n.

1. The circumstances or conditions that surround one; surroundings.
2. The totality of circumstances surrounding an organism or group of organisms, especially:
   1. The combination of external physical conditions that affect and influence the growth, development, and survival of organisms: “We shall never understand the natural environment until we see it as a living organism” (Paul Brooks).
   2. The complex of social and cultural conditions affecting the nature of an individual or community.
3. Computer Science.
   1. The entire set of conditions under which one operates a computer, as it relates to the hardware, operating platform, or operating system.
   2. An area of a computer's memory used by the operating system and some programs to store certain variables to which they need frequent access.

The sum of all external factors, both biotic (living) and abiotic (nonliving), to which an organism is exposed. Biotic factors include influences by members of the same and other species on the development and survival of the individual. Primary abiotic factors are light, temperature, water, atmospheric gases, and ionizing radiation, influencing the form and function of the individual.

For each environmental factor, an organism has a tolerance range, in which it is able to survive. The intercept of these ranges constitutes the ecological niche of the organism. Different individuals or species have different tolerance ranges for particular environmental factors—this variation represents the adaptation of the organism to its environment. The ability of an organism to modify its tolerance of certain environmental factors in response to a change in them represents the plasticity of that organism. Alterations in environmental tolerance are termed acclimation. Exposure to environmental conditions at the limit of an individual's tolerance range represents environmental stress. See also Adaptation (biology); Ecology; Physiological ecology (animal); Physiological ecology (plant).

Abiotic factors

The spectrum of electromagnetic radiation reaching the Earth's surface is determined by the absorptive properties of the atmosphere. Biologically, the most important spectral range is 300–800 nanometers, incorporating ultraviolet, visible, and infrared radiation. Visible light provides the energy source for most forms of life. Light absorbed by pigment molecules (chlorophylls, carotenoids, and phycobilins) is converted into chemical energy through photosynthesis. Light availability is especially important in determining the distribution of plants. Photosynthetic organisms can exist within a wide range of light intensities. Full sunlight in the tropics is around 2000 μmol photons · m⁻² · s⁻¹. Photosynthetic organisms have survived in locations where the mean light is as low as 0.005% of this value. See also Insolation; Photosynthesis; Solar radiation.

In addition to providing energy, light is important in providing an organism with information about its surroundings. The human eye, for example, is able to respond to wavelengths of light between 400 and 700 nm—the visible range. Within this range, sensitivity is greatest in the green part of the spectrum. This is the portion of the spectrum that plants absorb least, and so is the principal part of the spectrum to be reflected.

Temporal variation in light also provides an important stimulus. Life forms from bacteria upward are able to detect and respond to daily light fluctuations. Such a response may be directly controlled by the presence or absence of light (diurnal rhythms) or may persist when the variation in light is removed (circadian rhythms). In the latter case, regulation is through an internal molecular clock, which is able to predict the daily cycle. Such circadian clocks are normally reset by light on a daily basis. Processes controlled by circadian clocks range from the molecular (gene expression) to the behavioral (for example, sleep patterns in animals or leaf movements in plants). See also Photoperiodism.

Ultraviolet radiation has the ability to break chemical bonds and so may lead to damage to proteins, lipids, and nucleic acids. Damage to DNA may result in genetic mutations. The ozone layer in the stratosphere is responsible for absorbing a large proportion of ultraviolet radiation reaching the outer atmosphere. As ozone is destroyed by the action of pollutants such as chloroflurocarbons, the proportion of ultraviolet radiation reaching the surface of the Earth rises.

Water is ubiquitous in living systems, as the universal solvent for life, and is essential for biological activity. Many organisms have evolved the ability to survive prolonged periods in the total absence of water, but this is achieved only through the maintenance of an inactive state. Water availability remains a primary environmental factor limiting survival on land. Primitive land organisms possess little or no ability to conserve water within their cells and are termed poikilohydric. Examples include amphibians and primitive plants such as most mosses and liverworts. These are confined to places where water is in plentiful supply or they must be able to tolerate periods of desiccation. Lichens can survive total water loss and rapidly regain activity upon rewetting. Such organisms must be able to minimize the damage caused to cellular structures when water is lost. Dehydration causes irreversible damage to membranes and proteins. This damage can be prevented by the accumulation of protective molecules termed compatible solutes.

Homeohydric organisms possess a waterproof layer that restricts the loss of water from the cells. Such waterproofing is never absolute, as there is still a requirement to exchange gas molecules and to absorb organic or mineral nutrients through a water phase. Water conservation allows organisms to live in environments in which the water supply is extremely low. In extremely arid environments, behavioral adaptations may allow the water loss to be minimized. Animals may be nocturnal, emerging when temperatures are lower and hence evaporation minimized. Cacti possess a form of photosynthesis, crassulacean acid metabolism (CAM), that allows them to separate gas exchange and light capture. See also Ground-water hydrology; Osmoregulatory mechanisms; Plant-water relations.

Temperature is a determinant of survival in two ways: (1) as temperatures decrease, the movement of molecules slows and the rate of chemical reactions declines; (2) temperature determines the physical state of water.

The slowing of metabolic activity at low temperatures is illustrated in reptiles. Such poikilothermic animals, unable to maintain their internal temperature, are typically inactive in the cold of morning. They bask in the sun to increase their body temperature and so become active. High temperatures will cause the three-dimensional structure of proteins to break down, preventing the organisms from functioning. Organisms adapted to extremely high temperatures need more rigid proteins that maintain their structure. Temperature also affects the behavior of cell membranes, made up of lipids and proteins in a liquid crystalline state. At low temperatures, the membrane structure becomes rigid and liable to break. At high temperatures, it becomes too fluid and again liable to disintegrate. In adapting to different temperatures, organisms alter the composition of the lipids in their membranes, whose melting temperature is thereby changed. This outcome also applies to storage lipids. Hence, cold-water fish are a useful source of oils, whereas mammals, with their higher body temperature, contain fats. The effect of temperature on membranes is thought to be a key factor determining the temperature range that an organism is able to survive.

The effect of temperature on the physical state of water is essential to determining the availability of that water to organisms. Poikilothermic organisms may find that the water in their cells begins to freeze at low temperatures. Certain species can survive total freezing through the prevention of ice crystal formation altogether which would otherwise damage cellular structures. To survive low temperatures, cells must be able to survive desiccation, and so low-temperature tolerance involves the formation of compatible solutes. High temperatures increase the rate of evaporation of water. Hence, where water supply is limiting, an organism's ability to survive high temperatures is impaired.

Mammals and birds, homeothermic organisms, are able to regulate their internal temperature, limiting the effects of external temperature variations. Temperature still acts as an environmental constraint in such organisms, however. Cooling is achieved through sweating and hence loss of water. Heat is produced through the metabolism of food, and hence survival in cold climates requires a high metabolic rate. See also Cryptobiosis.

The atmosphere on Earth is thought to be determined to a large extent by the presence of life. At the same time, organisms have evolved to survive in the atmosphere as it is. The atmospheric constitutents with the most direct biological importance are oxygen (O₂) and carbon dioxide (CO₂). Oxygen makes up approximately 20% of the atmosphere and is due to the occurrence of oxygenic photosynthesis. This process involves the simultaneous uptake of CO₂ to make sugars. Aerobic respiration involves the reverse of this process, the release of CO₂ and the uptake of O₂ to form water. Hence, the current atmosphere represents the balance of previous biological activity. For most terrestrial organisms, neither CO₂ nor O₂ is limiting in the atmosphere; however, the need to get either or both of these gases to cells may represent a limitation on size or on the ability to tolerate water stress. Limitation of either gas may be important in aquatic environments, where the concentration of each is significantly lower.

Nitrogen is also required by all organisms but cannot be used by most in the gaseous form. Nitrogen fixation, the conversion of N₂ gas into a biologically useful form, occurs in some species of bacteria and cyanobacteria or may be caused by lightning.

Atmospheric gases are important in determining the climate and the light environment. Absorption of electromagnetic radiation by the atmosphere determines the spectrum of light reaching the Earth's surface. Absorption and reflectance of infrared radiation by greenhouse gases such as CO₂ and water vapor regulate temperature. See also Photorespiration; Respiration.

Among other environmental factors determining the range and distribution and form of organisms are mechanical stimuli such as wind or water movement, and the presence of metals, inorganic nutrients, and toxins in the air, soil, or food.

Biotic factors

The biotic environment of an individual is made up of members of the same or other species. Intraspecific interactions involve the need to breed with other individuals, to gain protection through living in a group, and to compete for resources such as food, light, nutrients, and space. The optimal population density depends on the availability of resources and on the behavior, size, and structure of the organism. Interspecific interactions may also be positive or negative. For example, symbiotic relationships involve the mutual benefit of the individuals involved, whereas competition for resources is deleterious to both. Although predation exerts a negative influence on the population as a whole, the success of an individual may be enhanced if a predator removes one of its conspecific competitors.

Humans alter their environment in ways that exceed the impact of all other organisms. For example, the release of greenhouse gases into the atmosphere contributes to climate alterations over the entire planet. This in turn has impacts on the distribution of all other species. The release of pollutants into the environment brings organisms into contact with stresses to which they were not previously exposed. This causes the evolution of new varieties, eventually perhaps new species, adapted to the polluted environments. See also Air pollution; Biosphere; Human ecology; Water pollution.

For any given organism, it is often possible to identify a factor in the environment that limits survival and growth. The limiting factor may change through time. Such a change may cause the organism to be at the limit of or outside its tolerance range for that or another environmental factor. In such cases, the organism is said to suffer stress. If the stress to which an individual is exposed is extreme, it may result in irreversible damage and death. Exposure to moderate stress, however, results in a period of acclimation within the organism that allows it to adjust to the new conditions. Organisms exposed gradually to new conditions usually have a higher chance of survival than those exposed suddenly. See also Population ecology.

Where a particular environmental factor (or combination of factors) dominates the growth and development of organisms, it is often found that the adaptations and gross features of the landscape will be the same, even when the actual species are different. Thus, mediterranean vegetation is found not only around the Mediterranean Sea but also in California and South Africa, where the conditions of hot dry summers and warm wet winters occur. Regions with similar environmental conditions are classed as biomes. The occurrence of such global vegetation types clearly illustrates the role played by the environment in determining the form and function of individual species.

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A particular configuration of hardware or software. "The environment" refers to a hardware platform and the operating system that is used in it. A programming environment would include the compiler and associated development tools.

Environment is used in other ways to express a type of configuration, such as a networking environment, database environment, transaction processing environment, batch environment, interactive environment and so on. See platform.

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noun

1. Existing surroundings that affect an activity: circumstance (often used in plural), condition (used in plural). Slang scene. See be.
2. A surrounding area: environs, locale, locality, neighborhood, precinct (used in plural), surroundings, vicinity. See near/far/distance, place.
3. The totality of surrounding conditions and circumstances affecting growth or development: ambiance, atmosphere, climate, medium, milieu, mise en scène, surroundings, world. See be, limited/unlimited, place.

(envī′rən-ment, en-vī′urn-ment)
n

The aggregate of all the external conditions and influences affecting the life and development of an organism.

Prior to the late 1960s, state common law doctrines comprised the primary legal instruments for resolving environmental disputes. The torts of nuisance, and to a lesser extent trespass, were the most important of these common law remedies. Broad controls on pollution were upheld only to abate public nuisances (Georgia v. Tennessee Copper Co., 1907).

In the late 1960s and early 1970s, increasing public concern about the environment and the inability of traditional common law doctrines to satisfactorily resolve ecological problems led to the congressional enactment of both comprehensive and specific federal environmental statutes focused on the protection of air, water, land, natural resources, and species. The Supreme Court has molded the substantive content of these environmental laws primarily through constitutional and administrative law doctrines dealing with their legitimacy, meaning, and implementation, and the law of remedies.

The Commerce Clause

Congress had made few attempts to impose national conservation or environmental standards on the states prior to the late 1960s. Federal legislation was permissible only if based on a specific grant of power to Congress; and it was uncertain whether the general power of the federal government over interstate commerce was a sufficient basis for national environmental controls. The Court's post–New Deal Commerce Clause decisions, however, generally affirmed the power of Congress to regulate commerce and repudiated the Tenth Amendment as an independent limit on federal regulatory authority. These decisions helped pave the way for the extensive federal regulatory programs that Congress would pass during the late 1960s and early 1970s.

The Commerce Clause prohibits states from enacting laws that burden interstate commerce. The Court has repeatedly interpreted the Commerce Clause to invalidate state efforts to regulate disposal of waste generated in other states, holding as per se invalid any restriction that facially discriminates against interstate commerce in its regulation of waste from other states—even where the restriction was motivated by genuine environmental concern (Philadelphia v. New Jersey, 1978). Restrictions that are not facially discriminatory are assessed to determine if their legitimate local benefits outweigh the burden imposed on interstate commerce, and whether any less burdensome alternatives exist that would accomplish the state's goal.

In Pennsylvania v. Union Gas Co. (1989), the Court held Congress was authorized under the Commerce Clause to waive a state's sovereign immunity from suit. However, in Seminole Tribe of Florida v. Florida (1996), the Court overruled the precedent established in Union Gas and held that Congress does not have the authority to abrogate state immunity under the Commerce Clause. As a result of the Court's reversal, states are now able under the Eleventh Amendment to avoid liability for response costs under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), commonly known as Superfund, in contribution actions by private parties—despite the fact that CERCLA imposes strict, joint, and several liability for the costs of cleaning up releases of hazardous substances dumped by companies. Eleventh Amendment immunity, however, does not extend to counties and municipalities.

The Takings Clause

According to the Fifth Amendment's Takings Clause, “private property may [not] be taken for public use without just compensation.” Until the 1980s, the Supreme Court accepted extensive restrictions on the use of property. So long as the owner retained some reasonable use of his or her property, considered within the context of the overall impact of a regulatory scheme, there was no constitutional violation and thus no need for compensation (*Penn Central Transportation Co. v. New York, 1978). In such circumstances, the Court found that property owners were merely being asked to share the burdens, as well as the benefits, of government (Agins v. City of Tibouron, 1980).

More recently, the Court has shown a greater willingness to apply the Takings Clause to regulatory action (see Regulatory Taking). While restrictions on activities analogous to a nuisance are still considered appropriate exercises of police power (Keystone Bituminous Coal Association v. DeBenedictis, 1987), other restrictions for general land use control or aesthetics now receive more careful scrutiny. Under Lucas v. South Carolina Coastal Council (1992), a regulation that deprives a property owner of “all economically viable use” of private property constitutes a per se regulatory taking under the Fifth and Fourteenth Amendments unless nuisance or property law principles that existed when the owner acquired the land make the use prohibitable. The Court has further held that a property owner is not barred from pursuing a takings claim merely because he or she acquired title to the property after a regulation's effective date (Palazzolo v. Rhode Island, 2001).

The Tenth Amendment's Anti‐Commandeering Principle

Until the early 1990s, the Tenth Amendment's reservation to the states of powers not constitutionally delegated to the federal government, existed as a potential, though somewhat unlikely, limitation on Congress's authority to pass federal environmental laws. However, while past decisions of the Court have repeatedly upheld Congress's authority to force states to comply with federal regulatory standards, two decisions have halted this trend. In New York v. United States (1991) and Printz v. United States (1997), the Court held that the Tenth Amendment prohibits Congress from “commandeering” the states in the implementation of federal regulatory programs. Nevertheless, under the authority granted to it by the Spending Clause, Congress can induce states to comply with federal environmental regulations by conditioning the receipt of federal funds on their compliance.

Federal Preemption of State and Local Laws

Under the Constitution, federal law is supreme and supplants any inconsistent state or local laws. This doctrine of federal preemption has led the Court to declare state and local laws invalid that interfere with comprehensive federal environmental laws and regulations (Burbank v. Lockheed Air Terminal, 1973). Additionally, while many federal environmental statutes contain specific “non‐preemption” provisions that authorize states to enact complementary laws, the Court has narrowly interpreted these provisions, and often restricted states from applying state statutes and state common law in areas where there are comprehensive federal laws and regulations (Exxon Corp. v. Hunt, 1986; International Paper Co. v. Ouillette, 1987).

Standing to Sue

Standing to sue has assumed great practical importance because many important environmental actions are brought by public interest groups and nongovernmental organizations (NGOs), seeking to vindicate public rights established by environmental statutes. Under Article III of the Constitution, courts decide “cases and controversies” and are not expressly authorized to entertain an actio popularis in which the plaintiff seeks to uphold community rights without suffering personal injury. However, in the early 1970s, the Court adopted a very generous view of standing. The Court held that while a mere allegation of an interest in the subject matter of a dispute, as distinct from a showing of injury, did not confer standing, shared injuries to environmental and aesthetic interests were nonetheless cognizable for purposes of standing (Sierra Club v. Morton, 1972). In United States v. Students Challenging Regulatory Agency Procedures (1973), the Court further expanded standing to include prospective injuries traceable to governmental actions by “an attenuated line of causation.” However, the Court began tightening standing requirements in the 1990s emphasizing the need for “injury in fact.”

The Court's jurisprudence when dealing with federal statutes providing for citizen standing to implement environmental mandates has not been consistent. In Lujan v. National Wildlife Federation (1990) and Lujan v. Defenders of Wildlife (1992), the Court denied standing to those who spent recreation time in the vicinity of a natural area, or planned on visiting countries where certain specie were endangered. However, in Friends of the Earth, Inc v. Laidlaw Environmental Services (TOC), Inc. (2000), the Court recognized standing for citizen plaintiffs to pursue civil penalties for ongoing violations of permits issued under the Clean Water Act. The aesthetic and recreational concerns of the plaintiffs gave them standing even where they were unable to demonstrate that a defendant's permit violations caused actual harm to the environment. The Court has also held that Congress has the power to create “qui tam” actions, by which citizens can sue to obtain damages on behalf of the United States—though in such actions the plaintiff receives the money—in order to recover damages done to the United States (Vermont Agency of Natural Resources v. United States, 2000).

Remedies

When a statute is breached, the Supreme Court's decisions on whether or not to grant an injunction to stop the impugned action lack uniformity, and are perhaps best explained by how the Court perceives the objective of the statute. In TVA v. Hill (1978), the Court granted an injunction against the completion of a dam, on which multimillions had already been expended, because the dam threatened extinction of a tiny fish protected under the Endangered Species Act (ESA). The Court reasoned that the protection of endangered species was the overriding objective of the ESA and could not be weakened by concerns of equity or economics. By contrast, in Weinberger v. Romero Barcelo (1982), the Navy failed to obtain a permit under the Clean Water Act (CWA), but the Court declined to grant an injunction, and gave the Navy time to obtain a permit because any delay occasioned in doing so did not compromise the objectives of the CWA. The principle established in Weinberger was followed in Amoco Production Co. v. Village of Gamble (1987), which involved a procedural infraction of the controlling statutes rather than a substantive environmental injury.

Judicial Review of Agency Actions

The New Deal Congress created a host of new federal regulatory agencies and endowed them with very broad powers through open‐ended statutes. While the Court might ensure that agencies acted within the bounds of their statutory powers, those bounds were so wide as to give agencies vast discretionary powers, creating the threat of arbitrary power. The Supreme Court voided the National Industrial Recovery Act as an unconstitutional delegation of legislative power to agencies (Schechter Poultry Corp. v. United States, 1935). However, federal regulatory invalidations by the Court on non‐delegation grounds have not occurred since.

In Whitman v. American Trucking Association, Inc. (2001), the Court of Appeals for the District of Columbia ruled that EPA had promulgated ozone standards pursuant to a standardless delegation of lawmaking authority in violation of the non‐delegation doctrine. However, the Supreme Court overturned the circuit court's decision and held that Congress had in fact provided an “intelligible principle” limiting the EPA's discretion.

With the enactment of the Administrative Procedure Act in 1946, the Court confronted the question of what standards to employ in the judicial review of the discretionary powers conferred by Congress on federal agencies. Early Supreme Court cases indicated that the Court would take a “hard look” at agency attempts to implement environmental laws (Citizens to Preserve Overton Park v. Volpe, 1971). Later, however, the Court limited its review and has accorded broad discretionary powers to agencies. Under the doctrine announced by the Court in Chevron U.S.A., Inc. v. Natural Resources Defense Council, Inc. (1984), a court's independent task in interpreting a regulatory statute extends only so far as deciding whether Congress has directly addressed the precise question at issue. If the court finds an unambiguously expressed congressional intent on the question, that intent controls. However, if the statute is silent or ambiguous with respect to the specific issue further judicial inquiry is limited to whether the agency's interpretation is based on a permissible construction of the statute.

In Solid Waste Agency of Northern Cook County v. United States Army Corps of Engineers (2001) the Court addressed the question of whether the Corp had properly interpreted the jurisdictional scope of the Clean Water Act (CWA) to extend to isolated, non‐navigable intrastate wetlands used by migratory birds. In rejecting the Corp's regulatory interpretation, the Court noted that the CWA expressly authorized the Corp to regulate the activity in question only to “navigable waters.” The Court based its denial of the Corp's request for agency deference under Chevron U.S.A., Inc. v. Natural Resources Defense Council, Inc. (1984) on the grounds that enforcement of the regulatory interpretation would significantly impinge upon the states' traditional power over land and water use. In Whitman the Court held that unless explicitly granted authority to do so by the enabling statute the Environmental Protection Agency is not permitted to consider implementation costs in setting new standards.

Conclusion

For approximately ten years (1970–1980), the great surge of environmental legislation and regulation controlling pollution control and protecting natural resources was generally welcomed and even expansively interpreted by the Court. Since the early 1990’s, however, the Court has been more sensitive to constitutional law limitations, and constructed environmental statutes more strictly, while exercising significant restraint in reviewing agency decisions. Nonetheless, these later decisions have been pragmatic rather than doctrinally dogmatic and the extent to which the Court is intentionally charting a new course for environmental law generally remain unclear.

See also Property Rights.

Bibliography

• Bradley C. Karkkainen, Plain Meaning: Justice Scalia's Jurisprudence of Strict Statutory Construction, Harvard Journal of Law and Public Policy 17 (1994): 401–477.
• William H. Rodgers, Environmental Law, 2d ed. (1994; exp. ed., 1999).
• Richard B. Stewart, A New Generation of Environmental Regulation, Capital University Law Review 29 (2001): 21–182

— Martin H. Belsky

The surroundings. The natural environment includes the nature of the living space (sea or land, soil or water), the chemical constituents and physical properties of the living space, the climate, and the assortment of other organisms present. The phenomenal environment includes changes and modifications of the natural environment made by man. The effect of the environment on man is modified, in part, by the way the environment is perceived, and human geographers distinguish this—the subjective environment—from the objective environment—the real world as it is. The objective environment is of less importance to the individual than his or her perceived image of it. A division may also be made between the built environment and the social environment which is made up of the various fields of economic, social, and political interactions.

Simmons (Geography 85) integrates the sub-categories above by describing the ‘many layers’ of environment as ‘something more like a double helix of mind and matter, whose gyre seems to be ever-widening, spinning unpredictable combinations of society and economy into the main space, but also throwing off minor gyres, which might be short-lived but might equally be the germs of the main arms of the future…at any one moment we can slice through the whole and think about the layers that are discernible to our minds, conscious though we are that to try to freeze such processes inevitably robs them of some of their life and that, like Peer Gynt, the existence, let alone the discovery, of a heart is a bit unlikely.’

[Ge]

The total surroundings in which a human society finds itself; all the factors that in any way affect its mode of life.

In a sporting context, the surroundings in which a sport takes place. It is the sum of the outside influences on the athletes, including all the physical conditions, the surrounding buildings, weather, and the audience. This external environment may also include the social or cultural conditions. Other types of environment include the intracellular environment, consisting of the conditions within a cell; the intercellular environment, composed of tissue fluid between cells; and the prenatal environment, which is the immediate surroundings of an embryo or foetus.

To reflect squarely upon the environment of early modern Europe, one needs to adopt a perspective shaped by the rise of environmentalism, a way of thinking that gained prominence in the 1960s and 1970s. This philosophy calls for a recognition of the intrinsic value of nature and a rejection of the view that humans are somehow outside of nature. Environmental historians are revisiting many of the issues familiar to historians of the early modern age through the perspective of environmentalism, balancing the traditional attention given to people and society with a focus on the environment itself—the natural and the man-made.

Early modern Europeans thought about the world they lived in. Most earned a precarious living directly from the land, and a minority had the leisure to reflect on the links between their society and the milieus it depended upon. Some worried about perceived changes to the natural world surrounding them, while others eagerly sought ways to improve or better control the features most relevant to economic or social life. Others immersed themselves in the study of nature and reflected upon the place of humankind in the universe. Voyages to very different lands, advances in science and technology, political clashes, and the sheer intellectual dynamism of the period from the Renaissance to the Enlightenment all contributed to the transformation of European thinking about the environment.

Early modern Europeans drained wetlands, tried to improve agricultural practices, and coped with the pollution associated with dense populations. They discovered new resources and worried about the depletion of forests. They sailed to the tropics and mapped their own lands, planted gardens, and fought diseases. All of this can be studied in the long-established fields of history: economic, political, social, and cultural. Other aspects of the period's environment can be explored in works on early modern agriculture and fisheries, mining, public works, urbanism, forestry, science, and medicine.

Not all environmental historians adopt the most rigorous tenets of environmentalism. Some simply share an attitude of respect for nature, perhaps founded on a new awareness of the intricacies and the fragility of ecosystems. Others remain attached to the deeply rooted concept of human stewardship of nature or, more uniquely, proclaim the hybrid character of much of the world around us. Many, in the end, cling to the centrality of human beings to life and, therefore, to history. Yet, however amenable it may be to a variety of interpretations, environmentalism represents an elemental reformulation of an enduring inquiry into the divide between nature and culture. It has led to a genuine broadening of historical research. The following sketch of the thematic and methodological wealth of early modern environmental history is structured around the three poles of the human experience of nature: first, its many and changing representations; second, the rich bodies of knowledge it has fostered; and third, the broad range of institutions and practices developed to guide our daily interactions with the natural world.

Environmental History and Representations of Nature

The evolution of ideas about nature was first studied through textual analyses before cultural historians expanded this process to a quest for meaningful signs in countless objects. Long before the rise of environmentalism, historians of literature were drawn to the many meanings of the word nature and, distinctly, the quasi-universal explanatory power that it acquired in the eighteenth century. The early modern period soon emerged as a key stage in the evolution of European attitudes toward the natural world. The Renaissance and the scientific revolution advanced more materialistic, less religious, and certainly less magical interpretations of natural phenomena, even before enhancing human agency in these matters. The Enlightenment furthered this positivist trend, readily extending its faith in the perfectibility of humans to society and to its surroundings, while new articulations of private and public interests prepared the way for radical changes in European economies. At the same time, an aesthetic revolution, precursor to the Romantic movement, encouraged a less instrumental, yet still anthropocentric, appreciation of nature. Unsurprisingly, studies of the impact of these key cultural currents upon the ways in which Europeans conceived of their place in the environment reflect regional disparities in their timing and relative strength.

Although for most authors the natural world generally remained just a background, incidental to or even deliberately drawn to advance a thesis, the wealth of early modern literature permits some wide-ranging inquiries. Asking new questions from well-known texts has, for example, identified a great shift in the significance of mountains to early modern society, from repulsive poles to objects of curiosity and, eventually, to a veritable cult rooted in a new appreciation of the sublime. In turn, mountains lent themselves to speculations on the relationship of humans with what must pass for, in a European context, wild spaces. Similar investigations enriched the history of many sciences, including ecology, and influential revisions have turned to social groups often ignored by scholars, revealing, most notably, the pertinence of gender to environmental history.

Students of literature have also invigorated historical research through their probes of the autonomy of a text from its surroundings and the multiplicity of its meanings. This late-twentieth-century trend allows for more critical readings of references to the cultural processes that made sense of the features of a natural milieu for its inhabitants. For instance, considerable work (enriched through collaboration with scientists) has taken place in areas such as the history of natural disasters and of animals, where written records proved singularly opaque because of their moral and exemplary style. More generally, the recent swell of cultural studies also irresistibly expanded the definition of the records likely to expose the mental images familiar to each society. A striking range of cultural manifestations and objects may now testify to the many meanings of various environments, be they obviously man-made, like a garden, or apparently more natural, like a lake, as lasting as a rural landscape or as fleeting as a fair, as universal as bad weather or as singular as early modern tastes for monsters and fantastic lands. Environmental history has much to gain from this blossoming of cultural history since all societies tightly weave their "sites of memory" with their surroundings. Most notably, cultural history has carried the history of landscapes well beyond the social, economic, and agricultural mechanisms of their formation and evolution. It has also brought modes of perception other than the visual within the reach of investigations. Odors, sounds, and tastes now enrich our understanding of the clashes of modernity and tradition characteristic of early modern life, perhaps most evidently in the jumble of urban environments.

Detractors of this embrace of the cultural dimensions of all environments may regret a loss of the "natural," turned into one of the dimensions of human experience rather than a fundamental and unique component of human experience as well as a reality outside of it. Indeed, a cultural analysis tends to present even very natural phenomena as hybrids. Yet, this juxtaposition of the natural and the artificial is precisely what is of interest to many historians when they turn to early modern Europe, because its preindustrial societies remained highly dependent upon environmental conditions while steadily expanding the range of tools available to control their fate.

The ambiguity of early modern stances vis-à-vis nature is perhaps most evident within the context of the great transoceanic expansion that created a frontier of tremendous economic and intellectual importance. This surge of European power, be it associated with the exploitation of tropical islands or the creation of "neo-Europes" by settlers, their animals, their crops, and their parasites, thoroughly challenged perspectives upon nature and the place of humans within their environments. The inquisitive mind of the Enlightenment entertained a great range of interpretations, from highly simplistic schemas to a nascent grasp of the interrelatedness of natural phenomena. Indeed, a loose parallel may be drawn between these intercontinental ventures and recent forays of environmental historians into the similarly unpredictable field of cultural history. Just as the former eventually fostered more relative assessments of the links between social structures and environment, the latter are helping to wrench environmental history away from an overly "essentialist" penchant, most evident in many historical uses of geography and the field of climate history. Exposing the complexities, the vagaries, and the relative weight of the cultural and natural forces that shape identity has made it easier to resist the temptation to link identity and locale too tightly. This is important to the field of environmental history, never entirely free from the specter of determinism.

Interdisciplinary Approaches to Environmental History

The contribution of geographers to environmental history is more readily recognized than that of historians of literature. Indeed, it is fair to say that the key to the history of a region or a nation has repeatedly been sought in its geography.

The influence of the French Annales historical school is perhaps most telling in this regard. Starting after World War II, its many disciples were intent on expanding their investigations beyond the political and narrative history that had been common until then. They sought to show history in its social, economic, and geographical contexts by articulating the relationships between a society and its milieu around the concept of "possibilism," that is, suggesting that throughout history, communities strove to make the most of the possibilities offered by a natural milieu while at the same time respecting their own priorities.

The range of closely or loosely Annales-inspired studies of interest to environmental historians is remarkable, in spite of a recognizable rural bias that was perhaps most evident in the early years of this movement. Cities have found the researchers they deserved, ordinary as well as exceptional settings have been treated, and syntheses were not long in appearing. Countless communities, from modest villages to great composite units such as the Mediterranean basin, have been firmly inscribed within their natural parameters, especially with regard to local symbioses between economic practices and resources. Nevertheless, many environmental historians will regret that, in these theses, the significance of a milieu resides precisely in the "thickness" of its links to the socioeconomic structures that it harbored. Environmental features less related to a community and its survival are likely to receive little attention, and some significant fluctuations or even deteriorations of the natural systems surrounding it may remain hidden behind its adaptability.

Like studies of the Annales school, historical geographies of the early modern age may also be said at times to treat nature as a significant but passive background. Nonetheless, historically minded geographers continue to contribute to our knowledge of the evolution of urban and rural landscapes, the emergence of industrial clusters, the ever-changing map of commerce, patterns of land degradation or land reclamation, and so forth. Environmental historians will always profitably revisit such social and spatial arrangements, even if, in their call for a full recognition of the dynamics of a milieu, they choose to focus on the processes of greatest interest to them. They may, for instance, analyze the anthropization of a milieu, that is, the growing role played by humans in its evolution, or they may question its sustainability, seeking in effect a measure of the lasting power of the relationship between a society and its environment.

Many disciplines besides geography are contributing to the growth of environmental history. "Hard sciences," such as medicine, botany, zoology, and ecology, are helping to decipher the material traces of earlier environments. Their contributions are most welcome with regard to prehistoric or particularly long periods with a lack of written sources. However, historians of the early modern age are also learning to use the data provided by ever-sharper scientific tools, to make sense of pollen deposits, animal remains, traces of contaminants, climate fluctuations, epidemics, or, less dramatically, diets. From the social sciences, disciplines such as anthropology, ethnology, archaeology, sociology, or economics, all familiar with the conceptualization of networks and practices that are frequently connected with the environment, also inform many inquiries of an environmental and historical nature. Indeed, the border between environmental history and neighboring fields such as economic history or historical demography ought to remain porous. After all, many productions severely taxed a region's natural resources, and population levels often had a direct impact on European environments, notably in marginal regions. Historians of agriculture, technology, consumption patterns, the material world, military affairs, and many others have much to say about early modern landscapes.

Institutions and Practices

Because the early modern period is at the root of much of the institutional context of European life, the role played by various authorities in mediating the relations between rural or urban communities and their natural surroundings has, quite logically, attracted the attention of environmental historians. A first area of interest concerns the many regulations that anticipated the protection and conservation measures initiated in the twentieth century. Medieval and early modern controls of nuisances were intended to benefit human beings rather than the environment itself. Nonetheless, the range and coherence of the principles they invoked remain significant in the eyes of environmental historians. An array of edicts, intended to protect public health as well as property or the rights of corporate bodies, became law. In many different contexts across Europe, municipal, regional, or even royal powers reached deep into legal precedents to control the deeds of entrepreneurs. While never crafted to safeguard an environment for its own sake, these measures nonetheless tenaciously articulated its many values. Research in this area is often pursued within urban settings, a preference justified by the intricacies and intensities of the issues they raised and the records they left. Beyond the walls of cities, forests also receive considerable attention. Initial probes fueled a long polemic on the overexploitation and an eventual scarcity of wood before the age of coal. Thoughts then turned to the state's intrusions in the relations between these territories and surrounding villages, and soon to the multitude of functions played by forests in the lives of these communities.

Environmental historians also explore the rich world of public works, the early modern period marking an important step in the affirmation of the will of Europeans to restructure their environment. From the great designs of the Renaissance to the sustained eighteenth-century focus on movement and exchanges, from dams to enclosures to land reclamation initiatives, environmental historians are reworking a field familiar to students of engineering, architecture, institutions or, again, agriculture and technology. Their goal is to direct attention away from the heroes or even villains of these stories to the natural milieus where they competed, and their agendas are shaped by important regional distinctions in the timing and types of works undertaken.

Finally, major political landmarks often play a role in environmental histories. Most evidently, the great revolutions that concluded the early modern period were not without impact upon European environments, although it is now clear that in this area as in many others, continuities and changes are not easily sorted out. This truism simply recalls the fact that the early modern age was an age of transition. Then, as before, Europeans continued to reshape their environment without escaping its many imperatives. Yet their successes and failures are of particular interest to environmental historians because they prepared European societies for the radically more assertive attitudes of the nineteenth and twentieth centuries.

Bibliography

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Brimblecombe, Peter, and Christian Pfister, eds. The Silent Countdown: Essays in European Environmental History. Berlin, 1990.

Cosgrove, Denis E. The Palladian Landscape: Geographical Change and its Cultural Representations in Sixteenth-Century Italy. Leicester, U.K., 1993.

Corbin, Alain. The Foul and the Fragrant: Odor and the French Social Imagination. Cambridge, U.K., 1986; 1st French ed., 1982.

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Grove, Richard H. Green Imperialism: Colonial Expansion, Tropical Island Edens, and the Origins of Environmentalism, 1600–1860. Cambridge, U.K., 1995.

Johns, Alessa. ed. Dreadful Visitations: Confronting Natural Catastrophe in the Age of Enlightenment. New York, 1999.

Kjaergaard, Thorkild. The Danish Revolution, 1500–1800: An Ecohistorical Interpretation. Cambridge, U.K., 1994; 1st Danish ed., 1991.

Merchant, Carolyn. The Death of Nature: Women, Ecology, and the Scientific Revolution. San Francisco, 1980.

Schama, Simon. Landscape and Memory. New York, 1996.

Smout, T. Christopher. Nature Contested: Environmental History in Scotland and Northern England since 1600. Edinburgh, 2000.

Thomas, Keith V. Man and the Natural World: Changing Attitudes in England, 1500–1800. New York, 1983.

Watkins, Charles. ed. European Woods and Forests Studies in Cultural History. New York, 1998.

Worster, Donald. Nature's Economy: A History of Ecological Ideas. Cambridge, U.K., 1994; 1st ed., 1977.

Zupko, Ronald, and Robert Laures. Straws in the Wind: Medieval Urban Environmental Law, The Case of Northern Italy. Boulder, 1996.

Further references will be found through the web sites of the European Society for Environmental History (ESEH) and the American Society for Environmental History (ASEH).

—PIERRE CLAUDE REYNARD

People farm Earth's biosphere to produce food for the sustenance of the human species. Thus, human food systems are part of Earth's complex ecological systems. All of these systems begin with interactions with the sun, which is the ultimate energy source. Sunlight enables plants to manufacture carbohydrates through the process of photosynthesis, in which chlorophyll converts sunlight into chemical energy, synthesizing organic compounds from inorganic compounds. Plants take carbon dioxide, water, and inorganic elements for this conversion process from the air and soil. Humans obtain their nourishment directly from plants, or from animals nourished directly or indirectly by plants. Thus humans ultimately rely on air, soil, water, and sunlight for sustenance.

Humankind has a strong interest in not fouling the environment, as contaminants in the air, water, or soil can end up in the plants that people or their food animals eat. An extreme example of such contamination was the 1986 Chernobyl nuclear power plant explosion in the Ukraine. Although hundreds of thousands of people fled the area that was immediately affected by the explosion, as many as three million people still live in contaminated areas in this farming region. As a result of the ecological devastation from this disaster, enormous amounts of money have been and continue to be spent in an effort to relocate communities and decontaminate the rich farmland.

Environmental Progress and Challenges for Agriculture

Agriculture and food systems play a major role in the ecological health of Earth, including the number and diversity of life forms that inhabit it. Half of the land mass of the United States, excluding Alaska, is privately owned crop, pasture, and range land. As noted in America's Private Lands: A Geography of Hope, the farmers and ranchers who manage these 907 million acres play a key role in maintaining the abundance of these natural resources for present and future generations.

Driven by changing economic and demographic trends, agriculture has become more consolidated, intensified, and specialized. At the same time, there has been increased scientific and public awareness of the detrimental environmental impacts of some agricultural activities, such as the problem of soil erosion. However, by adopting new practices and working with government conservation cost-share and technical-assistance programs, farmers are significantly reducing many of those detrimental impacts. Although soil erosion threatens the future productivity of 29 percent of cultivated acres in the United States, farmers reduced soil erosion on U.S. farmland by 38 percent from 1982 to 1997. Much of this reduction was accomplished by changing from traditional plowing to no-till or minimum-tillage systems that disturb the soil less and leave a protective layer of crop residue. The United States Department of Agriculture (USDA) programs, such as the Conservation Reserve Program and Wetland Reserve Program, take marginal or fragile croplands out of production and assist landowners with plantings or practices to buffer stream banks and enhance wildlife habitat. Wetlands, including productive yet fragile ecosystems like prairie potholes, have been restored, and the nesting success of ducks has increased.

Many livestock farmers and ranchers have improved grazing management to benefit livestock productivity as well as soil, water, and wildlife resources. For example, the United States and several western European nations are addressing the problem of excess manure in areas with high concentrations of livestock. Farmers are developing nutrient-management plans to make the best use of fertility-building resources in manure and to prevent excessive field applications or run-off into waterways.

Problems with water quality and water supply due to agricultural practices persist in some areas and have recently emerged in others, such as in the northeastern United States, where the water supply has not been a problem historically. Water quality also affects both freshwater and saltwater fisheries (discussed in more detail below). Careful management of agricultural production is critical in maintaining the ecological health of many estuaries (nurseries for fish and shellfish stocks and food webs). Efforts to improve nutrient management and agricultural conservation practices in the extensive watershed of the U.S. Chesapeake Bay are evidence of the growing awareness of the ecological links between farming and fishing.

Developed countries in North America and western Europe use a combination of technical assistance, incentives, and regulatory approaches to address environmental problems associated with agriculture. However, a lack of human and economic resources limits the ability of developing countries to address environmental problems associated with agriculture or other human activities. The clearing of forests in Brazil continues to accelerate in an effort to develop agricultural production for export. Land is cleared for crops and cultivated pasture, much of it to expand livestock and crop production for export markets. The USDA's Agricultural Baseline Projections February 2002 report (Westcott) predicted that the conversion of undeveloped land into arable land in Brazil's interior will gain momentum over the next decade. Brazil's share of the world soybean market is projected to grow from 28 to 35 percent by 2011.

In his 2000 Nobel anniversary lecture, agricultural researcher Norman Borlaug noted that irrigated agriculture uses 70 percent of global water withdrawals, covers 17 percent of cultivated land (about 679 million acres), and accounts for 40 percent of world food production.

Loss of genetic diversity in crop plants and livestock—driven by market rewards for high yield, cost-efficiency, and product uniformity—is increasingly recognized as an environmental concern for agriculture. Other concerns include agriculture's effects on biodiversity and health of critical habitats. Working agriculture can be a positive or negative factor in all these areas of environmental concern, depending on local site conditions and management practices.

World Fisheries and Food Security

Fisheries contribute to world food security, especially since fish are a major source of protein for some of the world's poorest populations. Per capita fish consumption varies among countries, depending on economic wealth, cultural traditions, and fisheries resource base. According to the United Nations Food and Agriculture Organization (FAO), world per capita fish consumption has been increasing since the 1960s, a trend that has been accompanied by increasing incomes. Global trade in fish and shellfish continues to grow and gain importance in developing countries. However, a practice of over-fishing now threatens fisheries around the world. Consumption of fish has been increasing quite dramatically for at least half a century, and stocks have been severely depleted. Too many fish have been harvested with too little thought or provision for protecting the resource base so that it can continue to produce sustainably. U.S. efforts to protect fisheries from over-fishing are showing some results. For example, some long-threatened resources, such as cod and haddock stocks in New England, have begun to recover after decades of decline. However, achieving international cooperation to protect coastal and estuarine environments and to manage and sustain world fisheries remains a challenge.

Toward a More Sustainable Aquaculture

Aquaculture, often promoted as a solution to over-fishing, has expanded dramatically in Asia for domestic and export markets. As with agriculture, the environmental impacts of aquaculture can vary greatly over the range of management systems and practices. The article "Effect of Aquaculture on World Fish Supplies," by Naylor et al., describes the paradox of aquaculture as both a possible solution and a contributing factor to the collapse of fisheries stocks worldwide.

In the late twentieth and early twenty-first centuries, capture fisheries provided a decreasing share of world food fish, while the share that aquaculture provided surged—nearly tripling from 10 million metric tons in 1987 to 29 million metric tons in 1997. World capture fish harvests leveled off at around 85–95 million metric tons per year, with the catch shifting from larger, higher value carnivorous species of fish to smaller, lower value fish used to make feed for farmed fish. Four of the top five capture fish species were used in feed production for the aquaculture and livestock industries.

Alteration of habitat—especially the large-scale transformation of mangroves and coastal wetlands in Asia into fish-and shrimp-farming ponds—also harms wild fish nurseries and the ecological health of coastal wetlands, coral reefs, and related marine habitat. Other factors that diminish wild fisheries are the collection of wild seed stock, food-web interactions (e.g., over-fishing of small fish species that form the food supply for marine predators, including valuable fish species consumed by humans), introduction of exotic species and pathogens, and nutrient pollution from fish farms.

Aquaculturists farm more than 220 species of finfish, shellfish, and crustaceans. Raising carnivorous species such as salmon, which consume wild fish for feed (producing one pound of farm-raised salmon takes eight pounds of wild fish), can create problems such as inter-breeding of wild fish with escaped farmed fish. But some aquaculture benefits estuarine and marine ecosystems, such as filter-feeding oysters, mussels, clams, and some carp, all of which help purify water. A range of fish and shellfish farming systems are being developed for different species, locations, and conditions. Naylor et al. (pp. 1021–1023) offered four primary goals for the sustainability and continued growth of the aquaculture industry: (1) expand farming of smaller, lower feeding-level fish; (2) reduce use of fish meal and fish oils in feed; (3) develop integrated farming systems; (4) promote environmentally sound aquaculture practices and resource management.

Food and Ecosystems: Linked Since the Rise of Civilization

Humans have always interacted with their environment in order to obtain food. Local ecosystem characteristics, such as the types and quantities of edible plants and plants eaten by food-producing animals, have significantly affected the evolution and development of human societies and cultures. In his Pulitzer-Prize-winning book Guns, Germs, and Steel: The Fates of Human Societies, Jared Diamond traced many of the outcomes of human history, including the comparative advantages of different societies and the availability and relative abundance of different types of plants and animals. For example, a hospitable growing environment with deep, fertile soil, adequate rainfall, and moderate temperatures provides people with a food-producing advantage. (Examples are the traditional "breadbasket" regions of the world: the midwestern United States, the pampas of South America, the plains of central Europe and the Ukraine, and China's river valleys.) However, through ingenuity, skill, and careful stewardship of resources, humans have produced ample food supplies in challenging environments such as the mountains of Switzerland, the Nile Valley, and arid parts of Australia.

In his book, Diamond also links the development of civilizations to people's ability to produce abundant food supplies in an environment. For example, settlements could become permanent only when people no longer had to wander in search of food, and when they learned to protect and replenish the soil so that they did not have to abandon exhausted farming sites. A sustained and ample food supply enabled societies to develop technology, writing, and political systems, all of which advanced agriculture even further. Highly developed farming systems were the cornerstone of the rise of the Roman Empire and the unification of China. The ancient Romans understood, and wrote extensively about, the practice of sustainable agriculture. They improved plants and animals through selective breeding, and they emphasized the use of manure and composts to replenish and enrich the life-giving capacity of farmed soils.

Lessons from Famines and Ecological Disasters of the Middle Ages

Cycles of disaster and famine in medieval Europe offer an instructive study in the interplay of agriculture and the environment. A series of extreme natural disasters including floods, crop failures, and epidemics among humans and livestock culminated in the Great European Famine of the early 1300s. In the mid-fourteenth century, another wave of natural disasters, which included the spread of bubonic plague, resulted in the loss of about one-third of the population of Europe, with death rates as high as 60 percent in some communities. These famines and ecological disasters most likely resulted from a complex combination of causes. Bruce M. S. Campbell discussed several theories about the famines in "Ecology Versus Economics in Late Thirteenth-and Early Fourteenth-Century English Agriculture," in Agriculture in the Middle Ages (pp. 76–97). The floods were most likely part of a period of climate change to cooler, wetter weather, accompanied by storm surges in the North Sea.

Medieval agriculture lacked the dynamism to keep pace with the demands of growing urban populations. In response to food shortages, marginal lands that had been used for livestock, hay, and pasture were now used to raise crops for human consumption. However, reducing livestock numbers not only reduced the quantity of foods produced from animals, but also the supply and use of manure on cropland, which ultimately lessened crop yields.

Lack of technical progress in agriculture, nearly continuous wars, and the extractive feudal economic system made the bad situation worse. Campbell explained (p. 94) that warfare wreaked ecological havoc on the food and agriculture system through physical destruction of crops, livestock, stock, equipment, and physical structures. Burdensome taxes levied to finance warring armies and the expropriation of stock, crops, equipment, and marketing and transportation systems also weakened the existing agricultural systems.

This pattern of famine during and after periods of war or civil strife, often coinciding with epidemics and disastrous droughts or floods, recurs in most modern famines, such as those afflicting Africa since the 1970s. Modern famines show how the ecological, economic, and social destruction of war disrupts the production and distribution of food and, subsequently, a society's ability to feed itself.

From Renaissance to Agricultural Revolution

Significant changes in farming systems that began in parts of Europe during the later medieval period brought about major changes in the ecological health and productivity of the land. Farmers began to combine and integrate crops and livestock in ways that promoted soil quality and fertility and that boosted production. They adopted more intensive and flexible crop rotations, as well as new crops such as oats, turnips grown for animal feed, and nitrogen-fixing legumes. These innovations eliminated the need for fallowing (idling) of land, adding further to sustainable production gains. Campbell found (p. 92) that farmers adopted these systems most readily in areas with natural resource advantages, access to markets, or fewer institutional constraints such as feudal servile tenure or common property rights.

The enclosure of common lands across England in the 1700s and early 1800s transformed agriculture and the English landscape. Well over six million acres, or one-fourth of the cultivated acres in England, were converted from communally held and farmed lands to lands that were privately owned and managed. This conversion enabled farmers to integrate livestock and crops, using manure and crop rotations to restore and improve depleted lands that were formerly pastured or cultivated continuously. The dramatic gains in productivity and prosperity reflect the key role of private property and free enterprise in resource management.

The large amount of available land in the midwestern and western United States lured families to seek new land when the soil became depleted. As a result of this, President Theodore Roosevelt called for a national sense of duty to the land during a 1908 White House Conservation Conference. However, it was not until the dust bowl disaster of the 1930s that major efforts to protect soil and water finally emerged.

The Agricultural Revolution of 1750–1880 improved yields and adaptation of crops and livestock to local conditions around the world. This period of innovation also set the stage for unprecedented scientific and technical progress in the latter half of the twentieth century. In his Nobel address, Borlaug also noted that in 1940 U.S. farmers produced 56 million tons of corn on 77 million acres of land. In 1999 U.S. farmers produced 240 million tons of corn on 71.7 million acres—a greater than fourfold increase in yield per acre, reaped from hybrid seed, fertilizer, and weed control. The Green Revolution of the 1960s and 1970s applied these techniques to rice, wheat, and other crops in the developing world.

Biotechnology and Questions for the Future

In a response to critics who questioned the environmental effects of advances in agricultural science and technology, Borlaug noted that without the dramatic gains in yields brought about by those advances, three times as much land of equal quality would have been required to match food production in the world at that time. Much of that additional 4.4 billion acres of land would have to come from more marginal and environmentally fragile lands.

By the late twentieth century, biotechnology was yielding new adaptations of crops and animals for food and medicine. U.S. farmers quickly adopted new genetically modified crops. According to the USDA National Agricultural Statistics Service 2002 report Crop Production—Prospective Plantings, U.S. farmers intended to plant genetically modified seed on 74 percent of soybean acreage, 71 percent of cotton, and 32 percent of corn grown for grain in 2002. Most first-generation genetically engineered varieties were designed to reduce pesticide use or to allow use of more benign chemicals.

Proponents maintain that through biotechnology people will find new ways to increase yields, nutritional and health values, and environmental sustainability of food production. Still, controversy persists about environmental impacts, consumer concerns, and access to the new technology for impoverished people and nations. Some people question the new methods of genetic manipulation on philosophical grounds. Despite his strong support of biotechnology, Borlaug said that national, regional, and world policymakers must resolve serious issues raised by the dominant role of proprietary companies in biotechnology investment and research. He questioned how resource-poor farmers in developing countries could obtain products of biotechnology research and what amount of time product patents should last. Thus, in policymaking processes, societies, governments, and international agencies need to make policy decisions based on credible information about how best to meet human food needs from the land and water while safeguarding valuable resources, ecological integrity, and future productivity.

Urbanization and Development: the Greatest Threat to Agricultural Land in the United States

Between 1992 and 1997 more than 3.2 million acres of prime farmland were converted to developed land, at an average rate of 645,000 acres of prime farmland per year. From 1982 to 1997 approximately 30 percent of newly developed lands were converted prime farmland. Conversion of farms and farmland to the scattered and fragmented development of "urban sprawl" also causes the loss and fragmentation of other farm, pasture, and rangelands, as well as forests, wetlands, and other important habitats.

In Farming on the Edge, A. Ann Sorenson and others reported that 21 percent of prime or unique farmland conversions occurred in twenty major land resource areas that make up 7 percent of the U.S. land base. These most threatened land resource areas are part of or adjacent to expanding population centers and produce some of the highest value agricultural crops and products.

Shorelands and wetlands lose the buffering provided by farm-and forestlands, and non-point-source pollution from storm water runoff increases. Wetlands are a vital natural resource that provide flood protection and enhance water quality, wildlife habitat, and air quality. According to the 1997 National Resources Inventory, nearly 59 percent of wetland acreage is on forestland and 16.5 percent is on agricultural cropland, pasture, and land in the Conservation Reserve Program.

The Aquaculture Rush in China

Asia produces 90 percent of the world's aquaculture output, with China alone producing more than twothirds of the total. Europe, North America, and Japan combined produce just over 10 percent of the total, but these areas consume most of the internationally traded farmed seafood. Excluding mainland China, world fish supplies from aquaculture grew from 3.5 pounds per capita per year in 1991 to 4.7 pounds in 1998. During the same period, according to the United Nations Food and Agriculture Organization (FAO), the per capita supply of aquaculture products in mainland China nearly tripled, growing from 13.2 to 37.4 pounds. Fish consumption in China is strongly correlated with economic growth, and freshwater aquaculture is responding rapidly to market stimulus. Many Chinese aquaculture enterprises are family and cooperative farms, often using integrated multiple-species systems to produce lower value, herbivorous species for household subsistence and local markets. As competition increases for land and water resources, more operations are intensifying, and some are producing higher value carnivorous or omnivorous species such as shrimp for export.

The FAO ex