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Michael N. Moore
Humans have been exposed to naturally occurring toxic chemicals and materials over the course of their existence as a species. These materials include various metals, the metalloid arsenic, and atmospheric combustion particulates, as well as bacterial, fungal, algal, and plant toxins. They have also consumed plants that contain a host of phytochemicals, many of which are believed to be beneficial, such as plant polyphenols. People are exposed to these various substances from a number of sources. The pathways of exposure include air, water, groundwater, soil (including via plants grown in toxic soils), and various foods, such as vegetables, fruit, fungi, seafood and fish, eggs, wild birds, marine mammals, and farmed animals.
An overview of the various health benefits, hazards and risks relating to the risks reveals the very wide variety of chemicals and materials that are present in the natural environment and can interact with human biology, to both its betterment and detriment.
The major naturally occurring toxic materials that impact human health include metals, metalloids (e.g., arsenic), and airborne particulates. The Industrial Revolution is a major event that increased ecosystem degradation and the various types and duration of exposure to toxic materials. The explosions in new organic and organometallic products that were and still are produced over the past two centuries have introduced new toxicities and associated pathologies. The prevalence in the environment of harmful particulates from motor-vehicle exhaust emissions, road dust and tire dust, and other combustion processes must also be considered in the broader context of air pollution.
Natural products, such as bacterial, fungal, algal, and plant toxins, can also have adverse effects on health. At the same time, plant-derived phytochemicals (i.e., polyphenols, terpenoids, urolithins, and phenolic acids, etc.) also have beneficial and potential beneficial effects, particularly with regard to their anti-inflammatory effects. Because inflammation is associated with most disease processes, phytochemicals that have antioxidant and anti-inflammatory properties are of great interest as potential nutraceuticals. These potentially beneficial compounds may help to combat various cancers; autoimmune conditions; neurodegenerative diseases, including dementias; and psychotic conditions, such as depression, and are also essential micronutrients that promote health and well-being. The cellular and molecular mechanisms in humans that phytochemicals modulate, or otherwise interact with, to improve human health are now known.
In the early 21st century, some of the current pollution issues are legacy problems from past industrialization, such as mercury and persistent organic pollutants (POPs). These POPs include many organochlorine compounds (e.g., polychlorinated biphenyls, pesticides, polychlorinated and polybrominated dibenzo-dioxans and -furans), as well as polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs, and others. The toxicity of chemical mixtures is still a largely unknown problem, particularly with regard to possible synergies. The continuing development of new organic chemicals and nanomaterials is an important environmental health issue; and the need for vigilance with respect to their possible health hazards is urgent. Nanomaterials, in particular, pose potential novel problems in the context of their chemical properties; humans have not previously been exposed to these types of materials, which may well be able to exploit gaps in our existing cellular protection mechanisms.
Hopefully, future advances in knowledge emerging from combinatorial chemistry, molecular modeling, and predictive quantitative structure-activity relationships (QSARs), will enable improved identification of the potential toxic properties of novel industrial organic chemicals, pharmaceuticals, and nanomaterials before they are released into the natural environment, and thus prevent a repetition of past disastrous events.
Russian environmental history is a new field of inquiry, with the first archivally based monographs appearing only in the last years of the 20th century. Despite the field’s youth, scholars studying the topic have developed two distinct and contrasting approaches to its central question: How should the relationship between Russian culture and the natural world be characterized? Implicit in this question are two others: Is the Russian attitude toward the non-human world more sensitive than that which prevails in the West; and if so, is the Russian environment healthier or more stable than that of the United States and Western Europe? In other words, does Russia, because of its traditional suspicion of individualism and consumerism, have something to teach the West? Or, on the contrary, has the Russian historical tendency toward authoritarianism and collectivism facilitated predatory policies that have degraded the environment? Because environmentalism as a political movement and environmental history as an academic subject both emerged during the Cold War, at a time when the Western social, political, and economic system vied with the Soviet approach for support around the world, the comparative (and competitive) aspect of Russian environmental history has always been an important factor, although sometimes an implicit one. Accordingly, the existing scholarly works about Russian environmental history generally fall into one of two camps: one very critical of the Russian environmental record and the seeming disregard of the Russian government for environmental damage, and a somewhat newer group of works that draw attention to the fundamentally different concerns that motivate Russian environmental policies. The first group emphasizes Russian environmental catastrophes such as the desiccated Aral Sea, the eroded Virgin Lands, and the public health epidemics related to the severely polluted air of Soviet industrial cities. The environmental crises that the first group cites are, most often, problems once prevalent in the West, but successfully ameliorated by the environmental legislation of the late 1960s and early 1970s. The second group, in contrast, highlights Russian environmental policies that do not have strict Western analogues, suggesting that a thorough comparison of the Russian and Western environmental records requires, first of all, a careful examination of what constitutes environmental responsibility.
The Mississippi River, the longest in North America, is really two rivers geophysically. The volume is less, the slope steeper, the velocity greater, and the channel straighter in its upper portion than in its lower portion. Below the mouth of the Ohio River, the Mississippi meanders through a continental depression that it has slowly filled with sediment over many millennia. Some limnologists and hydrologists consider the transitional middle portion of the Mississippi, where the waters of its two greatest tributaries, the Missouri and Ohio rivers, join it, to comprise a third river, in terms of its behavioral patterns and stream and floodplain ecologies.
The Mississippi River humans have known, with its two or three distinct sections, is a relatively recent formation. The lower Mississippi only settled into its current formation following the last ice age and the dissipation of water released by receding glaciers. Much of the current river delta is newer still, having taken shape over the last three to five hundred years.
Within the lower section of the Mississippi are two subsections, the meander zone and the delta. Below Cape Girardeau, Missouri, the river passes through Crowley’s Ridge and enters the wide and flat alluvial plain. Here the river meanders in great loops, often doubling back on itself, forming cut offs that, if abandoned by the river, forming lakes. Until modern times, most of the plain, approximately 35,000 square miles, comprised a vast and rich—rich in terms of biomass production—ecological wetland sustained by annual Mississippi River floods that brought not just water, but fertile sediment—topsoil—gathered from across much of the continent. People thrived in the Mississippi River meander zone. Some of the most sophisticated indigenous cultures of North America emerged here. Between Natchez, Mississippi, and Baton Rouge, Louisiana, at Old River Control, the Mississippi begins to fork into distributary channels, the largest of which is the Atchafalaya River. The Mississippi River delta begins here, formed of river sediment accrued upon the continental shelf. In the delta the land is wetter, the ground water table is shallower. Closer to the sea, the water becomes brackish and patterns of river sediment distribution are shaped by ocean tides and waves. The delta is frequently buffeted by hurricanes.
Over the last century and a half people have transformed the lower Mississippi River, principally through the construction of levees and drainage canals that have effectively disconnected the river from the floodplain. The intention has been to dry the land adjacent to the river, to make it useful for agriculture and urban development. However, an unintended effect of flood control and wetland drainage has been to interfere with the flood-pulse process that sustained the lower valley ecology, and with the process of sediment distribution that built the delta and much of the Louisiana coastline. The seriousness of the delta’s deterioration has become especially apparent since Hurricane Katrina, and has moved conservation groups to action. They are pushing politicians and engineers to reconsider their approach to Mississippi River management.
Kimberly M. Carlson and Rachael D. Garrett
Oil crops play a critical role in global food and energy systems. Since these crops have high oil content, they provide cooking oils for human consumption, biofuels for energy, feed for animals, and ingredients in beauty products and industrial processes. In 2014, oil crops occupied about 20% of crop harvested area worldwide. While small-scale oil crop production for subsistence or local consumption continues in certain regions, global demand for these versatile crops has led to substantial expansion of oil crop agriculture destined for export or urban markets. This expansion and subsequent cultivation has diverse effects on the environment, including loss of forests, savannas, and grasslands, greenhouse gas emissions, regional climate change, biodiversity decline, fire, and altered water quality and hydrology. Oil palm in Southeast Asia and soybean in South America have been identified as major proximate causes of tropical deforestation and environmental degradation. Stringent conservation policies and yield increases are thought to be critical to reducing rates of soybean and oil palm expansion into natural ecosystems. However, the higher profits that often accompany greater yields may encourage further expansion, while policies that restrict oil crop expansion in one region may generate secondary “spillover” effects on other crops and regions. Due to these complex feedbacks, ensuring a sustainable supply of oil crop products to meet global demand remains a major challenge for agricultural companies, farmers, governments, and civil society.
David I. Stern
The environmental Kuznets curve (EKC) is a hypothesized relationship between environmental degradation and GDP per capita. In the early stages of economic growth, pollution emissions and other human impacts on the environment increase, but beyond some level of GDP per capita (which varies for different indicators), the trend reverses, so that at high income levels, economic growth leads to environmental improvement. This implies that environmental impacts or emissions per capita are an inverted U-shaped function of GDP per capita. The EKC has been the dominant approach among economists to modeling ambient pollution concentrations and aggregate emissions since Grossman and Krueger introduced it in 1991 and is even found in introductory economics textbooks. Despite this, the EKC was criticized almost from the start on statistical and policy grounds, and debate continues. While concentrations and also emissions of some local pollutants, such as sulfur dioxide, have clearly declined in developed countries in recent decades, evidence for other pollutants, such as carbon dioxide, is much weaker. Initially, many understood the EKC to imply that environmental problems might be due to a lack of sufficient economic development, rather than the reverse, as was conventionally thought. This alarmed others because a simplistic policy prescription based on this idea, while perhaps addressing some issues like deforestation or local air pollution, could exacerbate environmental problems like climate change. Additionally, many of the econometric studies that supported the EKC were found to be statistically fragile. Some more recent research integrates the EKC with alternative approaches and finds that the relation between environmental impacts and development is subtler than the simple picture painted by the EKC. This research shows that usually, growth in the scale of the economy increases environmental impacts, all else held constant. However, the impact of growth might decline as countries get richer, and richer countries are likely to make more rapid progress in reducing environmental impacts. Finally, there is often convergence among countries, so that countries that have relatively high levels of impacts reduce them more quickly or increase them more slowly, all else held constant.
María E. Ibarrarán and Jerónimo Chavarría
In Mexico, the laws and norms that regulate the environment emerged at the end of the 19th century to standardize infrastructure construction and preserve nature. However, it was not until the early 1970s that the first formal government entity dedicated to promote environmental protection, the Vice-Ministry for Environmental Improvement, under the Ministry of Health, was founded, mostly responding to a government initiative rather than social pressure. Other laws were then issued and applied by the Secretariat of Urban Development and Ecology. However, in the 1980s, civil society pressed for more regulations aimed at protecting the environment.
In the 1990s, the Ministry of the Environment, Natural Resources and Fisheries (SEMARNAP) was created, focusing on natural resources, biodiversity, hazardous waste, and urban-industrial environmental problems. Its objective was to reduce the trends of environmental deterioration and to promote economic and social development under criteria of sustainability. This and other institutions have evolved since then, covering a larger set of topics and media. Nevertheless, degradation has not been stopped and is far from being reverted, because even though there is a toolbox of policies and instruments, many of them economic, they have not been fully implemented in some cases or enforced in others because of economic and political factors.
With the changes in institutions, legislation was also modified. Mexico became part of international environmental agreements and included the rights to a safe environment in the constitution. However, this legislation has not been enough to modify behavior because often the incentives either for regulators or for polluters themselves are not enough.
Environmental degradation is a market failure. It can be shaped as an externality that markets alone cannot solve either because of overproduction, abuse of open access resources, or underprovision of public goods. In any of these cases, resolution comes only through government intervention. Regulations must include consideration of the benefits and costs they impose to change behavior. However, regardless of formal regulation, there are still a host of environmental problems that affect both urban and rural communities and Indigenous and non-Indigenous populations, and there is a regulatory vacuum integrating environmental aspects with economic and social development issues. Examples of this are the Energy Reform of 2013 and the Law of Waters, as well as the Law of Biodiversity, where impacts on communities are often left aside, because of a de facto prevalence of economic activity over human rights. On the other hand, legal loopholes prevent adequate management of wildlife resources and sufficient treatment of hazardous waste discarded by industries, even if they are regulated. Furthermore, environmental regulations are based on corrective regulations, such as obligations, restrictions, and sanctions, but these have not strengthened their preventive character. It is still less expensive to pollute or degrade the environment than take measures not to. A shift in the paradigm toward policies that create incentives to protect the environment, both for polluters and regulators, may foster much better environmental quality.
George Morris and Patrick Saunders
Most people today readily accept that their health and disease are products of personal characteristics such as their age, gender, and genetic inheritance; the choices they make; and, of course, a complex array of factors operating at the level of society. Individuals frequently have little or no control over the cultural, economic, and social influences that shape their lives and their health and well-being. The environment that forms the physical context for their lives is one such influence and comprises the places where people live, learn work, play, and socialize, the air they breathe, and the food and water they consume. Interest in the physical environment as a component of human health goes back many thousands of years and when, around two and a half millennia ago, humans started to write down ideas about health, disease, and their determinants, many of these ideas centered on the physical environment.
The modern public health movement came into existence in the 19th century as a response to the dreadful unsanitary conditions endured by the urban poor of the Industrial Revolution. These conditions nurtured disease, dramatically shortening life. Thus, a public health movement that was ultimately to change the health and prosperity of millions of people across the world was launched on an “environmental conceptualization” of health. Yet, although the physical environment, especially in towns and cities, has changed dramatically in the 200 years since the Industrial Revolution, so too has our understanding of the relationship between the environment and human health and the importance we attach to it.
The decades immediately following World War II were distinguished by declining influence for public health as a discipline. Health and disease were increasingly “individualized”—a trend that served to further diminish interest in the environment, which was no longer seen as an important component in the health concerns of the day. Yet, as the 20th century wore on, a range of factors emerged to r-establish a belief in the environment as a key issue in the health of Western society. These included new toxic and infectious threats acting at the population level but also the renaissance of a “socioecological model” of public health that demanded a much richer and often more subtle understanding of how local surroundings might act to both improve and damage human health and well-being.
Yet, just as society has begun to shape a much more sophisticated response to reunite health with place and, with this, shape new policies to address complex contemporary challenges, such as obesity, diminished mental health, and well-being and inequities, a new challenge has emerged. In its simplest terms, human activity now seriously threatens the planetary processes and systems on which humankind depends for health and well-being and, ultimately, survival. Ecological public health—the need to build health and well-being, henceforth on ecological principles—may be seen as the society’s greatest 21st-century imperative. Success will involve nothing less than a fundamental rethink of the interplay between society, the economy, and the environment. Importantly, it will demand an environmental conceptualization of the public health as no less radical than the environmental conceptualization that launched modern public health in the 19th century, only now the challenge presents on a vastly extended temporal and spatial scale.
Paolo Vineis and Federica Russo
While genomics has been founded on accurate tools that lead to a limited amount of classification error, exposure assessment in epidemiology is often affected by large error. The “environment” is in fact a complex construct that encompasses chemical exposures (e.g., to carcinogens); biological agents (viruses, or the “microbiome”); and social relationships. The “exposome” concept was then put forward to stress the relatively poor development of appropriate tools for exposure assessment when applied to the study of disease etiology. Three layers of the exposome have been proposed: “general external” (including social capital, stress and psychology); “specific external” (including chemicals, viruses, radiation, etc.); and “internal” (including for example metabolism and gut microflora). In addition, there are at least three properties of the exposome: (a) it is based on a refinement of tools to measure exposures (including internal measurements in the body); (b) it involves a broad definition of “exposure” or environment, including overarching concepts at a societal level; and (c) it involves a temporal component (i.e., exposure is analyzed in a life-course perspective). The conceptual and practical challenge is how the different layers (i.e., general, specific external, and internal) connect to each other in a causally meaningful sequence. The relevance of this question pertains to the translation of science into policy—for example, if experiences in early life impact on the adult risk of disease, and on the quality of aging, how is distant action to be incorporated in biological causal models and into policy interventions? A useful causal theory to address scientific and policy question about exposure is based on the concept of information transmission. Such a theory can explain how to connect the different layers of the exposome in a life-course temporal frame and helps identify the best level for intervention (molecular, individual, or population level). In this context epigenetics plays a key role, partly because it explains the long-distance persistence of epigenetic changes via the concept of “epigenetic memory.”
The animal world is under increasing pressure, given the magnitude of anthropogenic environmental stress, especially from human-caused rapid climate change together with habitat conversion, fragmentation, and destruction. There is a global wave of species extinctions and decline in local species abundance. To stop or even reverse this so-called defaunation process, in situ conservation (in the wild) is no longer effective without ex situ conservation (in captivity). Consequently, zoos could play an ever-greater role in the conservation of endangered species and wildlife—hence the slogan Captivity for Conservation.
However, the integration of zoo-based tools and techniques in species conservation has led to many conflicts between wildlife conservationists and animal protectionists. Many wildlife conservationists agree with Michael Soulé, the widely acclaimed doyen of the relatively new discipline of conservation biology, that conservation and animal welfare are conceptually distinct, and that they should remain politically separate. Animal protectionists, on the other hand, draw support from existing leading accounts of animal ethics that oppose the idea of captivity for conservation, either because infringing an individual’s right to freedom for the preservation of the species is considered as morally wrong, or because the benefits of species conservation are not seen as significant enough to overcome the presumption against depriving an animal of its liberty.
Both sides view animals through different lenses and address different concerns. Whereas animal ethicists focus on individual organisms, and are concerned about the welfare and liberty of animals, wildlife conservationists perceive animals as parts of greater wholes such as species or ecosystems, and consider biodiversity and ecological integrity as key topics. This seemingly intractable controversy can be overcome by transcending both perspectives, and developing a bifocal view in which zoo animals are perceived as individuals in need of specific care and, at the same time, as members of a species in need of protection.
Based on such a bifocal approach that has lately been adopted by a growing international movement of “Compassionate Conservation,” the modern zoo can only achieve its conservation mission if it finds a morally acceptable balance between animal welfare concerns and species conservation commitments. The prospects for the zoo to achieve such a balance are promising. Over the past decade or so, zoos have made serious and sustained efforts to ensure and enhance animal welfare. At the same time, the zoo’s contribution to species conservation has also improved considerably.
Juha Merilä and Ary A. Hoffmann
Changing climatic conditions have both direct and indirect influences on abiotic and biotic processes and represent a potent source of novel selection pressures for adaptive evolution. In addition, climate change can impact evolution by altering patterns of hybridization, changing population size, and altering patterns of gene flow in landscapes. Given that scientific evidence for rapid evolutionary adaptation to spatial variation in abiotic and biotic environmental conditions—analogous to that seen in changes brought by climate change—is ubiquitous, ongoing climate change is expected to have large and widespread evolutionary impacts on wild populations. However, phenotypic plasticity, migration, and various kinds of genetic and ecological constraints can preclude organisms from evolving much in response to climate change, and generalizations about the rate and magnitude of expected responses are difficult to make for a number of reasons.
First, the study of microevolutionary responses to climate change is a young field of investigation. While interest in evolutionary impacts of climate change goes back to early macroevolutionary (paleontological) studies focused on prehistoric climate changes, microevolutionary studies started only in the late 1980s. The discipline gained real momentum in the 2000s after the concept of climate change became of interest to the general public and funding organizations. As such, no general conclusions have yet emerged. Second, the complexity of biotic changes triggered by novel climatic conditions renders predictions about patterns and strength of natural selection difficult. Third, predictions are complicated also because the expression of genetic variability in traits of ecological importance varies with environmental conditions, affecting expected responses to climate-mediated selection.
There are now several examples where organisms have evolved in response to selection pressures associated with climate change, including changes in the timing of life history events and in the ability to tolerate abiotic and biotic stresses arising from climate change. However, there are also many examples where expected selection responses have not been detected. This may be partly explainable by methodological difficulties involved with detecting genetic changes, but also by various processes constraining evolution.
There are concerns that the rates of environmental changes are too fast to allow many, especially large and long-lived, organisms to maintain adaptedness. Theoretical studies suggest that maximal sustainable rates of evolutionary change are on the order of 0.1 haldanes (i.e., phenotypic standard deviations per generation) or less, whereas the rates expected under current climate change projections will often require faster adaptation. Hence, widespread maladaptation and extinctions are expected. These concerns are compounded by the expectation that the amount of genetic variation harbored by populations and available for selection will be reduced by habitat destruction and fragmentation caused by human activities, although in some cases this may be countered by hybridization. Rates of adaptation will also depend on patterns of gene flow and the steepness of climatic gradients. Theoretical studies also suggest that phenotypic plasticity (i.e., nongenetic phenotypic changes) can affect evolutionary genetic changes, but relevant empirical evidence is still scarce. While all of these factors point to a high level of uncertainty around evolutionary changes, it is nevertheless important to consider evolutionary resilience in enhancing the ability of organisms to adapt to climate change.
Agriculture has been the principal influence on the physical structure of the English landscape for many thousands of years. Driven by a wider raft of demographic, social, and economic developments, farming has changed in complex ways over this lengthy period, with differing responses to the productive potential and problems of local environments leading to the emergence of distinct regional landscapes. The character and configuration of these, as much as any contemporary influences, have in turn structured the practice of agriculture at particular points in time. The increasing complexity of the wider economy has also been a key influence on the development of the farmed landscape, especially large-scale industrialization in the late 18th and 19th centuries; and, from the late 19th century, globalization and increasing levels of state intervention. Change in agricultural systems has not continued at a constant rate but has displayed periods of more and less innovation.
Mark V. Barrow
The prospect of extinction, the complete loss of a species or other group of organisms, has long provoked strong responses. Until the turn of the 18th century, deeply held and widely shared beliefs about the order of nature led to a firm rejection of the possibility that species could entirely vanish. During the 19th century, however, resistance to the idea of extinction gave way to widespread acceptance following the discovery of the fossil remains of numerous previously unknown forms and direct experience with contemporary human-driven decline and the destruction of several species. In an effort to stem continued loss, at the turn of the 19th century, naturalists, conservationists, and sportsmen developed arguments for preventing extinction, created wildlife conservation organizations, lobbied for early protective laws and treaties, pushed for the first government-sponsored parks and refuges, and experimented with captive breeding. In the first half of the 20th century, scientists began systematically gathering more data about the problem through global inventories of endangered species and the first life-history and ecological studies of those species.
The second half of the 20th and the beginning of the 21st centuries have been characterized both by accelerating threats to the world’s biota and greater attention to the problem of extinction. Powerful new laws, like the U.S. Endangered Species Act of 1973, have been enacted and numerous international agreements negotiated in an attempt to address the issue. Despite considerable effort, scientists remain fearful that the current rate of species loss is similar to that experienced during the five great mass extinction events identified in the fossil record, leading to declarations that the world is facing a biodiversity crisis. Responding to this crisis, often referred to as the sixth extinction, scientists have launched a new interdisciplinary, mission-oriented discipline, conservation biology, that seeks not just to understand but also to reverse biota loss. Scientists and conservationists have also developed controversial new approaches to the growing problem of extinction: rewilding, which involves establishing expansive core reserves that are connected with migratory corridors and that include populations of apex predators, and de-extinction, which uses genetic engineering techniques in a bid to resurrect lost species. Even with the development of new knowledge and new tools that seek to reverse large-scale species decline, a new and particularly imposing danger, climate change, looms on the horizon, threatening to undermine those efforts.
Fisheries science emerged in the mid-19th century, when scientists volunteered to conduct conservation-related investigations of commercially important aquatic species for the governments of North Atlantic nations. Scientists also promoted oyster culture and fish hatcheries to sustain the aquatic harvests. Fisheries science fully professionalized with specialized graduate training in the 1920s.
The earliest stage, involving inventory science, trawling surveys, and natural history studies continued to dominate into the 1930s within the European colonial diaspora. Meanwhile, scientists in Scandinavian countries, Britain, Germany, the United States, and Japan began developing quantitative fisheries science after 1900, incorporating hydrography, age-determination studies, and population dynamics. Norwegian biologist Johan Hjort’s 1914 finding, that the size of a large “year class” of juvenile fish is unrelated to the size of the spawning population, created the central foundation and conundrum of later fisheries science. By the 1920s, fisheries scientists in Europe and America were striving to develop a theory of fishing. They attempted to develop predictive models that incorporated statistical and quantitative analysis of past fishing success, as well as quantitative values reflecting a species’ population demographics, as a basis for predicting future catches and managing fisheries for sustainability. This research was supported by international scientific organizations such as the International Council for the Exploration of the Sea (ICES), the International Pacific Halibut Commission (IPHC), and the United Nations’ Food and Agriculture Organization (FAO).
Both nationally and internationally, political entanglement was an inevitable feature of fisheries science. Beyond substituting their science for fishers’ traditional and practical knowledge, many postwar fisheries scientists also brought progressive ideals into fisheries management, advocating fishing for a maximum sustainable yield. This in turn made it possible for governments, economists, and even scientists, to use this nebulous target to project preferred social, political, and economic outcomes, while altogether discarding any practical conservation measures to rein in globalized postwar industrialized fishing. These ideals were also exported to nascent postwar fisheries science programs in developing Pacific and Indian Ocean nations and in Eastern Europe and Turkey.
The vision of mid-century triumphalist science, that industrial fisheries could be scientifically managed like any other industrial enterprise, was thwarted by commercial fish stock collapses, beginning slowly in the 1950s and accelerating after 1970, including the massive northern cod crisis of the early 1990s. In the 1980s scientists, aided by more powerful computers, attempted multi-species models to understand the different impacts of a fishery on various species. Daniel Pauly led the way with multi-species models for tropical fisheries, where the need for such was most urgent, and pioneered the global database FishBase, using fishing data collected by the FAO and national bodies. In Canada the cod crisis inspired Ransom Myers to use large databases for fisheries analysis to show the role of overfishing in causing that crisis. After 1980 population ecologists also demonstrated the importance of life history data for understanding fish species’ responses to fishery-induced population and environmental change.
With fishing continuing to shrink many global commercial stocks, scientists have demonstrated how different measures can manage fisheries for species with different life-history profiles. Aside from the need for effective scientific monitoring, the biggest ongoing challenges remain having politicians, governments, fisheries industry members, and other stakeholders commit to scientifically recommended long-term conservation measures.
Tomiko Yamaguchi and Shun-Nan Chiang
This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Environmental Science. Please check back later for the full article.
Food is one of the most fundamental requirements to sustain life, but food safety cannot be taken for granted. While a variety of chemical and microbial agents can potentially find their way into the food supply, the emergence of novel food such as genetically modified and cultured food has raised challenges for how to evaluate its safety. Since the late 1990s, citizens of many nations have faced food safety crises and scares caused by health concerns arising from threats as diverse as bovine spongiform encephalitis (BSE), dioxin contamination, melamine-tainted infant milk formula, and so forth. Food safety issues can lead to social conflicts because food safety concerns are entangled with the values and norms of individuals and groups. The persistent controversy over genetically modified food is a good example of this. Food safety has become a particularly complex issue in the context of a global economy. To be specific, the condition of food safety governance is entangled with several larger trends at the global scale, including (a) trade liberalization in the 1980s; (b) the adoption of a risk analysis framework by global and national food safety administrations; and (c) the spread of food quality management regimes throughout the entire food industry, from food production, to processing, to retail. Furthermore, there are vast differences between the food safety regulations and the prominent food safety issues within developed and developing countries. These facts, combined with the accelerating pace of globalization and the borderless nature of sociotechnical food systems, contribute to the extreme challenges for individual countries to manage food safety issues within their jurisdictions. This observation underscores the importance of global food safety governance, a goal that is, in itself, difficult to achieve.
Within this context, two noteworthy dilemmas have emerged vis-à-vis global food safety governance. The first issue concerns the cross-border risk management of food imports in the Global North and its implications for exporting countries in the Global South. How has the adoption of a risk analysis framework and a structured decision-making process impacted producers in those countries? The second issue is the social controversy that arises from consumers’ increased consciousness of the role of food safety in public health. These controversies frequently hinge on whether proposed food technologies meet societal needs and on concerns about the sufficiency of scientific knowledge to assure safety. Observations made on these issues from the perspectives of macro-sociology, risk studies, and social studies of science suggest that design of future food safety governance must incorporate careful examination of three components in particular: (a) the use of sound scientific information; (b) the management and communication of food safety risks; and (c) the balance between improving access to safe food for consumers and maintaining socioeconomic viability for producers.
Ng Wun Jern
This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Environmental Science. Please check back later for the full article.
Agricultural and food processing residues, and discarded food are largely organic and biodegradable, and may include important nutrients other than carbon. Inappropriate disposal of these have caused considerable adverse environmental impacts on air and water and continue to do so in 21st-century Asia. While water pollution issues have often been local or national in nature, air pollution arising from the burning of post-harvest crop residues have caused trans-boundary concerns.
Pollution control by means of treating wastes for safe disposal need not be the only approach, however, since such an approach, seen as costly by parties required to manage their wastes, may not engender enthusiasm. Given the nature of the wastes under discussion, a shift in mindset—toward viewing these wastes as another resource—may make waste management more attractive, since there is a possibility for economic gain.
One approach is the conversion of such wastes into added-value products through thermo-chemical processes (e.g., pyrolysis, gasification, and hydro-thermal action), resulting in products such as fuel gas, pyrolytic oil, and biochar. Biotechnology can be a suitable technique for such resource recovery. In addition, the argument, for conversion of waste to added-value products, is possibly more attractive than conversion to CO2 and H2O. Agricultural and food-processing residues, given their high organic content, have been fermented to yield fuel gases such as methane (anerobiosis and methanogenesis) and hydrogen (dark fermentation), and liquids such as butanol and ethanol. Biodiesel, produced from biomass by transesterification, is already used as a fuel to power vehicular engines. Bio-methanol is another biofuel with promise, given its high energy content. These represent opportunities for recovering energy.
Derivable from the organic content of waste is a spectrum of other products that can include useful microbes, phytohormones and antibiotics, enzymes, and polyhydroxyalkanoates (PHAs). Application of fermentation technologies to the wastes, for production of added-value materials, in itself results in residues. The latter, with its still high organic carbon content and possibly significant quantities of phosphorus, potassium, and nitrogen can be used as a delivery platform (with some fertilizing value) for beneficial microbes to apply to agricultural land damaged by excessive use of chemical fertilizers and pesticides, and so rebalance the soil’s microbial ecology. Soil ecology has become an issue requiring urgent attention, as damaged farm soils have resulted in lower crop yields in parts of Asia. This is an issue not only in rural farming or large-scale industrial farming, but also in urban farming, where the bioactives biologically recovered from resources such as discarded food can be used in hydro- and aeroponics. The application of recovered resources from residues represents a tangible example of the circular economy.
Hans Keune and Timo Assmuth
Framing and dealing with complexity are crucially important in environment and human health science, policy, and practice. Complexity is a key feature of most environment and human health issues, which by definition include aspects of the environment and human health, both of which constitute complex phenomena. The number and range of factors that may play a role in an environment and human health issue are enormous, and the issues have a multitude of characteristics and consequences. Framing this complexity is crucial because it will involve key decisions about what to take into account when addressing environment and human health issues and how to deal with them. This is not merely a technical process of scientific framing, but also a methodological decision-making process with both scientific and societal implications. In general, the benefits and risks related to such issues cannot be generalized or objectified, and will be distributed unevenly, resulting in health and environmental inequalities. Even more generally, framing is crucial because it reflects cultural factors and historical contingencies, perceptions and mindsets, political processes, and associated values and worldviews. Framing is at the core of how we as humans relate to, and deal with, environment and human health, as scientists, policymakers, and practitioners, with models, policies, or actions.
David E. Clay, Sharon A. Clay, Thomas DeSutter, and Cheryl Reese
Since the discovery that food security could be improved by pushing seeds into the soil and later harvesting a desirable crop, agriculture and agronomy have gone through cycles of discovery, implementation, and innovation. Discoveries have produced predicted and unpredicted impacts on the production and consumption of locally produced foods. Changes in technology, such as the development of the self-cleaning steel plow in the 18th century, provided a critical tool needed to cultivate and seed annual crops in the Great Plains of North America. However, plowing the Great Plains would not have been possible without the domestication of plants and animals and the discovery of the yoke and harness. Associated with plowing the prairies were extensive soil nutrient mining, a rapid loss of soil carbon, and increased wind and water erosion. More recently, the development of genetically modified organisms (GMOs) and no-tillage planters has contributed to increased adoption of conservation tillage, which is less damaging to the soil. In the future, the ultimate impact of climate change on agronomic practices in the North American Great Plains is unknown. However, projected increasing temperatures and decreased rainfall in the southern Great Plains (SGP) will likely reduce agricultural productivity. Different results are likely in the northern Great Plains (NGP) where higher temperatures can lead to increased agricultural intensification, the conversion of grassland to cropland, increased wildlife fragmentation, and increased soil erosion. Precision farming, conservation, cover crops, and the creation of plants better designed to their local environment can help mitigate these effects. However, changing practices require that farmers and their advisers understand the limitations of the soils, plants, and environment, and their production systems. Failure to implement appropriate management practices can result in a rapid decline in soil productivity, diminished water quality, and reduced wildlife habitat.
Anil Markandya, Elena Paglialunga, Valeria Costantini, and Giorgia Sforna
Economic damage from climate change includes several aspects that need to be considered at the global and regional levels to achieve an equitable common solution to global warming. The economic literature reviewed here analyzes this issue under three general perspectives.
First, the analytical estimation of the linkages between damages in monetary terms and climate variables, as projections of temperature, precipitation, and frequency of extreme events, is rapidly evolving. Damage functions are included in complex economic models in order to calculate the economic impact of the climate change on economic output and growth, thus informing the debate on the amount of resources that should be devoted to reducing greenhouse gas (GHG) emissions and limiting climate damages. The choice of the geographical aggregation in this respect is a crucial aspect to be considered if policy advice is to be formulated on the basis of model results. The higher the level of regional detail, the more reliable the results are in terms of geographical distribution of economic damages.
Second, the precise estimation of the costs associated with different damages caused by climate change is attracting growing interest. Climate costs present a wide range of heterogeneity for several reasons, such as the different formulation of the damage function adopted, the modeling design of the economic impact, the temporal horizon considered, and the differentiation across sectors. Two broad categories of analysis are relevant. The first refers to the choice of the sectoral dimension under investigation, where some studies cover multiple sectors and their interactions, while others analyze specific sectors in depth. The second classification criterion refers to the choice of the economic aspects estimated, where a strand of literature analyzes only market-based costs, while other analyses also include non-market (or intangible) damages. The most common sectors investigated are agriculture, forestry, health, energy, coastal zones and sea level rise, extreme events, tourism, ecosystem, industry, air quality, and catastrophic damages. Most studies consider market-based costs, while non-market impacts need to be better detailed in economic models.
Third, the computation of a single number through the analytical framework of the social costs of carbon (SCC) represents a key aspect of the process of adapting complex results in order to properly inform the political debate. SCC represents the marginal global damage cost of carbon emissions and can also be interpreted as the economic value of damages avoided for unitary GHG emission reduction. Several uncertainties still influence the robustness of the SCC analytical framework, such as the choice of the discount rate, which strongly influences the role of SCC in supporting or not mitigation action in the short term.
Although the debate on the economic damages arising from climate change is flourishing, several aspects still need to be investigated in order to build a common consensus within the scientific community as a necessary condition to properly inform the political debate and to facilitate the achievement of a long-term equitable global climate agreement.
Fred Mackenzie and Abraham Lerman
The tendency to represent natural processes as cycles—from Latin cyclus and Greek κυκλος—is undoubtedly rooted in the human observations of repeating or periodic phenomena. The oldest notions of the water cycle, as water cycling between the Earth, air, and back to earth, are mentioned in the Old Testament and by Greek philosophers, from the 900s to 300s
The main “bioessential” chemical elements are carbon (C), nitrogen (N), phosphorus (P), oxygen (O), and hydrogen (H). These are represented in the mean composition of aquatic photosynthesizing organisms as the atomic abundance ratio C:N:P = 106:16:1 or as (CH2O)106(NH3)16(H3PO4). In land plants, estimates of mean composition vary from C:N:P = 510:4:1 to 2057:17:1. On land, the photosynthesizing organisms are much more efficient than in water by being able to incorporate more carbon atoms for each atom of phosphorus. The bioessential elements are coupled by the living organisms in the exogenic cycle, the processes at and near the Earth’s surface, and in the endogenic cycle of the processes that include subduction into the Earth’s interior and return to the surface. The main reservoirs of the bioessential elements are very different: although oxygen is the most abundant element in the Earth’s crust, most of it is locked in silicate minerals as SiO2, and the forms available to biogeochemical cycling are oxygen in water and, as a product of photosynthesis, as gas O2 in the atmosphere. Carbon is in the atmospheric reservoir of CO2 gas and dissolved in ocean and fresh waters. The main nitrogen reservoir is the molecular N2 in the atmosphere and oxidized and reduced nitrogen compounds in waters. Phosphorus occurs in the oxidized form of the phosphate-ion in crustal minerals, from where it is leached into the water.
The natural cycle of the bioessential elements has been greatly perturbed since the late 1700s by human industrial and agricultural activities, the period known as the Anthropocene epoch. The increase in CO2, CH4 and NOx emissions to the atmosphere from fossil-fuel burning and land-use changes has rapidly and strongly modified the chemical composition of the atmosphere. This change has affected the balance of solar radiation absorbed by the atmosphere—generally known as “climate change”—and the acidity of surface-ocean waters, referred to as “ocean acidification.” CO2 in water is a weak acid that dissolves carbonate minerals, biogenically and inorganically formed in the ocean, and it thus modifies the chemical composition of ocean water. Overall, a major anthropogenic perturbation of the biogeochemical cycles has been the faster increase in atmospheric concentration of CO2 than its removal from the atmosphere by plants, dissolution in the ocean, and uptake in mineral weathering.
Rhett B. Larson
Increased water variability is one of the most pressing challenges presented by global climate change. A warmer atmosphere will hold more water and will result in more frequent and more intense El Niño events. Domestic and international water rights regimes must adapt to the more extreme drought and flood cycles resulting from these phenomena.
Laws that allocate rights to water, both at the domestic level between water users and at the international level between nations sharing transboundary water sources, are frequently rigid governance systems ill-suited to adapt to a changing climate. Often, water laws allocate a fixed quantity of water for a certain type of use. At the domestic level, such rights may be considered legally protected private property rights or guaranteed human rights. At the international level, such water allocation regimes may also be dictated by human rights, as well as concerns for national sovereignty. These legal considerations may ossify water governance and inhibit water managers’ abilities to alter water allocations in response to changing water supplies. To respond to water variability arising from climate change, such laws must be reformed or reinterpreted to enhance their adaptive capacity. Such adaptation should consider both intra-generational equity and inter-generational equity.
One potential approach to reinterpreting such water rights regimes is a stronger emphasis on the public trust doctrine. In many nations, water is a public trust resource, owned by the state and held in trust for the benefit of all citizens. Rights to water under this doctrine are merely usufructuary—a right to make a limited use of a specified quantity of water subject to governmental approval. The recognition and enforcement of the fiduciary obligation of water governance institutions to equitably manage the resource, and characterization of water rights as usufructuary, could introduce needed adaptive capacity into domestic water allocation laws. The public trust doctrine has been influential even at the international level, and that influence could be enhanced by recognizing a comparable fiduciary obligation for inter-jurisdictional institutions governing international transboundary waters.
Legal reforms to facilitate water markets may also introduce greater adaptive capacity into otherwise rigid water allocation regimes. Water markets are frequently inefficient for several reasons, including lack of clarity in water rights, externalities inherent in a resource that ignores political boundaries, high transaction costs arising from differing economic and cultural valuations of water, and limited competition when water utilities are frequently natural monopolies. Legal reforms that clarify property rights in water, specify the minimum quantity, quality, and affordability of water to meet basic human needs and environmental flows, and mandate participatory and transparent water pricing and contracting could allow greater flexibility in water allocations through more efficient and equitable water markets.