Biology - Biosphere

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  After you have finished reading this chapter, you should be able to: Discuss the Gaia hypothesis that Earth is a living organism. Relate the importance of the 3 Rs—reduce, reuse, and recycle—to thehealth of the biosphere. Compare renewable and nonrenewable resources. Discuss reasons why protecting the environment must be a worldwideeffort.  Plant a new Truffula. Treat it with care.Give it clean water. And feed it fresh air.Grow a forest. Protect it from axes that hack.Then the Lorax and all of his friends may come back. Dr. Seuss, The Lorax Introduction April 22, 1970, was a beautiful spring day across the United States. Morepeople joined demonstrations on that day for a single purpose than everbefore in history. That was the first Earth Day, and its purpose was to rallysupport to save the environment. (See Figure 28-1 on page 608.) Speeches,parades, marches, and rallies occurred everywhere. Fifth Avenue in NewYork City was closed to traffic so that people could walk in safety downthe street. Even the United States Congress closed so that politicians couldreturn home to attend local events.OnthatfirstEarthDay,itwasasifeveryoneawokeatthesametime.Everywhere,peoplerealizedthattheyhadsharedconcerns.Theenviron-ment,onwhichalllivingthingsdepend—ourland,ourair,ourwater—was 607 Saving the Biosphere 28  becomingincreasinglypolluted.ThisfirstEarthDaymarkedthebegin-ningofthemodernenvironmentalmovement.Italsomarkedthebegin-ningoftherealizationthatsomethinghadtobedone.Manyenvironmentalorganizationswerefoundedatthistime.TheUnitedStatesgovernmentpassedtheCleanAirActandtheCleanWaterAct.OtherlawsthatcreatedtheEnvironmentalProtectionAgencywerealsopassed.  WHAT NEEDS TO BE SAVED? All environmental problems are local, regional, and, in the end, global.Some examples may illustrate these points. Some streams that flowthrough towns are badly polluted. The water has a vile odor, the fish inthe stream are dying, and garbage is present everywhere. This is a localproblem. Most of the lakes in the northeastern United States have becomeacidic from acid rain. Today, the pH in these lakes is lower than it used tobe, and certain species of fish cannot reproduce. Acid rain creates regionalproblems. Finally, the average temperature of Earth may be rising. Thiswarming of the planet because of human and natural changes in theatmosphere is a global problem. (See Figure 28-2.)The biosphere is the total area of the land, water, and air on Earth’s sur-face where life is found. Saving the biosphere means paying attention tolocal, regional, and global problems. Can we find ways to live that allowus to protect the environment instead of hurting it? Can we protect theenvironment not only for our own species but for all species? What mustwe do to protect the environment for organisms that will be alive 50, 100,or 200 years from now? Figure 28-1 The environmentincludes cities andwilderness areas,such as the GrandTeton Mountainsand Snake River in Wyoming.   ACHANGE IN ATTITUDE We will look at some ways we can protect the biosphere. Sometimes themost important changes are the most difficult to make. It is often goodto examine some accepted attitudes in our society. For example, what if we thought it was most important that our lifestyle not harm our rela-tionship with the environment and other living species? Would we bewilling to make the necessary changes in our lifestyle to accomplish this?Attitudes would also have to change in how we view ourselves in rela-tion to the whole Earth. Often, an industrialized society views Earth onlyas a source of valuable resources for its use. In contrast, ecology teachesus that humans are just one of many species. All species on Earth, includ-ing ours, interact and are interdependent. From our study of ecology, welearn that in order for our species to survive, we must make sure that theseimportant relationships continue. (See Figure 28-3 on page 610.)  THE GAIA HYPOTHESIS In 1972, a powerful idea was introduced by British scientist James Love-lock. Through his study of Earth and its atmosphere, Lovelock came to asurprising conclusion. The whole Earth, he said, including its atmosphere,should be considered to be a single living organism. As a living organism,Earth is constantly adjusting its own conditions to keep life going. Henamed his idea the Gaia hypothesis. ( Gaia means “Earth” in Greek.) Tosupport his hypothesis, Lovelock and other scientists have shown thatthe mixture of gases in the atmosphere is continually changing. Earth Chapter 28/Saving the Biosphere 609Figure 28-2  Althoughenvironmental problemsstart out local, theybecome regional, and inthe end have a globalimpact.  itself and the living things on Earth make these adjustments. The pur-pose, he says, is to make sure that life can continue. Lovelock said thatthese adjustments have been occurring for billions of years. Because itcontinually changes itself, Earth as a single, huge organism is able to keepitself alive. Most scientists are not sure if the Gaia hypothesis is correct.But the idea that Earth is a living organism has made a big difference inthe way many people think about the planet. The Gaia hypothesis forcesus to regard Earth as one mighty being made up of many, many interre-lated components. We, as a single species, cannot interfere with theserelationships. If we do, other changes will occur on Earth that could bevery harmful to ourselves and other species.We need to find a way to balance how we live with how the environ-ment functions. A change in attitude may be one of the most difficultthings to do. However, it may also be one of the most important in orderto maintain life as we know it.  THINK GLOBALLY,ACT LOCALLY Environmental problems are often large and seemingly resistant to solu-tions. For example, if the air that covers your city is polluted, what canyou—just one person—do about it?You can do what a baby does when it learns to walk. It makes manylittle steps while gaining confidence as its small body learns to better coor-dinate its movements. One teacher offered the following advice to herclass. Begin by making a list. On the list, write down the things you cando as an individual to protect the environment. Many of the really largeproblems facing us today are the result of an accumulation of a numberof small problems. Let’s follow this procedure with an example. Sanitary 610 Interaction and Interdependence Figure 28-3 People, suchas this young shepherd,who work closely withanimals and the land oftenare more aware of our relationship with Earth and other species.
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