – Scientific understanding of our natural and social systems

• Environmental science helps us:– Understand our relationship with the environment – Informs our attempts to solve and prevent problems

• Identifying a problem is the first step in solving it• Environmental science can help find balanced solutions

to environmental problems