African domesticated animals, with the exception of the donkey, all came from the Near East. Some 8,000 years ago cattle, sheep, and goats came south to the Sahara which was much wetter than today. Pastoralism was an off-shoot of grain agriculture in the Near East, and those herders immigrating brought with them techniques of harvesting wild grains. With increasing aridity as the Saharan environment dried up around 5000 years ago, the herders began to control and manipulate their stands resulting in millet and sorghum domestication in the Sahel Zone, south of the Sahara. Pearl millet expanded to the south and was taken up by Bantu-speaking Iron Age farmers in the savanna areas of West Africa and then spread around the tropical forest into East Africa by 3000 b.p. As the Sahara dried up and the tsetse belts retreated, sheep and cattle also moved south. They expanded into East Africa via a tsetse-free environment of the Ethiopian highlands arriving around 4000 b.p. It took around 1000 years for the pastoralists to adapt to other epizootic diseases rife in this part of the continent before they could expand throughout the grasslands of Kenya and Tanzania. Thus, East Africa was a socially complex place 3000 years ago, with indigenous hunters, herders and farmers. This put pressure on pastoral use of the environment, so using another tsetse-free corridor from Tanzania, through Zambia to the northern Kalahari, then on to the Western Cape, herders moved to southern Africa, arriving 2000b.p. They were followed to the eastern part of South Africa by Bantu-speaking agro-pastoralists 1600 years ago who were able to use the summer rainfall area for their sorghum and millet crops.
Control and manipulation of African indigenous plants of the forest regions probably has a long history from use by hunter-gatherers, but information on this is constrained by archaeological evidence, which is poor in tropical environments due to poor preservation. Evidence for early palm oil domestication has been found in Ghana dated to around 2550b.p. Several African indigenous plants are still widely used, such as yams, but the plant which has spread most widely throughout the world is coffee, originally from Ethiopia. Alien plants, such as maize, potatoes and Asian rice have displaced indigenous plants over much of Africa.
281-300 of 312 Results
Article
Andrew B. Smith
Article
Stefanos Xenarios, Murat Yakubov, Aziza Baubekova, Olzhas Alshagirov, Zhassulan Zhalgas, and Eduardo Jr Araral
Central Asia (CA) hosts some of the world’s most complex and most extensive water management infrastructures allocated in the two major transboundary basins of the Amudarya and Syrdarya Rivers. The upstream countries of Tajikistan and Kyrgyzstan mainly utilize the rivers for hydropower and irrigation, whereas the downstream countries of Uzbekistan, Turkmenistan, and Kazakhstan primarily use them for irrigation purposes. The governance of the two river basins has been contested since Soviet times, and more so after the independence of the CA countries. The scheme of Small Basin Councils (SBCs) has been introduced in the region from 2010 to 2022 to improve local and transboundary water governance at a sub-basin and catchment level. Implementing SBCs in CA is still in the experimental phase, and its contribution to river basin management is insufficiently explored. However, there are indications that SBCs play a significant role in raising awareness of and engagement with local communities and improving local and transboundary governance management and coordination. Most important, SBCs can help resolve critical issues in agricultural water allocation, one of the most contentious issues for transboundary water governance in CA. The basin councils could become significant leverage for improving water governance on national and transboundary systems in CA by actively engaging local communities in management, planning, and administration.
Article
Erin O'Donnell and Elizabeth Macpherson
In settler colonial states like Australia and Aotearoa New Zealand, water for the environment and the water rights of Indigenous Peoples often share the common experience of being too little and too late. Water pathways have been constrained and defined by settler colonialism, and as a result, settler state water law has both a legitimacy problem, in failing to acknowledge or implement the rights of Indigenous Peoples, and a sustainability problem, as the health of water systems continues to decline. In both Australia and Aotearoa New Zealand, the focus of water law has historically been to facilitate use of the water resource to support economic development, excluding the rights of Indigenous Peoples and poorly protecting water ecosystems. However, in the early 21st century, both countries made significant advances in recognizing the needs of the environment and the rights of Indigenous Peoples. In Aotearoa New Zealand, Te Tiriti o Waitangi (the Treaty of Waitangi) provides an important bicultural and bijural framework that is beginning to influence water management. In 2017, as part of a Treaty dispute settlement, Aotearoa New Zealand passed legislation to recognize Te Awa Tupua (the Whanganui River) as a legal person and created a new collaborative governance regime for the river, embedding the interests and values of Māori at the heart of river management. In Australia, water recovery processes to increase environmental flows have been under way since the 1990s, using a combination of water buybacks and water savings through increased efficiency. There has been growing awareness of Indigenous water rights in Australia, although progress to formally return water rights to Indigenous Peoples remains glacially slow. Like Aotearoa New Zealand, in 2017, Australia also passed its first legislation that recognized a river (the Birrarung/Yarra River) as a living entity and, in doing so, formally recognized the responsibilities of the Wurundjeri Woi Wurrung people as Traditional Owners of the river. This trend toward more holistic river management under a relational paradigm, in which the relationships between peoples and places are centered and celebrated, creates a genuine opportunity for water governance in settler states that begins to address both the legitimacy and sustainability flaws in settler state water law. However, these symbolic shifts must be underpinned by relationships of genuine trust between Indigenous Peoples and the state, and they require significant investment from the state in their implementation.
Article
Wayne C. Zipperer, Robert Northrop, and Michael Andreu
At the beginning of the 21st century more than 50% of the world’s population lived in cities. By 2050, this percentage will exceed 60%, with the majority of growth occurring in Asia and Africa. As of 2020 there are 31 megacities, cities whose population exceeds 10 million, and 987 smaller cities whose populations are greater than 500 thousand but less than 5 million in the world. By 2030 there will be more than 41 megacities and 1290 smaller cities. However, not all cities are growing. In fact, shrinking cities, those whose populations are declining, occur throughout the world. Factors contributing to population decline include changes in the economy, low fertility rates, and catastrophic events. Population growth places extraordinary demand for natural resources and exceptional stress on natural systems. For example, over 13 million hectares of forest land are converted to agriculture, urban land use, and industrial forestry annually. This deforestation significantly affects both hydrologic systems and territorial habitats. Hydrologically, urbanization creates a condition called urban stream syndrome. The increase in storm runoff, caused by urbanization through the addition of impervious surfaces, alters stream flow, morphology, temperature, and water quantity and quality. In addition, leaky sewer lines and septic systems as well as the lack of sanitation systems contribute significant amounts of nutrients and organic contaminants such as pharmaceuticals, caffeine, and detergents. Ecologically, these stressors and contaminants significantly affect aquatic flora and fauna.
Habitat loss is the greatest threat to biodiversity. Urbanization not only destroys and fragments habitats but also alters the environment itself. For example, deforestation and fragmentation of forest lands lead to the degradation and loss of forest interior habitat as well as creating forest edge habitat. These changes shift species composition and abundance from urban avoiders to urban dwellers. In addition, roads and other urban features isolate populations causing local extinctions, limit dispersal among populations, increase mortality rates, and aid in the movement of invasive species. Cities often have higher ambient temperatures than rural areas, a phenomenon called the urban heat island effect. The urban heat island effect alters precipitation patterns, increases ozone production (especially during the summer), modifies biogeochemical processes, and causes stresses on humans and native species.
The negative effect of the expansion and urbanization itself can be minimized through proper planning and design. Planning with nature is not new but it has only recently been recognized that human survival is predicated on coexisting with biodiversity and native communities. How and if cities apply recommendations for sustainability depends entirely on the people themselves.
Article
Clare Heaviside
Towns and cities generally exhibit higher temperatures than rural areas for a number of reasons, including the effect that urban materials have on the natural balance of incoming and outgoing energy at the surface level, the shape and geometry of buildings, and the impact of anthropogenic heating. This localized heating means that towns and cities are often described as urban heat islands (UHIs). Urbanized areas modify local temperatures, but also other meteorological variables such as wind speed and direction and rainfall patterns. The magnitude of the UHI for a given town or city tends to scale with the size of population, although smaller towns of just thousands of inhabitants can have an appreciable UHI effect. The UHI “intensity” (the difference in temperature between a city center and a rural reference point outside the city) is on the order of a few degrees Celsius on average, but can peak at as much as 10°C in larger cities, given the right conditions. UHIs tend to be enhanced during heatwaves, when there is lots of sunshine and a lack of wind to provide ventilation and disperse the warm air. The UHI is most pronounced at night, when rural areas tend to be cooler than cities and urban materials radiate the energy they have stored during the day into the local atmosphere.
As well as affecting local weather patterns and interacting with local air pollution, the UHI can directly affect health through heat exposure, which can exacerbate minor illnesses, affect occupational performance, or increase the risk of hospitalization and even death. Urban populations can face serious risks to health during heatwaves whereby the heat associated with the UHI contributes additional warming. Heat-related health risks are likely to increase in future against a background of climate change and increasing urbanization throughout much of the world. However, there are ways to reduce urban temperatures and avoid some of the health impacts of the UHI through behavioral changes, modification of buildings, or by urban scale interventions. It is important to understand the physical properties of the UHI and its impact on health to evaluate the potential for interventions to reduce heat-related impacts.
Article
Stephan Pauleit, Rieke Hansen, Emily Lorance Rall, Teresa Zölch, Erik Andersson, Ana Catarina Luz, Luca Szaraz, Ivan Tosics, and Kati Vierikko
Urban green infrastructure (GI) has been promoted as an approach to respond to major urban environmental and social challenges such as reducing the ecological footprint, improving human health and well-being, and adapting to climate change. Various definitions of GI have been proposed since its emergence more than two decades ago. This article aims to provide an overview of the concept of GI as a strategic planning approach that is based on certain principles.
A variety of green space types exist in urban areas, including remnants of natural areas, farmland on the fringe, designed green spaces, and derelict land where successional vegetation has established itself. These green spaces, and especially components such as trees, can cover significant proportions of urban areas. However, their uneven distribution raises issues of social and environmental justice. Moreover, the diverse range of public, institutional, and private landowners of urban green spaces poses particular challenges to GI planning. Urban GI planning must consider processes of urban change, especially pressures on green spaces from urban sprawl and infill development, while derelict land may offer opportunities for creating new, biodiverse green spaces within densely built areas.
Based on ample evidence from the research literature, it is suggested that urban GI planning can make a major contribution to conserving and enhancing biodiversity, improving environmental quality and reducing the ecological footprint, adapting cities to climate change, and promoting social cohesion. In addition, GI planning may support the shift toward a green economy.
The benefits derived from urban green spaces via the provision of ecosystem services are key to meeting these challenges. The text argues that urban GI planning should build on seven principles to unlock its full potential. Four of these are treated in more detail: green-gray integration, multifunctionality, connectivity, and socially inclusive planning. Considering these principles in concert is what makes GI planning a distinct planning approach. Results from a major European research project indicate that the principles of urban GI planning have been applied to different degrees. In particular, green-gray integration and approaches to socially inclusive planning offer scope for further improvement
In conclusion, urban GI is considered to hold much potential for the transition toward more sustainable and resilient pathways of urban development. While the approach has developed in the context of the Western world, its application to the rapidly developing cities of the Global South should be a priority.
Article
Simanti Banerjee
Economics conceptualizes harmful effects to the environment as negative externalities that can be internalized through implementation of policies involving regulatory and market-based mechanisms, and behavioral economic interventions. However, effective policy will require knowledge and understanding of intended and unintended stakeholder behaviors and consequences and the context in which the policy will be implemented. This mandate is nontrivial since policies once implemented can be hard to reverse and often have irreversible consequences in the short and/or long run, leading to high social costs. Experimental economics (often in combination with other empirical evaluation methods) can help by testing policies and their impacts prior to modification of current policies, and design and implementation of new ones. Such experimental evaluation can include lab and field experiments, and choice experiments. Additionally, experimental policy evaluation should pay attention to scaling up problems and the ethical ramifications of the treatment. This would ensure that the experimental findings will remain relevant when rolled out to bigger populations (hence retaining policy makers’ interest in the method and evidence generated by it), and the treatment to internalize the externality will not create or exacerbate societal disparities and ethical challenges.
Article
The economics literature has developed various methods to recover the values for environmental commodities. Two such methods related to revealed preference are property value hedonic models and equilibrium sorting models. These strategies employ the actual decisions that households make in the real estate market to indirectly measure household demand for environmental quality. The hedonic method decomposes the equilibrium price of a house based on the house’s structural and neighborhood/environmental characteristics to recover marginal willingness to pay (MWTP). The more recent equilibrium sorting literature estimates environmental values by combining equilibrium housing outcomes with a formal model of the residential choice process. The two predominant frameworks of empirical sorting models that have been adopted in the literature are the vertical pure characteristics model (PCM) and the random utility model (RUM). Along with assumptions on the structure of preferences, a formal model of the choice process on the demand side, and a characterization of the supply side to close the model, these sorting models can predict outcomes that allow for re-equilibration of prices and endogenous attributes following a counterfactual policy change.
Innovations to the hedonic model have enabled researchers to more aptly value environmental goods in the face of complications such as non-marginal changes (i.e., identification and endogeneity concerns with respect to recovering the entire demand curve), non-stable hedonic equilibria, and household dynamic behavior. Recent advancements in the sorting literature have also allowed these models to accommodate consumer dynamic behavior, labor markets considerations, and imperfect information. These established methods to estimate demand for environmental quality are a crucial input into environmental policymaking. A better understanding of these models, their assumptions, and the potential implications on benefit estimates due to their assumptions would allow regulators to have more confidence in applying these models’ estimates in welfare calculations.
Article
Caitlin Dyckman
The concept of a uniform U.S. water policy is a fallacy, instead resembling a mythological hydra with three primary necks that broadly encapsulate the following topics: (a) water usage patterns and demands, (b) governance structures (legal and economic), and (c) evolving scientific information and analysis (projection, planning, etc.). The body, feet, and tail of the policy and planning hydra are the physical hydrologic reality of natural and built systems, responding to the heads’ decisions. During the 20th and early 21st centuries, the hydra was governed by concepts of stationarity maintenance in each of the necks, with devolved and pragmatic fragmentation in the governance and scientific information and analysis necks, as follows. Water supply achieves stationarity through physical storage and centralized infrastructure; federal engineers altered hydrologic systems for flood control, more consistent water supply, and transportation/commerce. Water governance increasingly fragmented from the heterogeneity of water users’ interests, authority, and separation between water quality and quantity. Water law and economics coevolved to buffer demand’s nonstationarity. Planning responsibility shifted from federal agencies to states, with guidance from the country’s closest effort to manifest a unified national water policy through the National Water Commission’s 1973 report recommendations, despite its lack of official enactment. Stationarity negatively impacted aquatic ecosystems through dam flow alteration, omission in water use accounting, lack of legal protection in state allocation structures, lack of a market value, and only early 21st century inclusion in federal, state, and local water planning. Climate change further stresses these existing flaws in social and physical water management systems and processes. Its extremity in the body of the hydra reverberates through each of the necks and heads in variable ways, upending stationarity and challenging already fragmentated governance capacity. Policy and planning face greater uncertainty by geographic area, necessitating adaptive water management. Water managers must ubiquitously realize greater efficiency through innovative demand reduction mechanisms and decentralized infrastructure that can withstand significant hydrological cycle alterations, including changes to peak flow and more substantial reservoir evaporation outside the stationarity envelope. Climate adaptation in water law will require additional sacrifice concurrent with the early 21st century legal allocation and acknowledgement of historically marginalized water rights. Planning approaches must increase their flexibility, relying more heavily on water governance that embraces a cooperative, holistic perspective, recognizing interreliance and connectivity to increase resilience. The federal Infrastructure Investment and Jobs Act of 2021 may be the first step toward a unified national water policy since the 1973 report. Climate change forces the question of whether to cede full water management authority to the federal government or to sustain the creative and localized solutions fomented by pragmatic federalism.
Article
Ashley Barfield and Craig E. Landry
The result of interactive dynamics of the ocean, landforms, and weather patterns, sandy beaches and dunes are a natural feature along many coastlines around the world. Their contributions to overall social welfare are multifaceted and complex. Providing water access, recreation and tourism potential, scenic beauty, and leisure amenities, sandy coastlines have witnessed extensive commercial and residential development. Intact beach–dune systems provide coastal development projects with protection from storms, erosion, flooding, and (to some extent) sea-level rise. While yielding value through capital investment, market expansion, and the enhancement of access to natural amenities, increases in buildings and infrastructure can upset the delicate dynamic equilibrium in coastal systems. This, in turn, puts beaches, dunes, wetlands, wildlife habitats, and other ecological resources at risk. Concerns about these impacts have provided the impetus for several environmental management initiatives. Critical to these initiatives is information about the multidimensional economic and social values of coastal amenities, especially beaches and dunes.
The economic valuation of beach quality and coastal ecosystem services has traditionally focused on the implementation of non-market valuation techniques, including revealed (e.g., hedonic prices and travel costs) and stated preference (e.g., contingent valuation and choice experiment) approaches, in conjunction with survey/experimental design methods. Analysis of beach quality has become a vibrant topic, especially in response to concerns about the need for climate change adaptation; the impacts of sea-level rise; worsening and more frequent storm events; and changes in ocean temperature, salinity, and alkalinity. Each of these factors can ultimately impact beaches and coastal economies. As a result, the literature has broadened to include a number of interdisciplinary studies that feature the contributions of environmental economics, marine science, applied geology, natural resource management, risk and insurance, and urban planning disciplines, among others. These collaborations have advanced the science of coastal economics and management, but many significant challenges remain. Questions about the optimal order and timing of adaptation procedures, how to balance the provision of synergistic or conflicting goods and services, and how to design dynamic models that incorporate real-world management scenarios across different jurisdictions all require further investigation.
Article
Bartosz Bartkowski
Massive population declines and species extinction have characterized the 20th and early 21st centuries. These local and global phenomena do not only involve the loss of particular species, habitats, and ecosystem services; they also result in a general reduction in biotic diversity. Ecological research has long indicated the importance of biodiversity within and across ecosystems. However, capturing the economic value of biodiversity remains a challenge.
Biodiversity is a multidimensional public good; it encompasses the diversity of genes, species, functional groups, habitats, and ecosystems. A large empirical literature in biology and ecology indicates that biodiversity has a stabilizing effect on ecosystems—the higher the biodiversity within a given ecosystem type, the more well-functioning (productive, stable, and resilient) is the ecosystem. However, the economic importance of biodiversity goes beyond this stabilizing effect.
The multidimensionality and complexity of the biodiversity concept has resulted in a multitude of approaches to its economic valuation. While the theoretical and conceptual literature has focused on biodiversity as insurance and as a pool of options, empirical studies have been much more diverse. Given the public-good nature and complexity of biodiversity, stated preference methods are particularly common. The focus on biodiversity valuation has fostered many important theoretical and methodological developments. Many estimates exist of the willingness to pay for biodiversity conservation in different countries across the world; however, relatively few studies have been conducted in developing countries despite the considerably higher biodiversity levels there as compared with the better-covered developed countries.
Valuation of biodiversity is a controversial subject, and the economic, predominantly anthropocentric approach has been criticized frequently. However, non-anthropocentric accounts of biodiversity value are problematic for their own reasons; an important question is whether biodiversity has intrinsic value and, if yes, whether this can be captured within the economic perspective. Valuation of biodiversity remains a vibrant topic at the intersections of disciplines such as ecology, environmental ethics, and economics.
Article
Edward B. Barbier
Since the 2004 Indian Ocean tsunami, there has been strong interest globally in restoring mangrove ecosystems and their potential benefits from protecting coastlines and people from damaging storms. However, the net economic gains from mangrove restoration have been variable; there have been some notable project successes but also some prominent failures. There is also an ongoing debate over whether or not the cost of mangrove restoration is justified by the benefits these ecosystems provide. Although the high costs of mangrove restoration and the risk of failure have led to criticism of such schemes, perhaps the more pertinent concern should be whether the ex post option of restoration is economically beneficial compared to preventing irreversible mangrove conversion to alternative land uses. Case studies on mangrove valuation from Brazil and Thailand illustrate the key issues underlying this concern. Since much recent mangrove restoration has been motivated by the trees’ potential storm-protection benefit, a number of studies have valued mangroves for this purpose. However, mangroves are also valued for other important benefits, such as providing collected products for local coastal communities and serving as nursery and breeding grounds for off-shore fisheries. The implications of these benefits for mangrove restoration can be significant. It is also important to understand the appropriate use of benefit transfer when it is difficult to value restored mangroves, methods to incorporate the potential risk of mangrove restoration failure, and assessment of cost-effective mangrove restoration.
Article
Achilleas Vassilopoulos and Phoebe Koundouri
Water accounts for more than 70% of Earth’s surface, making marine ecosystems the largest and most important ecosystems of the planet. However, the fact that a large part of these ecosystems and their potential contribution to humans remains unexplored has rendered them unattractive for valuation exercises. On the contrary, coastal zones, , being the interface between the land, the sea, and human activities competing for space and resources, have been extensively studied with the objective of marine ecosystem services valuation. Examples of marine and coastal ecosystems are open oceans, coral reefs, deep seas, hydrothermal vents, abyssal plains, wetlands, rocky and sandy shores, mangroves, kelp forests, estuaries, salt marshes, and mudflats. Although there are arguments that no classification can capture the ways in which ecosystems contribute to human well-being and support human life, very often policymakers have to decide upon alternative uses of such natural environments. Should a given wetland be preserved or converted to agricultural land? Should a mangrove be designated within the protected areas system or be used for shrimp farming? To answer these questions, one needs first to establish the philosophical basis of value within the ecosystems framework. To this end, two vastly different approaches have been proposed. On the one hand, the nonutilitarian (biocentric) approach relies on the notion of intrinsic value attached to the mere existence of a natural resource, independent of whether humans derive utility from its use (if any) or preservation. Albeit useful in philosophical terms, this approach is still far from providing unambiguous and generally accepted inputs to the tangible problem of ecosystem valuation. The utilitarian (anthropocentric) perspective, on the other hand, assumes that natural environments have value to the extent that humans derive utility from placing such value. According to the total economic value (TEV) approach, this value can be divided into “use” and “nonuse.” Use values involve some interaction with the resource, either directly or indirectly, while nonuse values are derived simply from the knowledge that natural resources and aspects of the natural environment are maintained. Existence and altruistic values fall within this latter category.
Not surprisingly, economists have long revealed a strong preference for the utilitarian approach. As a result, the valuation of marine ecosystems requires that we understand the ecosystem services they deliver and then attach a value to the services. But what tools are available to economists when valuing marine ecosystems? For the most part, ecosystem services are not traded in formal markets and thus actual prices are usually not available. Valuation techniques essentially seek different ways to estimate measures like Willingness To Pay (WTP), Willingness To Accept (WTA), or expenditures and costs. The techniques used for the valuation of ecosystem services can be divided into three main families: market-based, revealed preference, and stated preference. Finally, value-transfer methods are also used when estimates of value are available in similar contexts. All these methods have advantages and disadvantages, with different methods being suitable for different situations. Hence, extra caution is required during the design and implementation of valuation attempts.
Article
Different ecosystem values of the Amazon rainforest are surveyed in economic terms. Spatial rainforest valuation is crucial for good forest management, such as where to put the most effort to stop illegal logging and forest fires, and which areas to designate as new nationally protected areas. Three classes of economic value are identified, according to who does the valuation: values accruing to the local and regional populations (of South America); carbon values (which are global); and other global (noncarbon) values. Only the first two classes are discussed. Three types of value are separated according to ecosystem service delivered from the rainforest: provisioning services; supporting and regulating services; and cultural and other human services. Net values of provisioning services, including reduced impact logging and various non-timber forest products, are well documented for the entire Brazilian Amazon at a spatially detailed scale and amount to at least $20–50/ha/year. Less-detailed information exists about values of fish, game, and bioprospecting from the Amazon, although their total values can be shown to be sizable. Many supporting and regulating services are harder to value economically, in particular climate regulation and watershed and erosion protection. Impacts of changed rainfall when Amazon rainforest is lost have been valued at detailed scale, but with relative model values of $10–20/ha/year. Carbon values are much larger, at a carbon price of $30/ton CO2, around $14,000/ha as capitalized value. The average per-hectare value of tourism and the health benefits from having the Amazon forest are low, and such values cannot easily be pinned down to individual areas of the Amazon. Finally, the biodiversity values of the Amazon, as accruing to the local and regional population, seem to be small based on recent stated-preference work in Brazil. Most of the values related to biodiversity are likely to be global and may. in principle, be very large, but the global components are not valued here. The concept of value is discussed, and a marginal valuation concept (practically useful for policy) is favored as opposed to an average or total valuation. Marginal value can be below average value (as is likely for biodiversity and tourism), but can also in some contexts be higher. This can occur where losing forest at a local scale increases the prevalence of forest fires and where it increases forest dryness, leading to a multiplier process whereby more forest is lost. While strides have recently been made to improve rainforest valuation at both micro- and macroscales, much work still remains.
Article
Robert P. Berrens and Therese Grijalva
Against a backdrop of increasing species imperilment, there is considerable empirical evidence that preserving threatened, endangered, and rare (TER) species provides significant economic benefits to society. But efforts to measure these benefits has generated both strong methodological and philosophical criticisms. Since the 1960s, economists have developed a battery of nonmarket valuation approaches for estimating economic values associated with changes in the quantity or quality of environmental goods and services. This battery includes both revealed preference and stated preference (SP) approaches (including the contingent valuation [CV] method), with only the latter capable of providing willingness to pay (WTP) estimates for nonuse values. The total economic value of TER species preservation can include nonconsumptive use values (e.g., wildlife watching), and may be especially composed of nonuse values (e.g., based on existence value motivations).
By the early 1980s, applied CV studies focusing on TER species preservation had begun to accumulate. Early research centered in the United States. By the mid-1990s the first statistical meta-analysis of TER species NMV studies was completed, and was then updated a dozen years later. These metaregression functions facilitated potential benefit transfers, where the systematic structure of prior original studies could be used to estimate WTP values for a TER species in another setting (absent an original study). Since roughly 2010, the use of choice experiments as an alternative SP approach expanded rapidly. Likewise, the accumulation of additional SP studies generated new summary reviews and meta-analyses, including applications from both developed and developing countries, and expanded benefit transfer opportunities. Going forward, new studies will lead to updated meta-analyses, with additional statistical and theoretical sophistication. Critiques targeted to SP approaches (e.g., with respect to hypothetical bias and nonuse value motivations) will likely remain, and further validity testing and methods development are called for. However, from a pragmatic perspective, persistent efforts at quantification continue to help make the benefits of TER species preservation visible in the face of rapidly increasing species imperilment.
Article
Alexandra Dehnhardt, Kati Häfner, Anna-Marie Blankenbach, and Jürgen Meyerhoff
All types of wetlands around the world are heavily threatened. According to the Ramsar Convention on Wetlands, they comprise “areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish, or salt.” While they are estimated still to cover 1,280 million hectares worldwide, large shares of wetlands were destroyed during the 20th century, mainly as a result of land use changes. According to the Millennium Ecosystem Assessment (MEA), this applies above all to North America, Europe, Australia, and New Zealand, but wetlands were also heavily degraded in other parts of the world. Moreover, degradation is expected to accelerate in the future due to global environmental change. These developments are alarming because wetlands deliver a broad range of ecosystem services to societies, contributing significantly to human well-being. Among those services are water supply and purification, flood regulation, climate regulation, and opportunities for recreation, to name only a few. The benefits humans derive from those services, however, often are not reflected in markets as they are public goods in nature. Thus, arguing in favor of the preservation of wetlands requires, inter alia, to make the non-marketed economic benefits more visible and comparable to those from alternative—generally private—uses of converted wetlands, which are often much smaller. The significance of the non-market value of wetland services has been demonstrated in the literature: the benefits derived from wetlands have been one of the most frequently investigated topics in environmental economics and are integrated in meta-analyses devoted to synthesizing the present knowledge about the value of wetlands. The meta-analyses that cover both different types of wetlands in different landscapes as well as different geographical regions are supplemented by recent primary studies on topics of increasing importance such as floodplains and peatlands, as they bear, for example, a large flood regulation and climate change mitigation potential, respectively. The results underpin that the conversion of wetlands is accompanied by significant losses in benefits. Moreover, wetland preservation is economically beneficial given the large number of ecosystem services provided by wetland ecosystems. Thus, decision-making that might affect the status and amount of wetlands directly or indirectly should consider the full range of benefits of wetland ecosystems.
Article
Gianluca Grilli
Natural environments represent background settings for most outdoor recreation activities, which are important non-consumptive benefits that people obtain from nature. Recreation has been traditionally considered a non-market service because it is practiced free of charge in public spaces and therefore of secondary relevance for the economy. Although outdoor recreation in natural parks became relevant during the 19th century, the increased popularity of recreation after the Second World War required tools for the assessment of recreational benefits, which were not considered in the evaluation of investments in recreational facilities, and increasing spending for recreational equipment captured the attention of outdoor recreation as an economic sector. In the 1990s, it was observed that many recreational activities were commercialized and started being considered equally important to tourism as a means to boost the economy of local communities. The expansion of outdoor recreation is reflected in a growing interest in the economic aspects, including cost–benefit calculations of the investments in recreational facilities and research on appropriate methods to evaluate the non-market benefits of recreation. The first economic technique used for valuing recreation was the travel cost method that consisted in the assessment of a demand curve, where the demanded quantity is the number of trips to a specific site and the cost is the unit cost of travel to the destination. After this first intuition, the number of contributions on recreation valuation exponentially grew, and new methods were proposed, including methods based on stated preferences for recreation that can be used when travel cost data that reveal consumers’ behavior are not available. A regular assessment of recreational benefits has several advantages for public policy, including the evaluation of investments and information on visitor profile and preferences, income, and price elasticity, which are essential to understand the market of outdoor recreation and propose effective strategies and recreation-oriented management. The increasing environmental pressure associated with participation in outdoor recreation required effective conservation activities, which in turn posed limitations to economic activities of local communities who live in contact with natural resources. Therefore, a balance between environmental, social, and economic interests is essential for recreational destination to avail of benefits without conflicts among stakeholders.
Article
Amy W. Ando and Noelwah R. Netusil
Green stormwater infrastructure (GSI), a decentralized approach for managing stormwater that uses natural systems or engineered systems mimicking the natural environment, is being adopted by cities around the world to manage stormwater runoff. The primary benefits of such systems include reduced flooding and improved water quality. GSI projects, such as green roofs, urban tree planting, rain gardens and bioswales, rain barrels, and green streets may also generate cobenefits such as aesthetic improvement, reduced net CO2 emissions, reduced air pollution, and habitat improvement. GSI adoption has been fueled by the promise of environmental benefits along with evidence that GSI is a cost-effective stormwater management strategy, and methods have been developed by economists to quantify those benefits to support GSI planning and policy efforts. A body of multidisciplinary research has quantified significant net benefits from GSI, with particularly robust evidence regarding green roofs, urban trees, and green streets. While many GSI projects generate positive benefits through ecosystem service provision, those benefits can vary with details of the location and the type and scale of GSI installation. Previous work reveals several pitfalls in estimating the benefits of GSI that scientists should avoid, such as double counting values, counting transfer payments as benefits, and using values for benefits like avoided carbon emissions that are biased. Important gaps remain in current knowledge regarding the benefits of GSI, including benefit estimates for some types of GSI elements and outcomes, understanding how GSI benefits last over time, and the distribution of GSI benefits among different groups in urban areas.
Article
Norman Q. Arancon and Zachary Solarte
Vermiculture is the art, science, and industry of raising earthworms for baits, feeds, and composting of organic wastes. Composting through the action of earthworms and microogranisms is commonly referred to as vermicomposting. Vermiculture is an art because the technology of raising earthworms requires a comprehensive understanding of the basic requirements for growing earthworms in order to design the space and the system by which organic wastes can be processed efficiently and successfully. It is a science because the technology requires a critical understanding and consideration of the climatic requirements, nutritional needs, growth cycles, taxonomy, and species of earthworms suitable for vermicomposting in order to develop a working system that supports earthworm populations to process successfully the intended organic wastes. The nature of the organic wastes also needs to be taken into careful consideration, especially its composition, size, moisture content, and nutritional value, which will eventually determine the overall quality of the vermicomposts produced. The quality of organic wastes also determines the ability of the earthworms to consume and process them, and the rate by which they turn these wastes into valuable organic amendments. The science of vermiculture extends beyond raising earthworms. There are several lines of evidence that vermicomposts affect plant growth significantly. Vermiculture is an industry because it has evolved from a basic household bin technology to commercially scaled systems in which economic activities emanate from the cost and value of obtaining raw materials, the building of systems, and the utilization and marketing of the products, be they in solid or aqueous extract forms. Economic returns are carefully valued from the production phase to its final utilization as an organic amendment for crops.
The discussion revolves around the development of vermiculture as an art, a science, and an industry. It traces the early development of vermicomposting, which was used to manage organic wastes that were considered environmentally hazardous when disposed of improperly. It also presents the vermicomposting process, including its basic requirements, technology involved, and product characteristics, both in solid form and as a liquid extract. Research reports from different sources on the performance of the products are also provided. The discussion attempts to elucidate the mechanisms involved in plant growth and yield promotion and the suppression of pests and diseases. Certain limitations and challenges that the technology faces are presented as well.
Article
Francesca Greco, Martin Keulertz, and David Dent
Virtual water is the water contained in food, understood not only as the physical amount within the product but also as the amount of water required to generate it over time, from planting to final harvest. Despite Tony Allan defined virtual water in the context of the water needed to produce agricultural commodities, the concept has been subsequently expanded to include the water needed to produce non-agricultural commodities and industrial goods by Arjen Hoekstra, the creator of the water footprint indicator. Virtual water is a revolutionary concept because it describes something never conceptualized before: the water “embedded” in a product. Allan used virtual water “food water” and “embedded water” as interchangeable terms. Virtual water “trade” is the result of food trade: where agricultural goods are traded across countries, the water needed to produce that product in country A is, in fact, consumed in country B. Country B is therefore not consuming its own local resources when consuming imported food. Allan believed that this mechanism could alleviate irrigation water needs in water-scarce areas when food imports are in place. The virtual water content of a product (measured in liters per kilo) is provided not only by the sum of the irrigation water that has been withdrawn from surface and underground sources in order to grow crops—called “blue water.” Virtual water is also composed of the rainwater consumed by plants and persisting in agricultural soil moisture, which does not percolate down to the aquifers or go back to rivers and lakes. This second component is called “green water.” The green- and blue-water components form the total amount of water embedded in crops, and they are the two components of virtual water. Allan borrowed the concepts of green and blue water from the work of Malin Falkenmark. Virtual water and virtual water “trade” have been largely explored and studied at both local and global levels, becoming the subjects of thousands of papers between 1993 and 2022, which helped uncover global appropriation of a local resource that is unevenly distributed by nature and very often unequally “traded” by humans: water.
