Introduction

Introduction

Doing Science

Science & Society

Our Environmental Heritage

The Science of Global Change

Summary

The materials of science are the material of life itself.Science is part of the reality of living; it is the what, thehow, and the why of everything in our experience. It isimpossible to understand man without understanding hisenvironment and the forces that have molded himphysically and mentally. The aim of science is to discoverand illuminate truth.

Rachel Carson

Whatever knowledge is attainable, must be obtained byscientific methods, and what science cannot discover,mankind cannot know.

Bertrand Russell

2

Introduction• Earth science, geology and environmental geology involve

the study of the Earth and the processes that shape itssurface but have different emphases.

• The Earth System is composed of four principalcomponents: atmosphere, hydrosphere, biosphere, and thesolid Earth.

• The science of Earth becomes relevant to society when weexamine the interaction between human beings and theplanet we share.

The Good Earth represents an attempt to introduce students toEarth Science with an emphasis on our interaction with ourenvironment. Consequently, this text includes componentsfrom two common undergraduate courses, Earth Science andEnvironmental Geology. These courses have more elements incommon than they have differences.• Geology is the study of the Earth. That includes how the

planet was formed, what it is made from, and how it haschanged over time. Geologists study the processes thatoccur on Earth's surface and others taking place within theplanet's interior.

• Environmental geology views geology through the prismof the human experience. Environmental geologytraditionally places less emphasis on the origin and historyof the planet and focuses on geologic hazards, theconsequences of resource development, and the alterationof the natural environment.

• Earth science is broadly defined as the study of theinteractions of the four components of the Earth system -the atmosphere, hydrosphere, biosphere and solid Earth.Consequently, it overlaps with other disciplines such asmeteorology (weather systems, climate), oceanography(ocean processes), biology (ecosystems), and geology.

However, increasingly, the boundaries between Earth scienceand environmental geology are blurring as scientists defineenvironmental problems at a global scale that require us tounderstand the interaction between all elements of the Earthsystem. Consequently, this text looks at the interaction betweensociety and the Earth system as a whole. For the study of Earthto be relevant to our lives it must involve an examination ofhow people are affected by the processes that shape the Earth

3

and how we utilize the planet's resources (minerals, energy,water, air, soil).

The Good Earth describes the interaction of rock on and belowthe surface of the solid Earth with waters of Earth'shydrosphere (streams, lakes, oceans), and the processes ofEarth's atmosphere that give us our daily weather and long-term climates. These components fit together to form the earthsystem, an environment that supports life on and near Earth'ssurface (biosphere). None of these components can existwithout the others. Without the oceans there would be littlesource of water to evaporate to supply the atmosphere withprecipitation. Without the atmosphere bringing precipitation,rocks could not break down to form soil. Without soilsvegetation would not flourish to absorb the toxic carbondioxide that we exhale and produce the oxygen we inhale (seeFig. 1).

This chapter is divided into six principal sections, includingthis introduction. We begin with the basics, describing thescientific process itself. In the section titled Doing Science weexplain how scientists conduct investigations that allow themto weave together data collected from experiments andobservations of the natural world. The application of thescientific approach is illustrated by discussions about theextinction of the dinosaurs and the investigation of ahypothesis of a potentially dangerous earthquake source in theGreat Plains. We also examine cases where individualsattempted to circumvent the rigors of the scientific process toforward controversial ideas founded on poor science.

Mankind has been unconsciously interacting with theenvironment since our human ancestors began to roam theearth. Our demands on the planet have been magnified astechnology evolved and population increased. The principalelements of the environment (air, water, soil) have specificchemical and physical characteristics that can be readilymeasured. Scientists can determine the volume of dust in theair or the abundance of a chemical in a stream to determine ifthe air or water quality falls below community standards. Thepresence of specific pollutants in the environment can bereadily detected and steps can be taken to protect the health ofthe community and of natural ecosystems. For example, theToxic Release Inventory (TRI) required companies to notifytheir communities about the volume of toxic emissions.Following the release of the first figures in the late 1980s,

Figure 1. The principalcomponents of the Earthsystem include the solidEarth (rocks, internal andsurficial earth processes),the hydrosphere (streams,oceans, ice caps), theatmosphere (weather,climate), and thebiosphere (population,ecosystems, land use).Image courtesy of NASA'splanetary photojournal.

4

emissions declined precipitously as many companies learned itwas both good business and good public relations to reduceemissions.

Such social or cultural influences on decisions affecting theenvironment are more difficult to quantify than physical andchemical conditions. Consequently, they are more complex toevaluate in decision making and are often the subject ofvigorous debate. Furthermore, the influence of these factorschange with time as social perceptions change. For example,our view of the role of wilderness has evolved in the fourhundred years since the earliest European settlers arrived onthe North American continent. Wilderness was regarded withhostility by early colonists who considered the virgin forests tobe home to hostile natives and mythical beasts. However, aspopulation expanded and the number of wilderness areasdwindled the remaining natural lands began to be consideredimportant cultural asset and were protected by legislation suchas as the Wilderness Act (1964).

The third section of the chapter, Science and Society,examines how our knowledge of the Earth allows us to protectpeople from hazardous earth processes, manage economicresources, and protect the Earth from activities that mayendanger natural ecosystems. We discuss the principal roles ofthe Earth sciences in our lives, from the benefits of basicresearch to the implications of global change for the future ofhumanity. This section serves as an introduction to thesethemes that are present throughout The Good Earth. Links tospecific chapters are included, think of the Science and Societysection as a road map of the text.

Americans’ interaction with the environment can be tracedback to the continent's earliest inhabitants. However, it was theactions of European colonists that first resulted in widespreadenvironmental degradation and led to early legislation toprotect wildlife. An appreciation for the land blossomed in thenineteenth century, prompting the creation of forest reservesand the earliest national parks. This century has been markedby a growing concern for pollution of the environment at bothregional and global scales. Two sections of the chapter divideour collective environmental heritage into two parts(Environment pre-1899, Environment post-1900) andexamine the evolution of environmental thought in the U.S.

Regulations thatmeasure physical or

chemical environmentalcharacteristicsClean Air Act

Safe Drinking Water Act

Examples of legislationenacted for cultural

concernsWilderness Act

Endangered Species Act

Finally, we finish the chapter by introducing the concept ofglobal change, an idea that is currently generating research ina variety of disciplines including geology, ecology, chemistry,oceanography, and climatology. In this chapter we willdescribe the scale of the scientific enterprise behindinvestigating a substantial problem such as global change. Itwill become evident that such research requires the work ofthousands of scientists throughout the globe. This research hasimplications for the long-term quality of life for humanity andis likely to require difficult social decisions within yourlifetime. Future economic, cultural, and political choices in allthe world's nations will depend on the rate and degree of globalchange. We will follow the theme of global change throughmany of the chapters of The Good Earth. Global changerepresents a consistent idea that we will use to link together theprincipal components of the Earth system to illustrate howtightly the atmosphere, hydrosphere, biosphere and solid Earthare linked together.

Think about it . . .1. Examine the photograph located below and identify the

components of the Earth system represented in theimage, and consider what information we would need tohave about the natural environment to live in such alocation.

2. Draw a concept map that illustrates examples ofinteractions between the four components of the Earthsystem.

5

6

Doing Science• Scientists use observations to form testable hypotheses.• Inaccurate hypotheses often do not follow the traditional

procedure for formulating scientific ideas.

Science advances by the application of the scientific method, asystematic approach to answering questions about the Earth.We make the assumption that the components of the universeinteract in a consistent manner. The scientific method infersthat sufficient observation can reveal patterns that can beinterpreted to understand the origin and history of Earth and topredict future events in the Earth system. Earth science is adetective story, where circumstantial evidence is piecedtogether by teams of scientists to generate imaginativeexplanations of the workings of our home planet. Theseexplanations are constantly being refined and/or challengedcausing some to be discarded while others gain wideacceptance.

From Observation to TheoryAll of us make observations that we use to mold our personalviews of the cultural and physical worlds we inhabit. Throughexperience we test the limits of our personal world, allowingthem to expand to accommodate a positive stimulus or recoilfrom a negative interaction. Scientists also use observations tomold ideas. Their ideas are known as hypotheses. Personalobservations will vary with the individual but valid scientificobservations are empirical, that is, they can be measured andconfirmed by others.

A scientific hypothesis (usually several competing hypotheses)is developed to provide a potential explanation of theobservations. Hypotheses can be generated and tested usingtwo basic reasoning procedures; inductive and deductivereasoning (Fig. 2). Inductive reasoning results when scientistsdraw general conclusions from specific observations. Thesuccess of this method comes from recognizing patterns andidentifying similarities between comparable systems. Incontrast, deductive reasoning occurs when scientists drawspecific conclusions based upon general principles. Deductionmay be based upon the application of laws or rules (e.g. law of

The construction ofhypotheses is acreative act ofinspiration, intuition,invention; its essenceis the vision ofsomething new infamiliar material.

M. Friedman

Most institutionsdemand unqualifiedfaith; but the institutionof science makesskepticism a virtue.

R.K. Merton

7

gravity). This type of reasoning is useful when we cannotreadily identify the cause of a natural event.

Consider the statement, red sky at night is a sailor's delight, redsky in the morning is a sailor's warning. If we were to view ared sky we could apply deductive reasoning to form thehypothesis that it would be followed by good or bad weather.However, the original statement was generated as a result ofinductive reasoning based upon numerous observations of therelationship between sky color and subsequent weatherconditions.

The best hypotheses are logical and can be readily tested byexperiment or by further observation. Continued observationsover time will confirm if a hypothesis is accurate or if it needsto be further refined. New information may become availablewith the development of increasingly sophisticated technologyand lead to minor or major changes in existing hypotheses.When a hypothesis has undergone sufficient inspection and hasbeen found to yield consistent results it is promoted to atheory. (Later in this text we will discuss the theory of platetectonics). With time, theories about some of the most basiccharacteristics of science may be termed scientific laws.

Few hypotheses or theories remain unchanged and none canever be proved. Widely accepted ideas will be confirmed andstrengthened by the work of many scientists but it is alwayspossible that the next person to test the idea may discover adifferent result and falsify the hypothesis. This is the strengthof science, the willingness to continually question prevailingideas and to modify or discard them as new informationbecomes available. There are no sacred cows in science, it is anopen book, a perpetual lie detector, limited only by theimagination and abilities of its practitioners.

Figure 2. An idealizedflowchart for twotypes of scientificreasoning. Deductivereasoning occurswhen scientists drawspecific conclusionsbased upon generalprinciples. Inductivereasoning resultswhen scientists drawgeneral conclusionsfrom specificobservations.Inductive reasoning isbased on experience.

8

Given the complex nature of the earth, no scientist makes anobservation, suggests a hypothesis or develops a theory alone.Everyone's work relies on the work of others who have gonebefore. Even Isaac Newton, whose law of gravity haswithstood the test of time, noted “If I have seen further it is bystanding on the shoulders of Giants”.

The Characteristics of Good ScienceGood scientific explanations follow basic principles like thosesummarized below. Scientific explanations are tentative andcan and do change. Early attempts to determine the age ofEarth were based upon erroneous assumptions and estimatedthe age of the planet to be a few million years old. With theadvent of radiometric dating methods scientists calculated thatEarth formed approximately 4.6 billion years ago.

Scientific explanations are based on empirical observations orexperiments. For example, the direction and rate of flow ofgroundwater in cave systems can be established by injectingnon-toxic colored dyes at one location and then monitoringflow at several points downslope from the source. The dataobtained from such analyses should be reproducible by others.Scientific explanations should be predictable and testable withsuccessful hypotheses. The daily weather forecast is a commonexample of the use this rule. Meteorologists use theirknowledge of how air and moisture circulate through theatmosphere to predict short-term changes in weather patterns.

Scientific explanations may be limited by available technologyand new technologies can lead to new fields of inquiry. Forexample, prior to the invention of the telescope, knowledgeabout Earth's position in space was based upon observationsmade with the naked eye. Astronomers such as Galileo usedsome of the first telescopes to identify perturbations inplanetary orbits that would result in the hypothesis that theSun, not Earth, was the center of the solar system.

Science cannot answer all questions. Questions that center onethics or theology often have more to do with cultural or socialnorms than scientific concepts. Recent concerns about thepotential for cloning humans can be separated into two distinctquestions, one is scientific the other ethical. Can we clonehumans? is a scientific question and the current answer is No,but research suggests that a future response could be Yes.

How to Do Bad Science

Attack the scientist, notthe science : Sciencedoesn't advance based onpersonalities of the scientistsbut on verification of factsand observations.

Argue from authority: Justbecause you are importantdoesn't make you right.

Post hoc, ergo propterhoc: "it happened after so itwas caused by" - confusionof cause and effect. Justbecause day follows nightdoes not mean that days arecaused by nights.

Poor Statistics: Choose asample size that is too smallto be representative or use abiased sample.

9

Should we clone humans? is an ethical question. If the answeris No, we may never clone a person even if the scientificknowledge exists to do so.

A valid scientific hypothesis offers a well-defined naturalcause or mechanism to explain the occurrence of a naturalevent. For example, scientists who study earthquakes recognizea clear relationship between the amount of movement onfractures in Earth's crust and the size of earthquakes. Scientificanalyses are discussed openly at conferences and published injournals so all ideas may be exposed to criticism or supportfrom other scientists. Scientific journals require that articles arereviewed by other scientists before publication. This peerreview process ensures that published research is original andadds to the body of scientific information.

Poor scientific reasoning rarely reaches a public forum becauseof the checks and balances inherent in the scientific method.However, sometimes hypotheses are unveiled in the mediabefore they can be rigorously tested by others. Unfortunately,with further analysis, some of these ideas may be provenwrong prompting increased skepticism with the scientificmethod and scientists in general. The following cases includean example of correctly using a series of observations tosupport a novel hypothesis for the extinction of the dinosaursand two examples of hypotheses that were not supported by themajority of scientists but that nonetheless received widespreadpublicity.

Asteroid Collisions with EarthApproximately 20 years ago, a team of scientists led by thefather-son pair Luis and Walter Alvarez suggested that theextinction of the dinosaurs was caused by a collision betweenthe Earth and an asteroid (Fig. 3) or comet 65 million yearsago. Their hypothesis was based on several observations madeby themselves and other scientists:1. Dinosaurs died out relatively suddenly 65 million years

ago.2. The extinction occurred everywhere at the same time.3. The rare element iridium is present in unusually high

concentrations in rock layers 65 million years oldworldwide.

Figure 3. The asteroidGaspra viewed from theGalileo spacecraft, October1991. The asteroid isapproximately 29kilometers (18 miles)across. Image courtesy ofNSSDC photogallery.

10

4. Iridium is found in extraterrestrial bodies such asmeteorites and asteroids. It is still a rare element in thesebodies but it is more concentrated than on Earth.

The Alvarez hypothesis was that the impact generated somuch debris that it blocked incoming sunlight for several years.Vegetation died in the absence of sunlight, resulting in thedeaths of plant-eating dinosaurs. Carnivorous dinosaurs alsodied out when their prey, the herbivores, died. Recentgeophysical exploration has discovered a possible impact site(Chicxulub Crater) in the Yucatan Peninsula, Mexico. Thecrater is in rocks that are older than the impact event and iscovered by rocks that are less than 65 million years old. Thecrater is much larger than the asteroid or meteor that wasresponsible for its formation. It is over 300 km across, fallingsomewhere between West Virginia and South Carolina in totalarea.

Bad ScienceScientists who don't engage in peer review to evaluate theirresearch may be discredited if their results can't be reproducedby others. Alternatively, occasionally hypotheses receivepublicity before they have had an opportunity to be criticallyreviewed by experts. Two recent examples of very public failedhypotheses are given below.

• Cold fusion: March 23, 1989: Researchers (Stanley Ponsand Martin Fleischmann) at the University of Utahannounced that they had used a simple, low-costexperiment to achieve a controlled nuclear fusion reactionfor more than 100 hours in a small glass flask (cold fusion).The report prompted hope of a cheap, clean future energysource but their hypothesis: that a chemical reaction in abeaker of heavy water generated excess energy, has notbeen supported by scientists at other institutions.

• Midcontinent earthquake and tidal forces: December 3,1990 - Date proposed by self-proclaimed climatologist andbusinessman Iben Browning for an earthquake on the NewMadrid fault zone, southeast Missouri. New Madrid wasthe location for a series of major earthquakes over a three-month span from December 1811 to February 1812(sometimes called the Mississippi Valley earthquakes).Browning’s hypothesis, that tidal forces could triggeranother big earthquake on the fault zone, generated media

interest and caused local schools to close but was widelydisputed by earthquake specialists. Nothing happened onthe fateful day.

S•

•

•

•

Wp(Hainscq

Think about it . . .1. Use the first letter of each of the key characteristics

of good science to create a mnemonic(memorization). Create a sentence composed ofwords that begin with the initial letter of each term.

2. Create a simple concept map that illustrates thecharacteristics of good science.

3. How did Lewis and Clark use the scientific methodto make a crucial decision on which way to goduring their exploration of the Missouri River?Examine the problem at the end of the chapter.

11

cience & SocietyA basic knowledge of Earth science is necessary forcitizens to make informed choices about how they interactwith their local, national, or global environment.Earth scientists protect people and property from naturalhazards but must also protect the environment from short-sighted human activities that have the potential to alternature.We rely on Earth to supply us with the all our basicresources. Earth science provides us with information onthe distribution and quality of mineral and energy resourcesessential for maintaining or improving our quality of life.Global-scale threats to the future of humanity require thatwe understand the complex workings of all aspects of theEarth system and the time scales on which they operate.

hy should you care about science, and Earth science inarticular? Most of us are removed from the process of science.

ow many scientists do you know?). If we think of science atll it is through the mirror of technology. Would you supportitiatives that increase or decrease government funding forientific research? This is not a question of science, but a

uestion about the role of science in society.

12

Past experiences have convinced some people that they willnever understand science whereas others may view the study ofEarth Science or the environment to be irrelevant in thistechnologically-rich world. Many people are understandablybewildered by media reports that portray battling teams ofscientists, each presenting opposing explanations for complexscientific problems. If the experts cannot agree they reason,how can I be expected to make a decision? Finally, even if weunderstand environmental problems, we are often frustrated bythe apparent inability of those responsible to do anything aboutthem. This can range from simple individual actions (Whydoesn't my neighbor recycle?) to issues of corporateresponsibility (Why do companies produce air pollutants?).

How can we become enlightened citizens, capable ofidentifying problems and participating in their solution? Wewill suggest a simple three-step process: know, care, act.• Know: The first step requires that we take responsibility

for our world by learning about how it works.• Care: We are part of a society that works best when we

care about how our actions will affect others at a range ofscales. But we should also be aware of how we will beaffected by the actions of others.

• Act: Do something. Make your opinion known. Go to atown meeting, write a letter to your local paper, contactyour congressperson or senator, vote.

Earth scientists have several roles to play in modern society.These roles have become more crucial as global populationsclimbed to over 6 billion people in 2000 with 78 million moreadded each year. We are concerned about protecting life andproperty from the dangers of natural hazards, obtainingsufficient natural resources to maintain or improve our standardof living, and protecting the health of the natural environment.A final more comprehensive goal, ensuring the future ofhumanity, has recently received increasing attention as weglimpse a future where climate is impacted by human actionsand where we recognize the global-scale devastation that mayresult from a potential meteorite or asteroid impact.

Natural Hazards as Facts of LifeScientists play a role in determining the potential risks fromnatural phenomena that may harm people and damageproperty. Natural processes such as earthquakes, landslides,

Never doubt that a smallgroup of thoughtful,committed citizens canchange the world. Indeed,it is the only thing thatever has.

Margaret Mead

Think globally but actlocally.

Rene Dubos

13

flooding, volcanic eruptions, tornadoes, and hurricanes areconsidered hazards when they occur in populated areas. Thedetailed study of hazards in one area can help predict thepotential risks elsewhere. Scientists used the information theylearned from investigations of the 1980 Mt. St. Helens eruptionto make accurate predictions of the size and timing of the 1992eruption of Mt. Pinatubo in the Philippines (see Fig. 4).

The effects of some of these phenomena can be partially offsetby technological advances:• Weather satellites are used to track hurricanes and predict

landfall sites allowing timely evacuation of residents (Fig.5);

• Doppler radar stations have more than doubled the advancewarning of tornadoes;

• Networks of stream gauges are used to monitor streamflow and predict the magnitude and timing of floodsallowing emergency construction of levees and evacuationof residents;

• Areas at greatest risk from earthquakes have strict buildingcodes designed to ensure that buildings, although damaged,will remain standing when the shaking subsides;

• Ongoing volcanic activity can be monitored by satellites todetermine the timing and location of eruptions and redirectaircraft out of the path of the cloud of volcanic debris.

The principal advantage of technology is in providing safety topeople living in areas at risk of natural hazards. Human beingsare unlikely to be able to stop volcanoes from erupting or to

Figure 4. An exampleof a map illustratingareas at risk in theU.S. from one of sixnatural hazards. Clickon the maps to viewexpanded versionswith descriptions atthe USGS hazardswebsite. Go towww.usgs.gov/themes/hazards.html to reviewall the maps.

Averageannual cost ofU.S. naturaldisasters:

$50 billion

14

banish earthquakes. We can do little to prevent huge propertylosses associated with hazards but the use of technology canhelp save lives. Unfortunately, our faith in artificial structuressuch as stream levees often prompts increased development inareas at risk from hazards, ultimately resulting in greaterdamages when disaster strikes.

We can either attempt to prevent natural hazards fromoccurring or recognize that they will happen and adjust ourlifestyles to deal with them. Hazards such as volcaniceruptions, large earthquakes, hurricanes, and tornadoes aresufficiently infrequent and extreme that we cannot prevent theiroccurrence. However, we can make adjustments that willminimize their impact through careful land use planning, theenforcement of building codes and the purchase of insurancepolicies. These steps ensure that areas at risk are not developed,key structures are built to withstand the hazard, or that fundsare available to repair damages following a hazardous event.Floods and landslides are clearly linked to streams and slopes,allowing scientists to make local alterations to the environmentin the hope that future hazardous events can be avoided.Building levees to contain rising streams or reservoirs to storefloodwaters can locally diminish or eliminate flooding. Addingbetter slope drainage or retaining walls can reduce landslidefrequency. However, we should be aware that any alteration ofa natural system has the potential to cause unanticipatedchanges. For example, building a levee may reduce floodinglocally but actually increase the flood risk downstream wherethe stream is in its natural state.

In assessing the risks associated with natural hazards,geologists must try to answer several questions: How often dosuch hazards occur? How large an area will be affected? Howgrave is the risk to people and property? What actions can betaken in both the short and long term to prevent some of theseevents or lessen their impact? Determining the correct answersto these questions requires knowledge of earth processes, thecharacter of the landscape, the type and distribution of rocksunderlying a region, and their physical and chemical properties.

Earth's Economic ResourcesOur lifestyles are supported by the use of natural resources.Basic resources such as water and soil vary in availability andquality around the globe. These essentially renewable resourcesare vital to food production and have to be carefully managed

Figure 5. Hurricane Franapproaching the Atlanticcoast, September 1996. Franmade landfall along the coastof North Carolina with windspeeds of over 190 km/hr.Image from Goddard SpaceFlight Center's PublicPhotographic Image RetrievalSystem (PPIRS).

to support future populations. Nonrenewable resources such asmetallic minerals (Fig. 6) and fossil fuels are used most heavilyby the more affluent societies of developed nations such as thecountries of North America, Europe, and the Pacific Rim.However, the rapidly expanding economies of China and Indiahave the potential to place much greater demands on globalmineral and energy supplies. Together these two nationsaccount for a third of the world's population.

Geologists must determine: Are there are sufficient resourcesto support the growing global population? What steps can betaken to preserve the most heavily exploited resources? Howcan resources be mined safely and economically? Tosuccessfully answer these questions requires that we exploreever more remote parts of Earth's surface, including rainforests, rugged mountain ranges, and the deep ocean floor.Earth scientists seek to establish the type, distribution, and ageof rocks underlying a region to discover if they may hostmetallic ores or contain oil, gas, or coal deposits.

The use of resources carries with it decisions about lifestyle.

Figure 6. Homestakemine, Lead, SouthDakota. Homestake isthe longest operatinggold mine in the UnitedStates. Opened in thelast century, the mineproduces gold from asurface pit (picturedhere) and from shaftsdrilled thousands ofmeters below the groundsurface.

Proportion of worldgold productionused in jewelry:

85%

Area of the Pacificisland of Nauru

that will beuninhabitable

followingmining: 80%

15

The way we live varies from nation to nation and is oftendictated by culture. For example, the Amish use fewerresources on average than other Americans because of religiousand cultural traditions. Nearly all human actions have animpact on Earth's resources. Individual actions such as turningon a light switch or pouring a glass of water involve relativelymodest resource use and require little thought except in themost extreme conditions. However, multiply those actions amillionfold and we may see an example of the economics ofsupply and demand when prices rise as supplies dwindle.Increases in gasoline and natural gas prices in the U.S. are justthe most recent examples of this phenomenon.

16

The Health of the EnvironmentEnergy and mineral resources must be either consumed orrecycled. The consumption of these resources generates wasteand pollution during extraction, refining, manufacturing, andmarketing. The industrial pollution that was once proudlyviewed as a by-product of economic growth is now largely athing of the past. Pollution is still widespread but its effects aremuted and much more subtle, hidden among reports ofrespiratory ailments and contaminated drinking water supplies.

Legislation ensures that the construction of large-scalefacilities that have the potential to degrade the environmentmust be preceded by an analysis of how such features mayaffect the surrounding area. The analysis produces anenvironmental impact statement (EIS). The NationalEnvironmental Policy Act (NEPA) signed into law byPresident Richard Nixon on January 1, 1970, directed that anEIS be filed for all federal activities that would have bearing onthe environment. The Act required the government to “use allpracticable means . . . to create and maintain conditions inwhich man and nature can exist in productive harmony.”Environmental impact statements must be filed for federalprojects such as the construction of dams, sanitary landfills, ornuclear power plants.

Human activities that involve the use of technology or themanufacture of hazardous materials inevitably lead to failuresthat are unanticipated and may endanger human life or naturalecosystems. For example, we have found a variety of ways tocontaminate stream systems, three examples of which arebriefly described below.• Lower Mississippi River, winter, 1963/1964. The

pesticide endrin, used to protect cotton and sugar canecrops, was found responsible for killing millions of fish inthe Lower Mississippi River. Too much pesticide wasapplied and then washed from the fields by rains andsurface runoff.

• Cuyahoga River, Cleveland, Ohio, June 1969. TheCuyahoga River burned for the third time when a section ofthe polluted waterway in downtown Cleveland was ignitedby molten slag from a nearby steel mill. The river burnedfor 20 minutes, setting fire to an old bridge. Today the riverhas been largely restored and the area is now occupied byan entertainment district.

• Ashland oil storage tank, Pittsburgh, Pennsylvania,January 1988. The worst inland oil spill in U.S. historyoccurred when an oil storage tank collapsed, releasing750,000 gallons of diesel fuel into the Monongahela andOhio Rivers.

Environmental Impact StatementsThe NEPA directed that an environmental impact statement (EIS) be filed for all federalactivities that would have bearing on the environment. The act required that an EIS hadto be filed if a venture met three criteria:1. The activity was a federal project;2. The project was considered major, involving a substantial commitment of fiscal and

human resources;3. The project had a significant impact on the human environment.The terms "major," "substantial," and "significant" went largely undefined leaving thedoor open to hundreds of court challenges each year. The first challenge filed under theNEPA guidelines was Wilderness Society vs. Hickel (Secretary of Interior) and involvedthe environmental impact statement for the construction of the Trans-Alaska oil pipeline.

Environmental Impact Statement: Trans-Alaska oil pipeline1968 Atlantic Richfield found the greatest accumulation of oil in North America along the

northern coast (North Slope) of Alaska.1969 A consortium of oil companies announce plans to build a 48-inch pipeline to carry

North Slope oil over 800 miles to the tanker port of Valdez on Alaska’s southern coast.Initial plans called for pumping heated oil through a buried pipeline. A governmentstudy found the heated oil would melt surrounding permafrost, leading to damage tothe pipeline and the Arctic ecosystem.

1970 March 26: The Wilderness Society, Friends of the Earth, and the EnvironmentalDefense Fund challenged the consortium’s application for permits. One aspect of theirobjection was that a sufficient environmental impact statement had not beencompleted for the pipeline.

1971 January 13: The Department of Interior issued a 196-page-draft environmental impactstatement that concluded that North Slope oil was essential for the nation’s economy;a pipeline across Alaska was the best way to transport the oil; and an elevatedpipeline could be built with little environmental disruption. Congressional hearingsfeatured environmental groups that were critical of the EIS, claiming it underestimatedearthquake risk, overlooked potential problems with tanker traffic, and did not fullyexamine the option of an overland pipeline through Canada.

1972 March 20: Final EIS was released as a 30-pound, six-volume text.1974 January 23: Secretary of Interior Morton issued construction permits for the pipeline.1977 July: First oil began to flow through the pipeline.

The pipeline itself has withstood the test of time reasonably well. There have been nomajor oil spills along the route and little negative effect on the wildlife of the area. Thewreck of the Exxon Valdez and subsequent spill of 11 million gallons of oil in PrinceWilliam Sound are indirectly linked to the pipeline project. The potential for tankerproblems was one of the reasons cited by the pipeline’s opponents. However, this mustbe balanced against the billions of gallons of oil that have been successfully delivered toU.S. oil refineries since the pipeline was built.

17

18

The Long-Term View: The Future of HumanityAll of the issues discussed above are of local, regional, ornational scale. All involve events that are significant on humantime scales measured in hours to years. Taking a longer view ata global scale we can identify two processes that have thepotential to affect everyone, everywhere, for decades andperhaps centuries into the future.

The impact of a large meteorite with Earth represents a global-scale natural hazard that has the potential to end all life as weknow it or to devastate a continent-size area of the planet (Fig.7). Concerns about such an impact have increased recently asscientists became aware that such events were morecommonplace in the geological past than was previouslythought. Although there is no shortage of ideas about how tostop a meteorite on a collision course with Earth, there is noexisting mechanism for dealing with such an event.

Global warming represents an alteration of global climatepatterns as a result of human activity. An international panel ofscientists has concluded that carbon dioxide and other gases ofhuman origin have altered global climates over the last century.Higher concentrations of carbon dioxide are associated withclimate intervals characterized by warmer temperatures.Warmer conditions have the potential to cause wholesalechanges in natural systems around the world. Climate modelssuggest that an increase in the frequency of extreme weatherevents, a shift in the distribution of ecosystems, higher rates ofspecies extinction, wider areas of tropical disease, and a rise inglobal sea levels are all possible with higher temperatures. Thequality of life for future generations, not to mention the long-

Figure 7. Aoroungaimpact crater, Chad, 17km across, was formedwhen a meteorite orasteroid collided withEarth. Image courtesy ofNASA.

19

term health of the environment, will depend upon the degreeand rate of these changes. But these changes will also beinfluenced by future decisions to be made by the governmentsof the world's most populous nations and the actions of theircitizens.

A program that attempts to address either of these issues wouldbe both complex and expensive, requiring cooperation betweenmany nations and potentially taking decades to complete.

Our Environmental Heritage, before 1899• American concern for the environment can be traced back

to the continent's earliest inhabitants.• Actions of European colonists resulted in land degradation

and reduction of species habitat and led to early legislationto protect some favored species.

• An appreciation for the land blossomed in the nineteenthcentury, prompting the creation of forest reserves and theearliest national parks.

Introduction to the Continent, pre-1780Some of North America’s earliest inhabitants entered thecontinent by way of a narrow finger of land that joined Alaskaand Siberia over 10,000 years ago at the close of the last greatice age. Much of the Northern Hemisphere was coming out of adeep freeze as ice sheets thousands of feet thick began toretreat toward the Arctic. The first Americans crossed what isnow the floor of the Bering Sea and migrated southward insearch of a warmer climate. Over the course of thousands ofyears these peoples differentiated into the native tribes thatgreeted European explorers such as Columbus, De Soto, andCoronado. The maximum population of pre-Columbian NorthAmerica has been estimated as two million (approximately thepopulation of Utah). Limited numbers muted the environmentalimpact of the continent's earliest residents. Although nativephilosophies encouraged stewardship for the land rather thanexploitation for economic gain it is probable that NativeAmerican hunters were responsible for the extinction of somelarge animal species following the ice age.

20

Small groups of European settlers, scattered along thecontinent’s eastern fringe in the seventeenth century, viewedthe new lands as a threatening wilderness that contrasted withthe tame, domestic landscapes of northern Europe. A passengerof the Mayflower viewed his new home as a “hideous anddesolate wilderness” but the early colonists were not above alittle creative advertising to lure others to the “particularbeauty” of the wilderness that one could not view without"contentment." Population growth forced exploration inland,pushing the frontier westward. The transplanted Europeansbegan to develop a distinctive national identity that historianFrederick Jackson Turner would later suggest “came out of theforests and gained new strength each time it touched afrontier.”

Gradually a new perspective evolved - nature as a garden -that saw nature not as a threat but as a resource to be exploited.Forests and wetlands were converted to farmlands. Nativespecies began to disappear as their habitats were destroyed orthey were hunted to near extinction. Early settlers' descriptionsof rivers teeming with fish and forests full of game leave littledoubt that wildlife went into a steep decline after coming faceto face with the colonists. Diminishing wildlife populationsencouraged colonial governments to introduce closed huntingseasons before the end of the seventeenth century. However,the view of wildlife was heavily weighted in favor of "useful"animals (game suitable for hunting, e.g., deer) and againstpredators that were often targeted for extinction by bountyprograms (e.g., wolves). Such policies remained in effect forthe three centuries in many regions of the continent. In 1753,Swedish botanist Peter Kalm reported “. . . about sixty orseventy years ago [1680-1690], a single person could killeighty ducks in a morning, but at present you frequently waitedin vain for a single one . . . since the arrival of great crowds ofEuropeans, things are greatly changed.”

Figure 8. A teepee ringin central Wyomingmarks the location of atemporary settlementapproximately 100 yearsago. The ring of stones(~4 meters wide) helddown the edges of ateepee.

21

The early economy of the colonies was tied to agriculture butthe vast expanse of available lands made the colonists poorstewards of their new land. The colonists’ relatively primitiveagricultural methods typically began with the burning ofvirgin forests to create new farmlands. In Virginia and othersouthern colonies, crops such as corn and tobacco werecultivated in open rows with little ground cover, leading toerosion that stripped the topsoil from the fields. Soil waswashed into streams, degrading water quality and destroyingfreshwater habitats. Such early environmental problems did notgo unnoticed. George Washington, Thomas Jefferson (Fig. 9),and James Madison all experimented with soil conservationstrategies. Madison's rules for better care of the soil included:don't plow shallow furrows, don't plow up and down the slopeof the land, and add manure to increase soil fertility.

Thoughts about the Land, 1780-1899J.H. St. John de Crevecoeur's observations on nature inAmerica were published in Letters from an American Farmerin 1782. When Crevecoeur noted that Americans had “done themost in the least time of any people” he was recognizing thechanges to the natural world as well as the progress fromdisparate colonies to a newly forged nation. Resourceexploitation fueled the economy of the recently christenedUnited States. Lewis and Clarke's trip up the Missouri River(1804-1806) opened the way for trappers and other settlers topush westward in search of furs or farmland. The destruction ofnorthern forests kept pace with the westward migration ofsettlers. Nathaniel Shaler noted that flooding in the Ohio riversystem had increased because “a large part of the forestcoating of the Ohio Valley has disappeared, and what remainsis marked all over by the hand of man.” New York Statepassed legislation to create the Adirondack Forest Reserve in1885 and the first national reserves (later to become nationalforests) were created in 1891.While miners were exploring forgold in the Black Hills (South Dakota) in violation of treatyagreements, the government was passing legislation to open uppublic lands for mining at bargain basement rates ($2.50 or$5.00 per acre) that still apply today.

Nature, in the form of the vast continent and its bountifulresources came to define the new America in contrast to therecord of art and architecture that defined the Old World. ArtistGeorge Catlin, traveling on the Great Plains in 1832, firstsuggested the creation of a “nation's park” to preserve the

Figure 9. Harpers Ferry,West Virginia, and theconfluence of the Potomac(bottom) and Shenandoah(top) Rivers viewed fromMaryland Heights. ThomasJefferson considered theview "perhaps one of themost stupendous scenes innature . . . This scene isworth a voyage across theAtlantic." Of course, hewasn't looking at thisparticular photograph.

22

culture and associated bison of the Plains Indians. In lieu of thereal thing, the citizens of Louisville, Kentucky, packed theatersto view the gradual unfurling of a mammoth panorama of theMississippi River. Frederick Law Olmstead designed CentralPark with Calvert Vaux in 1858, creating a welcome openspace among New York's million residents. Olmstead was anearly advocate for creating public parks as “the enjoyment ofscenery employs the mind . . . gives the effect of refreshing restand reinvigoration of the whole system.” Yellowstone, thenation's (and world's) first national park was designated byCongress in 1872, but only after it became clear that the landhad little commercial potential.

Early naturalists like painter John James Audubon began todraw America's attention to the beauty in nature and man'simpact on the natural world. It was a Vermont native, GeorgePerkins Marsh (Fig. 10) who first thoroughly documentedhow human actions had harmed the environment. Marshaddressed the degradation of the land and rivers resulting fromthoughtless logging practices before the Agricultural Society ofRutland County, Vermont, in 1847. Deforestation was soextensive in New England by 1840, that timber mills inBurlington, Vermont, had to import timber from Canada tomaintain production. Marsh’s subsequent travels as a diplomatin Europe convinced him that “. . . man is everywhere adisturbing agent. Wherever he plants his foot, the harmonies ofnature are turned to discords.” Henry David Thoreau'sWalden, published in 1854, remains a classic of conservationliterature. Thoreau (Fig. 10) recognized the dramatic changesin nature in the preceding centuries and anguished over thelosses that had occurred, “When I consider what nobleranimals have been exterminated here - the cougar, the panther,lynx, wolverine, wolf, bear, moose, deer, the beaver, the turkey,etc., etc. - I cannot but feel as if I have lived in a tamed, and, asit were, emasculated country . . . I wish to know an entireheaven and an entire earth.”

Figure 10. Henry DavidThoreau (far left), andGeorge Perkins Marsh,wrote two of the mostinfluential books on thestate of nature of thenineteenth century.Thoreau's Walden is stillwidely read and Marsh'sMan and Nature (1864)was the first book to givedetailed examples of howhuman beings had alterednature. Images courtesy ofLibrary of Congress.

Increasing numbers of people were drawn to join neworganizations with the goals of protecting lands (AppalachianMountain Club, Sierra Club), birds (American Ornithologist’sUnion, Audubon Society), trees (American ForestryAssociation) and wildlife. Awareness of decreasing wildlifepopulations prompted the formation of several conservationorganizations among hunters. Groups such as the New YorkSportsmen’s Club, the Boone & Crockett Club, and the Leagueof American Sportsmen recognized that restrictions wereneeded to prevent overexploitation of some game species.

Likewise Congress began to act to protect wildlife fromcommercial hunting operations. This was perhaps bestexemplified by actions taken to prevent the extinction of thebison (buffalo). An estimated 30 million bison had originallyroamed through most of the U.S. but westward expansion andwidespread hunting had reduced the population to less than athousand animals, most of which lived in the recently createdYellowstone National Park (Fig. 11). Congress passed theNational Park Protective Act (1894) to prohibit hunting innational parks in an effort to prevent poaching of the remainingbison. A national campaign to protect bison was launched byWilliam Temple Hornaday that would later (1905) result in thecreation of wildlife refuges in Oklahoma and other westernstates to begin to rebuild the bison population.

Figure 11. Bisonamong hot springs,YellowstoneNational Park,Wyoming.

Think about it . . .Read an abbreviated version of a speech given by GeorgePerkins Marsh in 1847 (see end of chapter). What wasMarsh concerned about over 150 years ago? How dothese issues compare with modern environmentalconcerns?

23

24

Our Environmental Heritage, 1900-today• An appreciation for the land blossomed in the nineteenth

century, prompting the creation of forest reserves and theearliest national parks.

• The second half of the twentieth century was marked by agrowing concern for pollution of the environment at bothregional and global scales.

Government and the Public Lands, 1900-1950The federal government took increasingly active steps topreserve the environment during the last few decades of thenineteenth century. The next century began with passage of theLacey Act, the first comprehensive national legislation toprotect wildlife. Following on the heels of the Lacey Act,President Theodore Roosevelt issued an executive order todesignate the nation's first bird reservation on Pelican Island,Florida, in 1903. This would be the first of nearly five hundrednational wildlife refuges to be established by the federalgovernment, from the tiny (0.6 acre) Mille Lac refuge(Minnesota) to the massive Yukon Delta site (19 million acres)in Alaska. Several state Audubon groups joined together toform the national Audubon Society (1905) a few years after theestablishment of Pelican Island. What began as a groupdedicated to studying and protecting birds has grown into anorganization that today counts its members in the millions. Justeleven years later the passenger pigeon became extinct whenthe last bird (Martha) died in the Cincinnati zoo. Passengerpigeons had once been numbered in the billions, flying inmassive flocks they made easy targets. Even the most prolificof species was vulnerable to the threat of extinction.

President Benjamin Harrison created the nation's first forestreserves in 1891 but it would be Roosevelt who moved mostaggressively to create new forest lands in the rechristened(1907) National Forests. There were over 150 million acres ofnational forest lands, almost exclusively in the western states,by the end of Roosevelt's tenure in the White House.

Figure 12. DevilsTower, Wyoming,the nation's firstnational monument,created byTheodore Rooseveltin 1906.

25

Roosevelt, the first conservationist president, would also createthe first national monuments using the Antiquities Act (Fig.12). A decade later the National Park Service was created tomanage the growing number of parklands that would expandinto the approximately 370 sites that exist today.

Roosevelt's initiatives were primarily concerned with resourceconservation. His chief forester, Gifford Pinchot, summed itup this way, “. . . the object of our forest policy is not topreserve the forests because they are beautiful or the habitat ofwild animals; it is to ensure a steady supply of timber forhuman prosperity. Every other consideration comes assecondary.”

Others viewed nature as an aesthetic resource that should bepreserved simply because it looked good or represented aunique natural environment that would be lost with theintrusion of human beings. The chief advocate of this view wasJohn Muir, a respected writer/naturalist and Sierra Clubfounder. Pinchot's pragmatic view of conservation collidedwith Muir's instinct for preservation over the fate of the HetchHetchy valley within Yosemite National Park. San Franciscosought to dam the valley to create a reservoir to alleviate futurewater needs. The city needed congressional approval becausethe site was within the boundaries of a national park. SanFrancisco was granted use of the valley after a contentiousdecade-long battle waged in the pages of the popularmagazines and newspapers of the day. The debate over HetchHetchy would foreshadow conflicts in the second half of thecentury.

Conservation Becomes Environmentalism, 1950-todayState and local governments sought ways to ensure a steadysupply of water as populations of the dry western statesincreased during the twentieth century. An early step (1902)was the passage of the Reclamation Act to promote dambuilding in western states. Twenty years later the Colorado

Figure 13. John Muir (left)and Teddy Roosevelt,Glacier Point, YosemiteNational Park. Imagecourtesy of Library ofCongress.

Figure 14. Nationalforest lands, BlackHills, South Dakota

26

River Compact was signed by seven western states(Wyoming, Colorado, Utah, New Mexico, Nevada, Arizona,California), allocating the waters of the Colorado River (Fig.15) for future use in irrigation, hydroelectric power generation,and domestic water supply. Unfortunately, the agreement wassigned during a period of heavier than normal flow,culminating in so much water being withdrawn from the riverthat it no longer reaches its delta in northern Mexico.

Debate over future use of water in the Colorado River basinignited a second national debate on dam construction when theBureau of Reclamation sought to build a dam in DinosaurNational Monument, and later near Grand Canyon NationalPark. Both projects were eventually scrapped after widespreadopposition but the Glen Canyon Dam (Fig. 15) near Page,Arizona, was built in their place drowning tens of miles oflightly-visited canyons.

The consequences of technology and industrialization becamerealized in the more densely populated regions of the U.S.Smog became a daily nuisance in California and industrial airpollution was a fact of life in much of the Midwest andNortheast. Deaths were tied to toxic air pollution in Donora,Pennsylvania, and London, England (approximately 5,000 onone weekend in 1952). Later scientific studies would linkindustrial emissions to acid rain that contaminated lakeshundreds of miles downwind in the Adirondack Mountains ofNew York. Conservation organizations that had beenconcerned with public land issues were being transformed intoenvironmental groups focusing on the consequences ofpollution.

Rachel Carson's Silent Spring (1962) warned of the perils ofpesticide use (especially DDT which was later banned in theU.S.). Carson was attacked by a chemical industry bent onpromoting “better living through chemistry” but public opinionand, eventually, government agencies, came out in her favor

Figure 15. ColoradoRiver, from Dead HorsePoint, Utah, (left); GlenCanyon Dam wascompleted on the riveramid controversy in the1960s (right).

27

and people began to be more apprehensive about the quality oftheir drinking water. To drive home the point that not allprogress was wholly beneficial, 1969 featured two dramaticenvironmental calamities. The Cuyahoga River ignited andburned as it flowed through, Cleveland, Ohio, and millions ofgallons of oil were spilled from a leaky well off the coast ofCalifornia, polluting the beaches of neighboring SantaBarbara.

However, the next year things began to look up. PresidentRichard Nixon signed the National Environmental Policy Actinto law on January 1, 1970, marking the first of an impressiveseries of environmental laws to be created in the followingdecade (e.g. Clean Water Act, 1972; Endangered Species Act,1973; Safe Drinking Water Act, 1974; Fig. 16). A few monthslater the nation became swept up in the first Earth Day, whenmillions of people participated in workshops, rallies, andcelebrations of the natural environment.

Rene Dubos' maxim “Think globally, act locally” decoratedbumper stickers everywhere as our impact on the planetbecame clearer in the 1980's and 1990's. Fifty years after DuPont introduced Freon, British scientists would publish the firstdescription of a hole in the ozone layer over Antarctica(1985), demonstrating the price we sometimes pay fortechnological advances. The next year, a nuclear accident atChernobyl in the Soviet Union spread radioactivecontamination far beyond the boundary of its host nation andillustrated how local environmental problems were becomingregional or global in scale. Such catastrophic events providedthe images and examples that environmental groups required toconvince a wary public of the need for stronger regulations toprotect the increasingly crowded environment.

Evidence that significant positive change can occur wasprovided by the Montreal Protocol, an international

Figure 16. Like manysites, this chemicaldump in northernOhio has beencleaned up andreplaced by greenfields. Image courtesyof David Wertz.

2

agreement signed in 1987 and revised in later years, thatbanned the chemical agents responsible for destruction of theozone layer over Antarctica. Recent attempts (Earth Summit,1992; Kyoto Conference, 1997) to forge alliances to offset thethreat of global warming have set deadlines that must be metlater this decade. It is not yet apparent if the politicalestablishment in key nations has the will to enforce theregulations needed to meet these optimistic goals.

The global population topped six billion people in 1999 andwill add another billion by the end of this decade. Earlierwarnings of massive starvation have proven unfounded butconcern remains about how to feed more and more peopleusing the finite resources of our planet. As poorer nations settheir sights on the material goods and basic resources (cleanwater, air) found in more affluent countries, many arewondering if there will be enough of everything to go around.A few years ago a group of distinguished scientists issued aWarning to Humanity, and suggested that we should (1)protect the planet by reducing activities that causeenvironmental harm and become better managers of Earth'sresources and, (2) change the culture that leads toenvironmental degradation by reducing population growth,eliminating poverty, and promoting sexual equality.

To protect Earth we must understand the physical environmentas defined by the laws of nature. However, we must workwithin the cultural perspective of our time in striking a balancebetween science and economics and political forces. Historyshows that committed individuals can change the way weinteract with our planet. Our perspectives have changeddramatically in the last four hundred years. The early colonistsviewed wilderness as dangerous while we protect it, preservingit through careful stewardship for future generations wherewild, natural spaces will be increasingly rare.

Think about it . . .Do you agree or disagree with the following quote byHarlan Cleveland:"This is the first generation in the history of the world thatfinds that what people do to their natural environment ismaybe more important than what the natural environmentdoes to and for them."

8

29

The Science of Global Change• Global change involves changes in the Earth's climate

related to changing conditions in the atmosphere,hydrosphere, biosphere and solid earth.

• Thousands of scientists worldwide are working to betterunderstand the linkages between the different componentsof the Earth system and how they are affected by changingclimate.

• The U.S. government spent nearly $2 billion on climatechange research that focused on seven broad topics andinvolved scientists in chemistry, physics, geology, andbiology as well as workers in a variety of other fields.

Global change involves the analysis of changes in Earth'sclimate over time. These changes have influenced all elementsof the Earth system throughout the geological past and willcontinue to have a significant impact in the future. Some ofthese changes will occur gradually, on the time scale of theplanet, perhaps taking thousands of millions of years. Othershave the potential to occur on human time scales measured inyears or decades. Some changes will be relatively benignwhereas others may result in the catastrophic transformation ofthe climate system.

The climate system is linked to or influenced by almost allprocesses that occur on Earth (Fig. 17). The science of globalchange requires that we understand not only how Earth worksbut also how the different elements of the Earth system areinterwoven and how they impact each other. Consequently,scientific research on global change is the definition of "bigscience," it involves researchers around the world working onthousands of different projects, all contributing a piece to amuch larger puzzle. Research on global change within the U.S.involves scientists at numerous government agencies,universities, corporations, and research centers. The U.S.

Figure 17. Global cloudcover, sea surfacetemperatures, and landsurface temperaturesduring spring. Cloudsare present over theequator and clear skiesover the tropics. Sea andland temperaturesdecrease toward higherlatitudes. Image courtesyof the Space Science andEngineering Center at theUniversity of Wisconsin.

30

government budgeted nearly $1.8 billion for climate changeresearch initiatives in 2000. A little under half of these fundssupported scientific research with the remainder going tospace-based observation programs.

The objectives of research on global change span a wide rangeof disciplines including chemistry, biology, geology, physics,economics, and geography. The U.S. Global Change ResearchProgram divides research objectives into seven broadcategories briefly described below. Each objective involveshundreds of scientists examining many different problems thatwill all contribute to our understanding of global change. Eachteam of scientists must make a research plan, collect data,make observations, draw conclusions, present their work atprofessional meetings, and write technical articles during theterm of their research. Scientists seek to piece together a storyabout past and future climate change by reading literallythousands of publications and synthesizing hundreds of ideas.This represents a lot of hard work and the process movesslowly forward in careful increments. This is the nature ofscience.

Global Change Research Objectives Associated with U.S. Government AgenciesGov.Agency

YR2000Budget($M)

Comp.of theAtmos.

GlobalCarbonCycle

Eco-systems

Population& GlobalChange

AncientClimates

Earth'sClimateSystem

GlobalWaterCycle

DoA 89 • • •NOAA 70 • • • • • •DoE 125 • • • • • •DoHHS 40 •DoI 27 • •EPA 23 • •NASA 261 • • • • •NSF 187 • • • • • • •Smithsonian 7 • • • • • •

$829 million was budgeted for scientific research (Year 2000 budget column), most going to supportprojects funded by NASA, NSF and DoE.Abbreviations: DoA, Department of Agriculture; NOAA, National Oceanographic and AtmosphericAdministration (and Department of Commerce); DoE, Department of Energy; DoHHS, Department ofHealth and Human Services; DoI, Department of Interior; EPA, Environmental Protection Agency; NASA,National Aeronautical and Space Administration; NSF, National Science Foundation; Smithsonian,Smithsonian Institution.

We will introduce several of the key concepts of global changebelow but we will return to them in greater detail as we movethrough The Good Earth. This is fitting because it is a topicthat you will see and hear more about in the years ahead and it

31

gives us an opportunity to look over the shoulders of theresearchers to see the scientific process in action.

Composition of the AtmosphereThe concentrations of key gases in the atmosphere has changedas a result of human activities including the use of fossil fuelsand the production of emissions from industrial andagricultural operations. Natural variations in the composition ofthe atmosphere are a consequence of volcanic eruptions, solarradiation, and the normal functions of weather systems and thebiosphere.

Key Questions• How will the changing composition of the atmosphere

influence harmful incoming solar radiation?• Will airborne pollutants serve to cool or warm the lower

atmosphere and how long will such substances remain inthe air?

What We Need to Know• Data on the composition of the atmosphere at different

altitudes from surface stations, balloons and airbornemonitors, and satellites.

• The distribution, degree, and character of pollutants and theinfluence of local, regional, and global weather systems.

The Carbon CycleThe concentration of carbon dioxide in the atmosphere islinked to the global carbon cycle. The oceans and the landsystem store carbon dioxide that is not held in the atmosphere.Understanding the connections between the sources, wherecarbon is released, and sinks, where carbon is absorbed, andhow they are influenced by human activity will allow us toidentify the most appropriate mitigation efforts. The capacityof some natural sinks is poorly understood, making it difficultto accurately estimate the future potential for carbon storage atthese sites.

Key Questions• What is the fate of carbon dioxide produced by human

activity?• How will human production of carbon dioxide change in

the next century?

32

What We Need to Know• Measurements of the relative proportions of carbon dioxide

absorbed by land and ocean sinks.• How much carbon emissions can be reduced through

improved technology and how much emissions willincrease from increasing populations.

EcosystemsThe biosphere will be influenced by climate changes. Scientistsare studying how different ecosystems respond to suchchanges. The scale of climate change will strongly influencethe impact on ecosystems. We must determine how large anarea will be affected and how fast the changes will take place.We rely on the managed biosphere to provide food resourcesfor almost all of the world's population. Our ability to feed theworld's peoples may be determined by how agriculturalresources respond to climate change.

Key Questions• How will land use patterns change, including the character

of land cover, the operation of local ecosystems, and wateravailability?

• How will the biosphere respond to changes in atmosphericquality and composition?

• How will ecosystems respond to multiple simultaneousstresses?

What We Need to Know• Our degree of reliance on natural and managed land use

systems and how that will change with variations inclimate.

• The feedback mechanisms between atmosphere, biosphere,hydrosphere, and soils.

• How plants and animals respond not only to temperaturechanges but also changes in water availability, atmosphericgases, and soil composition.

Population and Global ChangeThe linkage between human activities and changes in naturalsystems needs to be fully comprehended to identify potentialchanges that might result. The future will lead a to a near-doubling of global populations and a general increase inconsumption but such changes will not be evenly distributedworldwide. Some regions may experience extreme changes in

33

both climate and resource use and we need to understand thepotential economic and social consequences of such changes.Humanity has caused widespread alteration of the land surfaceand the composition of the atmosphere yet we are dependent onthe most basic natural resources (land, air, water) for survival.

Key Questions• How sensitive are different social systems to potential

changes in climate and their consequences?

What We Need to Know• The impact of different social systems on their

environments and the range of options available to ensure ahealthy future. We need data on population growth,resource consumption patterns, land use, social supportstructures, rate of technological change, and economicdevelopment.

Ancient ClimatesWe can use the record of global change in the geological pastto identify the natural variability in the Earth system. Scientistsattempt to strip away the natural variability in climate patternsto recognize the influence of human activities and therefore geta better perspective on the potential rate and range of changesthat may occur and how we might combat their negativeconsequences. A number of different components of the naturalenvironment can be used to learn about past climates.

Key Questions• How much natural variation in climate is possible and how

rapidly can such changes occur?• What are the potential triggers and signals of such changes?

Are there some specific thresholds or limits for catastrophicchange?

What We Need to Know• Data from the natural environment on past climates by

analyzing a variety of proxy climate indicators such as treerings, coral growth patterns, ice cores, and sedimentrecords from lakes and oceans.

• The forcing factors that cause climate to change. We areespecially susceptible to rapid climate changes that occurover years or decades. What causes such dramatic short-term changes?

34

Earth's Climate SystemMuch of our cultural and physical characteristics as nations aredefined by climate. Short-term climate fluctuations such as ElNino may disrupt "normal" climate patterns for a few years andhave negative consequences for some regions (natural hazards,agricultural loses) while producing benefits for others (lowerheating costs, agricultural gains). The resulting economiclosses or gains may be measured in billions of dollars.

Key Questions• How do we understand the mechanisms of regional and

global climate patterns?

What We Need to Know• Monitor key elements in these systems to identify the onset

of climate events to allow the recognition of characteristicpatterns that can be used to predict future events.

The Global Water CycleWater represents perhaps the most important basic resource onthe planet. Its presence or absence is dependent upon globalclimate systems and its quality is closely linked to humanactivity. However, the linkage between weather and climateultimately determines how much water is supplied to a givenregion by precipitation.

Key Questions• How is the availability of water on land related to the

global climate cycle?• How would a change in climate impact the evaporation,

transport, and precipitation of water in regional weathersystems?

• How will natural and managed systems be affected bychanges in water availability?

What We Need to Know• The factors that lead to extreme events that will result in

too much or too little water being delivered at time scalesof hours to decades.

• The route of water through the global hydrologic cycle,especially the transport of water through the atmosphere.

• What social systems are in place to address water-relatedproblems?

35

Summary1. Define the terms geology and environment.Geology – the study of the origin, composition and structure ofthe Earth and the processes that shape its surface; Environment– the physical and chemical characteristics of the world inwhich we live and the cultural conditions that influence ourinteraction with Earth.

2. What factors influence the decisions we make about theenvironment?

The physical and chemical factors that can be measured andother social and cultural criteria including those that aresubjective.

3. How does the scientific method work?The scientific method involves using observations to formtestable hypotheses; a successful hypothesis becomes a theory.A hypothesis that the extinction of the dinosaurs was caused bythe impact of the asteroid with Earth is linked to a crater inMexico. Inaccurate hypotheses often do not follow thetraditional procedure for formulating scientific ideas.

4. What is the role of Earth scientists in modern society?Evaluating natural hazards: Scientists determine the potentialrisks from natural phenomena that may harm people anddamage property. The effects of some of these phenomena canbe partially offset by technological advances. Managingresources: Human existence requires the use of basic resources(water, soil, minerals, oil, coal) which must be managed toensure sufficient future supply and minimal environmentaldegradation during exploitation. The health of the environment:Human activities that involve the use of technology or themanufacture of hazardous materials inevitably lead to failuresthat are unanticipated and may endanger human life or naturalecosystems. The future of humanity: Scientists must evaluatepotential global-scale problems associated with meteoriteimpacts or changes in Earth's climate system.

5. How has America's environmental heritage relied on theactions of individuals and citizens’ groups?

American concern for the environment can be traced back tothe continent's earliest inhabitants. Actions of Europeancolonists resulted in land degradation and reduction of specieshabitat and led to early legislation to protect some favoredspecies. An appreciation for the land blossomed in the

36

nineteenth century, prompting the creation of forest reservesand the earliest national parks. The second half of the twentiethcentury was marked by a growing concern for pollution of theenvironment at both regional and global scales.

37

Lewis and Clark and the Scientific Method

June 3, 1805The Lewis and Clark expedition, following the Missouri River west toward theRocky Mountains, arrive at the junction of two rivers. The natives of the area hadtold the explorers that they would soon arrive at a series of falls and rapids (theGreat Falls of the Missouri River) but had not given them any information aboutwhich fork in the river to follow. Lewis wrote in his journal:

“An interesting question now to be determined, which of these rivers is the Missouri. . . to mistake the stream at this period of the season . . . and to ascend such stream. . . and then be obliged to return and take the other stream would not only lose usthe whole of this season but would probably so dishearten the party that it mightdefeat the expedition altogether . . .”

Lewis and Clark decided the only option was to investigate both rivers in the hopeof finding evidence that would allow them to predict which was the Missouri River.Two teams of three men each are sent to spend the day investigating each river.

1. What observations could they have made to help in their decision?

The team that investigated the North Fork reported that the waters flowed “in thesame boiling and rolling manner which had uniformly characterized the Missourithroughout its whole course so far.” At this point all members of the expeditionagreed on which one of the rivers was the Missouri.

2. Which river do you think they chose?a) The South Fork b) The North Fork

However, Lewis and Clark themselves were still not convinced. They realized that amistake might have severe consequences for their exploration and decided to dosome further investigation. The next day, Clark and Lewis each led teams of six upthe South and North Forks, respectively. Clark took three days and traveled 40miles upstream; Lewis spent five days on his reconnaissance, which reached 60miles upstream.

3. What additional observations could they have made to aid in their decision?

On June 11, the Lewis and Clark expedition ascended what they determined mustbe the Missouri River and two days later, Lewis roving ahead of the rest of theexpedition, encountered the Great Falls of the Missouri, confirming that they hadmade the right decision. Which river did they ascend?

38

George Perkins Marsh (1801-1882)Read a much abbreviated version of a speech (below) given byGeorge Perkins Marsh to the Agricultural Society of RutlandCounty (Vermont), September 30, 1847. The text of theoriginal presentation is available at the Library of CongressHistory of Conservation site.

Selections from an address delivered before theAgricultural Society of Rutland County (Vermont),September 30, 1847, by George Perkins Marsh

America offers the first example of the struggle betweencivilized man and barbarous uncultivated nature. In all otherprimitive history, the hero of the scene is a savage, the theatre awilderness, and the earth has been subdued in the sameproportion, and by the same slow process, that man has beencivilized. In North America, on the contrary, the full energiesof advanced European civilization, stimulated by its artificialwants and guided by its accumulated intelligence, were broughtto bear at once on a desert continent, and it has been but thework a day to win empires from the wilderness, . . . Thismarvelous change . . . has converted unproductive wastes intofertile fields, and filled with light and life, the dark and silentrecesses of our aboriginal forests and mountains.

In purely savage life, the wants of man are supplied by thedestruction of the fruit, or plant, or animal, which clothes orfeeds the human beast of prey, . . . takes no thought for thereproduction of that which he improvidently consumes, buttrusts implicitly to the bounty of spontaneous nature to supplythe demands which the appetites and needs of her own childrenhave created. Civilization begins with arrangements forsecuring the continued and regular supply of man's two greatphysical wants, food and clothing . . . The arts of the savage arethe arts of destruction; he desolates the region he inhabits, hislife is a warfare of extermination, a series of hostilities againstnature or his fellow man . . . Civilization, on the contrary, is atonce the mother and the fruit of peace. Social man repays tothe earth all that he reaps from her bosom, and her fruitfulnessincreases with the numbers of civilized beings who draw theirnutriment and clothing from the stores of her abundantharvests. The fowls of the air, too, and the beasts of the field,find in the husbandman a cherishing friend . . . Savage manthen is the universal foe, both of his own kind and of allinferior organized existences, an incarnation of the evilprinciple of productive nature; civilization transforms him into

39

a beneficent, . . . and a protective influence, and makes him themonarch not the tyrant of the organic creation.

Men now begin to realize what, as wandering shepherds, theyhad before dimly suspected, that man has a right to the use, notthe abuse, of the products of nature; that consumption shouldeverywhere compensate by increased production; and that it isa false economy to encroach upon a capital, the interest ofwhich is sufficient for our lawful uses.

The progress of agriculture, within the last half century thoughgreat in itself and full of future promise, has been but a tardymovement, in comparison with the swift advancement of themechanic arts (technology). The steamboat, the locomotive, thepower loom, and the power press, have all been brought intouse since the beginning of the present century, and what arevolution have they wrought upon the face of the globe! . . .The mechanic arts are eminently democratic in their tendency.They popularize knowledge, they cheapen and diffuse thecomforts and elegancies as well as the necessaries of life, theydemand and develop intelligence in those who pursue them,they are at once the most profitable customers of theagriculturist, and the most munificent patrons of theinvestigator of nature's laws.

There are certain other improvements connected withagriculture, to which I desire to draw your special attention.The increasing value of timber and fuel ought to teach us, thattrees are no longer what they were in our fathers’ time, anencumbrance. We have undoubtedly already a largerproportion of cleared land in Vermont than would be required,with proper culture, for the support of a much greaterpopulation than we now possess, and every additional acre . . .deprives succeeding generations of what, though comparativelyworthless to us, would be of great value to them.

The inconveniences resulting from a want of foresight in theeconomy of the forest are already severely felt in many parts ofNew England, and even in some of the older towns inVermont. Steep hill-sides and rocky ledges are well suited tothe permanent growth of wood, but when in the rage forimprovement they are improvidently stripped of this protection,the action of sun and wind and rain soon deprives them of theirthin coating of vegetable mould (top soil), and this, whenexhausted, cannot be restored by ordinary husbandry (farmingpractices).

40

On the other hand, where too large a proportion of the surfaceis bared of wood, the action of the summer sun and windscorches the hills which are no longer shaded or sheltered bytrees, the springs and rivulets that found their supply in thebibulous (thirsty) soil of the forest disappear, and the farmer isobliged to surrender his meadows to his cattle . . . andsometimes even to drive them miles for water. (Rains) nolonger intercepted and absorbed by the leaves or the open soilof the woods, but falling everywhere upon a comparativelyhard and even surface, flow swiftly over the smooth ground,washing away the vegetable mould (top soil) as they seek theirnatural outlets, fill every ravine with a torrent, and convertevery river into an ocean. The suddenness and violence of ourfreshets (floods) increases in proportion as the soil is cleared;bridges are washed away, meadows swept of their crops andfences, and covered with barren sand, . . . and there is reason tofear that the valleys of many of our streams will soon beconverted from smiling meadows into broad wastes of shingleand gravel and pebbles, deserts in summer, and seas in autumnand spring.

The changes, which these causes have wrought in the physicalgeography of Vermont, within a single generation, are toostriking to have escaped the attention of any observing person .. . The signs of artificial improvement are mingled with thetokens of improvident waste, and the bald and barren hills, thedry beds of the smaller streams, the ravines furrowed out by thetorrents of spring, . . . seem sad substitutes for the pleasantgroves and brooks and broad meadows of his ancient paternaldomain. If the present value of timber and land will not justifythe artificial re-planting of grounds injudiciously cleared, . . . inour future husbandry (farming practices) a more carefulselection should be made of land for permanent improvement.It has long been a practice in many parts of Europe, as well asin our older settlements, to cut the forests reserved for timberand fuel at stated intervals. It is quite time that this practiceshould be introduced among us. In many European countries,the economy of the forest is regulated by law; but here, wherepublic opinion determines, or rather in practice constitutes law,we can only appeal to an enlightened self-interest to introducethe reforms, check the abuses, and preserve us from an increaseof the evils I have mentioned.