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Science and the Environment Chapter 1
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At the end of this chapter I can … 1.Define environmental science and compare environmental science with ecology. 2.List the five major fields of study that contribute to environmental science. 3.Describe how the agricultural revolution changed the human population and ultimately the environment. 4.Distinguish between renewable and nonrenewable resources. 5.Classify environmental problems into three major categories: Pollution, Resource Depletion, & Loss of Biodiversity
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I. Understanding Our Environment A. What Is Environmental Science? Environmental science – the study of how humans interact with the environment -goal is to understand and solve environmental problems -to meet the goal scientists study two types of interactions between humans and their environment 1-how we use natural resources 2-how our actions alter our environment
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Scientists gather evidence from many different disciplines -Environmental science is interdisciplinary – involves many fields of study Ecology – study of how living things interact with each other and with their nonliving environment Chemistry – nature of pollutants, geology – how pollutants travel underground, botany and zoology – need to preserve species, paleontology – study of fossils help us understand how Earth has changed -Also involves studying human populations – social sciences like economics, politics, law, geography
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B. Scientists as Citizens, Citizens as Scientists Studying the environment is vital to maintaining a healthy and productive society Nonscientists are usually the first to observe an environmental problem
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C. Our Environment Through Time Wherever humans have been, they have changed the environment. For most of human history, people were hunter-gatherers – or people who obtain food by collecting plants and hunting wild animals Early hunter-gatherer groups were small and they migrated from place to place as different types of food became available at different times of the year.
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Early societies affected their environment in many ways. -burned prairies so they kept trees from growing so they could hunt bison -helped spread plants to where they did not originally grow -rapid climate changes and overhunting may have led to disappearance of large mammal species (giant sloths, giant bison, mastodons, cave bears, and saber-toothed cats)
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hunter-gatherer groups began to collect the seeds of the plants they gathered and domesticate some of the animals Agriculture – the practice of growing, breeding, and caring for plants and animals that are used for food, clothing, housing, transportation, and other purposes. Started over 10,000 years ago and the shift from hunter-gatherer society to agricultural society – called the agricultural revolution Changes
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Effects of The Agricultural Revolution *Allowed human populations to grow – land can support 500 times more people by farming than by hunting and gathering populations began to concentrate in certain areas putting pressure on the local environment *Changed the foods we eat – the plants we eat today are descended from wild plants *Grasslands, forests, and wetlands were replaced with farmland -causes soil loss, floods, and water shortages -converted land was farmed poorly and is no longer fertile -destruction of farmland had far-reaching environmental effects
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The Industrial Revolution Mid-1700s Shift from energy sources such as animal muscle and running water to fossil fuels such as coal and oil Increased use of fossil fuels and machines changed society and greatly increased the efficiency of agriculture, industry, and transportation Began large-scale production of goods in factories Spinning Ginny for fabric/textiles
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The Industrial Revolution Machinery reduced the amount of land and human labor needed to produce food Increase in urban area (city) populations Fossil fuels and motorized vehicles also allowed food and other goods to be transported cheaply across great distances Improved quality of life -light bulb -sanitation, nutrition, medical care vastly improved
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New Environmental Problems human population grew leading to pollution and habitat loss 1900s modern societies began using artificial substances to replace raw animal and plant products -plastics, artificial pesticides and fertilizers -made life easier but brought a host of environmental problems
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D. Spaceship Earth Earth has been compared to a ship traveling through space that cannot dispose of waste or take on new supplies at it travels. Earth is a closed system - the only thing that enters is energy from the sun and the only thing that leaves is heat
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Running Out -because nothing else can enter or leave there are problems created like as the population grows, the resources will be used more rapidly and production of wastes more quickly than we can dispose of them Environmental problems can occur on different scales: local, regional, or global
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Population Growth many environmental problems are so pressing today because the Agricultural Revolution and Industrial Revolution These Revolutions allowed the human population to grow much faster than it had ever before - the development of modern medicine and sanitation helped increase the population The human population has almost quadrupled (4X) during the 20th century
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FOOD – Yummy FOOD – Yummy -producing enough food for all these people has had environmental consequences -we have used vast amounts of resources to meet the world’s need for food -habitat destruction and pesticide pollution are the result of feeding the world in the 20th century -habitat destruction and pesticide pollution are the result of feeding the world in the 20th century
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Wow! there are many different predictions of population growth for the future, but most scientists think that the human population will almost double in the 21st century before it begins to stabilize. What is the current world population? 6.79 billion people US population 309 million China population 1.35 billion India population 1.21 billion
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What will we do? -pressure on the environment will continue to increase as the human population and its need for food and resources grows
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1- Resource Depletion Any natural material used by humans is called a natural resource -natural resources can be classified as renewable or nonrenewable
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Resources -renewable resource – is a resource that can be replaced relatively quickly by natural processes -this is unless the resource is used faster than it can be replaced naturally then the resource becomes nonrenewable -examples include fresh water, air, soil, trees, crops, energy from the sun - nonrenewable resource – is a resource that forms at a much slower rate than the rate that it is consumed -most common are minerals and fossil fuels -once the supply is used up it may take millions of years to replenish it
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2- Pollution One effect of the Industrial Revolution is that societies began to produce wastes faster than the wastes could be disposed of – these accumulate in the environment and cause pollution. Pollution – an undesired changed in air, water, or soil that adversely affects the health, survival, or activities of humans or other organisms. -much of the pollution that troubles us today is produced by human activities
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2 main types of pollutants – biodegradable and nondegradable pollutants biodegradable pollutants – pollutants that can be broken down by natural processes -examples are human sewage or a stack of newspapers -these are a problem only when they accumulate faster than they can be broken down nondegradable pollutants – pollutants that cannot be broken down by natural processes -examples include mercury, lead, and some types of plastic -these build up to dangerous levels in the environment
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3 - Loss of Biodiversity Biodiversity – the number and variety of species that live in an area -the Earth has been home to hundreds of millions of species yet only a fraction are alive today Extinction is a natural process and several large-scale extinctions or mass extinctions have occurred throughout Earth’s history
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Extinction -a modern mass extinction is severe because the organisms that share the world with us can be considered natural resources -we depend on them for food, for the oxygen we breathe, and for many other things -a species that becomes extinct is gone for good, and so a species can be considered a nonrenewable resource Quagga Africa 1883
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What is a species worth? -many scientists think that if current rates of extinction continue it can cause problems for the human population in the future -species also have potential economic, ecological, scientific, aesthetic, and recreational value so it is important to preserve them
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II. The Environment and Society A. The Tragedy of the Commons In 1968, ecologist Garrett Hardin published an essay titled “The Tragedy of the Commons” which addressed the questions like how we decide how to share common resources
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Tragedy on the Commons conflict between short-term interests of individuals and the long-term welfare of society someone or some group has to take responsibility for maintaining a resource, if no one does, the resource is overused and becomes depleted Hardin thought people would continue to deplete natural resources by action in their own self-interest to the point of society’s collapse
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Tragedy on the Commons The solution may override the interests of individuals in the short term, but it improves the environment for everyone in the long term. Prisoner's Dilemma
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http://www.garretthardinsociety. org/info/cartoon_commons1.ht ml
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B. Economics and the Environment Economic forces influence how we use resources Law of supply and demand – the greater the demand for a limited supply of something, the more that thing is worth You can’t be pro-job and anti-business. That’s like being pro-egg and anti-chicken.’ ~Tim Pawlenty
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Cost-benefit analysis balances the cost of the action against the benefits one expects from it. -for example to determine how much to spend to control air pollution a community may perform a cost benefit analysis the results often depend on who is doing the analysis for example the industry says the cost of pollution control outweighs the benefits while the community thinks the benefits may be worth the price the cost of environmental regulation is often passed onto the consumer – the consumer then has a choice- to pay for the more expensive product that meets environmental regulations, or the cheaper product that may not have the same environmental safeguards
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Risk Assessment – calculating the risk of an undesirable outcome -often part of the cost-benefit analysis - its purpose is to come up with an effective solution to an environmental problem, the public must perceive the risk accurately – does the media always present risk accurately?
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C. Developed and Developing Countries The decisions and actions of all people in the world affect our environment. The unequal distribution of wealth and resources around the world influences the environmental problems Countries are either developed or developing
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Developed countries – have higher average incomes, slower population growth, diverse industrial economies, and stronger social support systems examples – US, Canada, Japan, countries of Western Europe
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Developing countries have lower average incomes, simple and agriculture-based economies, and rapid population growth examples – most African countries, parts of Latin America In between developed and developing are middle-income countries, such as Mexico, Brazil, and Malaysia
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D. Population and Consumption All environmental problems can be traced back to two root causes the human population in some areas is growing too quickly for the local environment to support people are using up, wasting, or polluting many natural resources faster than they can be renewed, replaced, or cleaned up
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Local Population Pressures when the population in an area grows rapidly, there may not be enough natural resources for everyone in the area to live a healthy, productive life as people struggle for survival in severely overpopulated regions, forests are stripped bare, topsoil is exhausted, and animals are driven to extinction malnutrition, starvation, and disease can be constant threats
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Where is Population Growing? population tends to grow more rapidly in developing areas – food production, education, and job creation cannot keep pace with population growth -as population grows each person gets fewer resources There are 4.5 billion people in developing countries and fewer than half have access to enough food, safe water, and sanitation
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The Face of Poverty
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Consumption Trends -For people in the wealthier world, life is better than ever before. Can it continue? -Pollution controls have improved and many environmental problems are being addressed -population has stabilized or is growing slowly
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The Luxury of Dubai
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Developed Countries -to support this quality of life, developed nations are using much more of Earth’s resources than developing nations are -developed nations uses about 75% of the world’s resources even though they make up only about 20% of the world’s population -this rate of consumption creates more waste and more pollution per person than in developing countries
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Ecological footprint – shows the productive area of Earth needed to support one person in a particular country -it estimates the land used for crops, grazing, forest products, and housing, it also includes the ocean area used to harvest seafood and the forest area needed to absorb the air pollution caused by fossil fuels -shows differences in consumption between nations
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E. Environmental Science in Context Environmental problems are complex and simple solutions are rare, and sometimes they cause more damage than the original problem did The environment has become a battleground for larger issues that affect human societies -rights of individuals and property owners, human rights
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Critical thinking and the environment -people on any side of an environmental issue feel passionately about their cause and they can distort information and mislead people about the issues -research done by environmental scientists is often used to make political points or is misrepresented to support controversial views
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Critical thinking economic dimensions of an issue can also be oversimplified -the media often sensationalizes environmental issues -make your own decisions about environmental issues by using your critical thinking skills -Learning to think critically is important – be prepared to listen to many different viewpoints
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How to see the issues try to understand the reasons for their viewpoints identify your own bias investigate the source of information you encounter do the authors have reason for bias? question the conclusions that are drawn from the data Ask -does the data support the claims that are made be especially critical of information on the internet, flashy graphics, persuasive text might be hiding a biased agenda gather all the information you can before drawing a conclusion
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F. A Sustainable World A key goal of environmental science is achieving sustainability Sustainability – condition in which human needs are met in such a way that a human population can survive indefinitely-being able to meet the needs of the present without compromising the ability of future generations to meet their needs
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Are we sustainable? The present time, we live in a world that is far from sustainable the standard of living in developed countries is so high because those countries are using resources faster than they can be replaced Achieving a sustainable world requires everyone’s participation
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Can you … 1.Define environmental science and compare environmental science with ecology. 2.List the five major fields of study that contribute to environmental science. 3.Describe how the agricultural revolution changed the human population and ultimately the environment. 4.Distinguish between renewable and nonrenewable resources. 5.Classify environmental problems into three major categories: Pollution, Resource Depletion, & Loss of Biodiversity
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