Honors Environmental Science Lecture 2: Intro to Env. Sci. What is Science?

QUESTION: Review The term “environment” does NOT include: a)Animals and plants b)Oceans and rivers c)Structures and urban centers d)All of the above are included in this term

QUESTION: Review The term “environment” does NOT include: a)Animals and plants b)Oceans and rivers c)Structures and urban centers d)All of the above are included in this term

The nature of science Science:  A systematic process for learning about the world and testing our understanding of it  The accumulated body of knowledge arising from the dynamic process of observation, testing, and discovery A way of learning about the world that tries to eliminate sources of error when determining the truth

The nature of science Civilization depends on science and technology – Science tries to understand the world and steer a safe course – Vital for growth and development of new knowledge and technologies

The nature of science Science is essential to sort fact from fiction: – Attempts to eliminates subjective human elements – Develop solutions to the problems we face – It must be accessible and understandable to the public

Applications of science Restoration of forest ecosystems altered by human suppression of fire Policy decisions and management practices Developing technology Vaccines can prevent infection and disease

QUESTION: Review Which of the following is correct about the term “environmental science”? a)It is a social movement to protect the environment. b)It studies how the natural world works. c)It usually does not include human activities. d)It is a declining science.

Scientists ask and answer questions: It is an incremental approach to the truth Scientists do not simply accept conventional wisdom – They judge ideas by the strength of their evidence Scientists must be willing to change their ideas and accepted notions in the presence of new, valid, and contradictory data or experimental results Not knowing and being wrong are keystones of science!!!

Science asks and answers questions Observational (descriptive) science: – Information is gathered (observed) about organisms, systems, processes, etc.  Cannot be manipulated by experiments  Phenomena are observed and measured  Used in astronomy, paleontology, taxonomy, genomics, epidemiology Hypothesis-driven science: – Targeted research- Asks a particular question and predicts an answer  Experiments test hypotheses using the scientific method  Results of experiment shape the course of the research

The scientific method: a traditional approach It tests ideas – Scientists in different fields approach problems differently Assumptions: – The universe works according to unchanging natural laws – Events arise from causes, and cause other events – We use senses and reason to understand natural processes

The scientific process is part of a larger process Quality control mechanisms guards against faulty research – Includes  peer review  Publication  competition for funding  redaction of false or dishonest work

The Scientific Method A scientist makes an observation and asks questions of some phenomenon Hypothesis: a statement that tries to explain the question – A starting point for more investigation The hypothesis generates predictions: specific statements that can be directly tested The test results either support or reject the hypothesis

Experiments test the validity of a hypothesis Variable: ______________________________  Independent variable: ______________________  Dependent variable: _______________________ Controlled experiment: __________________ – Except the ____________ whose effect is being tested Control: _______________________________ Quantitative data: ______________________ Qualitative data: ________________________

Experiments test the validity of a hypothesis Variable: a condition that can change or be manipulated  Independent variable: ______________________  Dependent variable: ________________________ Dependent variable: ____________________ Controlled experiment: __________________ – Except the ____________ whose effect is being tested Control: _______________________________ Quantitative data: ______________________ Qualitative data: ________________________

Experiments test the validity of a hypothesis Variable: a condition that can change or be manipulated  Independent variable: variable that is manipulated  Dependent variable: ________________________ Controlled experiment: __________________ – Except the ____________ whose effect is being tested Control: _______________________________ Quantitative data: ______________________ Qualitative data: ________________________

Experiments test the validity of a hypothesis Variable: a condition that can change or be manipulated  Independent variable: variable that is manipulated  Dependent variable: depends on the independent variable Controlled experiment: __________________ – Except the ____________ whose effect is being tested Control: _______________________________ Quantitative data: ______________________ Qualitative data: ________________________

Experiments test the validity of a hypothesis Variable: a condition that can change or be manipulated  Independent variable: variable that is manipulated  Dependent variable: depends on the independent variable Controlled experiment: the effects of all variables are controlled – Except the ____________ whose effect is being tested Control: _______________________________ Quantitative data: ______________________ Qualitative data: ________________________

Experiments test the validity of a hypothesis Variable: a condition that can change or be manipulated  Independent variable: variable that is 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: _______________________________ Quantitative data: ______________________ Qualitative data: ________________________

Experiments test the validity of a hypothesis Variable: a condition that can change or be manipulated  Independent variable: variable that is 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: a non-manipulated point of comparison Quantitative data: ______________________ Qualitative data: ________________________

Experiments test the validity of a hypothesis Variable: a condition that can change or be manipulated  Independent variable: variable that is 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: a non-manipulated point of comparison Quantitative data: uses numbers and measurements Qualitative data: ________________________

Experiments test the validity of a hypothesis Variable: a condition that can change or be manipulated  Independent variable: variable that is 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: a non-manipulated point of comparison Quantitative data: uses numbers and measurements Qualitative data: focuses on subjective, quality related variables

QUESTION: Interpreting Graphs and Data What happens if test results can not reject a hypothesis? a)The scientist formulates a new hypothesis. b)It shows the test failed. c)The hypothesis was supported d)The predictions may not have been correct.

Hypotheses are tested in different ways Manipulative experiments yield the strongest evidence (why?) Can reveal causal relationships Lots of things can’t be manipulated Natural tests show real-world complexity Results are not neat and clean Answers aren’t black and white

Hypotheses are tested in different ways Experiments are better at producing a strong body of evidence to support causation. Experimentation is important to all fields of science, though not always possible (or ethical) Correlations are also important for establishing relationships between events. Correlations relies on statistical relationships to typically establish attribution rather than causation.

Hypotheses are tested in different ways Bradford Hill Criteria for Causation:  Strength of Association  Consistency of Findings (across studies)  Specificity- lack of other possibilities  Temporality- sequence of events (cause must precede effect)  Biological gradient- more means greater effect  Plausibility- a plausible mechanism exists whereby the cause can effect change (sometimes limited by current knowledge  Coherence-between epidemiological and laboratory findings  Experiment- occasionally available  Analogy- similar factors might have similar effects

QUESTION: Review If you add various amounts of fertilizer to plants in a laboratory, the fertilizer would be a ______ variable. a)Correlative b)Natural c)Independent d)Rare

QUESTION: Review If you add various amounts of fertilizer to plants in a laboratory, the fertilizer would be a ______ variable. a)Correlative b)Natural c)Independent d)Rare

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

Theories and paradigm shifts Paradigm shift – changes in how one sees information. New Paradigms emerge that are different and better. Examples:  Ptolemaic to Copernican Cosmology  Spontaneous generation to Biogenesis  Continental Drift to Plate tectonics

Science and the Environment Environmental Science deals with many complex systems to determine relationships and establish patterns  Food production  Pollution  Biodiversity  Energy  Climate  Solutions!

We face challenges in agriculture Technology expanded food production – Leading to increased population and consumption Agriculture is one of humanity’s greatest achievements, but it can come at an enormous environmental cost – Nearly half of the land surface is used for agriculture – Chemical fertilizers and pesticides pollute and change natural systems – Erosion, climate change and poor management destroy millions of acres each year

Humans have changed the Earth’s landscape Agriculture, urban sprawl, and other land uses have substantially affected most of the landscape of all nations

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

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

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 well- being and economic development, but at a cost – Environmental degradation could get much worse – Degradation can be reversed, but it requires work

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?

Sustainable solutions abound Renewable energy and efficiency Organic agriculture Legislation and technology to reduce pollution Protect species and their habitat Recycling, decreasing waste Decrease greenhouse gas emissions We must develop solutions that protect both our quality of life and the environment

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?

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

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

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

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

QUESTION: Weighing the Issues Do you think it is ethical for the United States to have the largest ecological footprint in the world? a)Yes, because we find the most new technologies and resources. b)Yes, because the footprint of the United States is not really that large. c)Definitely not; people in the United States need to reduce their footprint. d)It does not matter; it’s not that important.