261-280 of 298 Results

Article

Ubiquitous marine plastic pollution has become a prominent ecological issue, as it provokes implications that threaten marine species, induces health concerns, and causes vast economic damages. The complex dynamics behind its pervasive occurrence are multipronged and multidimensional, and simple clear-cut causal chains cannot always be identified. Analytical appraisals aiming to advance the understanding of pervasive plastic pollution need to address these complexities and acknowledge the interconnectedness of social and ecological systems. Orthodox economic analyses have insufficiently addressed this integration and are frequently characterized by shallow transdisciplinary and monodisciplinary approaches. As a result, several mechanisms that are highly relevant in constituting the problem tend to be neglected by presuming simplistic assumptions about human agency and inadequate nature-economy relationships. This reductionism in the conceptualization is mirrored in the policy responses that are advocated to address the issue. A broader perspective and the integration of different disciplinary concepts (such as biophysical limits as a result of the laws of thermodynamics, the notion of power, cognitive biases, institutions, and incommensurability) can underpin a more holistic perspective that considers the issue’s inherent complexities. While in a market idealist world consumers can “vote with their wallets” and transcend their values into purchasing decisions on the market, in reality there are essential difficulties to such an approach. Marine plastic pollution thus challenges economic thinking to address this real-world ecological challenge with insights that are compatible with and noncontradictory to the broad body of knowledge already elaborated by natural sciences. These perspectives are essential not only for forming a substantive interdisciplinary analysis and understanding the underlying institutions of consumption and production, clear key drivers of the problem, but also to identify promising political solutions for meaningful change.

Article

Venetia Alexa Hargreaves-Allen

Marine protected areas (MPAs) remain one of the principal strategies for marine conservation globally. MPAs are highly heterogeneous in terms of physical features such as size and shape, habitats included, management bodies undertaking management, goals, level of funding, and extent of enforcement. Economic research related to MPAs initially measured financial, gross, and net values generated by the habitats, most commonly fisheries, tourism, coastal protection, and non-use values. Bioeconomic modeling also generated important insights into the complexities of fisheries-related outcomes at MPAs. MPAs require a significant investment in public funds for design, designation, and ongoing management, which have associated opportunity costs. Therefore cost-benefit analysis has been increasingly required to justify this investment and demonstrate their benefits over time. The true economic value of MPAs is the value of protection, not the resource being protected. There is substantial evidence that MPAs should increase recreational values due to improvements in biodiversity and habitat quality, but assumptions that MPAs will generate such improvements may not be justified. Indeed, there remains no equivocal demonstration of spillover in fisheries adjacent to MPAs, due in part to the variability inherent in ecological and socio-economic processes and limited evidence of tourism benefits that are biologically or socio-cultural sustainable. There is a need for carefully designed valuation studies that compare values for areas within MPAs compared the same areas without management (the counterfactual scenario). The ecosystem service framework has become widely adopted as a way of characterizing goods and services that contribute directly or indirectly to human welfare. Quantitative analyses of the marginal changes to ecosystem services due to MPAs remains rare due to the requirements of large amounts of fine-grained data, relatively undeveloped bio-physical models for the majority of services, and the complexities of incorporating ecological nonlinearities and threshold effects. In addition while some services are synergistic (so that double counting is difficult to avoid), others are traded off. Such marginal ecosystem service values are highly context specific, which limits the accuracy associated with benefits transfer. A number of studies published since 2000 have made advances in this area, and this is a rapidly developing field of research. While MPAs have been promoted as a sustainable development tool, there is evidence of significant distributive impacts of MPAs over time, over different time scales and between different stakeholders, including unintended costs to local stakeholders. Research suggests that support and compliance is predicated on the costs and benefits generated locally, which is a major determinant of MPA performance. Better understanding of socio-economic impacts will help to align incentives with MPA objectives. Further research is needed to value supporting and regulating services and to elucidate how ecosystem service provision is affected by MPAs in different conditions and contexts, over time and compared to unmanaged areas, to guide adaptive management.

Article

Daphne Gondhalekar, Hong-Ying Hu, Zhuo Chen, Shresth Tayal, Maksud Bekchanov, Johannes Sauer, Maria Vrachioli, Mohammed Al-Azzawi, Hannah Patalong, Hans-Dietrich Uhl, Martin Grambow, and Jörg E. Drewes

With economic and population growth, industrialization, urbanization, and globalization, demand for natural resources such as water, energy, and food continues to increase, particularly in cities. Overconsumption of resources has led to degradation of the environment, a process that is interacting with and is further accelerated by a dangerous alteration to the climate. Fast growing cities worldwide already face severe technical difficulties in providing adequate infrastructure and basic services in terms of water and energy. This situation is set to become increasingly difficult with climate change impacts. The latter are increasingly affecting economically developing as well as developed countries. However, cities often have limited capacities to take comprehensive climate action. Hence, practicable, scalable, and adaptable solutions that can systematically target key entry points in cities are needed. The Water-Energy-Food (WEF) Nexus concept is one potential integrated urban planning approach offering cities a more sustainable development pathway. Within this concept, urban water reclamation with resource recovery offers a key potential: reclaimed products such as water, bioenergy, nutrients, and others are valuable resources for which markets are emerging. Reclaiming water can also reduce stress on natural resources and support the prevention of environmental pollution. Thus, it can support water, energy, and food security and the achievement of the United Nations Sustainable Development Goals. However, so far there are few implemented examples of urban water reclamation with resource recovery at urban scales. Examples of good practice in cities in China, India, and Europe highlight key enablers and barriers to the operationalization of water reclamation with resource recovery and implications in terms of environmental economics relevant for cities worldwide. These findings can support a systemic sociotechnical transition to a circular economy.

Article

The relationship between environmental ethics and the application of economic values to the environment has followed two main paths: (1) blocking attempts to value the environment economically by extending the concept of moral standing to elements of the natural world, and (2) attempting a pragmatic reconciliation that harnesses the efficacy of economic motivation while avoiding the excesses of an exclusively economic perspective. The pragmatic reconciliation must still come to grips with several ethical issues that confront environmental valuation. The fact that economics is grounded in a utilitarian consequentialism renders it susceptible to some long-standing deontological challenges having to do with rights and justice. Other challenges include a reluctance to embrace value pluralism, overly ambitious attempts at pricing, failure to incorporate deeper value commitments that do not take the form of preferences, and the inadequacies of a preference-satisfaction account of well-being.

Article

Michael Hanemann

Water marketing and property right reform are intertwined. Water markets are advocated as a solution for water scarcity, but changes in water rights are often required if the scope of water marketing is to expand. This is true in many countries, including (but not limited to) the United States and Australia. The focus here is on the United States. So far, water marketing in the Western United States is not producing long-run reallocation on the scale expected. The chief impediment is the complexities in existing water rights. An important distinction is between a property right to extract water and put it to use versus a contractual right to receive water from a supply organization. In the United States, the property right to water is a unique form of property. Unlike land, it is a right of use, not ownership; the quantity afforded by the right is incompletely specified; and the ability to transfer it is constrained by the obligation to avoid harm through the externality of return flows and also by unreliable historical records of rights. These constraints are often relaxed for short-term transfers (leases) of a property right lasting only a year or two. Also, these constraints generally do not apply to a contract right to receive water. Thus, most of the surface water transferred in the United States is either contract water moving within supply system boundaries or short-term leases of appropriative rights. These transfers tend to provide short-run flexibility for water users rather than long-run reallocation. For more significant long-run reallocation of water, some modification of the property right to water is essential. Devising a politically acceptable way to make the needed changes is the ultimate constraint on water marketing.

Article

Ahmad Abbasnejad and Behnam Abbasnejad

A qanat is a kind of subterranean horizontal tunnel and usually excavated in soft sediments. It conducts groundwater to the surface at its emerging point. In addition to the tunnel, each qanat contains anywhere from several to hundreds of vertical wells for removal of dig materials and ventilation of the tunnel. These wells get increasingly deep until the deepest and last one, which is known as the mother well. According to the literature, qanat was first developed around 800 to 1000 bc in northwest of Iran and afterward was utilized in many other countries in Asia, Africa, southern Europe, and even (through independent invention) in the Americas. The areas utilizing the qanat have three characteristics in common: the shortage of surficial water (streams) indicating an arid or semiarid climate; suitable topographical slopes that help conduct groundwater to the surface for a distance by a gently sloping tunnel (qanat); and the presence of unconsolidated sediments (usually alluvial) that both act as subsurface reservoirs and as material that can be easily excavated using primitive tools. In another words, dry areas with mountain-plain topography, alluvial fans, and stream beds (wadis) are suitable for digging qanats. Major parts of Iran and some parts of the Maghreb have such conditions. This is why these two regions have been somewhat dependent on qanats for their water supply. Although the invention of qanats helped human settlement and welfare in drier countries, it had some negative impacts. The presence of humans due to qanats directly impacted the wildlife and vegetation cover of those areas. And in some cases, changes in the groundwater regime caused wilting and drying because of limited water resources for plants and wildlife. The history of qanat development may be viewed as undergoing three major stages in the dry zones of Iran and the Maghreb, as well as in many other countries where they are present. During the first stage, from 1,000 to 2,000 years after their introduction (depending upon the region) qanats rapidly proliferated as technology spread to new areas. During the second stage, new qanat construction halted, as they had been developed in almost all suitable areas. In the third stage, beginning in some places in the early 20th century, such factors as increasing demand for groundwater, technical developments in water well drilling, and problems with qanat maintenance and urban sprawl caused many qanats to dry out; their numbers in operation have dropped. This decline will continue with varying rates in different countries. Unfortunately, the rate of decline in Iran, the home country of qanats, is more than many other places. This is mainly due to mismanagement.

Article

Juha Helenius, Alexander Wezel, and Charles A. Francis

Agroecology can be defined as scientific research on ecological sustainability of food systems. In addressing food production and consumption systems in their entirety, the focus of agroecology is on interactions and processes that are relevant for transitioning and maintaining ecological, economic, political, and social-cultural sustainability. As a field of sustainability science, agroecology explores agriculture and food with explicit linkages to two other widespread interpretations of the concept of agroecology: environmentally sound farming practices and social movements for food security and food sovereignty. In the study of agroecology as science, both farming practices and social movements emerge as integrated components of agroecological research and development. In the context of agroecology, the concept of ecology refers not only to the science of ecology as biological research but also to environmental and social sciences with research on social systems as integrated social and ecological systems. In agroecological theory, all these three are merged so that agroecology can broadly be defined as “human food ecology” or “the ecology of food systems.” Since the last decades of the 20th century many developments have led to an increased emphasis on agroecology in universities, nonprofit organizations, movements, government programs, and the United Nations. All of these have raised a growing attention to ecological, environmental, and social dimensions of farming and food, and to the question of how to make the transition to sustainable farming and food systems. One part of the foundation of agroecology was built during the 1960s when ecologically oriented environmental research on agriculture emerged as the era of optimism about component research began to erode. Largely, this took place as a reaction to unexpected and unwanted ecological and social consequences of the Green Revolution, a post–World War II scaling-up, chemicalization, and mechanization of agriculture. Another part of the foundation was a nongovernmental movement among thoughtful farmers wanting to develop sustainable and more ecological/organic ways of production and the demand by consumers for such food products. Finally, a greater societal acceptance, demand for research and education, and public funding for not only environmental ecology but also for wider sustainability in food and agriculture was ignited by an almost sudden high-level political awakening to the need for sustainable development by the end of 1980s. Agroecology as science evolved from early studies on agricultural ecosystems, from research agendas for environmentally sound farming practices, and from concerns about addressing wider sustainability; all these shared several forms of systems thinking. In universities and research institutions, agroecologists most often work in faculties of food and agriculture. They share resources and projects among scientists having disciplinary backgrounds in genetics (breeding of plants and animals), physiology (crop science, animal husbandry, human nutrition), microbiology or entomology (crop protection), chemistry and physics (soil science, agricultural and food chemistry, agricultural and food technology), economics (of agriculture and food systems), marketing, behavioral sciences (consumer studies), and policy research (agricultural and food policy). While agroecologists clearly have a mandate to address ecology of farmland, its biodiversity, and ecosystem services, one of the greatest added values from agroecology in research communities comes from its wider systems approach. Agroecologists complement reductionist research programs where scientists seek more detailed understanding of detail and mechanisms and put these into context by developing a broader appreciation of the whole. Those in agroecology integrate results from disciplinary research and increase relevance and adoption by introducing transdisciplinarity, co-creation of information and practices, together with other actors in the system. Agroecology is the field in sustainability science that is devoted to food system transformation and resilience. Agroecology uses the concept of “agroecosystem” in broad ecological and social terms and uses these at multiple scales, from fields to farms to farming landscapes and regions. Food systems depend on functioning agroecosystems as one of their subsystems, and all the subsystems of a food system interact through positive and negative feedbacks, in their complex biophysical, sociocultural, and economic dimensions. In embracing wholeness and connectivity, proponents of agroecology focus on the uniqueness of each place and food system, as well as solutions appropriate to their resources and constraints.

Article

Street-level bureaucrats (SLBs) interact directly with users and play a key role in providing services. In the Global South, and specifically in India, the work practices of frontline public workers—technical staff, field engineers, desk officers, and social workers—reflect their understanding of urban water reforms. The introduction of technology-driven solutions and new public management instruments, such as benchmarking, e-governance, and evaluation procedures, has transformed the nature of frontline staff’s responsibilities but has not solved the structural constraints they face. In regard to implementing solutions to improve access in poor neighborhoods, SLBs continue to play a key role in the making of formal and informal provision. Their daily practices are ambivalent. They can be both predatory and benevolent, which explains the contingent impacts on service improvement and the difficulty in generalizing reform experiments. Nevertheless, the discretionary power of SLBs can be a source of flexibility and adaptation to complex social settings.

Article

Raheel Anwar, Tahira Fatima, and Autar K. Mattoo

The modern-day cultivated and highly consumed tomato has come a long way from its ancestor(s), which were in the wild and not palatable. Breeding strategies made the difference in making desirable food, including tomato, available for human consumption. However, like other horticultural produce, the shelf life of tomato is short, which results in losses that can reach almost 50% of the produce, more so in developing countries than in countries with advanced technologies and better infrastructure. Food security concerns are real, especially taking into consideration that the population explosion anticipated by 2050 will require more food production and the production of more nutritious food, which applies as much to the tomato crop as the other crops. Today’s consumer has become aware and is looking for nutritious foods for a healthful and long life. Little was done until recently to generate nutritionally enhanced produce including fruits/vegetables. Also, extreme environments add to plant stress and impact yield and nutritional quality of produce. Recent developments in understandings of the plant/fruit genetics and progress made in developing genetic engineering technologies, including the use of CRISPR-Cas9, raise hopes that a better tomato with a high dose of nutrition and longer-lasting quality will become a reality.

Article

Environmental aesthetics encompasses aesthetic relationships to and in the environment, including an urban aesthetic and an aesthetic of nature—which emerged in the 18th and 19th centuries both from the sciences and from the distinction from the scientific in the aesthetic observations of nature. Environmental aesthetics notably comprises philosophical, artistic, and geographical work. Increasingly since the 1990s, the social and environmental crisis, and particularly climate change, is and has been causing shifts within this field of research and reflection. As of the 2020s, the admiration humans can bear toward nature is not without fear of its disappearance caused by their own activities. Ethics is more and more linked to aesthetics as humans are morally affected by this catastrophic environmental degradation. Thus, a certain anxiety quickly reveals itself in the face of planetary transformations. What can the geographer do? Since the 1990s, the discipline has been inviting thought about the environment from the aesthetic experience, challenging or interrogating the perception, understanding, and relationship to the natural surroundings. The geographer has been attempting to apprehend through creative research—such as “psychogeographical” situational walks (dérive, situation of inquiry, influence map), and, more generally, artistic works firmly rooted in the whole landscape question—the ways of redefining local situations and places. The need is to face three major challenges. First, there is the necessity to explore how planetary threats transform the perceptions of the environment. Anxieties reflect the difficulties of politics. Second, an aesthetic of the ordinary should be investigated as an ordinary environmentalism, meaning that which is related to the daily creation of environments. Third, the importance of research creation and ecoplastic forms of art needs to be highlighted (art and environment-making processes).

Article

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.

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

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

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

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

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.