Environmental Science For Dummies®
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Table of Contents
About This BookConventions Used in This BookWhat You’re Not to ReadFoolish AssumptionsHow This Book Is OrganizedPart I: Demystifying Science and the EnvironmentPart II: Planting the Seed: Foundational Concepts in Environmental SciencePart III: Getting Your Needs Met: Earth’s Natural ResourcesPart IV: Giving a Hoot: Pollution and Environmental QualityPart V: Follow the Recycled Brick Road: A Sustainable FuturePart VI: The Part of TensIcons Used in This BookWhere to Go from Here
Chapter 1: Investigating the EnvironmentPutting the “Science” in Environmental ScienceUsing the scientific methodUnderstanding the connection between atoms, energy, and lifeAnalyzing the Earth’s Physical Systems and EcosystemsSorting the world into climate categoriesDividing the Earth into ecosystemsObserving the interactions between organisms within an ecosystemSupplies Limited! Natural Resources and Resource ManagementFactoring in food, shelter, and moreThinking about energy alternativesKeeping Things HabitableClearing the air (and water)Tracking toxins and garbageInfluencing climateImagining the FutureRealizing a sustainable economyPutting it on the books: Environmental policyChapter 2: Lab Coats and Microscopes: Thinking ScientificallyAsking and Answering Questions with the Scientific MethodReasoning one way or another: Inductive versus deductiveWorking through the scientific methodPresenting Data GraphicallyQuantifying UncertaintyRecognizing Good Science When You See ItChapter 3: What’s the Matter? Living and Nonliving MaterialChanging States of MatterExamining Atomic StructureMaking and Breaking Chemical BondsIonic bondingCovalent bondingHydrogen bondingOxidizing and reducing compoundsSurveying the Properties of WaterTaking a closer look at the water moleculeThe unbearable lightness of iceWhat’s pH Got to Do with It? Acids and BasesDefining acids and basesMeasuring reactivity with the pH scaleIt’s Alive! Organic Matter and CompoundsProteinsNucleic acidsCarbohydratesLipidsBuilding Organisms One Cell at a TimeWorking together: Cell specializationSeparating plant cells from animal cellsChapter 4: Making Things Happen: EnergyIdentifying the Different Types of EnergyTransferring heat: Thermal energySetting things in motion: Work and kinetic energyStoring potential energyMoving in wavesDefining the Thermodynamic LawsCounting Calories (And Joules)Converting the Sun’s Energy to a Useable FormSpinning sugar from sunlight: PhotosynthesisWaiting to exhale: Respiration
Chapter 5: Studying the Environment and Your Place in ItIntegrating Multiple DisciplinesApplying Common Tools of Environmental ScienceReviewing case studiesAssessing environmental indicatorsMeasuring human impacts: The ecofootprintTracing the Development of Modern Environmental EthicsManaging for use: Utilitarian conservationA life of its own: Preservation of wildernessReducing pollution: Battling pesticides and other toxinsIt’s a small world after all: Global environmentalismThe Overall Goal: Seeking SustainabilityTo Be or Not to Be a Tree-Hugger: Looking Past Political DebatesChapter 6: Exploring EcosystemsUnderstanding SystemsDefining open and closed systemsMapping out system dynamicsSystematically Understanding the Earth’s EnvironmentFlowing through the hydrologic cycleRecognizing important nutrient cyclesTransferring Energy and Matter through an EcosystemDefining ecosystem boundariesGetting caught in the food webMeasuring productivityBuilding ecological pyramids: Illustrating energy and biomass flowChapter 7: Biogeography: How Earth’s Climate Shapes Global Ecosystem PatternsPositioning Ecosystems: Latitude and AltitudeRecognizing Major Climate DriversBringing on the heat: Differential absorption of the sun’s energyThe wide blue yonder: Atmospheric circulationMaking waves around the globe: Patterns of ocean circulationSeparating the Globe into BiomesTundra to tropics: Terrestrial biomesDepending on depth: Aquatic biomesSwimming out to sea: Ocean ecosystemsChapter 8: Playing Well with Others: Population BiologyCharacterizing a PopulationPredicting Population ChangeRegulating populations with different growth factorsModeling population growthReproducing strategiesWatching Species InteractSurvival of the fittest: CompetitionEat or be eaten: PredationMutually surviving: SymbiosisFrom Indicator Species to Ecosystem Engineers: Filling Every NicheWorking Together: Biological CommunitiesSucceeding through different stagesResponding to disturbancesThe People Principle: Human Population BiologyTracking exponential growthCalculating population sizeDiagramming age structureExperiencing a demographic transitionGetting caught in a demographic trapUnderstanding human impacts
Chapter 9: Water, Water Everywhere: Freshwater ResourcesThirsty for More: The Never-Ending Need for Fresh WaterWithdrawal versus consumptionScarcity and stressMeeting human water needsFinding Fresh WaterDiverting surface flowTapping what flows below: GroundwaterConserving Fresh WaterCreating Fresh WaterChapter 10: This Land Belongs to You and Me: Land as a ResourceSharing LandWatching a tragedy unfold: Land resource depletionClassifying shared landManaging Land ResourcesTimber! Harvesting the forestGrazing the grasslandsQuestioning Smokey the Bear: Fire managementConsidering the Connection between Urbanization and Land UseSprawling across the horizonGrowing smarterChapter 11: Dishing It Up: Food ResourcesSeeking Food SecurityIdentifying the factors that lead to famineEating for healthFeeding the world: The green revolutionDigging in the Dirt: Components of Healthy SoilLearning the ABC’s of soilConsidering erosion: The removal of topsoilThe Pitfalls of PesticidesConcocting a formula for every pestRunning in circles: The pesticide treadmillSpreading poisons far and wide“Frankenfood”: Genetically Modifying FoodSplicing and dicing chromosomesDebating GMOsConsidering the ethical issues related to GMOsFarming Fish and Other AnimalsEating less efficientlyConfining animals for mass productionFarming fishEstablishing Sustainable AgricultureConserving soilIntegrating pest managementDefining OrganicChapter 12: Greater Than the Sum of Its Parts: BiodiversityVariety Is the Spice of Life: Defining BiodiversityExamining species richness and evennessBenefitting from biodiversityBecoming Biodiverse: Evolution by Natural SelectionCombining genetic materialSelecting for survivalThe HIPPO in the Room: Major Threats to BiodiversityHabitat destructionInvasive speciesPollutionPopulation growth (of the human variety)OverharvestingCreating Effective Conservation PlansOf singular importance: The species approach to conservationSize does matter: Preserving entire ecosystemsChapter 13: Hitting the Hard Stuff: Geologic Resources and EnergyGetting to Know the EarthFinding Value in RocksRocks and mineralsMetals and oresExtracting Geologic ResourcesScraping the surface: Surface miningDigging deep: Subsurface miningForming and Depleting Fossil FuelsCreating rocks from lifeDown and dirty: Mining and burning coalPerusing petroleum and natural gas resourcesReacting to Nuclear EnergySplitting atoms: Nuclear fissionFusing atoms: Nuclear fusionThe once and future fuel: Debating nuclear energyChapter 14: Shifting Gears: Alternative EnergyLooking for Alternative EnergyFarming Fuel: Biofuel Energy SourcesBiomassBiodiesel, ethanol, and other liquid biofuelsMethane gasHarnessing Energy from WaterDamming rivers: HydropowerFeeling the pull: Tidal and wave energyGetting Steamed: Geothermal EnergySoaking Up the Sun: Solar EnergyChasing Windmills: Wind EnergyEnergy on Demand: Creating Fuel CellsMaking the Most of the Energy You Already Have: Energy ConservationCogenerating: A two-for-one dealBuilding smarter power gridsGetting around town more efficientlyCapturing energy at home
Chapter 15: Breathing Room: Addressing Manmade Air PollutionSorting Out Common PollutantsObserving the Effects of Air PollutionLosing vegetationTinting the sky a hazy shade of brownTrapping pollutants: Temperature inversion and smogMelting monuments: Acid rainHoly Ozone! Remembering the Hole in the Ozone LayerCreating ozone naturallyDepleting the ozone layerHalting ozone depletion: The Montreal ProtocolThe Air in There: Watching Out for Indoor Air PollutionClearing the AirChapter 16: Drip Drop Splash: Water PollutionPolluting Water in Many WaysGetting to the Point(And Nonpoint) SourceEndangering Human HealthBacteria, viruses, and parasites, oh my!Pesticides, drugs, and metalsDisrupting EcosystemsMeasuring dissolved oxygenCreating zones in aquatic ecosystemsGrowing to extremes: Nutrient pollutionBreaking with Tradition: Wastewater Treatment and Constructed WetlandsChapter 17: What’s Your Poison? Toxins and Infectious DiseaseIdentifying Common ToxinsSticking Around: Persistent Organic PollutantsUnderstanding the Ins and Outs of Toxic ExposureAccumulating in fatty tissue: BioaccumulationMagnifying up the food chain: BiomagnificationRisky Business: Assessing the Dangers of ChemicalsMeasuring riskPerceiving riskChoosing a risk management strategyTracking Infectious DiseaseEmerging on the scene: Modern infectious diseaseEvolving resistanceChapter 18: A River of Garbage Runs through It: Solid and Hazardous WasteWading into the Waste StreamDisposing of WasteTossing it aside and covering it up: Dumps and landfillsBurning trash: IncinerationExporting electronics: E-waste disposalSwimming in Waste: The Ocean Garbage PatchesSwirling and whirling: Concentrating trash in ocean gyresFighting photodegradable flotsamStopping trash at the sourceReduce, Reuse, Recycle (and Compost): Shrinking the Waste StreamHandling Hazardous WasteCleaning up the mess: The SuperfundDanger lying dormant: Bringing up brownfieldsChapter 19: Is It Getting Warm in Here? Modern Climate ChangeHothouse Humans: The Greenhouse EffectFilling the air: The top six greenhouse gasesRecognizing human influencesThe proof is in the isotopesConsidering Past, Present, and Future ClimatesThe ghost of climates pastMeasuring carbon dioxide levels in the atmosphereTracking patterns of variabilityPredicting the future: Climate modelsFeeling the Heat: Environmental Effects of Modern Climate ChangeFacing a Warmer FutureFeeling the effects on human societyTurning down the heat: Mitigating human influencesAdapting along the way
Chapter 20: Building a Sustainable FutureOverlapping Spheres of SustainabilityLooking at Ecosystem LessonsCounting Coins: Mainstream EconomicsMeasuring Earth’s capitalGoing to the marketCalculating a nation’s wealthTripling the Bottom LineTaxing harmful practicesInstituting incentive-based regulationsExercising the Precautionary PrincipleLooking at the World in New WaysEvolving economicsReevaluating production and consumptionIt Takes a Global Village: Poverty and SustainabilitySeeking justiceMicrolending a handChapter 21: Cooperating to Sustain the EarthUnderstanding What’s at StakeUniting Nations: International Agreements on Planetary StewardshipThe Ramsar Convention on WetlandsThe Convention on International Trade in Endangered SpeciesThe Convention on Biological DiversityUnited Nations agreementsOther international agreementsFrom Sea to Shining Sea: Environmental Protection in the U.S.Overseeing environmental regulationsLegislating for the environment
Chapter 22: Ten Ways to Live SustainablyReducing Household Energy UseEating LocallyDisposing with DisposablesPlanting SeedsRecyclingReselling and Donating ItemsDrinking from the TapSaving WaterRelying Less on Your CarPurchasing Fair-Trade ProductsChapter 23: Ten Real-Life Examples of the Tragedy of the CommonsGrand Banks FisheriesBluefin TunaPassenger PigeonsOcean Garbage GyresEarth’s AtmosphereGulf of Mexico Dead ZoneTraffic CongestionGroundwater in Los AngelesUnregulated LoggingPopulation GrowthChapter 24: Ten Careers in Environmental ScienceMarketing SustainabilityRestoring Natural LandscapesSpreading the Word and Educating OthersContinuing Study and ResearchDefending the EnvironmentAssessing RiskAnalyzing PolicyEngineering SolutionsConserving Farm and Ranch LandAdvising InvestmentCheat SheetEnd User License Agreement
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About the Author
Alecia M. Spooner teaches Earth and environmental sciences at Everett Community College in Everett, Washington. She has degrees in anthropology (a BA from the University of Mississippi), archaeology (an MA from Washington State University), and geology (an MS from the University of Washington). In graduate school, she reconstructed paleoclimate and paleoenvironments from fossil pollen records in lake sediments of the Pacific Northwest. She teaches by using active learning and inquiry. She lives in Shoreline, Washington, with her husband, two boys, a cat, and two chickens.
Dedication
To the many teachers who inspired me to look at the world more closely.
“We shall never achieve harmony with land, any more than we shall achieve absolute justice or liberty for people. In these higher aspirations, the important thing is not to achieve but to strive.”
—Aldo Leopold
Author’s Acknowledgments
This book was created with support and encouragement from the following people: Igor, Pasha and Dima, Mom and Dad, Heather and Julie, Alli and Holly, Janice and Kysa, Rene and Matt, and Elizabeth, Amanda, and Lindsay. Thank you.
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Introduction
Environmental science is the study of Earth’s environment. To study the environment, scientists draw from many other disciplines, including chemistry, geography, economics, and everything in between. No wonder students new to environmental science often find themselves dizzy at the breadth of information needed to study and solve environmental problems.
Fortunately, you’ve found Environmental Science For Dummies! Regardless of whether you picked up this book to help you through a science class or to begin an independent exploration of environmental science, I hope it’s a useful reference for you, providing an introduction to the most important concepts and issues in modern environmental science.
I’ve written this book to cover as many environmental science concepts as possible, while at the same time helping you understand how these concepts apply to your life. If you’re already familiar with some of the topics explained in the book, perhaps this book will help renew your interest in environmental studies and sustainable living. If these topics are completely new to you, I hope it helps you realize that you can take action daily and make choices that affect your environment in a positive way.
About This Book
Environmental Science For Dummies presents an introduction to the core concepts in environmental science and the most important issues studied by environmental scientists today.
The topics in environmental science are so intricately linked that there’s simply no way to explain one without explaining a little bit of another as well. In each chapter, I use cross-references to other chapters to help you link together the related concepts and to provide a more complete understanding of the complex topics in environmental science.
Throughout the book, you also find multiple illustrations. These drawings expand on what I’ve written in places where a visual representation may be helpful. But don’t forget to look up from reading once in a while! You have plenty of first-hand experience with the environment. As you read about certain topics or issues, you may find it useful to look at them in the context of your own life.
Conventions Used in This Book
Here are some of the conventions I use in the book to keep things easy to find and follow:
Anytime I use a word that I think you may not have seen before, I put it in italics and define it.
Boldface words highlight a bulleted list or sequence of steps.
Internet and web addresses appear in monotype
to help them stand out.
What You’re Not to Read
Throughout this book, you find sidebars highlighted in gray. The sidebars include extra information or particularly interesting tidbits that I thought you might enjoy. I find them interesting — and I hope you do, too — but they aren’t required reading to understand the concepts in the book. Feel free to skip these sidebars, as they’re not integral to the information presented in each chapter.
Similarly, any portion of text with the Technical Stuff icon beside it indicates that it explains or describes a concept in extra detail, beyond what you need to have a basic grasp of the idea. Feel free to skip these portions or to breeze through them.
Foolish Assumptions
As the author of this book, I’ve made some assumptions about you, my reader. For instance, I assume that you live on Earth, drink water, breathe air, and use energy for various things such as heating and transportation. I assume that you’re familiar with basic geography, such as the location of continents and some countries around the world.
However, I don’t assume that you have any background in chemistry, biology, geology, ecology, economics, or any of the other disciplines that are part of environmental science. And you don’t need a background in any of these to benefit from the explanations in this book. Wherever the details of another science are important, I provide those details in my explanations.
Each topic in environmental science could fill an entire book of its own, so if you find that something in particular catches your interest, I encourage you to look for books that offer more detail into that topic specifically.
How This Book Is Organized
I’ve broken this book into chapters and organized those chapters into parts that group topics together. Here’s a brief overview of each part.
Part I: Demystifying Science and the Environment
In Part I, I introduce you to environmental science, the study of Earth’s environment and the living and nonliving things within it. I describe the scientific method and explain how scientists design effective experiments and portray information by using graphs.
This part includes a discussion of matter, the “stuff” that makes up all things, and a quick look at how atoms bond to form molecules. It describes inorganic matter and the important organic molecules that are the building blocks for life. And it includes a chapter on what scientists understand about energy: what it is, how it works, and how it flows. This is where you find details on photosynthesis and cellular respiration.
Part II: Planting the Seed: Foundational Concepts in Environmental Science
Like any science, environmental science has a few key concepts or principles that provide the foundation for greater understanding. In Part II, I introduce you to these concepts, including how to measure human impact with the ecological footprint and how to use the ecosystem as a unit of study.
The plants and animals that inhabit an ecosystem are determined largely by the climate (temperature and moisture) conditions of the region. Scientists link living communities to climate by classifying ecosystems into defined categories called biomes, which I describe in this part.
This part also scratches the surface of population biology, which is the study of how organisms interact with one another. I explain competition, cooperation, and predation within an ecosystem, as well as some of the complex ways that scientists measure and track changes in populations (including human populations) over time.
Part III: Getting Your Needs Met: Earth’s Natural Resources
A major focus of environmental science is how to use and care for Earth’s natural resources so that they can continue to meet the needs of human beings for as long as possible. Part III describes Earth’s natural resources and the issues humans face in trying to conserve them, or make them last.
You’re familiar with some of these resources — water, land, and energy. But you may not realize that the diversity of biological organisms, or biodiversity, is also a natural resource. I describe all these resources in this part and explain why biodiversity is so important and why it’s in danger in many parts of the world. I also explain the pros and cons of alternative energy sources.
Part IV: Giving a Hoot: Pollution and Environmental Quality
Along with managing natural resources, environmental scientists are often asked to help solve problems created by pollution. Part IV covers topics of environmental quality, including air and water pollution. It’s also the place to look for information about what dangerous substances or toxins are present in the environment and how garbage and hazardous waste can be managed to reduce further environmental damage.
This part also addresses what scientists currently understand about Earth’s climate and how human actions continue to affect the global climate system.
Part V: Follow the Recycled Brick Road: A Sustainable Future
The goal of most environmental scientists is sustainability. This means using the environment and its resources in such a way that it can continue to provide for human needs long into the future, possibly forever. In this part, I describe some basic economic principles and explain how shifting your perspective from human-centered to ecosystem-centered may lead you to make more sustainable choices as a consumer.
Millions of people with different desires and priorities share Earth. In this part, you uncover some of the most successful policies across the U.S. and across the world that have come about to help protect the environment and conserve Earth’s resources for future generations.
Part VI: The Part of Tens
In the final part of Environmental Science For Dummies, you find three lists. The first is a list of ten simple ways to live life more sustainably. The second describes ten examples of how unsustainable practices have ruined shared resources, or commons. And the last chapter of the book lists ten careers that center on environmental science. You may be surprised at the variety of options you have for working in an environmental science field!
Icons Used in This Book
Throughout this book I use icons to catch your eye and highlight certain kinds of information. Here’s what these little pictures mean:
Where to Go from Here
I’ve written this book to function as a reference that you can open to any page and dive into. If you choose to start from the beginning, you’ll find the information organized in what I hope is a logical way that answers your questions as soon as you think to ask them! But you can also browse the table of contents to find topics you’re interested in knowing more about and then turn to the chapters on those topics.
If you’ve never thought much about how you’re connected to everything around you, you may want to start with Chapter 6, which explains what an ecosystem is and does. This chapter may dramatically change your perspective!
If you’re intrigued by the idea of alternative energy sources, flip to Chapter 14, where I cover many different ways to fuel daily living without using fossil fuels (coal, gas, and oil) or nuclear power. Environmental scientists have found ways to capture or produce energy in cleaner, more efficient ways than have ever been possible before.
For a real wake-up call, turn to Chapter 18 to see how the packaging and convenience of modern life (think bottles of water, to-go containers, and plastic utensils) have resulted in oceans full of trash. In particular, plastic bits that don’t decompose are interfering with ocean ecosystems, which is just one of the consequences of waste I describe in that chapter.
Part I
Demystifying Science and the Environment
In this part . . .
At its core, environmental science is like any science — based on a methodical way of asking and answering questions to expand the human understanding of the natural world.
In this part, I describe how the scientific method shapes the process of learning about the environment. I also cover foundational scientific ideas about what makes up everything around you (atoms, molecules, and compounds) and how energy moves things through the environment. This is also where you find out how green plants capture energy from the sun and transform it into sugar through the process of photosynthesis.
Chapter 1
Investigating the Environment
In This Chapter
Applying a scientific approach
Studying environmental systems
Protecting natural resources
Reducing pollutants in the air and water
Looking forward to a sustainable future
In its simplest terms, environmental science is the study of the air you breathe, the water you drink, and the food you eat. But environmental scientists study so much of the natural world and the way humans interact with it that their studies spill over into many other fields. Whether you’re a student in a college course or someone who picked up this book to find out what environmental science is all about, you’ll find that the ideas in this book apply to your life.
Like any living creature, you depend on environmental resources. More importantly perhaps is the fact that humans, unlike other living creatures, have the ability to damage these resources with pollution and overuse. This chapter provides a quick overview of the environment, its systems, and its many resources. It also talks about what humans can do to reduce their impact on the environment today and into the future. After all, maintaining the health of the Earth and its resources at both the local and global level is something everyone has a stake in.
Putting the “Science” in Environmental Science
Environmental science draws on knowledge from many different fields of study, including the so-called hard sciences like chemistry, biology, and geology and the social sciences like economics, geography, and political science. This section offers a quick overview of some of the scientific concepts, such as how to apply the scientific method to answer questions, that you need to be familiar with as you start your exploration of environmental science. I explain these foundational scientific concepts in more detail throughout the rest of Part I.
Using the scientific method
The scientific method is simply a methodical approach to asking questions and collecting information to answer those questions. Although many classes teach it as something that only scientists use, you use it just about every day, too.
You may not write down each step of the scientific method when you use it, but anytime you ask a question and use your senses to answer it, you’re using the scientific method. For example, when standing at a crosswalk, you look both ways to determine whether a car is coming and whether an approaching car is going slow enough for you to safely cross the street before it arrives. In this example, you have made an observation, collected information, and based a decision on that information — just like a scientist!
Understanding the connection between atoms, energy, and life
Studying the environment includes studying how matter, energy, and living things interact. This is where other fields of study, such as chemistry, physics, and biology, come into play. Here are just a few of the core ideas from these sciences that you need to understand as you study environmental science:
All matter is made of atoms.
Matter is never created or destroyed, but it does change form.
Living matter, or life, is made up of complex combinations of carbon, hydrogen, and oxygen atoms.
Most of the energy at Earth’s surface comes from the sun.
Energy transfers from one form to another.
Living things, or organisms, either capture the sun’s energy (through photosynthesis) or get their energy by eating other living things.
Analyzing the Earth’s Physical Systems and Ecosystems
The environment consists of many different systems that interact with one another on various levels. Some systems are physical, such as the hydrologic system that transfers water between the atmosphere and the Earth’s surface. Other systems are built on interactions between living things, such as predator-prey relationships.
Scientists recognize that systems can be either open or closed. An open system allows matter and energy to enter and exit. A closed system keeps matter and energy inside of it. Figure 1-1 illustrates both types of systems.
Figure 1-1: Open and closed systems.
Illustration by Wiley, Composition Services Graphics
Very few systems in the natural world are truly closed systems. Scientists view the planet as a closed system in terms of matter (no matter enters or leaves the Earth), but they consider it an open system in terms of energy (energy enters the Earth from the sun). The following sections introduce you to a few of the Earth’s other systems that you need to be familiar with. (Part II goes into a lot more detail on the different systems on Earth.)
Sorting the world into climate categories
One of the most important and complex systems that scientists study is the climate. The climate system includes but is actually much larger than local weather systems. Climate scientists observe how different parts of the Earth are warmed by the sun to greater or lesser degrees, and they track how heat from the sun moves around the globe in atmospheric and ocean currents.
The movement of heat and water around the Earth sets the scene for living things. Every living plant and animal has a preferred range of temperature and moisture conditions. The patterns of living communities on Earth are called biomes. Scientists define each biome according to its temperature and moisture levels and the types of plants and animals that have adapted to live within those limits. Understanding the complex link between climate factors and the distribution of life on Earth has become even more important as scientists document changes in the global climate and predict more dramatic changes to come. Turn to Chapter 7 for details on global climate patterns and biomes.
Dividing the Earth into ecosystems
Within every biome, scientists recognize various ecosystems, or communities of living organisms and the nonliving environment they inhabit. Studying how matter and energy move around ecosystems is at the core of environmental science. Specifically, scientists recognize that
Matter is recycled within the ecosystem.
Energy flows through an ecosystem.
Whether they’re small or large, discrete or overlapping, ecosystems provide a handy unit of study for environmental scientists. Because plants are the energy base of most ecosystems (capturing energy from the sun), the type and number of plant species in an ecosystem determine the type and number of animals that the ecosystem can support. See Chapter 6 for details on ecosystems.
Observing the interactions between organisms within an ecosystem
Scientists called ecologists are particularly interested in how living things interact within an ecosystem. Plants and animals compete with one another for access to water, nutrients, and space to live. Evolution by natural selection has resulted in a wide array of survival strategies. Here are some examples (see Chapter 8 for more details):
Resource partitioning: When two species, or types of animals, depend on the same resource, they may evolve behaviors that help them share the resource. This is called resource partitioning. An example is when one species hunts at night, while another hunts the same prey during the day.
Coevolution: Coevolution occurs when a species evolves in response to its interaction with other species. Scientists have documented multiple cases of insects and the plants they feed on (and help pollinate) evolving to become more and more suited to one another over time.
Symbiosis: Organisms that benefit from an interaction with another species live in what scientists call symbiosis. Symbiotic relationships between organisms may benefit both individuals, benefit only one while harming the other (such as with a parasite), or benefit one without harming the other.
Supplies Limited! Natural Resources and Resource Management
Environmental scientists do a lot of research to find ways to meet the needs of human beings for food, water, and energy. The environment provides these natural resources, but if their users (namely humans) don’t care for them properly, they can be reduced, damaged, or destroyed. Managing natural resources for the use of human beings now while ensuring that the same resources will be available for humans in the future is called conservation.
Factoring in food, shelter, and more
People need food, water, air, and shelter to survive. But as human populations have grown into the billions, they’ve tested the ability of the environment to provide enough food, fresh water, and shelter. In Part III, I describe methods of sustainable agriculture and water conservation that can help meet the needs of so many people. (So far, there’s still plenty of air to go around.)
Other resources that people depend on are less obvious, such as the biological diversity, or biodiversity, found in certain regions. Human actions have reduced biodiversity around the world, particularly in biodiversity hotspots, or regions with a combination of high levels of diversity and increasing human impacts. In Chapter 12, I explain what biodiversity is and why it’s so important.
Thinking about energy alternatives
One of the most critical natural resources that modern living depends on is energy. Energy in most ecosystems streams from the sun every day, but to fuel modern life, humans have tapped into the stored energy of fossil fuels hidden deep in the Earth. Unfortunately, fossil fuel sources of energy are both limited in supply and damaging to the Earth’s environment when humans burn them as fuel.
Searching for alternative sources of energy is an important part of environmental science research. Some of the current alternatives to fossil fuels include
Solar energy
Wind energy
Hydro (river) energy
Tidal and wave energy
Geothermal heat
Fuel cell electricity
Liquid biofuel energy
I describe the pros and cons of these various options and explain how each one can help meet the energy needs of modern life in Chapter 14.
Keeping Things Habitable
Clean air, fresh water, food, and a safe place to live are critical to the survival of human beings. Unfortunately, in most parts of the world, decades of pollution have damaged environmental quality and endangered human health. How humans can repair the damage already done to air, water, and land resources is the focus of Part IV.
Clearing the air (and water)
You may be familiar with some of the problems caused by air pollution: smog, acid rain, ozone depletion, and lung disease. In Chapter 15, I describe all the ways air is polluted and the results of pollution on ecosystems and human health. Similarly, in Chapter 16, I describe the sources and effects of water pollution.
In both cases, scientists classify the source of pollution as one of the following:
Point source pollution: Point source pollution flows directly out of a pipe or smokestack and is easy to locate and regulate.
Nonpoint source pollution: Nonpoint source pollution enters the air or water from a diluted or widespread area, such as when rainfall washes everything from city streets into nearby waterways via storm drains. This type of pollution is difficult to pinpoint and nearly impossible to regulate.
Tracking toxins and garbage
Toxic substances are all around you — in your home and in the environment. Many identified toxins today were once acceptable chemicals to use in agriculture or manufacturing. In some cases, scientists know the effects of a toxin, and as a result, it’s no longer allowed to be used. In other cases, however, research is still being done to determine the danger of chemicals found in many household products.
In some places, toxins have entered the environment from improper waste disposal. Humans have to store (or burn) trash and other manmade garbage somewhere. All too often that garbage ends up in the oceans. I describe the problems related to waste disposal in Chapter 18.
Influencing climate
These days, few environmental issues appear in the media and politics as often as modern climate change, or global warming. In Chapter 19, I explain how the greenhouse effect on Earth is beneficial and how greenhouse gases, both natural and manmade, change the composition of the atmosphere and affect climate patterns around the globe.
Some of the changes scientists expect with future climate warming include droughts in regions that are already water stressed, rising sea levels, and marine ecosystem disruption. The climate is definitely warming, so I also describe ways that humans can mitigate, or repair, the damage already done and adapt to a future climate that’s very different from anything modern human civilization has experienced before.
Imagining the Future
Managing the Earth’s resources so that human needs and desires today don’t reduce the planet’s ability to support future generations is called sustainability. The future is in your hands. The choices you make each day and the leaders you choose to create policies determine how people share, use, or abuse the Earth’s resources in the coming decades. Regardless of your religious, political, cultural, or national values, you have a stake in your right and the rights of your children to a healthy, clean environment.
Realizing a sustainable economy
Many people think the biggest challenge in making sustainable choices is the cost, and some politicians want you to believe that a sustainable economy will destroy the world. Neither of these views is true. In Chapter 20, I describe some basic economic ideas and offer ways to look at the economy more sustainably. The transition to a more sustainable economy will take time, but in the long run, it’ll be worth the effort!
Putting it on the books: Environmental policy
In Chapter 21, I introduce you to some of the most important and effective international agreements on global stewardship. The Montreal Protocol is one international agreement that was created to protect the environment. Specifically, this agreement reduced the production of ozone-damaging molecules around the world and halted the destruction of the ozone layer.
You may not have realized this, but 50 years ago many of the rivers, lakes, wetlands, and shorelines in the U.S. were much more polluted than they are today. After Congress amended the Clean Water Act in the 1970s, major cleanups began, improving water quality across the nation during the next few decades. These days new issues, such as climate change and environmental toxins, have taken a front seat in environmental science and policy. But no matter what issues are currently taking up the most attention on TV and in scientists’ labs, the choices you and I make every day will determine the future health of the global environment.