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Wheat is the most widely grown food crop in the world and the dominant staple crop in temperate countries where it contributes between about 20% and 50% of the total energy intake. About 95% of the wheat grown is hexaploid bread wheat, with tetraploid durum wheat being grown in the hot dry Mediterranean climate and very small volumes of ancient species. About 80% of the dry weight of the mature grain is starchy endosperm. This is the major grain storage tissue, which is separated by milling to give white flour, the outer layers and germ together forming the bran. However, white flour and bran differ significantly in their compositions, with white flour being rich in starch (about 80% dry wt) and protein (about 10% dry wt) and the bran rich in fiber, minerals, vitamins, and phytochemicals.
Most of the wheat consumed by humankind is in the form of bread, noodles, pasta, and other processed foods, and the quality for processing is determined by two major characteristics: the grain texture (hardness) and the viscoelastic properties conferred to dough by the gluten proteins.
In addition to being a source of energy, wheat also contributes protein and a range of other essential and beneficial components, particularly dietary fiber. However, because most of these components are concentrated in the bran, it is important to increase the consumption of whole grain products or to improve the composition of white flour. Although there is concern among consumers about possible adverse effects of consuming wheat products on health, these are unlikely to affect more than a small proportion of the population, and wheat should form part of a healthy balanced diet for the vast majority.
Mainaak Mukhopadhyay and Tapan Kumar Mondal
Tea, the globally admired, non-alcoholic, caffeine-containing beverage, is manufactured from the tender leaves of the tea [Camellia sinensis (L.)] plant. It is basically a woody, perennial crop with a lifespan of more than 100 years. Cultivated tea plants are natural hybrids of the three major taxa or species, China, Assam (Indian), or Cambod (southern) hybrids based on the morphological characters (principally leaf size). Planting materials are either seedlings (10–18 months old) developed from either hybrid, polyclonal, or biclonal seeds, or clonal cuttings developed from single-leaf nodal cuttings of elite genotypes. Plants are forced to remain in the vegetative stage as bushes by following cultural practices like centering, pruning, and plucking, and they are harvested generally from the second year onward at regular intervals of 7–10 days in the tropics and subtropics, with up to 60 years as the economic lifespan. Originally, the Chinese were the first to use tea as a medicinal beverage, around 2000 years ago, and today, around half of the world’s population drink tea. It is primarily consumed as black tea (fermented tea), although green tea (non-fermented) and oolong tea (semifermented) are also consumed in many countries. Tea is also used as vegetables such as “leppet tea” in Burma and “meing tea” in Thailand.
Green tea has extraordinary antioxidant properties, and black tea plays a positive role in treating cardiovascular ailments. Tea in general has considerable therapeutic value and can cure many diseases. Global tea production (black, green, and instant) has increased significantly during the past few years. China, as the world’s largest tea producer, accounts for more than 38% of the total global production of made tea [i.e. ready to drink tea] annually, while production in India, the second-largest producer. India recorded total production of 1233.14 million kg made tea during 2015–2016, which is the highest ever production so far.
Since it is an intensive monoculture, tea cultivation has environmental impacts. Application of weedicides, pesticides, and inorganic fertilizers creates environmental hazards. Meanwhile, insecticides often eliminate the fauna of a vast tract of land. Soil degradation is an additional concern because the incessant use of fertilizers and herbicides compound soil erosion. Apart from those issues, chemical runoff into bodies of water can also create problems. Finally, during tea manufacturing, fossil fuel is used to dry the processed leaves, which also increases environmental pollution.
Dairy has intertwined with human society since the beginning of civilization. It evolves from art in ancient society to science in the modern world. Its roles in nutrition and health are underscored by the continuous increase in global consumption. Milk production increased by almost 50% in just the past quarter century alone. Population growth, income rise, nutritional awareness, and science and technology advancement contributed to a continuous trend of increased milk production and consumption globally. With a fourfold increase in milk production per cow since the 1940s, the contemporary dairy industry produces more milk with fewer cows, and consumes less feed and water per liter of milk produced. The dairy sector is diversified, as people from a wider geographical distribution are consuming milk, from cattle to species such as buffalo, goat, sheep, and camel. The dairy industry continues to experience structural changes that impact society, economy, and environment. Organic dairy emerged in the 1990s as consumers increasingly began viewing it as an appropriate way of both farming and rural living. Animal welfare, environmental preservation, product safety, and health benefit are important considerations in consuming and producing organic dairy products. Large dairy operations have encountered many environmental issues related to elevated greenhouse gas emissions. Dairy cattle are second only to beef cattle as the largest livestock contributors in methane emission. Disparity in greenhouse gas emissions per dairy animal among geographical regions can be attributed to production efficiency. Although a number of scientific advancements have implications in the inhibition of methanogenesis, improvements in production efficiency through feeding, nutrition, genetic selection, and management remain promising for the mitigation of greenhouse gas emissions from dairy animals. This article describes the trends in milk production and consumption, the debates over the role of milk in human nutrition, the global outlook of organic dairy, the abatement of greenhouse gas emissions from dairy animals, as well as scientific and technological developments in nutrition, genetics, reproduction, and management in the dairy sector.
Christiane Runyan and Jeff Stehm
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.
Eight thousand years ago, forests covered an estimated 47% of Earth’s land surface. In 2015, forests covered roughly 30% of the Earth’s land surface, a cumulative loss over the last 8,000 years of approximately 2.2 billion hectares (ha). Between 1990 and 2015, forest losses occurred at the rate of about 0.13% annually, but this rate appears to be slowing. These losses mostly occur in tropical forests (58%), followed by boreal (27%) and temperate forests (8%). Deforestation is driven by a number of direct and indirect factors and processes that vary across regions and interact in complex ways. The primary driver of deforestation is agricultural expansion (both commercial and subsistence), followed by mining, infrastructure extension, and urban expansion. Indirectly, population and economic growth increase the demand for agricultural and timber products. Global food demand will increase 70% by 2050, requiring a net increase of 70 million ha of arable land under cultivation, with approximately 80% of this expansion occurring in the tropics. Deforestation is affected by other indirect factors such as land tenure uncertainties, poor governance, low capacity of public forestry agencies, and inadequate planning and monitoring. Forest loss has a number of environmental, economic, and social implications. Environmentally, forests provide an expansive range of benefits across local, regional, and global scales, including hydrological benefits (e.g., regulating water supply and river discharge), climate benefits (e.g., precipitation recycling, regulating local and global temperature, and indirectly, by taking up atmospheric CO2 during photosynthesis), biogeochemical benefits (e.g., enhancing nutrient availability and reducing nutrient losses), and by supporting greater biodiversity as well as ecosystem stability and resiliency, to name a few. The loss of forest vegetation may negatively affect important ecosystem processes and services, and may induce bistable ecosystem dynamics. The existence of bistable ecosystem dynamics in some forest ecosystems suggests that these forests are prone to abrupt and irreversible shifts to a stable and often degraded state with no trees. In addition to environmental impacts, the long-term loss of forest resources negatively affects societies. About 8% (450 million) of the world’s population live in forest ecosystems, with an estimated 350 million people entirely dependent on forest ecosystems for their livelihoods. The forest sector, in 2011, contributed an estimated total amount of USD 600 billion to global GDP, or about 0.9% of global GDP. Understanding how to best manage forest resources to preserve their unique qualities is a challenge that will require an integrated and concentrated effort from scientists and policymakers alike. In particular, improving forest management will require being able to more accurately measure and monitor forest resources, identifying the trade-offs between competing objectives, valuing forest goods and services, and equitably balancing costs and benefits. On the policy front, approaches to strengthen land tenure and property rights, reduce corruption, improve the capacity of public agencies, and develop more inclusive governance arrangements are needed. Underlying these management and policy goals is the need to better understand the environmental processes occurring in forests—to improve their management, minimize adverse impacts, and strengthen our models of these systems, because the long-term loss of forest resources affects not only the functioning of ecosystems but also the societies whose health and livelihoods depend upon them.
Deforestation in Brazilian Amazonia destroys environmental services that are important for the whole world, and especially for Brazil itself. These services include maintaining biodiversity, avoiding global warming, and recycling water that provides rainfall to Amazonia, to other parts of Brazil, such as São Paulo, and to neighboring countries, such as Argentina. The forest also maintains the human populations and cultures that depend on it. Deforestation rates have gone up and down over the years with major economic cycles. A peak of 27,772 km2/year was reached in 2004, followed by a major decline to 4571 km2/year in 2012, after which the rate trended upward, reaching 7989 km2/year in 2016 (equivalent to about 1.5 hectares per minute). Most (70%) of the decline occurred by 2007, and the slowing in this period is almost entirely explained by declining prices of export commodities such as soy and beef. Government repression measures explain the continued decline from 2008 to 2012, but an important part of the effect of the repression program hinges on a fragile base: a 2008 decision that makes the absence of pending fines a prerequisite for obtaining credit for agriculture and ranching. This could be reversed at the stroke of a pen, and this is a priority for the powerful “ruralist” voting bloc in the National Congress. Massive plans for highways, dams, and other infrastructure in Amazonia, if carried out, will add to forces in the direction of increased deforestation.
Deforestation occurs for a wide variety of reasons that vary in different historical periods, in different locations, and in different phases of the process at any given location. Economic cycles, such as recessions and the ups and downs of commodity markets, are one influence. The traditional economic logic, where people deforest to make a profit by producing products from agriculture and ranching, is important but only a part of the story. Ulterior motives also drive deforestation. Land speculation is critical in many circumstances, where the increase in land values (bid up, for example, as a safe haven to protect money from hyperinflation) can yield much higher returns than anything produced by the land. Even without the hyperinflation that came under control in 1994, highway projects can yield speculative fortunes to those who are lucky or shrewd enough to have holdings along the highway route. The practical way to secure land holdings is to deforest for cattle pasture. This is also critical to obtaining and defending legal title to the land. In the past, it has also been the key to large ranches gaining generous fiscal incentives from the government. Money laundering also makes deforestation attractive, allowing funds from drug trafficking, tax evasion, and corruption to be converted to “legal” money. Deforestation receives impulses from logging, mining, and, especially, road construction. Soybeans and cattle ranching are the main replacements for forest, and recently expanded export markets are giving strength to these drivers. Population growth and household dynamics are important for areas dominated by small farmers. Extreme degradation, where tree mortality from logging and successive droughts and forest fires replace forest with open nonforest vegetation, is increasing as a kind of deforestation, and is likely to increase much more in the future.
Controlling deforestation requires addressing its multiple causes. Repression through fines and other command-and-control measures is essential to avoid a presumption of impunity, but these controls must be part of a broader program that addresses underlying causes. The many forms of government subsidies for deforestation must be removed or redirected, and the various ulterior motives must be combated. Industry agreements restricting commodity purchases from properties with illegal deforestation (or from areas cleared after a specified cutoff) have a place in efforts to contain forest loss, despite some problems. A “soy moratorium” has been in effect since 2006, and a “cattle agreement” since 2009. Creation and defense of protected areas is an important part of deforestation control, including both indigenous lands and a variety of kinds of “conservation units.” Containing infrastructure projects is essential if deforestation is to be held in check: once roads are built, much of what happens is outside the government’s control. The notion that the 2005–2012 deforestation slowdown means that the process is under control and that infrastructure projects can be built at will is extremely dangerous. One must also abandon myths that divert efforts to contain deforestation; these include “sustainable logging” and the use of “green” funds for expensive programs to reforest degraded lands rather than retain areas of remaining natural forests. Finally, one must provide alternatives to support the rural population of small farmers. Large investors, on the other hand, can fend for themselves. Tapping the value of the environmental services of the forest has been proposed as an alternative basis for sustaining both the rural population and the forest. Despite some progress, a variety of challenges remain. One thing is clear: most of Brazil’s Amazonian deforestation is not “development.” Trading the forest for a vast expanse of extensive cattle pasture does little to secure the well-being of the region’s rural population, is not sustainable, and sacrifices Amazonia’s most valuable resources.
Bartosz Bartkowski and Nele Lienhoop
While economic values of nonmarket ecosystem goods and services are in high demand to inform decision-making processes, economic valuation has also attracted significant criticism. Particularly, its implicit rationality assumptions and value monism gave rise to alternative approaches to economic nonmarket valuation. Deliberative monetary valuation (DMV) originated in the early 2000s and gained particular prominence after 2010, especially in the context of the United Kingdom National Ecosystem Assessment (UK NEA). It constitutes a major methodological development to overcome the limitations of conventional nonmarket valuation methods by incorporating deliberative group elements (information provision, discussion, time to reflect in a group setting) in the valuation process.
DMV approaches range from those that focus on facilitating individual preference formation for complex and unfamiliar environmental changes and stay close to neoclassical economic theory to those that try to go beyond methodological individualism and monetary valuation to include a plurality of different values. The theoretical foundation of DMV comprises a mix of economic welfare theory, on the one hand, and various strands of deliberative democratic theory and discourse ethics, on the other. DMV formats are mostly inspired by deliberative institutions such as citizens’ juries and combine those with stated preference methods such as choice experiments. While the diversity of approaches within this field is large, it has been demonstrated that deliberation can lead to more well-informed and stable preferences as well as facilitate the inclusion of considerations going beyond self-interest. Future research challenges surrounding DMV include the exploration of intergroup power relations and group dynamics as well as the theoretical status and the validity of DMV results.
P.S. Goh, A.F. Ismail, and N. Hilal
Water scarcity as an outcome of global population expansion, climate change, and industrialization calls for new and innovative technologies to provide sustainable solutions to address this alarming issue. Seawater and brackish water are abundantly available on earth for drinking water and industrial use, and desalination is a promising approach to resolving this global challenge. Recently, the considerable reduction in the cost of desalination has contributed to the growing capacity for global desalination. The desalination technologies that have been deployed worldwide for clean water production can be categorized into two main types: membrane-based and thermal-based. Technological advancement in this field has focused on the reduction of capital and operating cost, particularly the energy consumption of the systems. Seawater and brackish desalination technologies are promising solutions for water shortages.
Throughout the 1900s, the warmth of the current interglaciation was viewed as completely natural in origin (prior to greenhouse-gas emissions during the industrial era). In the view of physical scientists, orbital variations had ended the previous glaciation and caused a warmer climate but had not yet brought it to an end. Most historians focused on urban and elite societies, with much less attention to how farmers were altering the land. Historical studies were also constrained by the fact that written records extended back a few hundred to at most 3,500 years.
The first years of the new millennium saw a major challenge to the ruling paradigm. Evidence from deep ice drilling in Antarctica showed that the early stages of the three interglaciations prior to the current one were marked by decreases in concentrations of carbon dioxide (CO2) and methane (CH4) that must have been natural in origin. During the earliest part of the current (Holocene) interglaciation, gas concentrations initially showed similar decreases, but then rose during the last 7,000–5,000 years. These anomalous (“wrong-way”) trends are interpreted by many scientists as anthropogenic, with support from scattered evidence of deforestation (which increases atmospheric CO2) by the first farmers and early, irrigated rice agriculture (which emits CH4).
During a subsequent interval of scientific give-and-take, several papers have criticized this new hypothesis. The most common objection has been that there were too few people living millennia ago to have had large effects on greenhouse gases and climate. Several land-use simulations estimate that CO2 emissions from pre-industrial forest clearance amounted to just a few parts per million (ppm), far less than the 40 ppm estimate in the early anthropogenic hypothesis. Other critics have suggested that, during the best orbital analog to the current interglaciation, about 400,000 years ago, interglacial warmth persisted for 26,000 years, compared to the 10,000-year duration of the current interglaciation (implying more warmth yet to come). A geochemical index of the isotopic composition of CO2 molecules indicates that terrestrial emissions of 12C-rich CO2 were very small prior to the industrial era.
Subsequently, new evidence has once again favored the early anthropogenic hypothesis, albeit with some modifications. Examination of cores reaching deeper into Antarctic ice reconfirm that the upward gas trends in this interglaciation differ from the average downward trends in seven previous ones. Historical data from Europe and China show that early farmers used more land per capita and emitted much more carbon than suggested by the first land-use simulations. Examination of pollen trends in hundreds of European lakes and peat bogs has shown that most forests had been cut well before the industrial era. Mapping of the spread of irrigated rice by archaeobotanists indicates that emissions from rice paddies can explain much of the anomalous CH4 rise in pre-industrial time. The early anthropogenic hypothesis is now broadly supported by converging evidence from a range of disciplines.
Benjamin S. Arbuckle
The domestication of livestock animals has long been recognized as one of the most important and influential events in human prehistory and has been the subject of scholarly inquiry for centuries. Modern understandings of this important transition place it within the context of the origins of food production in the so-called Neolithic Revolution, where it is particularly well documented in southwest Asia. Here, a combination of archaeofaunal, isotopic, and DNA evidence suggests that sheep, goat, cattle, and pigs were first domesticated over a period of several millennia within sedentary communities practicing intensive cultivation beginning at the Pleistocene–Holocene transition. Resulting from more than a century of data collection, our understanding of the chronological and geographic features of the transition from hunting to herding indicate that the 9th millennium
Regimes of environmental stress are exceedingly complex. Particular stressors exist within continua of intensity of environmental factors. Those factors interact with each other, and their detrimental effects on organisms are manifest only at relatively high or low strengths of exposure—in fact, many of them are beneficial at intermediate levels of intensity. Although a diversity of environmental factors is manifest at any time and place, only one or a few of them tend to be dominant as stressors. It is useful to distinguish between stressors that occur as severe events (disturbances) and those that are chronic in their exposure, and to aggregate the kinds of stressors into categories (while noting some degree of overlap among them).
Climatic stressors are associated with extremes of temperature, solar radiation, wind, moisture, and combinations of these factors. They act as stressors if their condition is either insufficient or excessive, in comparison with the needs and comfort zones of organisms or ecosystem processes. Chemical stressors involve environments in which the availability of certain substances is too low to satisfy biological needs, or high enough to cause toxicity or another physiological detriment to organisms or to higher-level attributes of ecosystems. Wildfire is a disturbance that involves the combustion of much of the biomass of an ecosystem, affecting organisms by heat, physical damage, and toxic substances. Physical stress is a disturbance in which an exposure to kinetic energy is intense enough to damage organisms and ecosystems (such as a volcanic blast, seismic sea wave, ice scouring, or anthropogenic explosion or trampling).
Biological stressors are associated with interactions occurring among organisms. They may be directly caused by such trophic interactions as herbivory, predation, and parasitism. They may also indirectly affect the intensity of physical or chemical stressors, as when competition affects the availability of nutrients, moisture, or space.
Extreme environments are characterized by severe regimes of stressors, which result in relatively impoverished ecosystem development. This may be a consequence of either natural or anthropogenic stressors. If a regime of environmental stress intensifies, the resulting responses include a degradation of the structure and function of affected ecosystems and of ecological integrity more generally. In contrast, a relaxation of environmental stress allows some degree of ecosystem recovery.
There are continuing developments in the analysis of hunger and famines, and the results of theoretical and empirical studies of hunger and food insecurity highlight cases where hunger intensifies sufficiently to be identified as famine. The varying ability of those affected to cope with the shocks and stresses imposed on them are central to the development of food insecurity and the emergence of famine conditions and to explaining the complex interrelationships between agriculture, famine, and economics.
There are a number of approaches to understanding how famines develop. The Malthusian approach, which sees population growth as the primary source of hunger and famine, can be contrasted with the free market or Smithian approach, which regards freely operating markets as an essential prerequisite for ensuring that famine can be overcome. A major debate has centered on whether famines primarily emerge from a decline in the availability of food or are a result of failure by households to access sufficient food for consumption, seeking to distinguish between famine as a problem related to food production and availability and famine as a problem of declining income and food consumption among certain groups in the population. These declines arise from the interaction between food markets, labor markets and markets for livestock and other productive farm resources when poor people try to cope with reduced food consumption. Further revisions to famine analysis were introduced from the mid-1990s by authors who interpreted the emergence of famines not as a failure in markets and the economic system, but more as a failure in political accountability and humanitarian response.
These approaches have the common characteristic that they seek to narrow the focus of investigation to one or a few key characteristics. Yet most of those involved in famine analysis or famine relief would stress the multi-faceted and broad-based nature of the perceived causes of famine and the mechanisms through which they emerge. In contrast to these approaches, the famine systems approach takes a broader view, exploring insights from systems theory to understand how famines develop and especially how this development might be halted, reversed, or prevented.
Economists have contributed to and informed different perspectives on famine analysis while acknowledging key contributions from moral philosophy as well as from biological and physical sciences and from political and social sciences. Malthus, Smith, and John Stuart Mill contributed substantially to early thinking on famine causation and appropriate famine interventions. Increased emphasis on famine prevention and a focus on food production and productivity led to the unarguable success of the Green Revolution. An important shift in thinking in the 1980s was motivated by Amartya Sen’s work on food entitlements and on markets for food and agricultural resources. On the other hand, the famine systems approach considers famine as a process governed by complex relationships and seeks to integrate contributions from economists and other scientists while promoting a systems approach to famine analysis.
Mark Eiswerth, Chad Lawley, and Michael H. Taylor
Introductions of non-native invasive species can harm ecosystems, heighten the risk of native species extinctions and population reductions, and lead to substantial economic damages on a worldwide scale. Increasingly, economists have made contributions that help other researchers, policymakers, and society better understand the economic implications of invasive species as well as the most economically efficient approaches for managing them. The complexity of invasive species management problems has pushed economists to ask novel economic questions and to develop new analytical approaches in order to address specific policy questions. There are three areas, in particular, where the economic analysis of invasive species management has led to significant innovations. First, there are substantial challenges to quantifying economic damages from invasive species for application in benefit−cost analysis. The challenges relate to defining the counterfactual state of an invaded ecosystem with and without management/policy and to the fact that, in a given ecosystem, estimates of economic damages are available for only a subset of the species and for only a subset of damages for any one species. Recent economic research has proposed innovative approaches to systematically dealing with these two issues in the context of invasive species that have implications for applied benefit−cost analysis more broadly. Second, unique among natural resource management problems, invasive species have the feature that their current and future extents are directly tied to a country’s participation in international trade. This feature has led to innovative research into the design of efficient measures to prevent or delay invasive species introductions along national borders, and into the trade-offs between these measures and the use of border controls as protectionist tools. The issues of optimal inspection policy and the use of nontariff barriers as a form of covert protectionism both have implications beyond invasive species management. Third, researchers have developed bioeconomic models that integrate economic and biological factors in order to analyze strategies to more cost-effectively reduce the damages caused by invasive species. These modeling efforts have dealt with issues related to temporal and spatial dynamics of the biological invasions, imperfect information regarding the extent of the invasion and the effectiveness of management, linkages between management applied at different stages of an invasion, and complications arising from ecosystems’ crossing over ecological thresholds due to invasions. In the face of increasingly rapid ecosystem change due to global climate change, increases in extreme weather, urban encroachment into wild lands, and other factors, many of these features of invasive species management problems are likely to become features of ecosystem management more broadly in the near future if they are not so already.
Dominic Moran and Jorie Knook
Climate change is already having a significant impact on agriculture through greater weather variability and the increasing frequency of extreme events. International policy is rightly focused on adapting and transforming agricultural and food production systems to reduce vulnerability. But agriculture also has a role in terms of climate change mitigation. The agricultural sector accounts for approximately a third of global anthropogenic greenhouse gas emissions, including related emissions from land-use change and deforestation. Farmers and land managers have a significant role to play because emissions reduction measures can be taken to increase soil carbon sequestration, manage fertilizer application, and improve ruminant nutrition and waste. There is also potential to improve overall productivity in some systems, thereby reducing emissions per unit of product. The global significance of such actions should not be underestimated. Existing research shows that some of these measures are low cost relative to the costs of reducing emissions in other sectors such as energy or heavy industry. Some measures are apparently cost-negative or win–win, in that they have the potential to reduce emissions and save production costs. However, the mitigation potential is also hindered by the biophysical complexity of agricultural systems and institutional and behavioral barriers limiting the adoption of these measures in developed and developing countries. This includes formal agreement on how agricultural mitigation should be treated in national obligations, commitments or targets, and the nature of policy incentives that can be deployed in different farming systems and along food chains beyond the farm gate. These challenges also overlap growing concern about global food security, which highlights additional stressors, including demographic change, natural resource scarcity, and economic convergence in consumption preferences, particularly for livestock products. The focus on reducing emissions through modified food consumption and reduced waste is a recent agenda that is proving more controversial than dealing with emissions related to production.
Maria L. Loureiro and Maria Alló
Vessel oil spills are very serious natural hazards that have affected coasts worldwide for many decades. Although oil spills from tankers are highly publicized, very little is known about the role played by the incentives and regulatory instruments in place to prevent them. In order to shed some light on these issues, data were collected worldwide on large oil spills from multiple databases, starting in the 1970s, and merged with other socioeconomic records. A crucial concern is that that large oil spills have been undercompensated over time with respect to the damages caused. A meta-analysis was estimated in order to assess relevant factors affecting the damage claimed in oil spills and the compensations received by the affected parties. Meta-regression results show that the legislation applied (strict unlimited liability versus limited liability) played a crucial role in both the amount claimed and the final compensation received. Also, time-trend variables are shown as determining factors for both the damages and claims that are finally paid. To correct the large gap between damage claimed and compensation scenarios, it is recommended to strengthen compensation funds, while carrying out more comprehensive assessment studies which apply valuation methods comparable with those proposed by green capital initiatives for marine ecosystem services, and which could be used successfully during the litigation process.
Reforestation is the natural or intentional restocking of existing forests and woodlands that have been harvested or depleted, and afforestation is the establishing of a forest in an area where there were no trees. For economic and practical purposes, reforestation and afforestation have similar goals and processes and thus can be treated as identical activities. Although reforestation and afforestation have a long history, large-scale reforestation and afforestation activities started with industrialization, which caused scarcity in timber and forest-based ecosystem services. In a unified economic model of reforestation and afforestation, factors influencing investments in reforestation and in afforestation on private and public lands include timber prices, unit reforestation cost, interest rate, the responsiveness of tree growth to silviculture, and the value of nontimber benefits, such as ecosystem services. Market and public policies may facilitate, enhance, or hinder reforestation and afforestation activities, and nontimber benefits are an increasingly important motive for reforestation and, especially, afforestation efforts around the world.
Brent M. Haddad
Watersheds are physical regions from which all arriving water flows to a single exit point. The shared hydrology means that other biophysical systems are linked, typically with upper-gradient regions influencing lower-gradient ones. This situation frames the challenge of managing economic and other uses of watersheds both in terms of individual activities and their influence on other connected processes and activities. Economics provides concepts and methods that help managers with decision making in the complex physical, biological, and institutional environment of a watershed. Among the important concepts and methods that help characterize watershed processes are externalities, impacts of economic activity that fall upon individuals not party to the activity, and third parties, individuals impacted without consent. Public goods and common pool resources describe categories of things or processes that by their nature are not amenable to regular market transactions. Their regulation requires special consideration and alternative approaches to markets. Benefit-cost analysis and valuation are related methods that provide a means to compare alternative uses of the same system. Each is based on the normative argument that the best use provides the greatest net benefits to society. And intergenerational equity is a value orientation that argues for preservation of watershed processes for the benefit of future generations. The need for effective watershed management methods pushed 20th-century economists to adapt their discipline to the complexity of watersheds, from which emerged subdisciplines of natural resource economics, environmental economics, and ecological economics. The field is still evolving with a growing interest in data gathering through land-based low-cost data collection systems and remote sensing, and in emerging data analysis techniques to improve management decisions.
Boreal countries are rich in forest resources, and for their area, they produce a disproportionally large share of the lumber, pulp, and paper bound for the global market. These countries have long-standing strong traditions in forestry education and institutions, as well as in timber-oriented forest management. However, global change, together with evolving societal values and demands, are challenging traditional forest management approaches. In particular, plantation-type management, where wood is harvested with short cutting cycles relative to the natural time span of stand development, has been criticized. Such management practices create landscapes composed of mosaics of young, even-aged, and structurally homogeneous stands, with scarcity of old trees and deadwood. In contrast, natural forest landscapes are characterized by the presence of old large trees, uneven-aged stand structures, abundant deadwood, and high overall structural diversity. The differences between managed and unmanaged forests result from the fundamental differences in the disturbance regimes of managed versus unmanaged forests. Declines in managed forest biodiversity and structural complexity, combined with rapidly changing climatic conditions, pose a risk to forest health, and hence, to the long-term maintenance of biodiversity and provisioning of important ecosystem goods and services. The application of ecosystem management in boreal forestry calls for a transition from plantation-type forestry toward more diversified management inspired by natural forest structure and dynamics.
Leon C. Braat
The concept of ecosystem services considers the usefulness of nature for human society. The economic importance of nature was described and analyzed in the 18th century, but the term ecosystem services was introduced only in 1981. Since then it has spurred an increasing number of academic publications, international research projects, and policy studies. Now a subject of intense debate in the global scientific community, from the natural to social science domains, it is also used, developed, and customized in policy arenas and considered, if in a still somewhat skeptical and apprehensive way, in the “practice” domain—by nature management agencies, farmers, foresters, and corporate business. This process of bridging evident gaps between ecology and economics, and between nature conservation and economic development, has also been felt in the political arena, including in the United Nations and the European Union (which have placed it at the center of their nature conservation and sustainable use strategies).
The concept involves the utilitarian framing of those functions of nature that are used by humans and considered beneficial to society as economic and social services. In this light, for example, the disappearance of biodiversity directly affects ecosystem functions that underpin critical services for human well-being. More generally, the concept can be defined in this manner: Ecosystem services are the direct and indirect contributions of ecosystems, in interaction with contributions from human society, to human well-being.
The concept underpins four major discussions: (1) Academic: the ecological versus the economic dimensions of the goods and services that flow from ecosystems to the human economy; the challenge of integrating concepts and models across this paradigmatic divide; (2) Social: the risks versus benefits of bringing the utilitarian argument into political debates about nature conservation (Are ecosystem services good or bad for biodiversity and vice versa?); (3) Policy and planning: how to value the benefits from natural capital and ecosystem services (Will this improve decision-making on topics ranging from poverty alleviation via subsidies to farmers to planning of grey with green infrastructure to combining economic growth with nature conservation?); and (4) Practice: Can revenue come from smart management and sustainable use of ecosystems? Are there markets to be discovered and can businesses be created? How do taxes figure in an ecosystem-based economy? The outcomes of these discussions will both help to shape policy and planning of economies at global, national, and regional scales and contribute to the long-term survival and well-being of humanity.
Elisabet Lindgren and Thomas Elmqvist
Ecosystem services refer to benefits for human societies and well-being obtained from ecosystems. Research on health effects of ecosystem services have until recently mostly focused on beneficial effects on physical and mental health from spending time in nature or having access to urban green space. However, nearly all of the different ecosystem services may have impacts on health, either directly or indirectly. Ecosystem services can be divided into provisioning services that provide food and water; regulating services that provide, for example, clean air, moderate extreme events, and regulate the local climate; supporting services that help maintain biodiversity and infectious disease control; and cultural services.
With a rapidly growing global population, the demand for food and water will increase. Knowledge about ecosystems will provide opportunities for sustainable agriculture production in both terrestrial and marine environments. Diarrheal diseases and associated childhood deaths are strongly linked to poor water quality, sanitation, and hygiene. Even though improvements are being made, nearly 750 million people still lack access to reliable water sources. Ecosystems such as forests, wetlands, and lakes capture, filter, and store water used for drinking, irrigation, and other human purposes. Wetlands also store and treat solid waste and wastewater, and such ecosystem services could become of increasing use for sustainable development.
Ecosystems contribute to local climate regulation and are of importance for climate change mitigation and adaptation. Coastal ecosystems, such as mangrove and coral reefs, act as natural barriers against storm surges and flooding. Flooding is associated with increased risk of deaths, epidemic outbreaks, and negative health impacts from destroyed infrastructure. Vegetation reduces the risk of flooding, also in cities, by increasing permeability and reducing surface runoff following precipitation events.
The urban heat island effect will increase city-center temperatures during heatwaves. The elderly, people with chronic cardiovascular and respiratory diseases, and outdoor workers in cities where temperatures soar during heatwaves are in particular vulnerable to heat. Vegetation and especially trees help in different ways to reduce temperatures by shading and evapotranspiration. Air pollution increases the mortality and morbidity risks during heatwaves. Vegetation has been shown also to contribute to improved air quality by, depending on plant species, filtering out gases and airborne particulates. Greenery also has a noise-reducing effect, thereby decreasing noise-related illnesses and annoyances. Biological control uses the knowledge of ecosystems and biodiversity to help control human and animal diseases.
Natural surroundings and urban parks and gardens have direct beneficial effects on people’s physical and mental health and well-being. Increased physical activities have well-known health benefits. Spending time in natural environments has also been linked to aesthetic benefits, life enrichments, social cohesion, and spiritual experience. Even living close to or with a view of nature has been shown to reduce stress and increase a sense of well-being.
Giles Jackson and Megan Epler Wood
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.
Ecotourism is an evolving field that originated in the 1980s, when leading conservationists explored and wrote seminal papers on how tourism could contribute to the conservation of natural areas. Hector Ceballos Lascurain coined the first definition, and the International Union for Conservation of Nature, the World Wildlife Fund, Conservation International, and The Nature Conservancy all undertook research and documentation of the benefits and potential risks of ecotourism in the 1990s. The International Ecotourism Society, founded in 1990, brought together conservation organizations and businesses to create the first definition that was globally accepted in short form: Responsible travel to natural areas that conserves the environment and sustains the well-being of local people.
Small group tour operators flourished during the 1990s, bringing travelers to a growing number of natural areas worldwide, together with top guiding, high-caliber interpretation, and strong ethical contributions to local wellbeing. Many important micro, small, and medium sized enterprises were founded in high biodiversity regions of Latin America, Asia, Africa, Antarctica, Australia, and throughout the Pacific Islands and the Caribbean, offering life-changing experiences while helping build conservation economies and inspiring positive action.
In 2015, nature-based tourism was estimated to have an economic value worldwide of hundreds of billions of dollars annually in protected areas alone, driven by the growing need of a rapidly urbanizing world to experience and reconnect with wild nature. However, this growth has not resulted in growing budgets to safeguard and manage natural areas, which are increasingly under threat. Scientific concerns that poor business practices under the guise of ecotourism might irreversibly damage fragile natural areas have led the conservation community to de-emphasize ecotourism as a conservation tool in favor of business certification. But these efforts have reached only a small percentage of the corporate sector of the eight trillion dollar global tourism industry.
Although the net economic, social, and environmental contributions of ecotourism have not been fully accounted for, the research to date has confirmed the conservation value of ecotourism—among the first examples of social enterprise. One well-documented case is Wilderness Safaris, an $89 million company operating in 58 destinations in Southern Africa in 2015, which reinvests at least 5% of its gross profit (before taxation and depreciation) to help protect the natural assets and support local communities on which the business depends. This example suggests that ecotourism can yield benefits for the conservation of biodiversity and can benefit local communities on a large scale. To increase ecotourism’s role in sustainable development, more businesses will need to scale up, and government management of tourism will require improved impact measurements, updated regulatory strategies, and effective policy mechanisms to garner a greater portion of tourism revenue.