Chapter 1 Understanding Our Environment Notes PDF

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Chapter 1 Understanding Our Environment Notes

1.Environmental Science 1. the use of scientific approaches to understand the complex systems in which we live 1. the systematic study of our environment and our place in it 2. Is integrative 1. Field draws on wide range of disciplines and skills 1. Biology, chemistry, earth science and geography contribute ideads/evidence of basic science 2. Political Science, economics, communications and arts help understand how people share resources, compete for them and evaluate their impacts on society 2. Not the same as environmental advocacy 3. Helps the Planet be understood 1. compared to other planets, earth's temperatures are mild and relatively constant 2. supplies like clean air, fresh water, and fertile soil are regenerated endlessly/spontaneously by biogeochemical cycles and biological communities 4. Methods in Environmental Science 1. Observation 2. The Scientific Method 3. Quantitative Reasoning 1. means understanding how to compare numbers and interpret graphs in order to understand what they show about problems that matter 1. Often means interpreting changes in values like population size over time 4. Uncertainty 1. essential part of science 5. Critical/Analytical Thinking 2. Major Themes in Environmental Science 1. Environmental Quality 1. atmosphere retains heat near the earth's surface hence why its warmer than in space 1. past 200 years, increase in CO2 concentrations nearly 50% 1. by 2100 w/ current trends continuing, global mean temps will probably increase by 2 degrees to 6 degrees C 2. Last ice age was about 4 degrees cooler than now 1. severe droughts and heat waves are expected in many areas 2. greater storm intensity and flooding are expected in many regions 3. glaciers disappearances and snow fields threaten water supplies on which cities like Los Angeles and Delhi depended upon 2. Clean Water 1. at least 1.1 billion people lack access to safe drinking water 1. twice that don't have adequate sanitation 2. polluted water contributes to the death of more than 15 million people every year 3. 40% of population lives in countries where water demand exceeds supplies 1. UN projects that by 2025 as many as ¾ population could be living under similar conditions 3. Air Quality 1. quality has worsened in newly industrializing areas like China and India 2. many early deaths and illnesses are triggered by air pollution each year 3. Estimated more than 2 billion metric tons of air pollutants are released each year

1. air pollutants travel easily around the globe 2. some days, 75% of smog and airborne particulates in California originate in Asia 1. mercury, polychlorinated biphenyls( PCBs) and other industrial pollutants accumulate in artic ecosystems and in the tissues of native people in the far north 4. Human Population and Wellbeing 1. well over 7 billion people on Earth (twice as many as there were 40 years ago) 1. adding about 80 million more each year 2. Hunger and Food 1. in spite of population growth which added nearly a billion people to the world during the 1990s, number of people facing good insecurity/chronic hunger actually declined by about 40 million 2. despite the abundance of food, hunger remains a chronic problem worldwide due to unevenly distributed food resources 1. soil scientists report about 2/3s of all agricultural lands show signs of degradation 2. biotech and intensive farming techniques responsible for much of the recent production gains are too expensive for many poor farmers 3. currently more than 850 million people are chronically undernourished 1. at least 60 million people face acute food shortages due to weather, politics or war 5. Natural Resources 1. Biodiversity Loss 1. habitat destruction, overexploitation, pollution and intro of exotic organisms are eliminating species as quickly as the great extinction that marked dinosaurs' end 2. United Nations Environment Programme reports that more than 800 species have disappeared and 10000 are now threatened just over the past century 1. includes half of all primates and freshwater fish and about 10% of all plant species 2. top predators including nearly all the big cats in the world are considered rare and endangered 3. bird/butterfly populations have declined by 50-75% over past 20 years 4. half of the forests that existed before introduction of agriculture have been cleared while many ancient forests are rapidly being cut for timber, oil extraction or for agricultural production of globally traded commodities like palm oil or soybeans 2. Marine Resources 1. ocean provides irreplaceable and imperiled food resources 1. more than 1 billion people in developing countries depend on seafood for main source of animal protein 1. most commercial fisheries around the world are in steep decline 3. Energy Resources 1. Fossil fuels (oil, coal, and natural gas) provides around 80% of energy used in industrialized countries 1. costs of extracting and burning these fuels are among the most serious environmental challenges 2. costs include air/water pollution, mining damage, violent conflicts and climate change 3. Human Dimensions of Environmental Science 1. Describing Resource Use and Conservation

1. Throughput 1. important idea when considering resource consumption 2. the amount of resources used and disposed of 2. Ecosystem Services 1. refers to services or resources provided by environmental systems 2. Provisioning of resources, like fuels we burn, may be the most obvious of required services 3. Supporting services 1. less obvious until they're listed: 1. water purification 2. food production 3. atmospheric oxygen by plants and decomposition of waste by fungi and bacteria 4. Regulating services 1. include: 1. maintenance of temperatures suitable for life by earth's atmosphere and carbon capture by green plants which maintains stable atmospheric compostiion 3. Sustainability Means Environmental and Social Progress 1. Sustainability 1. search for ecological stability and human progress that can last over the long term 2. Sustainable Development 1. defined as meeting the needs of the present without compromising the ability of future generations to meet their own needs 2. Tasks: 1. addressing uneven distribution of resources is one of first tasks 4. State of Poverty and Wealthy today 1. Wealth is unevenly divided at the global scale 1. richest 200 people have combined wealth greater than that of 3.5 billion people making up the poorest half of the world's population 2. Countries w/ highest per capita income (more than $40000) per year make up only 10% of the world's population 5. Interpreting Graph/Map 1. Look for areas of high/low values 2. In legend, find difference in values between high/low areas 3. Find a known region and think about the reasons for the values 4. Look for areas w/ contrasting values 6. 10 key factors necessary for sustainable development (according to U.N agreement on development) 1. Environmental Science is essential to sustainable development 1. helps us understand how environmental systems work, 1. how they are degraded 2. what factors can help restore them 3. studying can prepare people to aid human development and environmental quality through better policies, resource protection and planning 2. Combating Poverty 1. central goal

2. poverty reduces access to health care, education and other essential components of development 3. Reducing Resource Consumption 1. global consideration 2. wealthy regions are responsible for most of world's consumption 3. U.S and Europe have less than 15% of world's population but consume half world's metals, food, energy and other resources 4. Population Growth 1. leads to ever greater resource demands 5. Health Care 1. essential for productive life 2. Underdeveloped areas can lead to disease, accidents, respiratory and digestive impairments and other conditions 3. without health, economic security is at risk 6. Sustainable Cities 1. key because over half of humanity now lives in cities 2. cities need to be healthy places to live and must cause minimal environmental impact 7. Environmental Policy 1. needs to guide decision making in local and national governments 1. ensures environmental quality is protected before it gets damaged 2. sets agreed upon rules for resource use 8. Protection of the Atmosphere 1. essential for minimizing rate of climate change and reducing air pollution impact on people, plants and infrastructure 9. Combatting Deforestation and Protecting Biodiversity 1. go together because world's biodiversity is in forests 2. humans depend on forests for water resources, climate regulation and resources like food, wood, medicine and building materials 3. Coral reefs, wetlands and coastal areas are other key zones of biodiversity 10. Combating desertification and drought 1. better management of water resources can save farms, ecosystems and lives 2. removal of vegetation and soil loss make drought worse 1. a few bad rainfall years can convert a landscape to desertlike conditions 11. Agriculture and Rural Development 1. affect lives of nearly half of humanity that doesn't live in cities 2. improving conditions by including more sustainable farming systems, soil stewardship to help stabilize yields and acces to land can help reduce urban slum populations 4. Science Helps Us Understand Our World 1. Science 1. process for producing knowledge based on observations 2. also refers to cumulative body of knowledge produced by many scientists 3. theories are developed and tested using observations 4. valuable when it comes to understanding world and meeting practical needs like new medicines, new energy sources or new foods 5. rests on the assumption that the world is knowable and careful observation and logical reasoning can educate about the world 2. Basic Principles of Science

1. Empiricism 1. can learn about world through careful observation of empirical (real/observable) phenomena 2. can expect to understand fundamental processes and natural laws by observation 2. Uniformitarianism 1. basic patterns and processes are uniform across time and space 2. forces at work are same as those that shaped the world 1. will continue to do so in the future 3. Parsimony 1. when 2 plausible explanations are reasonable, simpler (more parsimonious) one is preferable 1. rule is known as Ockham's razor after English philosopher who proposed it 4. Uncertainty 1. knowledge changes as new evidence appears and explanations (theories) change w/ new evidence 2. theories based on current evidence should be tested on additional evidence, w/ understanding that new data may disprove best theories 5. Repeatability 1. test and experiments should be repeatable 2. same results cannot be reproduced then conclusions are probably incorrect 6. Proof is Elusive 1. new evidence may always improve on current explanations 2. even evolution is referred to as a theory 7. Testable Questions 1. determing correction of theory must be tested 2. formulate hypotheses (testable statements) to test theories 3. Science depends on Skepticism and Reproducibility 1. Ideal that scientists are skeptical 1. cautios about accepting proposed explanation until enough evidence supports it 2. Reproductibility 1. scientists demands it 2. making an observation or obtaining a result just once doesn't count for much 1. result must be produced consistently to be sure first outcome wasn't a fluke 2. more importantly, condtions of the study must be describeable in such a way that someone else can reproduce the findings 3. Replication 1. repeating studies or tests 4. Use both Deductive/Inductive Reasoning 1. Deductive Reasoning 1. logical reasoning from general to specific 2. often general laws that guide natural systems are unknown and observations must be relied on to find general rules 2. Inductive Reasoning 1. Reasoning from many observations to produce a general rule 1. (specific to general) 2. ex. birds appear/disappear as a year goes by 1. repeated observations infer that birds move from place to place in spring and fall 5. Scientific Method 1. Observe

2. Propose a Hypothesis 3. Develop a test of hypothesis and predict result that would indicate hypothesis was correct 4. Gather Data 5. Interpret results 6. Scientific Theory 1. when an explanation has been supported by large number of tests and a majority of experts have reached general consensus that it is reliable description/explanation 7. Understanding Probability Reduces Uncertainty 1. Probability 1. one strategy to improve confidence in the face of uncertainty 2. measure of how likely something is to occur 3. usually probability estimates are based on a set of previous observations or on standard statistical measures 4. doesn't tell what will happen but will tell what is likely to happen 5. often more useful than proof 1. absolute proof is hard to achieve but strong trends/relationships can be frequently demonstrated 8. Experimental Design can Reduce Bias 1. Natural Experiment 1. experiment involving observations of events that have already happened 2. ex. geologist might want to study mountain building 2. Manipulative Experiments 1. experiment in which conditions are deliberately altered and all other variables are held constant 2. most are done in laboratory where condtions can be carefully controlled 3. Controlled Study 1. comparing a treatment group and a control (unexposed) group 2. study comparing two populations that are identical in every factor except the one being studied 3. Risk of Experimenter Bias 1. To avoid bias: 1. Blind Experiments 1. which researchers don't know which group is treated until after the data has been analyzed 2. Double-Blind Experiments 1. neither the subject nor the researcher knows who is in the treatment group and who is in the control group 9. Sound Science 1. generally means valid science according to basic scientific principles 2. when controversy surrounds science, claims about sound science and accusations of junk science often arise 5. Critical Thinking 1. term used to describe logical, orderly, analytical assessment of ideas, evidence and arguments 2. Helps w/ Information Analyzing 1. involves examining source of information and how much that source influences the kind of info received 2. Analytical thinking

1. helps break a problem down into its constituent parts 3. Creative thinking 1. asks “How might this problem be approached in a new and inventive way?” 4. Logical thinking 1. evaluates whether structure of an argument makes sense 5. Reflective thinking 1. asks “What does it all mean?” 3. Steps that can be used in Critical Thinking 1. Identify and Evaluate Premises and Conclusions in an Argument 2. Acknowledge and Clarify Uncertainties, Vagueness, Equivocation, and Contradictions 3. Distinguish Between Facts and Values 4. Recognize and Assess Assumptions 5. Distinguish Source Reliability or Unreliability 6. Recognize and Understand Conceptual Frameworks 4. Science is a Cumulative Process 1. consensus is important in science 2. Paradigm Shifts 1. change in explanatory frameworks that causes major shifts in scientific thought 2. 6. Major Environmental Movements 1. Preservation Movement 1. John Muir 1. first president of Sierra Club 2. opposed Punchot's utilitarian policies 3. argued nature deserves to exist for its own sake 4. aesthetic and spiritual values formed core of philosophy 1. prioritizes preservation 1. emphasizes fundamental right of other organisms and nature as a whole to exist and pursue their own interests 2. The Land Ethic 1. Aldo Leopold 1. wrote many essays calling for respect for natural world 2. founded Wilderness Society 3. Modern Environmental Movement 1. Rachel Carson 1. Silent Spring 1. 1962 2. response to pollution from chemical industries after WWII 3. awakened public to threats of toxic chemicals to humans and other species 4. Global Environmentalism 1. Environmental quality and social progress need to be addressed on global scale 2. Sustainable Development 1. economic improvement for world's poorest populations is possible without devastating the environment...