Chapter 1 & 2 - Studying the State of Our Earth & Environmental Science

CHAPTER ONE

Fracking: hydraulic fracturing, method of oil/gas extraction that uses high pressure fluids to force open cracks in underground rocks -> cheaper & larger quantities of natural gas (decrease burning coal/air pollution)

• large amt of water usage (millions of gallons). is taken away from local rivers & @ risk of contamination

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MODULE 1 - ENVIRONMENTAL SCIENCE

• Environment: Conditions surrounding us that influence life. (living or nonliving) major impact on how we live our lives (heath, growth, necessary supplies)
• Environmental Science: The field of study that looks at interactions among human systems & those found in nature (relationship between humans and the environment)
• System: components that influence each other by exchanging energy / materials (any size)

Ei. Fracking: causes changes within a system by contaminating drinking water

• Ecosystem: Specific location w constant interactions between living & nonliving components
• Biotic: living
• Abiotic: nonliving
• Environmentalism: Environmentalists that helps protect the environment through activism, and education
• Environmentalist: A person who participates in environmentalism
• Environmental studies: Field of study (chemistry, biology and ecology, earth science, toxicology, atmospheric science, law, literature/writing, ethics, politics/policy, economics)

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Humans alter natural systems

• Growing human population leads to manipulating systems by building cities, agricultural farms, neighborhoods & killing species (fertilizers)
• Humans often hunted large animals until extinction
• Humans used fire to capture animals -> prevented growth of trees & influence the increase of other species

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Converting Between Hectares and Acres

• Hectare: land area (ha is 100m by 100m)
• 2.5 (2.47) acres = 1 ha

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Module 1 summary: Fracking bad. as humans progress, habitats and species begin to suffer along

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MODULE 2 - ENVIRONMENTAL INDICATORS & SUSTAINABILITY

• Ecosystem services: The processes by which life-supporting resources are produced (clean water, timber, fisheries, & agricultural crops)
• How do humans affect the ecosystem’s services (positive & negative)
• Humans take environment for granted
• Environmental indicators: Describes/measures the current state of an environmental system
• Biological diversity, food production, average global surface temperature and carbon dioxide concentrations in the atmosphere, human population, and resource depletion

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Biological diversity

• Biodiversity (Biological diversity): Diversity of life forms in an environment (Ecosystem, species, and genetic)
• Genetic diversity: Measure of the genetic variation among individuals in a population
• Higher genetic diversity = responds better to change (vise versa)
• Species: A group of organisms that is distinct from other groups in its morphology (body form & structure), behavior, or biochemical properties
• Different sizes, shapes, colors, & roles
• Species Diversity: Number of species in a region or in a particular type of habitat
• Ecosystems with more species = more productive
• Scientists often focus on species diversity as a critical environmental indicator
• Ei. increase or decrease in population is an indicator
• Speciation: Evolution of new species (slow process)
• Natural evolutionary process: species naturally arise and others go extinct
• Background extinction rate: Average rate where species become extinct over a long period of time
• Stress to a species causes a faster extinction rate (habitat destruction, climate change, overharvesting, and other species)
• Ecosystem diversity: Measure of diversity of ecosystems/habitats that exist in a given region
• Measured in hectares (ha)

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Food Production

• Food production: Ability to grow food to nourish the human population
• Healthy ecosystems leads to healthy species/organisms
• Growth of human population is restricting the growth of food species
• Humans have found more ways to efficiently produce food -> World grain production has increased (expanding irrigation & new crop varieties)
• Food shortages lead to higher food prices
• (2008) Grain production has not increased w human population (bc of soil degradation, crop diseases, drought, flood) -> government discourages food production which will soon lead to uncultivated/preserved land
• Per Capita: how much each person individually takes/consumes

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Average Global Surface Temperature and Carbon Dioxide Concentrations

• Greenhouse gasses: Gasses in Earth’s atmosphere that trap heat near the surface (carbon dioxide) helps maintain a steady climate
• Anthropogenic: Derived from human activities (combustion of fossil fuels & lack of forests bc those two things store the most amt of CO2)

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Human Population (7.79 billion)

• Population shows the health of the environment by testing the Earth’s resources

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Resource Depletion

• Natural resources have been depleting since the human population began increasing
• Many human activities harm the environment (Pollution, mining, waste from manufactured products)
• Many natural resources are finite/can not be reused (coal, oil , and uranium)
• Many infinite resources do not have enough time to replenish
• Development: Improvement in human well-being through economic advancement (automobile use, meat consumption, living habits)
• As economics increase, so does resource consumption

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The Impact of Consumption on the Environment

• Sustainability: Living on Earth that allows humans to use its resources without depriving future generations of those resources
• Ei. Easter Island was overpopulated. led to the overuse of the island’s soil/water resources. No more trees led to erosion/decrease of food production
• Environmental systems must not be damaged beyond their ability to recover
• Renewable resources must not be depleted faster than they can regenerate
• Nonrenewable resources must be used sparingly
• Sustainable development: Development that balances current human well-being/economic advancement with resource management for the benefit of future generations
• depends on the number of people using a resource along w how they are using it
• conserving and finding alternatives to nonrefundable resources, securing the environment, and allowing it to supply renewable resources
• Human’s needs has advanced & modified over many years (Biophilia: Love of life)

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The Ecological Footprint

• Ecological footprint: Amt an individual consumes in their lifestyle (measured in area of land)
• Increase population = use of more resources
• Wealthier countries = ability to enforce pollution controls/invest to protect species
• Using or protecting one has chain effects on the others

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MODULE 3 - SCIENTIFIC METHOD

• Scientific method: A method to explore the natural world, draw inferences from it, & predict the outcome of certain events, processes, or changes (helps scientists communicate data)

1. Observing and questioning: figure out where to begin the scientific research
2. Forming hypothesis: A testable conjecture about how something works.
3. Easier to prove smth wrong. null hypothesis: Prediction that there is no difference between groups/conditions, a statement that can be proved wrong
4. Collecting data:
5. Replication: The data collection procedure of taking repeated measurements
6. Sample size: Number of times a measurement is replicated in data collection
7. Accuracy: How close a measured value is to the actual or true value
8. Precision: How close the repeated measurements are to one another
9. Uncertainty: Estimate of how much a measured value differs from a true value
   10. Interpreting results:
   11. Inductive reasoning: process of making general statements from specific facts
   12. Deductive reasoning: process of applying a general statement to a specific fact
   13. Disseminating Findings

• Theory: A repeated hypothesis that has reached wide acceptance (can't be contradicted)
• Control group: A group that experiences exactly the same conditions as the experimental group, except for the single variable under study
• Natural experiment: A natural event that acts as an experimental treatment in an ecosystem
• Critical thinking: Question the source of the information, consider the methods/processes that were used to obtain the information, and draw your own conclusions

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Environmental science presents unique challenges

• Lack of Baseline Data: nature experiments are not true bc of the alterations of the earth’s living environment
• Subjectivity: Choices may be difficult since it is unknown which one is more sustainable
• Interactions: Environmental systems have so many interacting parts that intertwine
• Human Well-Being: Ppl who are unable to meet their basic needs = less likely to be interested about the state of the natural environment -> The principle of environmental equity
• Environmental justice: the fair treatment and meaningful involvement of all people regardless of race with respect to the development of sustainability

City: biodiversity; energy, climate change, & ozone depletion; food/agriculture; hazardous materials; human health; parks, open spaces, & streetscapes; solid waste; transportation; & water

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CHAPTER TWO

MODULE 4 - SYSTEMS AND MATTER

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Radioactivity

• Isotope’s nuclei can be stable or unstable depending on mass number and amt of neutrons
• Unstable = radioactive
• Radioactive decay: Spontaneous release of material from the nucleus of radioactive isotopes
• Half-life: The time it takes for one-half of an original radioactive parent atom to decay
• Helps protect humans from harmful radioactive decay

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Chemical Bonds

• Polar molecule: Molecule in which one side is more positive & the other side is more negative

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Surface Tension and Capillary Action

• Surface tension: A property of water that results from the cohesion of water molecules at the surface of a body of water and that creates a sort of skin on the water’s surface (allows it to resist an external force)
• Stronger the surface tension = stronger cohesive forces (ie. water)
• Capillary action: A property of water that occurs when adhesion of water molecules to a surface is stronger than cohesion between the molecules (ie. absorption of a paper towel) (the movement of water within the spaces w/out an outside force)
• Many substances dissolve well in water bc their polar molecules bond easily with other polar molecules
• Boils at 212* F and freezes at 32*F

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Acids, Bases, and pH

• Acid: A substance that contributes hydrogen ions to a solution
• When dissolved in water, it dissociates into positive charged hydrogen ions
• Base: A substance that contributes hydroxide ions to a solution
• When dissolved in water, it dissociates into negative charged hydrogen ions & positive ions
• pH: The number that indicates the relative strength of acids and bases in a substance
• Pure water is 7 (# of hydrogen ions = # of hydroxide ions)
• +7 is basic (alkaline) & -7 is acidic

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Chemical Reactions and the Conservation of Matter

• Chemical reaction: occurs when atoms separate or recombine with molecules
• Atoms are not created or destroyed but bonds between atoms may change
• Can occur in any direction
• Law of conservation of matter: A law of nature stating that matter can not be created or destroyed; it can only change form
• Not able to disprove of hazardous materials bc the atoms will enter the atmosphere

Module 4 summary: Atoms can completely change bc of radioactiveness, water has skin that can conflict w other materials, water can move all by itself, acid releases more hydrogen, bases release more hydroxide

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MODULE 5 - ENERGY, FLOWS, AND FEEDBACK

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• Joule: Amount of energy used when a 1-watt light bulb is turned on for 1 second

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Forms of energy

• Potential energy: Stored energy that has not been released (water behind a dam)
• Kinetic energy: The energy in motion (water out of dam)
• Temperature: The measure of the average kinetic energy of a substance
• Changes in temp can convert matter (Fast moving molecules in ice turns into water)

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Law of thermodynamics

• First law of thermodynamics: A physical law which states that energy can neither be created nor destroyed but can change from one form to another
• Gasoline burns energy
• Second law of thermodynamics: The physical law states that when energy is transferred, the quantity of energy remains the same, but its ability to do work diminishes
• Waste heat: Energy that is converted into a useless form of energy
• Energy efficiency: The ratio of the amount of energy expended in the form you want to the total amount of energy that is introduced into the system
• Energy quality: The ease with which an energy source can be used for work
• Entropy: Randomness in a system (Randomness always increasing in a system, unless new energy from outside the system is added to create order)
• Little amt of energy comes from digested food, most becomes body heat (heat has lots of entropy bc it is random)

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System Dynamics

• Open system: Exchanges of matter of energy occur across system boundaries (majority)
• Closed system: Matter and energy do not occur across boundaries
• Input: An addition to a system
• Output: A loss from a system
• Systems analysis: An analysis to determine inputs, outputs, and changes in a system under various conditions
• Steady state: A state in which inputs = outputs so that the system is not changing over time
• First step - measure amt of energy and matter
• A system some things can be steady while other things are not
• Feedback: Adjustments in inputs or output rates caused by changes to a system (cycles)
• Negative feedback loop: A system responds to a change by returning to its original state, or by decreasing the rate at which the change is occuring
• Positive feedback loop: Change in a system is amplified

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