CH-1-2 Environmental Problems, Their Causes, and Sustainability – Living in the Environment: Principles, Connections, and Solutions : Book Guide

This Document Contains Chapters 1 to 2 HUMANS AND SUSTAINABILITY: AN OVERVIEW Chapter 1 Environmental Problems, Their Causes, and Sustainability Summary 1. All life depends on energy from the sun, solar capital, and the resources and ecological services of the earth, natural capital, to survive. An environmentally sustainable society provides for the current needs of its people without undermining the ability of future generations to do the same. 2. The world’s population is growing exponentially, adding about 80 million people per year. Economic growth increases a country’s capacity to provide goods and services to its people. Economic development uses economic growth to improve standards of living. Globalization is a process of increasingly interconnecting people through social, economic, and environmental global changes. 3. The earth’s main resources are perpetual resources like solar energy, renewable resources like forests and fresh water, and nonrenewable resources like oil and gas. The resources can be depleted or degraded by overuse, by waste, by pollution, and by man’s increasing “ecological footprint.” 4. The principle types of pollution are air, water, soil, and food pollutants. We can prevent pollution or clean up pollution. Prevention is far preferable because cleaning up pollution often causes additional pollutants in another part of the environment. 5. The basic causes of today’s environmental problems are population growth, wasteful use of resources, the tragedy of the commons, poverty, poor environment accounting, and ecological ignorance. They are interconnected because of political and economic practices that are not equitable for various populations, in resource consumption and in technological applications. 6. The world’s current course is not sustainable. Environmental sustainable development encourages environmentally beneficial forms of economic growth and discourages environmentally harmful growth. Key Questions and Concepts 1-1 What are three principles of sustainability? CORE CASE STUDY. Contemporary society faces many environmental problems. Sustainability is the capacity of natural systems and cultural systems to survive and flourish indefinitely. As we look to the future, our actions today are pivotal to our ultimate sustainability. A. The environment is everything around us. Environmental science is an interdisciplinary study of how humans interact with their environment. B. Three goals of environmental science are: 1. to learn how nature works. 2. to understand how we interact with the environment. 3. to find ways to address environmental problems and embrace sustainability. C. Ecology studies relationships between living organisms and their environment. D. Environmentalism is a social movement dedicated to protecting life support systems for all species. E. A path toward sustainability includes three overarching themes: 1. Reliance on solar energy. 2. Biodiversity. 3. Chemical or nutrient cycling. F. Natural capital is the natural resources (materials and energy in nature) and natural services (natural processes) that support ecosystems and economies. G. Resources are that which can be taken from the environment to meet our needs or wants. 1. Perpetual resources are continuously available (sunlight) 2. Renewable resources can be replenished in the foreseeable future (forests, fertile topsoil). 3. Non-renewable resources are found in fixed quantities and are not renewable on a human time scale. H. Economic growth is an increase in a nation’s output of goods and services, measured by gross domestic product (GDP). 1. Economic development uses economic growth to improve living standards a. More developed countries make up 20% of the world’s population and use 88% of all resources. 1-2 How Are Our Ecological Footprints Affecting the Earth? A. The process of depleting resources is known as environmental degradation or natural capital degradation. B. Pollution is any presence in the environment that is harmful to health or survival or humans or other organisms. 1. Point sources are single identifiable sources; non-point sources are dispersed. 2. Biodegradable pollutants break down over time and nonbiodegradable pollutants cannot break down. 3. Pollutants can have three kinds of effects: a. Disrupt or degrade life-support systems for humans or other species. b. Damage wildlife, human health, or property. c. Create nuisances. 4. There are two ways to deal with pollution: a. Pollution cleanup. b. Pollution prevention. C. The Tragedy of the Commons describes the overuse or degradation of freely available resources. The cumulative effect of many users exploiting a common resource can degrade it such that no one can benefit from it. D. Ecological footprint 1. The amount of biologically productive land and water needed to supply renewable resources and absorb waste for people in a given area. 2. Humanity’s ecological footprint exceeds by at least 30% the earth’s biological capacity to support life. E. IPAT summarizes environmental impact 1. Impact (I) = Population (P) x Affluence (A) x Technology (T). CASE STUDY: The number of affluent consumers is rising rapidly, as people in underdeveloped countries attain a middleclass lifestyle. China is already a leading consumer of many resources, and its economy and population are continuing to grow at a rapid rate. Thus, its ecological footprint and overall level of resource consumption are expected to continue to grow. F. Ecological tipping point refers to an irreversible shift in the behavior of a natural system. We currently face three potential tipping points: 1. Collapse of fish populations from overfishing. 2. Species extinction from overharvesting and habitat destruction. 3. Climate change from burning coal and oil. G. Culture describes a society’s knowledge, beliefs, technology and practices. 1. Three major cultural changes have occurred in human history a. Agricultural revolution: 10,000 – 12,000 years ago when people began growing and breeding plants. b. Industrial-medical revolution: 275 years ago machines and medical advances improved lives. c. Information-globalization revolution: 50 years ago new technologies allow for global communications and trade. d. A fourth, called the sustainability revolution, is advocated by many environmental scientists. 1-3 Why do we have environmental problems? A. Four major causes of environmental problems are: 1. Population growth. 2. Wasteful resource use. 3. Poverty. 4. Poor environmental accounting. B. Exponential growth occurs when a population increases by a fixed percentage per unit of time. 1. There are roughly 6.9 billion people on earth in 2010. There may be as many as 9.3 billion by 2050. No one knows how many people the Earth can support. C. Affluence results in high levels of consumption. 1. Affluence can lead to an unsustainable addiction to acquiring material things. 2. Affluence can lead to better education, improved health, and more resources to address environmental issues. D. Poverty occurs when people are unable to fulfill their basic needs. 1. 1/5 of the world population lives in extreme poverty. 2. Poverty conditions in heavily populated areas can have significant environmental impacts. 3. Pollution and environmental degradation can have severe impacts on the poor. Three significant health issues are: a. malnutrition b. inadequate sanitation and access to safe drinking water c. respiratory disease E. Prices of goods do not include their harmful environmental costs. F. Environmental worldviews and ethics determine the way people view the seriousness of environmental problems. 1. Your environmental worldview is your assumptions and values about the world and your role. 2. Environmental Ethics are beliefs about what is right and wrong in our treatment of the environment. a. The planetary management worldview holds that nature exists to meet our needs. b. The stewardship worldview holds that we manage the earth, but we have an ethical responsibility to be stewards of the earth. c. The environmental worldview holds that we are connected to nature and that nature exists for all species equally. 1-4 What is an environmentally sustainable society? A. An environmentally sustainable society meets the current and future basic resource needs of its people in a just and equitable manner by protecting natural capital and living off its income. 1. The shift to sustainability involves building social capital, which involves bringing together people with different views and values and finding common ground. CASE STUDY: Chattanooga, Tennessee, was once one of the most polluted cities in the United States. In the mid-1980s civic leaders gathered together community members to identify problems and brainstorm solutions. After years of encouraging zero-emission industries, implementing recycling programs, and renovating much of the city, Chattanooga is an example of what can be accomplished when cities build their social capital. B. Individuals matter 1. It takes only 5-10% of a community to bring about major social change. 2. Significant social change can occur very rapidly. Teaching Tips Large Lecture Courses: Ask students what are the greatest environmental problems facing the world today. List these on the board, and ask them to suggest what the consequences of these problems might be for them and their families. Then perform the same brainstorming activity focusing on the local region only. Ask the students to suggest reasons for any discrepancies between the two lists, such as local industries or activities. Use this exercise as an opportunity to highlight the main themes that will be touched on during the rest of the course and textbook, and to show the students the ways in which environmental issues permeate their own lives. Small Lecture Courses: Ask students to get in small groups of three to six students each. Have each group rank what they perceive to be the three greatest environmental crises facing their generation. For each they should list the reasons why that issue is so important. Then, have the groups place their original list on the board, and facilitate a debate between groups over which issue is most pressing and why. Use this exercise to illustrate the complexity of environmental issues, insofar as the public is generally not in agreement as to cause, severity, or potential solution. Key Terms biodiversity biodegradable pollutants culture developed countries developing countries ecological footprint ecological tipping point ecology economic development economic growth environment environmental degradation environmental ethics environmental science environmental wisdom worldview environmental worldview environmentalism environmentally sustainable society exponential growth gross domestic product (GDP) input pollution control less-developed countries more-developed countries natural capital natural income natural resources natural services nondegradable pollutants nonpoint sources nonrenewable resources nutrient cycling organisms output pollution control per capita ecological footprint per capita GDP perpetual resource planetary management worldview point sources pollution pollution cleanup pollution prevention poverty recycling renewable resource resource reuse social capital species stewardship worldview sustainability sustainable yield Term Paper Research Topics 1. Population: UN population projections. 2. Poverty: definition, roots, worldwide distribution, changing the current situation. 3. Technology: research, development, and distribution of new technologies in the United States. 4. State of the world: bibliography of current resources summarizing the state of the world; most important areas of concern. 5. Pollution and environmental degradation: report on one form of pollution or environmental degradation, and describe its existence in different countries or choose one incident as a case study. 6. Computer modeling methods: Limits to Growth by Meadows and Meadows; today's global climate models. 7. National: national efforts to address environmental needs; Blueprint for the Environment. 8. Global: global attempts to address the environment and the economy; the UN document Our Common Future. Activities and Projects 1. As a class project, "adopt" a developing country. Assign teams of students to investigate various aspects of the nation's physical, population, economic, social, political, and other characteristics as well as lifestyle and life quality. Allocate class time for periodic brief reports and discussions of research results. 2. As a class project or extra-credit exercise, contact the local Department of Transportation (DOT) and find out if they offer an Adopt-A-Highway program. Adopt a stretch of highway and have students pick up litter. Students can keep tallies of the different types of litter collected (metal cans, snack food wrappers, etc.) and prepare a pie chart and report to submit to the DOT. 3. As a class exercise, compute the cost of a hamburger, a movie ticket, a single-family home, and/or other commodities 30 years in the future, assuming the current inflation rate. 4. As a class exercise, compile a list of resources that are considered important today but were not recognized as resources 100 years ago. What are some things that have ceased to be significant resources during the last 50 years? What resources of the present will probably be of little value 50 years from now? 5. Have the class make a list of changes in your community's environment that have occurred over the last 10 years. Have them vote on which changes they consider desirable and which undesirable. Discuss the changes on which there is least consensus about desirability. Clarify the differences in values that underlie differences in students' responses. 6. Have students assume roles as futurists and predict life as it will be in the year 2010. 7. Have your students write scenarios describing what everyday life would be like in the United States after a transition is made to an earth-wise society. Identify areas of consensus and disagreement. 8. As a class exercise, have each student write out and hand in anonymously a list of the essential components of "the good life." Read some or all of the lists aloud to the class. Write a composite list on the blackboard and discuss each component in terms of sustainable-earth values and guidelines. News Videos Stuff That We Leave Behind; Environmental Science in the Headlines, 2007, DVD ISBN: 0495385433 A Closer Look, Alaska Adventure; Environmental Science in the Headlines, 2007, DVD ISBN: 0495385433 Additional Video Resources Indigenous Peoples: Humane and Environmental Sustainability (Documentary, 2005). A 45-minute documentary highlighting the thoughts and proposals of indigenous people. http://greenplanetfilms.org/product_info.php?cPath=103&products_id=178&osCsid=vj3q4lsjachb5olkbb4augq114 The Habitable Planet: A Systems Approach to Environmental Science, Looking Forward: Our Global Experiment (Documentary, 2007). Focuses on ingenuity and cooperation as a means of attaining sustainable solutions. http://www.learner.org/resources/series209.html Planet Earth: The Future Living Together (Documentary, 2007). The final episode of the Planet Earth series explores the intricacies of conservation and sustainability. http://www.bbc.co.uk/nature/animals/planetearth/ Reinventing the World (Documentary, 2000). Explores some of the biggest challenges facing us today, including urban sustainability . http://www.bullfrogfilms.com/catalog/rtw.html The 11th Hour (Documentary, 2008). A feature length film highlighting major environmental issues as well as approaches to sustainability. Web Resources Redefining Progress – Ecological Footprint Quiz http://www.rprogress.org/index.htm Environmental and Sustainability Resources http://earth911.org/ Online Community for the Environment – Many Resources http://www.envirolink.org/ Suggested Answers to End of Chapter Questions Review Questions 1. Review the Key Questions and Concepts for this chapter on p. 6. What is sustainability and why should we care about it? What are the three principles that nature has used to sustain itself for 3.5 billion years, and how can we use these principles to live more sustainably? Answer: • Sustainability is the capacity of the earth’s natural systems and human cultural systems to survive, flourish, and adapt to changing environmental conditions indefinitely. It is important that we embrace sustainability to ensure that future generations have access to adequate resources. • The three principles are reliance on solar energy, biodiversity, and chemical cycling. These principles entail sustainability insofar as they guarantee that we will value and preserve biodiversity, live with renewable energy, and continue to recycle and reuse the earth’s valuable resources. 2. Define environment. Distinguish among environmental science, ecology, and environmentalism. Distinguish between an organism and a species. What is an ecosystem? Define natural capital, natural resources , and natural services. Define nutrient cycling and explain why it is important? Describe how we can degrade natural capital and how finding solutions to environmental problems involves making trade-offs. Explain why individuals matter in dealing with the environmental problems we face. Answer: • The environment is everything around us. • Environmental science is an interdisciplinary study of how humans interact with living and nonliving parts of their environment. • Ecology is the biological science that studies how organisms, or living things, interact with one another and with their environment. • Environmentalism is a social movement dedicated to protecting the earth’s life-support systems for all forms of life. • Every organism is a member of a certain species: a group of organisms that have distinctive traits and, for sexually reproducing organisms, can mate and produce fertile offspring. • An ecosystem is a set of organisms within a defined area or volume interacting with one another and with their environment of nonliving matter and energy. • Natural capital—the natural resources and natural services that keep us and other forms of life alive and support our economies. • Natural resources are materials and energy in nature that are essential or useful to humans. These resources are often classified as renewable (such as air, water, soil, plants, and wind) or nonrenewable (such as copper, oil, and coal). • Natural services are processes in nature such as purification of air and water, which support life and human economies. • Nutrient cycling is the circulation of chemicals necessary for life, from the environment (mostly from soil and water) through organisms and back to the environment. This is a vital natural service because without it nutrients would become unavailable to living organisms. • We can degrade natural capital by overharvesting, or unsustainably managing resources. Solutions often involve conflicts necessitating trade-offs. • Individuals matter in dealing with environmental problems because what we all do on a daily basis has an overall impact. 3. What is a resource? Distinguish between a perpetual resource and a renewable resource and give an example of each. What is sustainable yield? Define and give two example of a nonrenewable resource. Distinguish between recycling and reuse and give an example of each. What is economic growth? Distinguish between gross domestic product (GDP) and per capita GDP. Distinguish between more-developed countries and less-developed countries and give an example of a high-income, a middle income and a low-income country. Answer: • Perpetual resources have continual supplies, and renewable resources will be replenished as long as we do not use them too rapidly. Solar energy is perpetual and wood resources are renewable. • Sustainable yield is the highest rate at which a resource can be used without indefinitely reducing it’s available supply. • Nonrenewable resources are resources that exist in a fixed quantity such as copper or oil. • Reuse involves using a resource over and over as in washing a reusing a bottle. Recycling entails collecting materials and processing them into new materials, as in melting discarded aluminum cans to make new aluminum products. • Economic growth is the increase in the capacity to provide people with goods and services; an increase in gross domestic product (GDP). • Economic growth is usually measured by the percentage of change in a country’s gross domestic product (GDP): the annual market value of all goods and services produced by all firms and organizations, foreign and domestic, operating within a country. Changes in a country’s economic growth per person are measured by per capita GDP: the GDP divided by the country’s total population at midyear. GDP and per capita GDP indicators provide a standardized and useful method for measuring and comparing the economic outputs of nations. The GDP is deliberately designed to measure such outputs without distinguishing between goods and services that are environmentally or socially beneficial and those that are harmful. • The United Nations classifies countries as economically developed or developing based primarily on their degree of industrialization and their per capita GDP PPP. Most developed countries are highly industrialized and have a high per capita GDP PPP. Some developing countries are middle- income and moderately developed while others are low-income and least developed. The United States is a high-income country, Brazil is a middle-income country, and Haiti is a low-income country. 4. Define and give three examples of environmental degradation (natural capital degradation). Define pollution. Distinguish between point source and nonpoint sources of pollution. Distinguish between pollution cleanup (output pollution control) and pollution prevention (input pollution control) and give an example of each. Describe three drawbacks to solutions that rely mostly on pollution cleanup. What is the tragedy of the commons? Answer: • Natural capital degradation involves using resources at an unsustainable rate. Examples include forests shrinking, topsoil eroding and deserts expanding. • Pollution is a presence in the environment that is harmful to the health, survival or activities of humans or other organisms. • Point sources have single identifiable sources, whereas nonpoint sources are dispersed. • Output control involves cleaning up after the pollutants have been released. And may involve physically removing a pollutant from the environment, while input control involves reducing or eliminating the production of pollutants, which may involve trapping the pollutants before they are released and then properly disposing of them. • The drawbacks of cleanup are that it may be a temporary “bandage,” cleanup may involve simply displacing the pollutant to another environment, and it may be too costly to reduce the chemicals to acceptable levels. • The tragedy of the commons is environmentally degrading many openly shared renewable resources. 5. What is an ecological footprint? What is a per capita ecological footprint? Compare the total and per capita ecological footprint s of the United States and China. Use the ecological footprint concept to explain how we are living unsustainably. What is the IPAT model for estimating our environmental impact? Explain how we can use this model to estimate the impacts of the human populations in less-developed countries and more developed countries. Describe the environmental impacts of China’s new affluent consumers. What is an ecological tipping point? Answer: • Ecological footprint refers to the amount of biologically productive land and water needed to provide the people in a particular country or area with an indefinite supply of renewable resources and to absorb and recycle the wastes and pollution produced by such resource use. • The per capita ecological footprint is the average ecological footprint of an individual in a given country or area. • The total ecological footprint for the United States in millions of hectares is 2810 versus 2050 for China. The U.S. per capita ecological footprint was about 6 times larger than China’s per capita footprint. • We are living unsustainably by over extracting resources, and not allowing adequate time for the processes of recycling and regeneration. • Impact (I) = Population (P) × Affluence (A) × Technology (T) • In less-developed countries, population tends to be a larger issue, while consumption is less of an impact. On the other hand, in more-developed countries, it is consumption that drives up the overall impact, with population being less of an issue. Technologies can either increase or reduce the overall impact in both cases. • China’s newly affluent consumers are putting immense pressure on the earth’s potentially renewable natural capital and its nonrenewable resources. • An ecological tipping point is a threshold level which causes an often irreversible shift in the behavior of a natural system. 6. Define culture? Describe three major cultural changes that have occurred since humans were hunter-gatherers. What would a sustainability revolution involve? Answer: • Culture is the whole of a society’s knowledge, beliefs, technology, and practices, and human cultural changes have had profound effects on the earth. • Three major cultural changes have occurred during mankind's history. First was the agricultural revolution when humans learned how to grow and breed plants and animals for food, clothing, and other purposes. Second was the industrial– medical revolution when people invented machines for the large- scale production of goods in factories. This involved learning how to get energy from fossil fuels, such as coal and oil, and how to grow large quantities of food in an efficient manner. Finally, in the information– globalization revolution we developed new technologies for gaining rapid access to much more information and resources on a global scale. • An environmental, or sustainability, revolution would involve learning how to reduce our ecological footprints and live more sustainability. 7. Identify four basic causes of the environmental problems that we face today. What is exponential growth? Describe the past, current, and projected exponential growth of the world’s human population. What is affluence? How do Americans, Indians, and the average people in the poorest countries compare in terms of consumption? What are two types of environmental damage resulting from growing affluence? How can affluence help us to solve environmental problems? What is poverty and what are three of its harmful environmental and health effects? Describe the connection between poverty and population growth. Answer: • Some basic causes of environmental problems are: 1. Population growth. 2. Unsustainable resource use 3. Poverty. 4. Exclusion of harmful environmental costs from the market prices of goods and services. • Exponential growth occurs when a quantity such as the human population increases at a fixed percentage per unit of time. • The exponential rate of global population growth has declined some since 1963. Nevertheless, unless death rates rise sharply, there will probably be 9.3 billion of us by 2050 (up from 6.9 in 2010). • Affluence is wealth that enables the consumption of large amounts of resources far beyond basic needs. • The average American consumes about 30 times as much as the average Indian and 100 times as much as the average person in the world’s poorest countries. • Growing affluence results in high levels of consumption and unnecessary waste of resources. • Affluence can allow for better education, which can lead people to become more concerned about environmental quality. It also provides money for developing technologies to reduce pollution, environmental degradation, and resource waste. • Poverty occurs when people are unable to meet their basic needs for adequate food, water, shelter, health, and education. • Poverty has a number of harmful environmental and health effects. People who are desperate for short- term survival people deplete and degrade forests, soil, grasslands, fisheries, and wildlife, at an ever- increasing rate. They do not have the luxury of worrying about long- term environmental quality or sustainability. Other problems include malnutrition and lack of access to clean drinking water. • Poverty can drive population growth, as people in poor regions often have more children to ensure that they will have assistance with daily work as well as someone to care for them in old age. 8. Explain how excluding from the prices of goods and services the harmful environmental costs of producing them affects the environmental problems we face. What is the connection between government subsidies, resource use, and environmental degradation? What is an environmental worldview? What are environmental ethics? Distinguish among the planetary management, stewardship, and environmental wisdom worldviews Answer: • Excluding the harmful environmental costs in the prices of goods and services can hurt the environment because the consumer does not realize the value being lost. • Environmentally harmful subsidies encourage the depletion and degradation of natural capital. • Environmental worldview is a set of assumptions and values reflecting how you think the world works and what you think your role in the world should be. • Environmental ethics are beliefs about what is right and wrong with how we treat the environment. • World view: ○ The planetary management worldview holds that we are separate from and in charge of nature, that nature exists mainly to meet our needs and increasing wants, and that we can use our ingenuity and technology to manage the earth’s life-support systems, mostly for our benefit, indefinitely. ○ The stewardship worldview holds that we can and should manage the earth for our benefit, but that we have an ethical responsibility to be caring and responsible managers, or stewards, of the earth. It says we should encourage environmentally beneficial forms of economic growth and development and discourage environmentally harmful forms. ○ The environmental wisdom worldview holds that we are part of, and dependent on, nature and that nature exists for all species, not just for us. 9. Describe an environmentally sustainable society. What is natural income? What is social capital? Describe the environmental transformation of Chattanooga, Tennessee. Answer: • An environmentally sustainable society is one that meets the current and future basic resource needs of its people in a just and equitable manner without compromising the ability of future generations to meet their basic needs. • Natural income is the renewable resources such as plants, animals, and soil provided by the earth’s natural capital. • Building social capital involves getting people with different views and values to talk and listen to one another, to find common ground based on understanding and trust, and to work together to solve environmental and other problems facing our societies. • Chattanooga’s story shows that a key to finding solutions to environmental problems is to recognize that most social change results from individual actions and individuals acting together (using social capital ) to bring about change through bottom- up grassroots action. 10. How long do some scientists estimate that we have to make a shift to more environmentally sustainable economies and lifestyles? Based on the three principles of sustainability, what are the three best ways to make such a transition as summarized in this chapter’s three big ideas? Explain how we can use these three principles to get us closer to the vision of a sustainable earth described in the Core Case Study that opens this chapter. Answer: • Many scientists argue that we must make changes now, as many would take as long as 50 years to take effect. • Rely more on renewable energy, protect biodiversity, and help to sustain the earth’s natural chemical cycles by reducing the production of wastes and pollution. • These strategies can help to reduce our ecological footprints, sustain the earth’s natural capital, and make a transition to more sustainable lifestyles and economies. Critical Thinking The following are examples of the material that should be contained in possible student answers to the end of chapter Critical Thinking questions. They represent only a summary overview and serve to highlight the core concepts that are addressed in the text. It should be anticipated that the students will provide more in-depth and detailed responses to the questions depending on an individual instructor’s stated expectations. 1. Do you think that you are living unsustainably? Explain. If so, what are the three most environmentally unsustainable components of your lifestyle? List two ways in which you could apply each of the three principles of sustainability (Figure 1-3) to making your lifestyle more environmentally sustainable. Answer: Answers may vary. Some examples include reducing energy consumption and relying more heavily on solar energy, reducing resource use and recycling when possible, and advocating a reduction in population growth. 1. High Energy Consumption: Using energy-intensive appliances or frequent travel. • Principle 1 (Reduce Consumption): Use energy-efficient appliances and reduce travel by choosing virtual meetings. • Principle 2 (Renewable Resources): Switch to renewable energy sources like solar or wind. • Principle 3 (Minimize Waste): Recycle and compost to reduce waste production. 2. Waste Generation: Producing a lot of non-recyclable waste. • Principle 1: Reduce single-use plastics and opt for reusable products. • Principle 2: Support products with minimal or biodegradable packaging. • Principle 3: Implement a zero-waste lifestyle by minimizing trash and properly recycling. 3. Excessive Water Use: Overusing water in daily activities. • Principle 1: Fix leaks and install water-saving fixtures. • Principle 2: Use water-efficient appliances and technologies. • Principle 3: Practice water conservation habits like shorter showers and turning off the tap while brushing teeth. 2. Do you believe a vision such as the one described in the Core Case Study that opens this chapter is possible? Why or why not? What, if anything, do you believe will be different from that vision? Explain. If your vision of what it will be like in 2060 is sharply different from that in the Core Case Study, write a description of your vision. Compare your answers to this question with those of your classmates. Answer: Whether a vision described in a Core Case Study is possible depends on its specific goals and challenges. Typically, such visions aim for significant advancements in sustainability, technology, or social equity by a future date like 2060. Possibility: Achieving these visions is possible but depends on current actions, innovations, and global cooperation. Progress in technology and shifts in societal behaviors can make ambitious goals feasible. Differences: Practical challenges, unforeseen technological limitations, or socio-political changes might lead to deviations from the vision. For instance, unexpected environmental crises or political conflicts could alter the trajectory. Vision for 2060: I envision a world with widespread adoption of clean energy, advanced recycling technologies, and equitable access to resources. Urban areas might be smart cities with integrated green spaces, while rural areas benefit from sustainable agriculture practices. Comparison: This vision may differ from classmates’ views based on their perspectives on technology, policy, or social changes. Comparing insights can highlight diverse approaches to achieving sustainability and innovation goals. 3. For each of the following actions, state one or more of the four scientific principles of sustainability (Figure 1-17) that are involved: (a) recycling soda cans; (b) using a rake instead of a leaf blower; (c) walking or bicycling to class instead of driving; (d) taking your own reusable bags to the grocery store to carry your purchases home; (e) volunteering to help restore a prairie; and (f) lobbying elected officials to require that 20% of your country’s electricity be produced by renewable wind power by 2020. Answer: (a) Nutrient Recycling/Reliance on Solar Energy: In nature there is no waste, so recycling the aluminum soda can mimics nutrient recycling. As less energy is used in the aluminum recycling process than starting from raw materials such as bauxite, we are less dependent on nonrenewable energy sources. (b) Reliance on Solar Energy: As no electrical or gasoline energy is expended by using the rake, we are less dependent on nonrenewable energy sources such as coal to generate the electricity to power the leaf blower. (c) Reliance on Solar Energy/Biodiversity: By not using gasoline to drive the car, you are relying more on renewable rather than nonrenewable energy and positively impacting biodiversity in areas where oil drilling is having harmful ecological effects. (d) Nutrient Recycling/Biodiversity/Reliance on Solar Energy: If you use a reusable grocery bag made from organically grown cotton, you will be relying on solar energy rather than nonrenewable energy sources that may have been used to make a plastic bag, which may or may not be recyclable; using paper bags can have an effect on the biodiversity of forest lands. (e) Biodiversity/Nutrient Recycling: By restoring habitat you will be enhancing biodiversity and also helping the future recycling of nutrients from the plantings. (f) Reliance on Solar Energy/Biodiversity: Promoting the use of renewable energy sources complies with the principle of relying on solar energy, and less reliance on nonrenewable sources such as coal and oil that adversely affect biodiversity in the extraction of these materials. 4. Explain why you agree or disagree with the following propositions: a. Stabilizing population is not desirable because without more consumers, economic growth would stop. b. The world will never run out of resources because we can use technology to find substitutes and to help us reduce resource waste. Answer: a. Disagree: The earth has a finite amount of resources. With ever-increasing numbers of consumers the economy may eventually max out as these resources are diminished and the costs skyrocket. This would lead to greater disparity between rich and poor people and end up promoting increased poverty rather than increased wealth. b. Agree: Companies like 3M have reduced their waste by selling their generated waste products to other companies that need the materials for the manufacturing processes for goods that they produce. With an increase in such technology in the future, more materials have the potential to be reused and recycled indefinitely. 5. What do you think when you read that: (a) the average American consumes about 30 times more resources than the average citizen of India, and (b) human activities are projected to make the earth’s climate warmer? Are you skeptical, indifferent, sad, helpless, guilty, concerned, or outraged? Which of these feelings help perpetuate such problems, and which can help to solve them? Answer: Again student answers will vary, but the benefit of such questions is that the instructor can facilitate a discussion that could help the students come to terms with the feelings they have on the issue and take the necessary steps to minimize their own ecological footprint. The instructor can help the students see how answers such as being indifferent to the issue, as in (b), lead to a perpetuation of the problem, and answers such as (f) may bring about a change in their own lifestyle. When reading that the average American consumes significantly more resources than an average Indian and that human activities are warming the climate, I would feel concerned. • Feelings that perpetuate problems: Indifference and helplessness can prevent taking meaningful action to address these issues. • Feelings that help solve problems: Concern, guilt, and outrage can drive individuals to adopt sustainable practices, advocate for policy changes, and raise awareness to mitigate the environmental impact. 6. When you read that about 16,400 children age five and younger die each day (13 per minute) from preventable malnutrition and infectious disease, how does it make you feel? Can you think of something that you and others could do to address this problem? What might that be? Answer: Student answers will vary. The instructor could lead a discussion in which each student is asked to explain their answer. Through this discussion students be spurred into action. Reading about the daily deaths of young children from preventable causes makes me feel saddened and motivated to act. Action: Supporting and funding organizations that provide nutrition, healthcare, and clean water to underserved regions can help address this issue. Advocacy for policies that improve global health infrastructure and education about preventable diseases can also contribute to reducing these deaths. 7. Explain why you agree or disagree with each of the following statements: (a) humans are superior to other forms of life, (b) humans are in charge of the earth, (c) the value of other forms of life depends only on whether they are useful to humans, (d) based on past extinctions and the history of life on the earth over the past 3.5 billion years, all forms of life eventually become extinct so we should not worry about whether our activities cause their premature extinction, (e) all forms of life have the inherent right to exist, (f) all economic growth is good, (g) nature has an almost unlimited storehouse of resources for human use, (h) technology can solve our environmental problems, (i) I do not believe I have any obligation to future generations, and (j) I do not believe I have any obligation to other forms of life. Answer: Student answers will vary and the instructor has the opportunity to lead a discussion where each student can elaborate on their own particular viewpoint. Here are the concise responses: (a) Disagree: No inherent superiority; all life has value. (b) Disagree: Humans are not solely in charge; we must act responsibly. (c) Disagree: Life’s value goes beyond human use; ecosystems depend on biodiversity. (d) Disagree: Premature extinction has significant consequences; we should prevent it. (e) Agree: All life forms have an inherent right to exist. (f) Disagree: Economic growth should be balanced with environmental sustainability. (g) Disagree: Nature’s resources are limited; sustainability is crucial. (h) Partially agree: Technology helps but must be combined with behavioral and policy changes. (i) Disagree: We have an obligation to future generations. (j) Disagree: We have a responsibility to other life forms for ecological balance. 8. What are the basic beliefs of your environmental worldview? Record your answer. Then at the end of this course return to your answer to see if your environmental worldview has changed. Answer: Student answers will vary. This question provides the instructor with the basis for a discussion on individual worldviews and allows for each student to consider their own current beliefs. It is hoped that by the end of the course everyone in the class has gained a greater understanding of the environment and increased their environmental literacy. It also provides the instructor the chance to discuss specific actions individual members of the class can take to make sure that if they “talk the talk” they also “walk the walk” from an environmental perspective. This will help students to minimize their ecological footprint individually, as well as the class on the whole. Basic Beliefs of My Environmental Worldview: 1. All life forms have intrinsic value and a right to exist. 2. Humans are part of a larger ecological system and must act responsibly to protect it. 3. Sustainability is crucial; resources are limited and should be managed wisely. 4. Economic growth must be balanced with environmental health. 5. We have obligations to future generations and other forms of life. 9. Are the beliefs included in your environmental worldview (Question 8) consistent with your answers to question 7? Are your actions that affect the environment consistent with your environmental worldview? Explain. Answer: Student answers will vary. This question provides the instructor with further basis for a discussion on individual worldviews and allows for the exploration of the implications of the students’ individual actions. Yes, the beliefs in my environmental worldview are consistent with the answers to Question 7. They emphasize the intrinsic value of all life, responsible stewardship, and sustainability, which align with rejecting ideas of human superiority and unchecked economic growth. Actions: Ideally, actions should reflect these beliefs by supporting sustainability, reducing resource consumption, and advocating for environmental policies. If they do not, adjustments should be made to align actions with the stated worldview. 10. List two questions that you would like to have answered as a result of reading this chapter. Answer: Student answers will vary and will provide a good starting point for a class discussion 1. How can individuals effectively balance personal consumption with environmental sustainability? 2. What are the most impactful policies and technologies currently available to combat climate change? Ecological Footprint Analysis If the ecological footprint per person of a country or of the world (Figure 1-13) is larger than its biological capacity per person to replenish its renewable resources and absorb the resulting waste products and pollution, the country or the world is said to have an ecological deficit. If the reverse is true, the country or the world has an ecological credit or reserve. Use the data below to calculate the ecological deficit or credit for the countries listed and for the world. (For a map of ecological creditors and debtors see Figure 6, p. S000, in Supplement 8.) Data from WWF Living Planet Report 2006 1. Which two countries have the largest ecological deficits? Why do you think they have such large deficits? 2. Which two countries have an ecological credit? Why do you think each of these countries has an ecological credit? 3. Rank the countries in order from the largest to the smallest per capita ecological footprint. Answers Data from WWF Living Planet Report 2006 1. Which two countries have the largest ecological deficits? Why do you think they have such large deficits? Answer: The United States has an ecological deficit of -5.4 hectares per person, and the United Kingdom has an ecological deficit of -4.0 hectares per person. This is likely due to affluence and overconsumption. 2. Which two countries have an ecological credit? Why do you think each of these countries has an ecological credit? Answer: Brazil has an ecological credit of +7.8 hectares per person and Canada has an ecological credit of +6.9 hectares per person. This may be due to low population sizes relative to available resources. 3. Rank the countries in order from the largest to the smallest per capita ecological footprint. Answer: U.S. Canada United Kingdom Germany Russia Japan México Brazil China India SCIENCE, ECOLOGICAL PRINCIPLES, AND SUSTAINABILITY Chapter 2 Science, Matter, Energy, and Systems Summary 1. Science is an attempt to discover the natural world’s order and use that in describing what is likely to happen in nature. Scientists ask a question or identify a problem to investigate. Then, they collect scientific data through observation and measurement. Experiments may be used to study specific phenomena. 2. The major components of complex systems are environmental inputs, flows within the system, and outputs to the environment. 3. The basic forms of matter are elements and compounds. Matter is useful to us as a resource because it makes up every material substance. 4. The major forms of energy are kinetic energy and potential energy. Energy is useful to us as a resource because it moves matter. 5. The Law of Conservation of Matter states that matter is neither created nor destroyed when a physical or chemical change occurs. 6. Matter can undergo three types of nuclear changes: natural radioactive decay, nuclear fission, and nuclear fusion. 7. The First Law of Thermodynamics states that in all physical and chemical changes, energy may be converted from one form to another but it is neither created nor destroyed. The Second Law of Thermodynamics states that when energy is changed from one form to another, there is always less usable energy left. 8. These laws, then, show that energy goes from a more useful to a less useful form and that high-quality energy cannot be recycled. So, the quality as well as the quantity of our resources and our environment will be reduced. Key Questions and Concepts 2-1 What do scientists do? CORE CASE STUDY. Controlled experiments involve an experimental group, in which a known variable is changed, and a control group, in which the variable is not changed. The example involves two drainages that were dammed. One was deforested and one left forested. The deforested landscape showed an increase in erosion and an increase in water flow carrying dissolved nutrients. A. Science assumes that events in the natural world follow orderly patterns and that, through observation and experimentation, these patterns can be understood. B. The scientific method used to learn about the world. 1. Identify the problem. 2. Find out what is known about the problem. 3. Propose a question. 4. Collect data 5. Suggest a hypothesis (possible explanation). 6. Make testable projections 7. Test with further experiments, models or observations. a. Models are approximate representations of a system. 8. Support or reject hypothesis. C. A scientific theory is well-tested and widely accepted scientific hypothesis. D. Four important features of the scientific process are curiosity, skepticism, reproducibility, and peer review. E. Critical thinking entails three main steps. 1. Be skeptical. 2. Evaluate available evidence. 3. Identify and evaluate personal assumptions. a. Imagination and creativity are equally important in science. SCIENCE FOCUS: Easter Island Revisited—an example of how a once accepted hypothesis has been replaced as a result of new evidence. F. Scientific laws are widely accepted descriptions of phenomena we find happening repeatedly in nature. G. Science is repeatedly tested 1. Frontier science is scientific results that have not been confirmed; reliable science is derived from scientific results that have been well tested and are widely accepted. 2. Unreliable science has not undergone peer review, or has been discredited. H. Science has limitations. 1. Scientists can disprove things, but not prove anything absolutely. 2. Scientists are sometimes biased. 3. Environmental phenomena often involve a multitude of interacting variables. 4. Environmental scientists often rely on estimates based on statistical sampling and other mathematical methods. SCIENCE FOCUS: Statistics enable scientists to collect, organize and interpret numerical data. Probability, the chance that something will happen or be valid, is used to evaluate their results. Sample size can be very important to obtaining meaningful results. 5. Science is limited to understanding the natural world and cannot be applied to morals or ethics. 2-2 What is matter? A. Matter is anything that has mass and takes up space, living or not. It comes in chemical forms, as an element or a compound. 1. An element is the distinctive building block that makes up every substance. 2. Chemists classify elements by their chemical behavior by arranging them in a periodic table of elements. B. The building blocks of matter are atoms, ions, and molecules. 1. An atom is the smallest unit of matter that exhibits the characteristics of an element. 2. An ion is an electrically charged atom or combinations of atoms. 3. A molecule is a combination of two or more atoms/ions of elements held together by chemical bonds. C. Each atom has a nucleus containing protons and neutrons. Electron(s) orbit the nucleus of an atom. 1. A proton (p) is positively charged, a neutron (n) is uncharged, and the electron (e) is negatively charged. 2. Each atom has an equal number of positively charged protons in the nucleus and negatively charged electrons outside the nucleus, so the atom has no net electrical charge. 3. Each element has a specific atomic number that is equal to the number of protons in the nucleus. 4. The mass number of an atom equals the total number of neutrons and protons in its nucleus. 5. Isotopes are various forms of an element that have the same atomic number, but different mass number. D. Atoms of some elements can lose or gain one or more electrons to form ions with positive or negative electrical charges. 1. Elements known as metals tend to lose one or more electrons; they are electron givers. 2. Elements known as nonmetals tend to gain more electrons; they are known as electron receivers. 3. Hydrogen ions (H+) in a solution are a measure of how acidic or basic the solution is. Neutral pH is 7, acid solutions are below 7, and basic solutions are above 7. E. Chemical formulas are a type of shorthand to show the type and number of atoms/ions in a compound. 1. Ionic compounds are made up of oppositely charged ions, (Na+ and Cl-). 2. Compounds made of uncharged atoms are called covalent compounds (CH4). F. Organic compounds contain carbon atoms combined with one another and with various other atoms. 1. Hydrocarbons: compounds of carbon and hydrogen atoms. 2. Chlorinated hydrocarbons: compounds of carbon, hydrogen, and chlorine atoms. 3. Simple carbohydrates: specific types of compounds of carbon, hydrogen, and oxygen atoms. G. Polymers are larger and more complex organic compounds that have molecular units. 1. Complex carbohydrates contain two or more monomers of simple sugars linked together. 2. Proteins are formed by linking monomers of amino acids together. 3. Nucleic acids are made of sequences of nucleotides linked together. 4. Lipids are a fourth type of macromolecule. H. Cells are the fundamental structural and functional unit of life. 1. Genes: specific sequences of nucleotides in a DNA molecule. 2. Chromosomes: combinations of genes that make a single DNA molecule, plus some proteins. I. All compounds without the combination of carbon atoms and other elements’ atoms are inorganic compounds. J. According to the usefulness of matter as a resource, it is classified as having high or low quality. 1. High-quality matter is concentrated with great potential for usefulness and is usually found near the earth’s surface. 2. Low-quality matter is dilute and found deep underground and/or dispersed in air or water. 2-3 What happens when matter undergoes change? A. When matter has a physical change, its chemical composition is not changed; the molecules are organized in different patterns. B. In a chemical change or reaction, the chemical composition of the elements/compounds change. 1. Nuclear change occurs in three ways: radioactive decay, nuclear fission and nuclear fusion. C. The Law of Conservation of Matter states that no atoms are created/destroyed during a physical or chemical change. 2-4 What is energy and what happens when it undergoes change? A. Energy is the capacity to do work and transfer heat; it moves matter. 1. Kinetic energy has mass and speed: wind, electricity are examples. Heat is also kinetic energy. 2. Electromagnetic radiation is energy that travels as a wave, a result of changing electric and magnetic fields. a. Each form of electromagnetic radiation has a different wavelength and energy content. 3. Potential energy is stored energy. a. Potential energy can be changed into kinetic energy. B. 99% of all energy on earth is solar; commercial energy in the marketplace makes up the remaining 1%, primarily derived from fossil fuels. C. Energy quality is measured by its usefulness; high energy is concentrated and has high usefulness. Low energy is dispersed and can do little work. D. The First Law of Thermodynamics states that energy can neither be created/destroyed, but can be converted from one form to another. E. The Second Law of Thermodynamics states that when energy is changed from one form to another, there is always less usable energy. Energy quality is depleted. 1. In changing forms of energy, there is a loss in energy quality; heat is often produced and lost. 2. Changing forms of energy produces a small percentage of useful energy; much is lost in the process. 3. High-quality energy cannot be recycled/reused. 2-5 What are systems and how do they respond to change? A. A system is a set of components that interact. SCIENCE FOCUS: The Usefulness of Models—models or simulations are used to learn how systems work, particularly when dealing with many variable, very long timeframes or situations where controlled experiments are not possible. 1. Most systems have inputs from the environment, throughputs of matter and energy within the system, and outputs to the environment. 2. Systems are affected by feedback and feedback loops (positive and negative). 3. Systems often show time delays between input and response. 4. Problems can build slowly in systems until reaching a tipping point. 5. Synergy is when processes interact such that the combined effect is greater than the individual effects. Teaching Tips Large Lecture Courses: Brainstorm ways in which the first law of thermodynamics might be applicable to daily life. You might begin with respiration and homeostasis, or jump straight into transportation and fuel costs. Bring in typical levels of efficiency for the internal combustion engine, and let the students calculate roughly how much of the money they spend on transportation actually is applied to mobility. Explain that most of the energy is dissipated as heat, and then compare with the efficiency of mass transit. This is a good opportunity to tie these concepts in to issues that are relevant to the students’ lives. Smaller Lecture Courses: Focus on experimental design and the scientific method by proposing a hypothetical situation (or perhaps a real one, from the local environment). Think of a problem or issue, such as vegetation change, pollution, a proposed dam or quarry, etc. Ask the students to brainstorm in groups how they might set up an experiment and control, and what variables would be most relevant to the experiment given the issue you presented. As an entire class, explore the perplexing issues that arise in environmental field studies when other factors and interactions within the system influence your study. Key Terms acidity atomic number atom atomic theory cells chemical change chemical element chemical formula chemical reaction chromosome compounds data electromagnetic radiation electrons elements energy energy quality feedback feedback loop first law of thermodynamics flows fossil fuels frontier science genes heat high-quality energy high-quality matter inorganic compounds inputs ion isotopes kinetic energy law of conservation of energy law of conservation of matter low-quality energy low-quality matter mass number matter matter quality model molecule negative feedback loop neutrons nuclear change nucleus organic compounds peer review pH physical change positive feedback loop potential energy protons reliable science science scientific hypothesis scientific (natural) law scientific theory second law of thermodynamics synergistic interaction synergy system throughputs time delay tipping point Term Paper Research Topics 1. The Nature of Science: questions, hypotheses, theories, laws, scientific methods, inductive and deductive reasoning. 2. Technology: applications of science to cultures; appropriate technologies; from the wheel to the assembly line; engines and the transportation revolution; computers and the Age of Information; the information superhighway. 3. Computer modeling: extending the power of the human brain; systems analysis; the consequences of feedback loops; the implications of chaos, homeostasis, delays, leverage, and synergy. 4. The universe: total amounts of matter and energy in the universe; the big bang theory of the origin of the universe; the role of entropy in the destiny of the universe. 5. Low-energy lifestyles: individual case studies such as Amory Lovins, and national case studies such as Sweden. 6. Nature's cycles and economics: recycling attempts in the United States; bottlenecks that inhibit recycling; strategies that successfully enhance recycling efforts. 7. Individual: analyze your own body and lifestyle as a system with material and energy inputs and outputs. Try to identify dangerous positive feedback loops. Design strategies that can help bring your body and life into balance. 8. Community: analyze the community in which you live as a system with material and energy inputs and outputs. Identify community services and agencies responsible for inputs and outputs. Try to identify dangerous positive feedback loops. Design strategies that can help bring your community into balance. 9. National: analyze the country in which you live as a system with material and energy inputs and outputs. Identify national services and agencies responsible for inputs and outputs. Try to identify dangerous positive feedback loops. Design strategies that can help bring your nation into balance. Explore the concept of the information superhighway. Consider its usefulness in addressing national issues of sustainability. 10. Global: analyze the earth as a system with material and energy inputs and outputs. Identify global services and agencies responsible for inputs and outputs. Try to identify dangerous positive feedback loops. Design strategies that can help bring the earth into balance. Explore the concept of global networking. Find out more about the networking results of the Rio Conference. Consider the usefulness of such networking in addressing global issues of sustainability. Discussion Topics 1. Scientific methods. The application of critical thinking and creative thinking to the scientific enterprise. Answer: The scientific method involves applying critical thinking and creative thinking to systematically explore phenomena, acquire new knowledge, or correct and integrate previous knowledge. Critical thinking is used to rigorously analyze data, question assumptions, and ensure logical consistency. Creative thinking contributes to generating novel hypotheses, designing innovative experiments, and interpreting findings in unique ways. Together, these approaches help in formulating testable theories and developing evidence-based conclusions. 2. The role of models in the scientific experience. Answer: Models are essential tools in science as they provide simplified representations of complex systems, allowing scientists to predict, analyze, and understand phenomena. They serve as a bridge between theory and real-world observations, helping to formulate hypotheses and test their validity. Models can be physical, mathematical, or computational, and they play a crucial role in developing new technologies, improving scientific accuracy, and communicating findings. 3. The effect of delays, leverage, and synergism in complex systems. Answer: Delays, leverage, and synergism are key dynamics in complex systems that influence their behavior and outcomes. Delays can cause feedback loops to act out of sync, leading to oscillations or instability. Leverage points are critical areas where small changes can lead to significant impacts on the system. Synergism occurs when different components or actions within the system interact to produce a combined effect greater than the sum of their individual effects. Understanding these factors is crucial for managing and optimizing complex systems. 4. An evaluation of the positive and negative contributions of nuclear technologies: nuclear weapons in World War II and the Cold War; radioisotopes in research and medical technology; nuclear power plants. Answer: Nuclear technologies have had both positive and negative contributions. The use of nuclear weapons in World War II and the Cold War brought devastating consequences, highlighting the destructive power of nuclear arms. However, radioisotopes have significantly advanced research and medical technology, aiding in diagnostics and treatments. Nuclear power plants provide a substantial amount of low-carbon electricity, though they pose risks related to radioactive waste and potential accidents. The evaluation of these technologies requires balancing their benefits and drawbacks. 5. How much are you willing to pay in the short run to receive economic and environmental benefits in the long run? Explore costs and payback times of energy efficient appliances, energy saving light bulbs, and weather stripping. Answer: Investing in energy-efficient appliances, energy-saving light bulbs, and weather stripping often entails higher initial costs but results in long-term economic and environmental benefits. These investments typically have payback periods ranging from a few months to several years, depending on the energy savings and upfront costs. Consumers must weigh short-term financial outlays against future savings on utility bills and the environmental benefits of reduced energy consumption, often finding that the long-term advantages outweigh the initial expenses. 6. Is convenience more important than sustainability? Explore the influence of the U.S. frontier origins on the throwaway mentality. Answer: The U.S. frontier origins have contributed to a cultural preference for convenience, which often manifests in a throwaway mentality. This mindset prioritizes immediate ease and disposability over long-term sustainability. While convenience can save time and effort, it often leads to increased waste and environmental degradation. The challenge lies in shifting societal values toward sustainability, emphasizing the importance of resource conservation and responsible consumption. Balancing convenience with sustainable practices is crucial for addressing environmental challenges. Activities and Projects 1. Ask a systems analyst to visit your classroom. Work with the analyst to produce a class consensus model of the environment. 2. As a class exercise, try to inventory the types of environmental disorders that are created in order to maintain a classroom environment—the lighting, space heating and cooling, electricity for projectors, and other facilities, equipment, and services. 3. Ask an ecologist, a pollution treatment technologist (for instance a technologist who designs sewage treatment equipment) and a worker in pollution prevention to visit your class. Ask the types of questions and problems that concern them. Consider the role that each of these thinkers plays in an ecosystem model. 4. As a class exercise, make lists of the beneficial and harmful consequences that have resulted from America's adoption of automobile technology. 5. Ask a physics professor or physics lab instructor to visit your class and, by using simple experiments, demonstrate the matter and energy laws. 6. As a class exercise, try to inventory the types of environmental disorders that are created in order to maintain a classroom environment—the lighting, space heating and cooling, electricity for projectors, and other facilities, equipment, and services. 7. Invite a medical technician to speak to your class on the beneficial uses of ionizing radiation. What controls are employed to limit the risks associated with the use of radioisotopes for diagnostic and treatment procedures? 8. Use Green Lives/Green Campuses as a starting point for analyzing your campus as a system. This is an excellent opportunity to view the campus as an interacting system of material and energy flows governed by human policies as well as to enhance the democratic and team skills of your students. The goal would be to complete a full environmental assessment of the campus with recommendations to move toward a sustainable future. Each student or small group of students could be held accountable for one part of the assessment. 9. A human body at rest yields heat at about the same rate as a 100-watt incandescent light bulb. As a class exercise, calculate the heat production of the student body of your school, the U.S. population, and the global population. Where does the heat come from? Where does it go? 10. As a class exercise, conduct a survey of the students at your school to determine their degree of awareness and understanding of the three basic matter and energy laws. Discuss the results in the context of high-waste, recycling, and low-waste societies. Attitudes and Values 1. How does it feel to imagine being a system made of inputs, flows, and feedbacks? Answer: Imagining oneself as a system of inputs, flows, and feedbacks emphasizes interconnectedness and interdependence. It brings awareness to the constant exchange of energy and information within and outside oneself, highlighting how external factors shape our internal state and vice versa. This perspective can enhance understanding of the complexity of human experiences and behaviors, making one more mindful of the impacts of their actions. 2. How does it feel to imagine being one component of a larger system made up of inputs, flows, and feedbacks? Answer: As one component of a larger system, it feels humbling and grounding, recognizing the interconnected roles that contribute to the system's overall function. This viewpoint fosters a sense of responsibility and awareness of how individual actions affect the whole. It can lead to a greater appreciation of the broader ecosystem and the importance of cooperation and balance within it. 3. How does science contribute to your quality of life? What are its limits? Answer: Science significantly enhances quality of life through advancements in medicine, technology, and understanding of the natural world. It provides solutions to complex problems, improves health and safety, and expands knowledge. However, science has limits, such as ethical boundaries, incomplete knowledge, and the inability to address subjective experiences or moral questions fully. Its scope is confined to empirical and measurable phenomena. 4. How does technology contribute to your quality of life? What are its limits? Answer: Technology improves quality of life by increasing convenience, efficiency, and access to information and services. It enhances communication, healthcare, education, and entertainment. However, its limits include potential over-reliance, loss of privacy, environmental impact, and the digital divide. While technology solves many problems, it can also create new ones and may not address deeper human needs for connection and fulfillment. 5. Do you feel a part of the flow of energy from the sun? Answer: Yes, the flow of energy from the sun is fundamental to life on Earth, and humans are an integral part of this cycle. The sun's energy drives photosynthesis, which sustains the food chain, and influences weather patterns and climate. Recognizing this connection can deepen appreciation for natural processes and the interdependence of all living beings. 6. Do you feel you play a role in nature's cycles? Answer: Yes, humans play a significant role in nature's cycles, including carbon, water, and nutrient cycles. Through activities like respiration, consumption, and waste production, individuals contribute to these cycles. Awareness of this role emphasizes the importance of sustainable practices and environmental stewardship to maintain the balance and health of natural systems. 7. What right do you have to use Earth's material resources? Are there any limits to your rights? What are they? Answer: The right to use Earth's material resources comes with the responsibility to use them sustainably and equitably. There are limits to these rights, including the necessity to preserve resources for future generations, minimize environmental impact, and respect the rights of other species. Ethical and legal frameworks guide these limits, emphasizing conservation, responsible consumption, and stewardship. 8. What rights do you have to Earth's energy resources? Are there any limits to your rights? What are they? Answer: Humans have the right to access Earth's energy resources for survival and development. However, these rights are limited by the need to prevent environmental degradation, ensure equitable access, and transition to renewable energy sources. The limits include ethical considerations, such as reducing carbon footprints and mitigating climate change, as well as legal regulations and international agreements. 9. Do you believe that cycles of matter and energy flow from the sun have anything to do with your lifestyle? With your country's policies? Answer: Yes, cycles of matter and energy flow from the sun are deeply connected to individual lifestyles and national policies. Personal energy consumption, dietary choices, and transportation habits impact these cycles. National policies on energy production, environmental protection, and resource management influence how these cycles are maintained or disrupted. Recognizing this connection highlights the importance of sustainable living and policy-making to support ecological balance. Additional Video Resources Acid Rain The Invisible Threat (Video plus Lab) Hands-on lab activities plus video. http://www.kelvin.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=K&Product_Code=360042 The Habitable Planet: A Systems Approach to Environmental Science (Documentary series, 2007). The videos in this series all explore the use of science as a means of understanding the world. http://www.learner.org/resources/series209.html Web Resources The Particle Adventure An exploration of the fundamentals of matter from the Lawrence Berkeley Labs. http://www.particleadventure.org/ Suggested Answers to End of Chapter Questions Review Questions 1. Review the Key Questions and Concepts for this chapter on p. 32. Describe the controlled scientific experiment carried out at the Hubbard Brook Experimental Forest. Answer: • Scientists compared the loss of water and nutrients from an uncut forest ecosystem (the control site) with one that was stripped of its trees the experimental site) in the Hubbard Brook Experimental Forest in New Hampshire . First the investigators measured the amounts of water and dissolved plant nutrients that entered and left an undisturbed forested area (the control site). They found that an undisturbed mature forest is very efficient at storing water and retaining chemical nutrients in its soils. Then the scientists set up an experimental forested area; they cut down all trees and shrubs in one valley (the experimental site) and sprayed the area with herbicides to prevent regrowth. They compared the inflow and outflow of water and nutrients in this experimental site with those in the control site for 3 years. With no plants to help absorb and retain water, the amount of water flowing out of the deforested valley increased by 30– 40%. As this excess water ran rapidly over the ground, it eroded soil and carried dissolved nutrients out of the deforested site. Overall, the loss of key nutrients from the experimental forest was six to eight times that in the nearby control forest. 2. What is science? Describe the steps involved in the scientific process. What is data? What is a model? Distinguish among a scientific hypothesis, scientific theory, and scientific law (law of nature). What is peer review and why is it important? Explain why scientific theories are not to be taken lightly and why people often use the term “theory” incorrectly. Describe how a hypothesis about the decline of a civilization on Easter Island has been challenged by new data. Answer: • Science is an attempt to discover how nature works and to use that knowledge to make predictions about what is likely to happen in nature. • There are a number of steps in the scientific method. A scientist will use the following procedure to study the natural world. ○ Identify a problem. ○ Find out what is known about the problem. A scientist will search the scientific literature to find out what was known about the area of interest. ○ Ask a question to be investigated. ○ Collect data to answer the question. To collect data— information needed to answer their questions— scientists make observations of the subject area they are studying. Scientific observations involve gathering information by using human senses of sight, smell, hearing, and touch and extending those senses by using tools such as rulers, microscopes, and satellites. Often scientists conduct experiments, or procedures carried out under controlled conditions to gather information and test ideas. ○ Propose a hypothesis to explain the data. Scientists suggest a scientific hypothesis, a possible and test-able explanation of what they observe in nature or in the results of their experiments. ○ Make testable predictions. Scientists use a hypothesis to make testable or logical predictions about what should happen if the hypothesis is valid. They often do this by making “ If . . . then” predictions. ○ Test the predictions with further experiments, models, or observations. These predictions can be compared with the actual measured losses to test the validity of the models. ○ Accept or reject the hypothesis. If their new data do not support their hypotheses, scientists come up with other testable explanations. This process continues until there is general agreement among scientists in the field being studied that a particular hypothesis is the best explanation of the data. • Data is the information needed to answer scientific questions usually obtained by making observations and measurements. • A model is an approximate representation or simulation of a system being studied. • Scientific hypothesis is a possible and testable explanation of what is observed in nature or in the results of experiments. A well-tested and widely accepted scientific hypothesis or a group of related hypotheses is called a scientific theory. A scientific law, or law of nature is a well-tested and widely accepted description of what we find happening in nature. • An important part of the scientific process is peer review, in which scientists openly publish details of the methods and models they used, the results of their experiments, and the reasoning behind their hypotheses for other scientists working in the same field (their peers) to evaluate. And any evidence gathered to verify a hypothesis must be reproducible. That is, scientists should repeat and analyze the work to see if the data can be reproduced and whether the proposed hypothesis is reasonable and useful. • A scientific theory should be taken very seriously. It has been tested widely, supported by extensive evidence, and accepted by most scientists in a particular field or related fields of study. Nonscientists often use the word theory incorrectly when they actually mean scientific hypothesis, a tentative explanation that needs further evaluation. The statement, “Oh, that’s just a theory,” made in everyday conversation, implies that the theory was stated without proper investigation and careful testing—the opposite of the scientific meaning of the word. • The gathering of new scientific data and the reevaluation of older data led to a revised hypothesis about the decline of civilization on Easter Island. 3. Explain why scientific theories and laws are the most important and most certain results of science. Answer: • Scientific theories and laws have a high probability of being valid, but they are not infallible. Occasionally, new discoveries and new ideas can overthrow a well- accepted scientific theory or law in what is called a paradigm shift. It occurs when the majority of scientists in a field or related fields accept a new paradigm, or framework for theories and laws in a particular field. 4. Distinguish among tentative science (frontier science), reliable science, and unreliable science. What is statistics? What is probability and what is its role in scientific conclusions and proof? What are three limitations of science and environmental science? Answer: • Tentative science or frontier science is the preliminary results that capture news headlines and may be controversial because they have not been widely tested and accepted by peer review yet. Reliable science consists of data, hypotheses, theories, and laws that are widely accepted by all or most of the scientists who are considered experts in the field under study, in what is referred to as a scientific consensus. The results of reliable science are based on the self-correcting process of testing, peer review, reproducibility, and debate. New evidence and better hypotheses may discredit or alter accepted views. Scientific hypotheses and results that are presented as reliable without having undergone the rigors of peer review, or that have been discarded as a result of peer review, are considered to be unreliable science. • Statistics consists of mathematical tools used to collect, organize, and interpret numerical data. • Probability is a mathematical statement about the likelihood that harm will be suffered from a hazard. Scientists often state probability in terms such as: “The lifetime probability of developing lung cancer from smoking one pack of cigarettes per day is 1 in 250.” • Environmental science and science in general have three important limitations: ○ Scientists cannot prove or disprove anything absolutely, because there is always some degree of uncertainty in scientific measurements, observations, and models. ○ A limitation of science is that scientists are human and thus are not totally free of bias about their own results and hypotheses. ○ A limitation—especially important to environmental science—is that many environmental phenomena involve a huge number of interacting variables and complex interactions. 5. What is matter? Distinguish between an element and a compound and give an example of each. Distinguish among atoms, molecules, and ions and give an example of each. What is the atomic theory? Distinguish among protons, neutrons, and electrons. What is the nucleus of an atom? Distinguish between the atomic number and the mass number of an element. What is an isotope? What is acidity? What is pH? Answer: • Matter is anything that has mass and takes up space. It can exist in three physical states—solid, liquid, and gas, and two chemical forms—elements and compounds. • A chemical element is a fundamental substance that has a unique set of properties and cannot be broken down into simpler substances by chemical means. Compounds are a combination of two or more different elements held together in fixed proportions. • The most basic building block of matter is an atom—the smallest unit of matter into which an element can be divided and still have its characteristic chemical properties, such as a single hydrogen atom. A second building block of some types of matter is an ion—an atom or group of atoms with one or more net positive (+) or negative (–) electrical charges, such as H+. A molecule is a combination of two or more atoms of the same elements held together by forces called chemical bonds, such as O2, oxygen. • The atomic theory is the idea that all elements are made up of atoms. • Three different types of subatomic particles: positively charged protons (p), neutrons (n) with no electrical charge, and negatively charged electrons (e). • Each atom consists of an extremely small and dense center called its nucleus—which contains one or more protons and, in most cases, one or more neutrons— and one or more electrons moving rapidly somewhere around the nucleus. • Each atom has equal numbers of positively charged protons and negatively charged electrons. Because these electrical charges cancel one another, atoms as a whole have no net electrical charge. Each element has a unique atomic number, equal to the number of protons in the nucleus of its atom. The mass of an atom is described by its mass number: the total number of neutrons and protons in its nucleus. • Forms of an element having the same atomic number but different mass numbers are called isotopes of that element. • Ions are also important for measuring a substance’s acidity in a water solution, a chemical characteristic that helps determine how a substance dissolved in water will interact with and affect its environment. • Scientists use pH as a measure of acidity, based on the amount of hydrogen ions (H+) and hydroxide ions (OH–) contained in a particular volume of a solution. 6. What is a chemical formula? Distinguish between organic compounds and inorganic compounds and give an example of each. Distinguish among complex carbohydrates, proteins, nucleic acids, and lipids. What is a cell? Distinguish among a gene, a trait, and a chromosome. What is matter quality? Distinguish between high- quality matter and low- quality matter and give an example of each. Answer: • Chemists use a chemical formula to show the number of each type of atom or ion in a compound. • Organic compounds contain at least two carbon atoms combined with atoms of one or more other element, such as table sugar and methane. All other compounds, except methane (CH4), are called inorganic compounds, such water. • Complex carbohydrates, such as cellulose and starch, consist of two or more monomers of simple sugars, such as glucose. • Proteins are formed by monomers called amino acids. • Nucleic acids (DNA and RNA) are formed by monomers called nucleotides. • Lipids, which include fats and waxes, are not all made of monomers, but are a fourth type of macromolecule essential for life. • Cells are the smallest and most fundamental structural and functional units of life. • Within some DNA molecules are certain sequences of nucleotides called genes. Each of these distinct pieces of DNA contains instructions, called genetic information, for making specific proteins. Each of these coded units of genetic information concerns a specific trait, or characteristic, passed on from parents to offspring during reproduction in most animals or plants. Thousands of genes, in turn, make up a single chromosome, a special DNA molecule together with a number of proteins. • Matter is anything that has mass and takes up space. It can exist in three physical states: solid, liquid, and gas and two chemical forms: elements and compounds. • High-quality matter is highly concentrated, is typically found near the earth’s surface, and has great potential for use as a resource, coal for example. Low-quality matter is not highly concentrated, is often located deep underground or dispersed in the ocean or atmosphere, and usually has little potential for use as a resource, a salt solution for example. 7. Distinguish between a physical change and a chemical change (chemical reaction) and give an example of each. What is a nuclear change? Explain the differences among natural radioactive decay, nuclear fission, and nuclear fusion. What is the law of conservation of matter and why is it important? Answer: • When a sample of matter undergoes a physical change, there is no change in its chemical composition. A piece of aluminum foil cut into small pieces is still aluminum foil. • When a chemical change, or chemical reaction, takes place there is a change in chemical composition of the substances involved. Chemists use a chemical equation to show what happens in a chemical reaction. For example, when coal burns completely, the solid carbon (C) in the coal combines with oxygen gas (O2) from the atmosphere to form the gaseous compound carbon dioxide (CO2). • Nuclear change is the process in which nuclei of certain isotopes spontaneously change, or are forced to change, into one or more different isotopes. • Nuclear fission occurs when the nuclei of certain isotopes with large mass numbers (such as uranium-235) are split apart into lighter nuclei when struck by a neutron and release energy plus two or three more neutrons. • Nuclear fusion occurs when two isotopes of light elements, such as hydrogen, are forced together at extremely high temperatures until they fuse to form a heavier nucleus and release a tremendous amount of energy. • The law of conservation of matter states whenever matter undergoes a physical or chemical change, no atoms are created or destroyed. This law helps us understand that we need to let our waste cycle back to its original nutrients/products in order for our resources to be sustainable.' 8. What is energy? Distinguish between kinetic energy and potential energy and give an example of each. What is heat? Define and give two examples of electromagnetic radiation. What are fossil fuels and what three fossil fuels do we use most to supplement energy from the sun? What is energy quality? Distinguish between high- quality energy and low- quality energy and give an example of each. What is the first law of thermodynamics (law of conservation of energy) and why is it important? What is the second law of thermodynamics and why is it important? Explain why the second law means that we can never recycle or reuse high- quality energy. Answer: • Energy is the capacity to do work or transfer heat. • There are two major types of energy: moving energy (called kinetic energy) and stored energy (called potential energy). Examples of kinetic energy include wind (a moving mass of air), flowing water, and electricity (flowing electrons). An example of potential energy is gasoline. • Heat is a form of kinetic energy, the total kinetic energy of all moving atoms, ions, or molecules within a given substance. When two objects at different temperatures contact one another, heat flows from the warmer object to the cooler object. • Electromagnetic radiation is energy that travels in the form of a wave as a result of changes in electrical and magnetic fields. Forms of electromagnetic radiation are short wavelengths such as gamma rays and X rays. • fossil fuels are ancient deposits of organic matter formed over millions of years as layers of the decaying remains of ancient plants and animals were exposed to intense heat and pressure within the earth’s crust. The three most widely used fossil fuels are oil, coal, and natural gas. • Energy quality is a measure of an energy source’s capacity to do useful work. • High-quality energy is concentrated and has a high capacity to do useful work. Examples are very high-temperature heat, nuclear fission, concentrated sunlight, high-velocity wind, and energy released by burning natural gas, gasoline, or coal. • Low-quality energy is dispersed and has little capacity to do useful work. An example is heat dispersed in the moving molecules of a large amount of matter (such as the atmosphere or an ocean) so that its temperature is low. • The first law of thermodynamics, also known as the law of conservation of energy, states that whenever energy is converted from one form to another in a physical or chemical change, no energy is created or destroyed. This scientific law tells us that no matter how hard we try or how clever we are, we cannot get more energy out of a physical or chemical change than we put in because energy input always equals energy output. • The second law of thermodynamics states that when energy is changed from one form to another, it always goes from a more useful to a less useful form. • We can never recycle or reuse high-quality energy because whenever energy is converted from one form to another, we always end up with a lower quality or less “usable” energy than we started with. 9. Define and give an example of a system. Distinguish among the input, flow (throughput), and output of a system. Why are scientific models useful? What is feed-back? What is a feedback loop? Distinguish between a positive feedback loop and a negative (corrective) feedback loop in a system, and give an example of each. Distinguish between a time delay and a synergistic interaction (synergy) in a system and give an example of each. What is a tipping point? Answer: • A system is a set of components that function and interact in some regular way. The human body, a river, an economy, and the earth are all systems • Most systems have the following key components: inputs from the environment, flows or throughputs of matter and energy within the system at certain rates, and outputs to the environment. • Scientists use models, or simulations, to learn how systems work. Some of our most powerful and useful technologies are mathematical and computer models. • Most systems are affected by feedback, any process that increases or decreases a change to a system. Such a process, called a feed-back loop, occurs when an output of matter, energy, or information is fed back into the system as an input and leads to changes in that system. • A positive feedback loop causes a system to change further in the same direction. For example, in the Hubbard Brook experiments, researchers found that when vegetation was removed from a stream valley, flowing water from precipitation caused erosion and loss of nutrients, which caused more vegetation to die. With even less vegetation to hold soil in place, flowing water caused even more erosion and nutrient loss, which caused even more plants to die. • Such accelerating positive feedback loops are of great concern in several areas of environmental science. One of the most alarming is the melting of polar ice, which has occurred as the temperature of the atmosphere has risen during the past few decades. As that ice melts, there is less of it to reflect sunlight, and more water is exposed to sunlight. Because water is darker, it absorbs more solar energy, making the area warmer and causing the ice to melt faster, thus exposing more water. The melting of polar ice thus accelerates. • A negative, or corrective, feedback loop causes a system to change in the opposite direction from which is it moving. A simple example is a thermostat, a device that controls how often, and how long a heating or cooling system runs. When the furnace in a house is turned on and begins heating the house, the thermostat can be set to turn the furnace off when the temperature in the house reaches the set number. The house then stops getting warmer and starts to cool. • Complex systems often show time delays between the input of a feedback stimulus and the response to it. For example, scientists could plant trees in a degraded area such as the Hubbard Brook experimental forest to slow erosion and nutrient losses, but it would take years for the trees and other vegetation to grow enough to accomplish this purpose. • A synergistic interaction, or synergy, occurs when two or more processes interact so that the combined effect is greater than the sum of their separate effects. • Scientific studies reveal such an interaction between smoking and inhaling asbestos particles. For example, lifetime smokers have ten times the risk that nonsmokers have of getting lung cancer. And individuals exposed to asbestos particles for long periods increase their risk of get-ting lung cancer fivefold. But people who smoke and are exposed to asbestos have 50 times the risk that non-smokers have of getting lung cancer. • Time delays can also allow an environmental problem to build slowly until it reaches a threshold level, or tipping point, causing a fundamental shift in the behavior of a system. 10. What are this chapter’s three big ideas? Relate the three principles of sustainability to the Hubbard Brook Experimental Forest controlled experiment. Answer: • The three big ideas are that we cannot do away with matter, we cannot get more energy out than we put in, and whenever energy is converted from one form to another in a physical or chemical change, we always end up with lower-quality or less usable energy than we started with. • The controlled experiment discussed in the Core Case Study that opened this chapter revealed that clearing a mature forest degrades some of its natural capital. The loss of trees and vegetation altered the ability of the forest to retain and recycle water and other critical plant nutrients— a crucial ecological function. The loss of vegetation also violated the other three scientific principles of sustainability. For example, the cleared forest had fewer plants that could use solar energy to produce food for animals. And the loss of plants and animals reduced the life-sustaining biodiversity of the cleared forest. This in turn reduced some of the interactions between different types of plants and animals that help control their populations. Critical Thinking The following are examples of the material that should be contained in possible student answers to the end of chapter Critical Thinking questions. They represent only a summary overview and serve to highlight the core concepts that are addressed in the text. It should be anticipated that the students will provide more in-depth and detailed responses to the questions depending on an individual instructor’s stated expectations. 1. What ecological lesson can we learn from the controlled experiment on the clearing of forest described in the Core Case Study that opened this chapter? Answer: Vegetation controls water and nutrient loss from ecosystems. Loss of vegetation diminishes the systems’ ability to retain nutrients and water. 2. You observe that all of the fish in a pond have disappeared. Describe how you might use the scientific process described in the Core Case Study and on p. 32 to determine the cause of this fish kill. Answer: The answer should begin with some observation that can lead to a hypothesis. An observation could be something like increased runoff, increased pollutants, decrease in vegetation or biodiversity, etc. 1. Observe: Fish are gone. 2. Question: Why did this happen? 3. Hypothesize: Possible causes like pollution, disease, or lack of oxygen. 4. Test: Check water quality, look for disease signs, or predator presence. 5. Analyze: Review data. 6. Conclude: Identify the most likely cause. 7. Share: Communicate findings. 3. Describe a way in which you have applied the scientific process described in the chapter (Figure 2-2) in your own life, and state the conclusion you drew from the process. Describe a new problem that you would like to solve using this process. Answer: One morning as you prepare to depart for your college, you find that your car will not start. You observe that there is no sound of the engine turning over. You hypothesize that you have a dead battery. You then devise an experiment to test this hypothesis. You reason that you can charge the battery or jumpstart the car to test whether or not the battery is truly the cause. Upon charging, your car will start, so you conclude that your battery must have died. Other problems the students could solve could range from issues that affect them directly to those affecting the community or the world. 4. Respond to the following statements: a. Scientists have not absolutely proven that anyone has ever died from smoking cigarettes. b. The greenhouse theory—that certain gases (such as water vapor and carbon dioxide) warm the atmosphere—is not a reliable idea because it is just a scientific theory. Answer: (a) The medical and scientific evidence that links smoking to premature death caused by a number of pathological conditions is overwhelming. As we are exposed to many chemical hazards in our environment it is often difficult to specifically link the cause and effect. The chances of an individual dieing from smoking one cigarette is statistically negligible and highly unlikely, but many years of heavy smoking has a much higher probability that death could result from a disease brought on as a result of smoking. (b) Sometimes people with a limited knowledge of the scientific method often confuse a theory with a hypothesis. A theory has been widely tested and is endorsed by a wide group of scientists working in that particular field of study. Many scientists concur with the scientific evidence, obtained through conducting controlled experiments, that water and carbon dioxide are greenhouse gases. 5. A tree grows and increases its mass. Explain why this phenomenon is not a violation of the law of conservation of matter. Answer: The growth of a tree is an example of a chemical change or chemical reaction. Small inorganic elements and compounds are combined to form more complex molecules that make up the material found in the tree. The components that were present in the soil and air have been rearranged to form other types of chemical components. The amount of material that was present before this rearrangement or chemical change took place is the same as the amount afterwards. A student may discuss photosynthesis to support and explain their answer. A tree increases its mass by absorbing carbon dioxide from the air and water from the soil. The mass gain is from the conversion of these absorbed substances into biomass through photosynthesis. The law of conservation of matter is not violated because the matter is neither created nor destroyed; it's simply transformed from one form to another. 6. If there is no “away” where organisms can get rid of their wastes because of the law of conservation of matter, why is the world not filled with waste matter? Answer: Just like when small molecules are combined to form larger compounds, as in the case of the growth of a tree, when larger compounds are broken down they release smaller molecules back into the environment. An example is that of a rotting log. A tree limb may break off and fall to the forest floor. Over a period of time it is decomposed by a variety of organisms and the materials contained in the log return once again into the environment. In this way nature recycles all matter that exists in the environment. The student may discuss cell respiration to support or explain their answer. 7. Someone wants you to invest money in an automobile engine that will produce more energy than the energy in the fuel (such as gasoline or electricity) used to run the motor. What is your response? Explain. Answer: That is not a good investment! The first law of thermodynamics states that energy can be changed from one form to another (such as chemical energy into mechanical energy), but energy cannot be created or destroyed. An engine that produces more energy than it consumes is simply not a feasible scientifically sound prospect. 8. Use the second law of thermodynamics to explain why a barrel of oil can be used only once as a fuel, or in other words, why we cannot recycle this high quality energy. Answer: The second law of thermodynamics states that when energy changes from one form to another, some of the useful energy is always degraded to lower-quality, more dispersed, less useful energy. When a barrel of oil that contains high-quality chemical energy is used as a fuel in order to do useful work, it is transformed or changed into low-quality energy such as heat, which has little ability to do useful work. Therefore the barrel of oil can only be used once as a fuel. 9. a. Imagine you have the power to revoke the law of conservation of matter for one day. What are the three most important things you would do with this power? Explain your choices b. Imagine you have the power to violate the first law of thermodynamics for one day. What are the three most important things you would do with this power? Explain your choices. Answer: (a) Student answers will vary but could include: make more oil to offset the world shortage; produce more water to supply areas that desperately need it; transform all chemical pollutants into useful materials that are not harmful. (b) Student answers will vary but could include: grow more crops to provide food; produce electricity that can be stored in batteries for later use; physically change more of the water in the Arctic Ocean into sea ice to offset the losses that have occurred in the past few decades. a. Revoking the Law of Conservation of Matter: 1. Eliminate Waste: Instantly remove all waste and pollution from the environment, creating a cleaner and healthier planet. 2. Create Resources: Generate essential resources like food, water, and materials to alleviate shortages and provide for those in need. 3. Eradicate Disease: Remove harmful pathogens and toxins from the human body and environment to promote health and eliminate diseases. b. Violating the First Law of Thermodynamics: 1. Unlimited Energy: Create limitless clean energy, ending the need for fossil fuels and reducing climate change impacts. 2. Global Cooling: Reduce global temperatures by removing excess heat, addressing the effects of global warming. 3. Instant Healing: Provide unlimited energy to heal injuries and diseases instantly, improving health and saving lives. 10. List two questions that you would like to have answered as a result of reading this chapter. Answer: Student answers will vary but could include: What other examples are there, apart from Easter Island, that show how civilizations have fallen as a result of degrading their resource base? How close are scientists to being able to mimic photosynthesis and use sunlight to split water into hydrogen and oxygen, similar to the process of electrolysis of water, and provide the world with hydrogen as a major energy source? 1. How do various environmental factors, such as pollution and climate change, impact the survival and growth of different species in an ecosystem? 2. What are the key mechanisms by which energy and matter cycles are maintained and balanced within ecological systems? Data Analysis Consider the graph below that shows loss of calcium from the experimental cutover site of the Hubbard Brook Experimental Forest compared with that of the control site. Note that this is very similar to Figure 2-6, which compares loss of nitrates from the two sites. After studying this graph, answer the questions below. 1. In what year did the calcium loss from the experimental site begin a sharp increase? In what year did it peak? In what year did it again level off? Answer: • 1965-1966 • 1967-1968 • 1971-1972 2. In what year were the calcium losses from the two sites closest together? In the span of time between 1963 and 1972, did they ever get that close again? Answer: • 1964-1965 • No. 3. Does this graph support the hypothesis that cutting the trees from a forested area causes the area to lose nutrients more quickly than leaving the trees in place? Explain. Answer: • Yes, this data supports the hypothesis that the cutover area had an increase in nutrient loss from the site. The data shows that nutrient loss then began to decline over time as the vegetation began growing again. Solution Manual for Living in the Environment: Principles, Connections, and Solutions G. Tyler Miller, Scott Spoolman 9780538735346