Common section

Chapter 18

Impacts on the Environment

In This Chapter

bulletLinking the parts of ecology

bulletMessing up a planet in so many ways

bulletTurning small problems into big ones

bulletMaking decisions that matter

T he Chesapeake Bay is the largest estuary (an inlet where the salty tide meets freshwater current) in the United States and perhaps the most economically important one, too. The greatest source of oysters in the U.S., Chesapeake Bay is also the world leader in blue crab production. Striped bass, perch, shad, flounder, and a host of other species help comprise this historically rich and robust fishery. So, naturally, it’s rather disturbing when fish by the thousands suddenly turn up dead.

The immediate culprits are algae, tiny aquatic plants that takes in oxygen from the water. Occasionally, algae reproduces by the gazillions, creating algal “blooms” that deplete oxygen over large portions of the Bay and suffocate large numbers of fish. These blooms are caused by periodic build-up of phosphate and nitrate in the water. Algae, it seems, just love these substances, and reproduce like crazy in their presence.

That, of course, leads one to inquire into the origins of the bloom-producing chemicals. The Bay is not an isolated body of water. Instead, rain and runoff connect it with a broad land expanse (see Figure 18-1). The phosphates originate mainly in sewage treatment plants that empty into rivers and streams that empty in turn into the Bay. Nitrates originate mainly in agricultural fertilizers that run off from farms into the same Chesapeake tributaries. Indeed, virtually hundreds of watercourses from six states drain into the Chesapeake, collecting phosphates and nitrates from many, many sources along the way.

Maybe you’re saying, “OK, but what does this have to do with geography? This sounds to me more like chemistry or biology.” Geography is concerned with human and natural phenomena that give character to different parts of Earth’s surface. Often, of course, important characteristics that we observe in a location or region are products of interaction between people and nature. While these relationships are sometimes harmless, they may also have negative consequences, as in the Chesapeake Bay example.

Environmental geography is the sub-field that focuses on human impact on the natural environment, and is the topic of this chapter. Previous chapters have referred to negative environmental impacts without mentioning environmental geography by name. Devoting an entire chapter to it is meant to emphasize both the magnitude of society’s ability to alter the face of the Earth, and the existence of a discreet area of geography that is devoted to the topic. Although ending the meaty part of this book with talk of pollution and such may seem like a downer, it affords the opportunity to think critically about the role of geography in assessing the present and planning for the future.

Grasping the Basics — Environmentally Speaking


Environment refers to the myriad of natural characteristics and conditions that affect and are affected by humans. Environmental geography, therefore, is the study of the characteristics of locations and regions that are the result of human-nature interaction. This is closely allied to the field of ecology, which studies the complex connections that link the following elements:

bulletAtmosphere: the climate surrounding Earth

bulletHydrosphere: water on Earth in all its forms

bulletLithosphere: the solid earth including soil and other loose surface particles

bulletBiosphere: all life on Earth

bulletCulturesphere: meaning people, and emphasizing that it is by means of culture that different human groups interact with nature

The emphasis on location and place is what most distinguishes environmental geography from ecology. Thus, while an ecologist might study agriculture-nitrate-algae-fish linkages in the abstract or at the scale of microbiology, environmental geography studies them as large-scale events that characterize locations or regions. In that regard, geography is very much at home with the study of ecosystems, the living things that occupy particular areas together with the inorganic elements on which they depend. In Chapter 2, for example, there was a discussion of the African lion that basically was about an ecosystem. Specifically, lions (biosphere) inhabit areas where the climate (atmosphere) results in rainfall (hydrosphere) characteristics that produce grassland (biosphere). These grasses attract grazing animals (biosphere) like wildebeest, zebra, and impala that in turn attract lions. But the grasslands also result in soils (lithosphere) that are amenable to agriculture. As a result, people (culturesphere) have converted grassland to farms and grazing lands, depriving lions of the habitat they need to thrive.

Contributing Factors: Pollution on the Move

Impacts on the environment take several forms. In the sections that follow, several kinds are described together with natural phenomena that often (and perhaps surprisingly) help to turn small environmental problems into major ones.

Making an impact


Perhaps the most obvious human impact involves pollution, the introduction of substances (pollutants) that are harmful to the environment. These may result in degradation, the reduction in quality of natural environmental elements, or in depletion, the reduction in quantity. Human impacts can also be manifested by acts of removal or addition. Thus, the wholesale removal of forests (clear-cutting) may not only deplete forest resources, but perhaps also contribute to soil erosion. On the other hand, introduction into the environment of some element for which no natural counterbalance exists may have an effect no less profound than, say, accumulation of phosphates and nitrates in the Chesapeake Bay. A good example is provided by the kudzu, a fast- growing vine that was let loose in the South and has proceeded to dominate the natural vegetation over large areas.

Geographically, pollution may originate as a location-specific point source or as a larger scale non-point source (sometimes called an area source). In the Chesapeake Bay example, a pipe at a sewage treatment plant that discharges phosphate would exemplify point source. Crop fields in, say, Maryland, on which fertilizers that are high in nitrates have been applied, would typify non-point source or area source.

Spreading the mess

By themselves, pollution sources per se generate limited environmental impact. The major problem, rather, is that pollutants tend not to stay put because they are released within an environment characterized by several kinds of motion. In other words, nature has mechanisms that “spread the mess.” As a result, pollution that starts out as a confined geographic event may end up affecting broad areas and having extensive consequences. Previous chapters have described these mechanisms in some detail. Here is a brief recap with examples.

The water cycle

The water cycle (see Chapter 8) is a major “culprit” for spreading the mess. Rainfall originates, falls to earth, and runs off the land to create streams that flow to the sea. In so doing, the water cycle acts as a pervasive and efficient mechanism that “spreads the mess.”

This process picks up the phosphate discharge, carries it away, and turns a local event (discharge) into a problem of Chesapeake-sized proportions. This process also produces run-off on an agricultural field that picks up nitrates from fertilizers and carries them away. And of course, the Chesapeake Bay does not have a tributary, but instead more than a hundred of them, which together collect pollutants from thousands of point and non-point sources.


In innumerable instances, smoke and pollutants from a manufacturing or electrical generating plant go up a chimney (point source) and end up in the atmosphere. Here, too, the resulting environmental impact would be nominal if nature just stayed put. But, of course, it does not. Wind is another component of the dynamic environment. In Chapter 9, I discussed how solar energy leads to creation of high- and low-pressure systems that cause wind. And as a result, pollution that starts out as a very localized phenomenon becomes geographically general.

For example, as sanitary landfills fill up, incineration is increasingly looked to as a means of solving garbage disposal problems, especially in big cities. But even the most efficient incinerators generate pollution that is released to the atmosphere, and then spread over wide areas, thanks to wind. Thus, a source of point pollution (the incinerator chimney) may affect the health of humans, vegetation, and property values over a wide area.


In many times and places, oceans have been convenient receptacles for human refuse. Also, as the global economy has grown and become more inter-connected, maritime traffic has increased, and with it the possibility of incidents that result in the release of cargo that is harmful to the environment. At this point the familiar story line repeats: If nature stayed put, then the impact would be minimal. But we live in a dynamic environment. The oceans are restless. Surface currents (see Chapter 9) can carry things far and wide while tides and waves can affect every coastal nook and cranny. Once again, therefore, nature can spread the mess, so what starts out as a local event is turned into an issue of greater geographical proportions.

The possibilities were amply demonstrated on March 24, 1989, when the Exxon Valdez oil tanker went aground in Prince William Sound, Alaska, and ultimately spilled about 11 million gallons of crude oil into the sea (Figure 18-2). Although the Sound is a somewhat confined water body, the Alaska Current slowly and inexorably began spreading the mess — in this case, the oil slick — in a westerly direction. Coastline 400 miles away was eventually affected. However, given the numerous islands and inlets that characterize the region, some 3,000 miles of shore were contaminated. (Dead wildlife included more than 575,000 birds.)

Bear bile, anyone?

One of the more intriguing human impacts on the environment concerns demand for animal body parts to serve as folk remedies. In China, for example, powdered tiger bone is the principal ingredient in a medicinal cocktail that is believed to relieve ulcers, malaria, rheumatism, and other ailments. A similar brew that uses ground rhinoceros horn is thought to heighten the sex drive and cure impotency. People use bile from the gallbladders of bears to treat liver disease, fever, hemorrhoids, and other ailments. Literally hundreds of millions (if not billions) of people belong to culture groups that swear by these age-old remedies.

Local demand for body parts has taken its toll on the local supply of desired animals. As a result, tigers and bears are nearly extinct in the wild in China. As numbers dwindle, prices skyrocket. Bear bile reportedly sells in China for as much as 15 times the price of gold. Tiger bone in parts of Asia sells for upwards of $500 per kilogram. As a result, captive breeding programs in China raise tigers for slaughter for bones, and bears for periodic “milking” of gallbladders. But even this cannot satisfy demand. Body parts must be imported from somewhere else. And at prices like these, it’s a poacher’s dream come true.

Here is where geography fully enters the picture. A geographically local (Chinese) demand for body parts has generated a geographically broad (global) trade in them as well as an attendant environmental impact. Thus, bears in Montana, Idaho, and Alaska (and probably other states) are known to have been illegally killed to provide body parts for Asian folk remedies. Likewise, tiger preserves in India and Nepal are periodically raided and impacted by people who profit from medicinal demand. Underlying these threats to the natural world is global connectivity. If Alaska was an isolated place, or if trade and communications mechanisms did not connect Montana and China, then the bear population would be safe — at least as regards to that particular threat. For better or worse, however, bears and everything else are part of a world in which geographically local demand can effect worldwide resource supply, and have global environmental implications.

Migration and trade

Human beings are a species on the move. We migrate (see Chapter 12). We travel for business and leisure. We engage in global trade and commerce (see Chapter 15). And in the process we sometimes purposefully or inadvertently transfer a particular species from its current home to a part of the world where it was previously unknown, possibly with negative environmental consequences. Following are two examples.

Rabbits were unknown in Australia until 1859, when a dozen or so were purposefully introduced to serve as a source of food. Lacking natural predators in their new homeland, their numbers went ballistic, reaching about a billion within a century. This could rank as the ultimate bunny joke, except that sheep are important to the Australian economy, and five rabbits eat about as much grass as one sheep. Poisoning campaigns have subsequently killed off literally hundreds of millions of rabbits, but people now fret about the impact of those substances on local food chains (a concept discussed in the next section.)

In 1988, an East European freighter in the Great Lakes dumped some ballast water (whose sole purpose is to add weight to a ship that would otherwise bob like a cork), and with it probably introduced the zebra mussel to North America. This diminutive critter with cute little stripes is native to the Black and Caspian Seas, where certain duck species and crayfish keep its numbers in check. Lacking a large predator population in the Great Lakes — plus the tendency of adult female zebras mussels to produce more than 30,000 eggs per year — the population soared at a rate that would make an Australian rabbit swoon. The mussels attach to hard surfaces, and in the process have caked and stopped up water intake vents of waste and industrial treatment plants.

Focusing on food chains

While one may decry negative environmental impacts on ethical or scenic grounds, the repercussions for human well-being is perhaps of paramount importance. Food chains provide an excellent example of how negative impacts may come back to haunt humans big time. No, not fast food chains that provide hamburgers, tacos, fried chicken, pizza, or other staple foodstuffs; but instead the food chains that involve consuming and passing along injurious substances in ways that prove ultimately harmful or fatal to humans and animals.

The “chain” of events

A food chain is a sequence of living things through which energy and other matter move in an ecosystem. That mumbo-jumbo clearly calls for a diagram — two in fact, inasmuch as there are terrestrial (land) food chains and aquatic (water) ones (see Figure 18-3). Though their specific components differ, the overall structures are quite similar.

bulletAt the base of any food chain are a number of primary producers that convert solar energy to organic matter — green plants in the case of terrestrial ecosystems, and aquatic plants or algae in the case of aquatic systems.

bulletAny animal that feeds upon a primary producer is a primary consumer. This may be a rabbit or squirrel (any herbivore will do) in the case of a terrestrial food chain, or a small fish in the case of an aquatic food chain.

bulletAny carnivore that feeds on a primary consumer is a secondary consumer.

bulletAny carnivore that feeds on a secondary consumer is called a tertiary consumer, and so forth. Humans can be primary, secondary, tertiary, or whatever consumers depending on what they are eating and whether that something had itself previously eaten another consumer.

bulletAll living things ultimately die (a major bummer) and decay. Decomposers, which consist of various microorganisms and bacteria, feed on organic waste and matter at all levels in the food chain and, as their name suggests, aid in decomposition. Ultimately, they disintegrate organic matter to an elemental chemical level that makes it suitable for reuse by plants and animals — completing the food chain.


Thus, every food chain may be thought of as a set of linked organic units in which matter is constantly used and recycled.

The potential for danger

While food chains sustain life in all its forms, they may also pose grave (perhaps fatal) harm when toxic substances are let loose in the environment. The scenario may easily follow these steps:

1. Toxic waste from a chemical manufacturer enters a lake and taints microscopic forms of life.

2. Small fish eat the tainted matter and store the harmful stuff in their fatty tissue.


3. Bigger fish eat the smaller fish, and with each meal increase the concentration of toxic matter in their own fatty tissue, a process call biological amplification.

4. Fishermen catch the affected fish, eat them, and so acquire the toxic substance, perhaps with fatal result if enough contaminated fish are consumed.

Fallout is another way in which hazardous materials can enter the environment. Fallout is a quaint term that most folks don’t fully appreciate. When a big explosion occurs, a lot of solid matter is instantly pulverized and becomes very fine particles that are thrust into the air. Being so small, they can remain aloft for a long period until, because they have weight, they “fall out.” Before that happens, however, wind may “spread the mess” over a wide area. If the explosion involves radioactive substances, then the fallout will be radioactive in nature. That alone may taint grass that is eaten by cattle and other livestock. Rainfall, however, may percolate radioactive matter into the soil, where it is taken up by roots and thus rather thoroughly contaminate the plants.

The Chernobyl disaster provides an instructive real-world case study. On April 26, 1986, a nuclear power plant in that Ukrainian (then Soviet) city suffered an explosion that resulted in discharge of a large quantity of radioactive matter into the atmosphere. Initial attempts by the government to squelch news of the incident were rendered futile when atmospheric monitoring stations in Sweden, hundreds of miles away, reported high levels of radioactive fallout.

In the case of Chernobyl, measurable amounts of fallout were recorded more than 1,200 miles away. As a result, the authorities ordered the destruction of thousands of cattle, pigs, and chickens out of fear that a contaminated food chain would lead to adverse human health impacts. Nevertheless, related sicknesses have subsequently occurred, and many public health officials predict more problems in the years ahead.

The role of attitudes toward nature

People generally have kindly attitudes toward some natural environments and less kindly attitudes toward others. These differences may result in concerted efforts to preserve some components of the natural world even as others are allowed or encouraged to be degraded or destroyed.

Consider, for example, forest and swamp. If you are like most people, then these two terms probably evoke different feelings. More specifically, most Americans have a rather benevolent and protective attitude towards forests and a much less benevolent and protective attitude toward swamps. Forests, of course, are places we humans can readily walk through and even make our home. Swamps, in contrast, are places we cannot similarly experience and are much less likely to call home. Wildlife may also play a role in explaining why these habitats are perceived so differently. Cartoons and other media have generated a generally positive mindset towards chipmunks, squirrels, deer and other forest animals (a phenomenon that has been called the Bambi Complex), but a less cuddly set of attitudes towards the reptiles and amphibians that tend to populate swamps.

This, of course, is bad news for swamps, which provide unique and necessary habitat for a great number of species. But how can one protect natural habitat and successfully lobby legislators to that effect if people simply have negative attitudes toward the thing that you seek to protect? In this case, the solution has been to drop swamp from the environmental vocabulary and replace it with wetland. Accordingly, a substantial body of environmental law aimed at wetland protection has been enacted during the past few decades and enjoys broad public support. People, it seems, are perfectly willing to protect a wetland rather than a swamp, even if the two places in question are one and the same.

Going Global: Multiple Sources Affect an Entire Population

The Chernobyl and Exxon Valdez accidents discussed earlier in the chapter illustrate how a one-time point-source release of pollutants in a dynamic environment can have wide-ranging effects. More serious, however, is a case of on-going discharge from multiple-point sources, which generate potential for negative human impact on a global environmental scale. “Potential?” No, scratch that. At least two phenomena have already sprung forth: acid rain and global warming.

Raining acid


Acid rain is precipitation that has an unusually high acid content. It has been identified as a major cause of forest demise in various parts of the world, and also of contamination of lakes and estuaries.

The principal cause of this phenomenon is the burning of fossil fuels to operate motor vehicles, manufacturing facilities, and electrical utility plants (see Figure 18-4). A lesser but important cause is the smelting of ores that contain sulphur. Two unfortunate by-products are sulfur dioxide and nitrogen dioxide. When sulfur dioxide interacts with atmospheric moisture, it transforms into a dilute solution of sulfuric acid, a very corrosive substance. Nitrogen dioxide is transformed into nitric acid, which is not particularly corrosive, but is harmful to organic matter.

The range of impacts

After sulfur dioxide and nitrogen dioxide have formed in the atmosphere, they may remain there for long periods and be carried by the wind far from their source areas. Ultimately, they fall to earth with snow, sleet, hale, or rain. Even dew may bring them to Earth. Thus, though the phenomenon is popularly called acid rain, it would be more properly called acid precipitation or acid deposition. Whatever the label, negative impacts may be manifested in the following ways:

bulletTerrestrial impacts: Terrestrial impacts concern vegetation and soil. After acid precipitation has seeped into the ground, it may be taken up by the root systems of plants. If a sufficient amount of acid is taken in, even as small dosages over a long period, the stress may be sufficient to kill individual trees and perhaps destroy entire forests. Obviously, the effects of such outcomes may be devastating for commercial logging as well as wildlife habitat and recreation. Loss of vegetation results in decreases in the maze of root systems that hold soil in place, perhaps leading to erosion and mudslides. In addition, the acid may also have a fatal effect on bacteria and microbes that break down organic nutrients in the topsoil and contribute to soil fertility. Thus, acid rain may have a harmful effect on both the quality and quantity of soil.

bulletAquatic impacts: Acid rain runoff may adversely impact streams, rivers, lakes, and oceans. Aquatic plants may be affected in the same manner as terrestrial ones. If they die, so does habitat for all kinds of animal species, as well as potentially significant elements in food chains. In addition, fish and other animal species may perish directly from prolonged exposure to the acids, or indirectly from silt laden runoff attendant to loss of roots that held soil in place.

Small lakes that collect runoff, but have no outlet, are particularly susceptible to harm. Literally and figuratively, they are dead ends, the final collecting place for acid rain. Acid concentrations may be such that lakes become, for all intents and purposes, sterile.

Estuaries may also be impacted, and with them, marine fisheries. The problem here is not so much the acid as the nitrates, a favorite of algae. The impact of that, as was discussed earlier in the chapter in the case of the Chesapeake Bay, may be fish kills on a significant scale.

bulletMaterial impacts: Material impacts principally concern deterioration of stonework and statuary (sculptures and statues), particularly ones made of marble. The corrosive effect of acid rain may literally eat away at these to the point where — to use an admittedly extreme example — statues become undistinguishable slabs of rock. Building facades are of more immediate importance, and thousands of them around the world are slowly dissolving.

Applied Geography: Watershed management

A watershed is an area that drains into a river, lake, bay, or reservoir. As we saw with the case of the Chesapeake Bay, the quality of a body of water may be intimately related to the quality of the watershed that feeds it. Watershed management concerns a wide rage of efforts that monitor and ensure the quality of watersheds and, thusly, the receiving bodies. This is a significant environmental undertaking in any case, but especially so when municipal or regional drinking water is at stake.

Various geographical techniques are routinely applied to this endeavor. The Global Positioning System (see Chapter 4), for example, is used in field surveys to pinpoint and map pollution sources. Aerial photography and satellite imagery may be used to assess the health of vegetation that anchors watershed soils. But perhaps the most intriguing technology is digital terrain modeling, in which the lay of the land in exacting detail is stored in computer memory, allowing managers to simulate all kinds of eventualities. Want to see what will happen if a small pollution source becomes a big one? Or if acid rain should reduce forest cover by 55 percent (or any other percentage)? Or if 2 inches of rain should fall anywhere or everywhere in 25 minutes? This computer technology facilitates simulation of all kinds of scenarios, the goal being watershed management that promotes and preserves the quality of drinking water.

The geographical dimension

To some extent, acid rain happens everywhere, but its intensity is very uneven (Figure 18-5). In general, the world’s principal industrial regions tend to the major source areas. That includes the southeastern Great Lakes region, Western Europe in general, plus the Ukraine and southwestern Russia, Eastern China, and Japan. Acid rain tends to be greatest in these immediate regions plus those directly downwind. Given the general west-to-east movement of the atmosphere at mid latitudes, the typical result is an elongated impact area that tails off easterly from the source region.

Thus, in North America, relatively pristine areas in northern New York, New England, and Canada’s Maritime Provinces have been hard hit. Forests are dying over large areas and numerous lakes, especially small ones, are becoming lifeless. The situation is similar in Europe, where the Black Forest and similar tracts are being affected.

Sometimes a state or country finds itself on the receiving end of pollution that originates in another state or country. This is called trans-boundary pollution. Thus, the nitrates that cause algae blooms that kill fish and hurt the economy in Maryland’s portion of the Chesapeake Bay may have their origin in fertilizers that were spread on agricultural fields in Pennsylvania. Similarly, acid rain that kills forests in eastern Canada may have their origins in power plants in the United States.

People who live in areas that suffer the effects of pollution (such as acid rain) tend to be among the most committed to finding a remedy. But how can you affect a solution to a problem that originates outside of your jurisdiction — in another state or country? Assuming no treaties or protocols have been broken, about all one can do is encourage your neighbors to clean up their act. In the case of acid rain, that is going to take some doing because so much of the problem is associated with fossil fuel consumption that is likely to continue for decades to come.

Getting warmer

Global warming is the term used to describe the increase in the average temperature of the atmosphere that has been occurring during the past several decades. This has ominous implications for sea level rise and local climate changes of various sorts. But why is global warming happening? Is it a natural process or the result of human activity? And can the process be slowed or reversed?

The Principal suspects

Several ice ages came and went long before Homo sapiens emerged as a major instrument of global change. That means that natural mechanisms capable of effecting significant global temperature change over time must exist. Perhaps, therefore, the present warming trend is merely part of a natural cycle that has occurred in the past, is happening at present, and is likely to repeat in the future. Or perhaps it is the result of some other natural cause that we have yet to identify.

On the other hand, the warming trend may be the result of atmospheric changes for which humans are responsible. Since the beginning of the Industrial Revolution in the mid- to late- 1700’s, humans have consumed (burned) large quantities of coal, petroleum, and natural gas to operate vehicles and machinery, provide power for manufacturing facilities and electrical utilities, and to heat up and cool down homes and buildings. In the process, huge quantities of certain gases have been added to the atmosphere. Most reputable scientists believe that these substances are the cause of the current warming trend.

The global greenhouse


The commonly held scenario for why the atmosphere is heating up likens the atmosphere to a greenhouse, whose glass panes allow sunshine to penetrate the structure, but then contain the solar energy’s heat and prevent it from escaping. Of course, no giant glass roof hovers over planet Earth. But gases in the atmosphere do act in much the same way (Figure 18-6). When these gases are scarce, a considerable amount of solar energy is able to radiate off Earth’s surface back into the coldness of space. When they are abundant, however, they produce an atmosphere that absorbs or “traps” this same heat, resulting in a warming atmosphere. The gases that accomplish this are called greenhouse gases and the over-all process is referred to as the greenhouse effect.

Following are two of the primary contributors to global warming:

bulletEffects of the Industrial Revolution: Carbon dioxide (CO2) is the most prolific greenhouse gas. Although it’s a naturally occurring substance, substantial quantities of it are released to the atmosphere when fossil fuels, wood, and other organic matter are burned. Increased fuel con-sumption, especially as regards to fossil fuels, has been a hallmark of the Industrial Revolution. Before it began, the carbon dioxide content of the atmosphere measured about 274 parts per million (ppm). By the beginning of the present century, that number had risen to more than 360 ppm. Because global consumption of fossil fuels continues to rise, one can only expect increasing levels of greenhouse gases in the atmosphere, and with them the likelihood of increasing temperatures.

Emissions vary geographically. Because economic development and fuel consumption go hand-in-hand, understandably developed nations generate a much greater portion of annual emissions than do developing ones. And because the United States is the world leader in fossil fuel consumption (see Chapter 16), it makes sense that it also leads the world in greenhouse gas emission. During the 20th Century, the U.S. was responsible for an estimated 30.3 percent of global carbon dioxide emissions. Europe accounted for another 27.7 percent and the lands of the former Soviet Union another 13.7 percent

bulletEffects of deforestation: This era of increased fuel consumption has been complemented by a general process of deforestation — first in Eurasia, then in North America, and now in the tropical rainforest areas. Trees take in carbon dioxide from the atmosphere and give off oxygen. Thus, when trees are cut and consumed, they are no longer available to effect this exchange. And if they are burned, they emit the CO2 stored in them, increasing the atmospheric store of that gas. Experts disagree about the impact of the current decline of tropical rainforest on global atmospheric balance, but the majority opinion is that its contribution to the greenhouse equation is measurable, if not significant.

Winners and losers

If you live in an area that experiences a cold winter, then you may be excused for thinking that global warming can’t be all bad. If continued increase in global warming comes to pass, then clearly some lands will benefit. For example, large parts of Canada and Siberia that are now too cold for agriculture are likely to become productive land.

But mathematical models predict that large, productive areas in the middle latitudes will dry up and become desert. Clearly, sea level will rise, resulting in coastal inundation and an overall decrease in land available for settlement. And with that will come salt-water intrusion of neighboring aquifers, resulting in an overall decline in the global supply of potable water. For these sorts of reasons, most models forecast more losers than winners should the warming trend continue. And that is likely given continued and growing consumption of fossil fuels.

Taking on the Challenges of Tomorrow

This chapter began by describing environmental events in Chesapeake Bay in terms of its connections to a much broader geographical expanse. In a manner of speaking, the same applies to you. Wherever you live, you are part of an environment that, by virtue of dynamic mechanisms, is connected to other places that may be miles away or next-door. While the results may affect you, you also have the capacity to effect results. Specifically, as citizens of a democracy, you have the opportunity to participate in decision-making that can effect at varying scales the quality of the world in which you live. Following are two examples that U.S. citizens have the opportunity to become geographically involved in.


Some 19 million barrels of petroleum are consumed in the United States each and every day, and more than half of them are imported. That kind of consumption scenario — particularly the reliance on foreign sources of oil — makes a strong argument for tapping domestic oil reserves to the fullest. But what if an area of proven potential coincides with a pristine wildlife reserve? Americans love their petroleum, but they also champion wildlife and wilderness. Can we have it both ways? Is drilling compatible with wildlife? Should it be prohibited in certain areas? Or should our need for oil dictate that we go ahead and drill wherever we can as long as we make an honest effort to protect the environment as best we can?

These questions are at the center of the debate concerning the Arctic National Wildlife Refuge (ANWR), a South Carolina-sized area in Alaska’s extreme northeast corner (Figure 18-7). The same Congressional Act that created the Refuge’s present boundary also designated 1.5 million acres of it along the coastal plain as a potential future site for oil exploration. That area is now estimated to contain anywhere between 4 and 16 billion barrels of oil (depending on whose data you consult), although the amount that can be profitably recovered is probably no more than 6 billion barrels. That figure turns out to be less than a year’s worth of annual U.S. petroleum consumption.

The zone with the greatest oil-producing potential lies within the principal calving area of the porcupine caribou, whose annual migration brings a herd of some 130,000 members to the coastal plain each summer. Numerous other species frequent the area for all or part of the year — after all, it is a National Wildlife Refuge. Debate rages concerning the effects of drilling (together with attendant construction and road building) on wildlife and whether or not the productive lifetime of the oil reserve (perhaps 40 years) is worth the risk. Ultimately, your elected representatives will make the decision.

Garbage and NIMBY

At the end of the day you take out the garbage. But where does it go? Or where should it go? A popular refrain is NIMBY — not in my back yard. “Put it somewhere, but not next to me.”

Refuse is very geographical on at least two accounts. First, a direct relationship exists between the geography of wealth and the geography of garbage. That is, the more affluent the society, the greater the amount and durability of its garbage. Because the United States is the world’s most developed country, it should come as no surprise that it ranks as the world leader in garbage production, whether measured nationally or per capita.

Second, garbage has got to go somewhere. But where? Landfills and incineration are the most popular responses, but both are susceptible to dynamic mechanisms — percolating water in the case of landfills, and wind as regards incinerators. Nobody wants it in their backyard, but increasingly the cities and counties that generate it are being forced to dispose of it somewhere within their own jurisdictions, as opposed, say, to empty lands far away. And once again, the question of “Where?” will be answered by public officials that one hopes are elected by and responsive to a geographically savvy citizenry.

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