Worldwide, governments subsidize agriculture at the rate of approximately 1 billion dollars per day. This figure rises to about twice that when export and biofuels production subsidies and state financing for dams and river basin engineering are included. These policies guide land use in numerous ways, including growers’ choices of crop and buyers’ demand for commodities. The three types of state subsidies that shape land use and the environment are land settlement programs, price and income supports, and energy and emissions initiatives. Together these subsidies have created perennial surpluses in global stores of cereal grains, cotton, and dairy, with production increases outstripping population growth. Subsidies to land settlement, to crop prices, and to processing and refining of cereals and fiber, therefore, can be shown to have independent and largely deleterious effect on soil fertility, fresh water supplies, biodiversity, and atmospheric carbon.
Christiane Runyan and Jeff Stehm
This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Environmental Science. Please check back later for the full article.
Eight thousand years ago, forests covered an estimated 47% of Earth’s land surface. In 2015, forests covered roughly 30% of the Earth’s land surface, a cumulative loss over the last 8,000 years of approximately 2.2 billion hectares (ha). Between 1990 and 2015, forest losses occurred at the rate of about 0.13% annually, but this rate appears to be slowing. These losses mostly occur in tropical forests (58%), followed by boreal (27%) and temperate forests (8%). Deforestation is driven by a number of direct and indirect factors and processes that vary across regions and interact in complex ways. The primary driver of deforestation is agricultural expansion (both commercial and subsistence), followed by mining, infrastructure extension, and urban expansion. Indirectly, population and economic growth increase the demand for agricultural and timber products. Global food demand will increase 70% by 2050, requiring a net increase of 70 million ha of arable land under cultivation, with approximately 80% of this expansion occurring in the tropics. Deforestation is affected by other indirect factors such as land tenure uncertainties, poor governance, low capacity of public forestry agencies, and inadequate planning and monitoring. Forest loss has a number of environmental, economic, and social implications. Environmentally, forests provide an expansive range of benefits across local, regional, and global scales, including hydrological benefits (e.g., regulating water supply and river discharge), climate benefits (e.g., precipitation recycling, regulating local and global temperature, and indirectly, by taking up atmospheric CO2 during photosynthesis), biogeochemical benefits (e.g., enhancing nutrient availability and reducing nutrient losses), and by supporting greater biodiversity as well as ecosystem stability and resiliency, to name a few. The loss of forest vegetation may negatively affect important ecosystem processes and services, and may induce bistable ecosystem dynamics. The existence of bistable ecosystem dynamics in some forest ecosystems suggests that these forests are prone to abrupt and irreversible shifts to a stable and often degraded state with no trees. In addition to environmental impacts, the long-term loss of forest resources negatively affects societies. About 8% (450 million) of the world’s population live in forest ecosystems, with an estimated 350 million people entirely dependent on forest ecosystems for their livelihoods. The forest sector, in 2011, contributed an estimated total amount of USD 600 billion to global GDP, or about 0.9% of global GDP. Understanding how to best manage forest resources to preserve their unique qualities is a challenge that will require an integrated and concentrated effort from scientists and policymakers alike. In particular, improving forest management will require being able to more accurately measure and monitor forest resources, identifying the trade-offs between competing objectives, valuing forest goods and services, and equitably balancing costs and benefits. On the policy front, approaches to strengthen land tenure and property rights, reduce corruption, improve the capacity of public agencies, and develop more inclusive governance arrangements are needed. Underlying these management and policy goals is the need to better understand the environmental processes occurring in forests—to improve their management, minimize adverse impacts, and strengthen our models of these systems, because the long-term loss of forest resources affects not only the functioning of ecosystems but also the societies whose health and livelihoods depend upon them.
P.S. Goh, A.F. Ismail, and N. Hilal
Water scarcity as an outcome of global population expansion, climate change, and industrialization calls for new and innovative technologies to provide sustainable solutions to address this alarming issue. Seawater and brackish water are abundantly available on earth for drinking water and industrial use, and desalination is a promising approach to resolving this global challenge. Recently, the considerable reduction in the cost of desalination has contributed to the growing capacity for global desalination. The desalination technologies that have been deployed worldwide for clean water production can be categorized into two main types: membrane-based and thermal-based. Technological advancement in this field has focused on the reduction of capital and operating cost, particularly the energy consumption of the systems. Seawater and brackish desalination technologies are promising solutions for water shortages.
Brent M. Haddad
Watersheds are physical regions from which all arriving water flows to a single exit point. The shared hydrology means that other biophysical systems are linked, typically with upper-gradient regions influencing lower-gradient ones. This situation frames the challenge of managing economic and other uses of watersheds both in terms of individual activities and their influence on other connected processes and activities. Economics provides concepts and methods that help managers with decision making in the complex physical, biological, and institutional environment of a watershed. Among the important concepts and methods that help characterize watershed processes are externalities, impacts of economic activity that fall upon individuals not party to the activity, and third parties, individuals impacted without consent. Public goods and common pool resources describe categories of things or processes that by their nature are not amenable to regular market transactions. Their regulation requires special consideration and alternative approaches to markets. Benefit-cost analysis and valuation are related methods that provide a means to compare alternative uses of the same system. Each is based on the normative argument that the best use provides the greatest net benefits to society. And intergenerational equity is a value orientation that argues for preservation of watershed processes for the benefit of future generations. The need for effective watershed management methods pushed 20th-century economists to adapt their discipline to the complexity of watersheds, from which emerged subdisciplines of natural resource economics, environmental economics, and ecological economics. The field is still evolving with a growing interest in data gathering through land-based low-cost data collection systems and remote sensing, and in emerging data analysis techniques to improve management decisions.
Boreal countries are rich in forest resources, and for their area, they produce a disproportionally large share of the lumber, pulp, and paper bound for the global market. These countries have long-standing strong traditions in forestry education and institutions, as well as in timber-oriented forest management. However, global change, together with evolving societal values and demands, are challenging traditional forest management approaches. In particular, plantation-type management, where wood is harvested with short cutting cycles relative to the natural time span of stand development, has been criticized. Such management practices create landscapes composed of mosaics of young, even-aged, and structurally homogeneous stands, with scarcity of old trees and deadwood. In contrast, natural forest landscapes are characterized by the presence of old large trees, uneven-aged stand structures, abundant deadwood, and high overall structural diversity. The differences between managed and unmanaged forests result from the fundamental differences in the disturbance regimes of managed versus unmanaged forests. Declines in managed forest biodiversity and structural complexity, combined with rapidly changing climatic conditions, pose a risk to forest health, and hence, to the long-term maintenance of biodiversity and provisioning of important ecosystem goods and services. The application of ecosystem management in boreal forestry calls for a transition from plantation-type forestry toward more diversified management inspired by natural forest structure and dynamics.
Leon C. Braat
The concept of ecosystem services considers the usefulness of nature for human society. The economic importance of nature was described and analyzed in the 18th century, but the term ecosystem services was introduced only in 1981. Since then it has spurred an increasing number of academic publications, international research projects, and policy studies. Now a subject of intense debate in the global scientific community, from the natural to social science domains, it is also used, developed, and customized in policy arenas and considered, if in a still somewhat skeptical and apprehensive way, in the “practice” domain—by nature management agencies, farmers, foresters, and corporate business. This process of bridging evident gaps between ecology and economics, and between nature conservation and economic development, has also been felt in the political arena, including in the United Nations and the European Union (which have placed it at the center of their nature conservation and sustainable use strategies).
The concept involves the utilitarian framing of those functions of nature that are used by humans and considered beneficial to society as economic and social services. In this light, for example, the disappearance of biodiversity directly affects ecosystem functions that underpin critical services for human well-being. More generally, the concept can be defined in this manner: Ecosystem services are the direct and indirect contributions of ecosystems, in interaction with contributions from human society, to human well-being.
The concept underpins four major discussions: (1) Academic: the ecological versus the economic dimensions of the goods and services that flow from ecosystems to the human economy; the challenge of integrating concepts and models across this paradigmatic divide; (2) Social: the risks versus benefits of bringing the utilitarian argument into political debates about nature conservation (Are ecosystem services good or bad for biodiversity and vice versa?); (3) Policy and planning: how to value the benefits from natural capital and ecosystem services (Will this improve decision-making on topics ranging from poverty alleviation via subsidies to farmers to planning of grey with green infrastructure to combining economic growth with nature conservation?); and (4) Practice: Can revenue come from smart management and sustainable use of ecosystems? Are there markets to be discovered and can businesses be created? How do taxes figure in an ecosystem-based economy? The outcomes of these discussions will both help to shape policy and planning of economies at global, national, and regional scales and contribute to the long-term survival and well-being of humanity.
Giles Jackson and Megan Epler Wood
This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Environmental Science. Please check back later for the full article.
Ecotourism is an evolving field that originated in the 1980s, when leading conservationists explored and wrote seminal papers on how tourism could contribute to the conservation of natural areas. Hector Ceballos Lascurain coined the first definition, and the International Union for Conservation of Nature, the World Wildlife Fund, Conservation International, and The Nature Conservancy all undertook research and documentation of the benefits and potential risks of ecotourism in the 1990s. The International Ecotourism Society, founded in 1990, brought together conservation organizations and businesses to create the first definition that was globally accepted in short form: Responsible travel to natural areas that conserves the environment and sustains the well-being of local people.
Small group tour operators flourished during the 1990s, bringing travelers to a growing number of natural areas worldwide, together with top guiding, high-caliber interpretation, and strong ethical contributions to local wellbeing. Many important micro, small, and medium sized enterprises were founded in high biodiversity regions of Latin America, Asia, Africa, Antarctica, Australia, and throughout the Pacific Islands and the Caribbean, offering life-changing experiences while helping build conservation economies and inspiring positive action.
In 2015, nature-based tourism was estimated to have an economic value worldwide of hundreds of billions of dollars annually in protected areas alone, driven by the growing need of a rapidly urbanizing world to experience and reconnect with wild nature. However, this growth has not resulted in growing budgets to safeguard and manage natural areas, which are increasingly under threat. Scientific concerns that poor business practices under the guise of ecotourism might irreversibly damage fragile natural areas have led the conservation community to de-emphasize ecotourism as a conservation tool in favor of business certification. But these efforts have reached only a small percentage of the corporate sector of the eight trillion dollar global tourism industry.
Although the net economic, social, and environmental contributions of ecotourism have not been fully accounted for, the research to date has confirmed the conservation value of ecotourism—among the first examples of social enterprise. One well-documented case is Wilderness Safaris, an $89 million company operating in 58 destinations in Southern Africa in 2015, which reinvests at least 5% of its gross profit (before taxation and depreciation) to help protect the natural assets and support local communities on which the business depends. This example suggests that ecotourism can yield benefits for the conservation of biodiversity and can benefit local communities on a large scale. To increase ecotourism’s role in sustainable development, more businesses will need to scale up, and government management of tourism will require improved impact measurements, updated regulatory strategies, and effective policy mechanisms to garner a greater portion of tourism revenue.
Jac van der Gun
Human behavior in relation to groundwater has remained relatively unchanged from ancient times until the early 20th century. Intercepting water from springs or exploiting shallow aquifers by means of wells or qanats was common practice worldwide, but only modest quantities of groundwater were abstracted. In general, the resource was taken for granted in absence of any knowledge regarding groundwater systems and their vulnerability. During the 20th century, however, an unprecedent change started spreading globally—a change so drastic that it could be called the Global Groundwater Revolution. It did not surface simultaneously everywhere but rather encroached into different regions as waves of change, with varied timing, depending on local conditions. This Global Groundwater Revolution has three main components: (1) rapid intensification of the exploitation of groundwater, (2) fundamentally changing views on groundwater, and (3) the emergence of integrated groundwater management and governance. These three components are mostly interdependent, although their emergence and development tend to be somewhat asynchronous. The Global Groundwater Revolution marks a radical historical change in the relation between human society and groundwater. It has taken benefits produced by groundwater to an unprecedented level, but their sustainability is assured only if there is good groundwater governance.
Maria A. Cunha-e-Sá and Sofia F. Franco
This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Environmental Science. Please check back later for the full article.
Economic development, technological change, and urbanization are typically identified as important drivers of land use change. Yet, land use change entails important environmental and socioeconomic consequences, namely by affecting the processes and functions of ecosystems, and, therefore, the provision of their services.
Urbanization comprises residential, commercial, industrial, and highway-related development. At the edge of this built environment is the urban-wildland interface (UWI), which has been the focus of environmental policies in several parts of the world. The reason rests on the fact that urban development at the UWI is linked to significant environmental damages, including air and water pollution, habitat destruction, landscape fragmentation, increased runoff, and wildfire risk, among others. These effects can reduce biological diversity and, furthermore, some of the ecosystem services (ES) can be irreversibly lost.
Though forests located nearby urban areas are a small fraction of the forest cover, a better understanding of the extent to which UWI forest conversion affects local economies and environmental services can help policymakers harmonizing urban development and environmental preservation at the UWI, with positive impact on the welfare of local communities.
The main income from most forest holdings at the UWI depends on wood production. However, forests and forestry practices also contribute to climate change mitigation. Yet, the public good nature of most forest ES distorts the forest market price below its social value. As a result, as development pressure increases, it is expected that interface traditional timber management practices become a transitional use as conversion to other valuable land use, such as residential use, occurs in the future and, the UWI open space is undervalued. This, in turn, raises concern given the current increasing trend of forestland conversion at the UWI.
Moreover, the value of developable land held by a private forest owner derives both from the returns from the current use (timber production) and from the expected returns from future urban uses. Given that the decision to convert is conditional on the relative magnitude and timing of the returns of the two alternative uses, decision-making at the UWI must reflect the factors that influence both, that is, urban (e.g., residential rents and switching costs) and forestry-related factors (e.g., stumpage prices and regeneration costs), when considering the optimal rotation periods and conversion dates. Accounting for the urban influences on UWI forestland practices is thus very important, because a growing population and increasingly land consumptive development patterns will require more effective policies and programs to stem the tide of urban sprawl seen in several municipalities worldwide.
Leslie Richardson and Bruce Peacock
Economics plays an important role not only in the management of national parks in developed countries, but also in demonstrating the contribution of these areas to societal well-being. The beneficial effect of park tourism on jobs and economic activity in communities near these protected areas has at times been a factor in their establishment. These economic impacts continue to be highlighted as a way to demonstrate the benefit and return on investment of national parks to local economies. However, the economic values supported by national parks extend far beyond local economic benefits. Parks provide unique recreation opportunities, health benefits, preservation of wildlife and habitat, and a wide range of ecosystem services that the public assigns an economic value to. In addition, value is derived from the existence of national parks and their preservation for future generations. These nonmarket benefits can be difficult to quantify, but they are essential for understanding and communicating the economic importance of parks. Economic methods used to estimate these values have been refined and tested for nearly seven decades, and they have come a long way in helping to elucidate the extent of the nonmarket benefits of protected areas.
In many developed countries, national parks have regulations and policies that outline a framework for the consideration of economic values in decision-making contexts. For instance, large oil spills in the United States, such as the Exxon Valdez spill of 1989 and the Deepwater Horizon spill of 2010, highlighted the need to better understand public values for affected park resources, leading to the extensive use of nonmarket values in natural resource damage assessments. Of course, rules and enforcement issues vary widely across countries, and the potential for economics to inform the day-to-day operations of national parks is much broader than what is currently outlined in such policies. While economics is only one piece of the puzzle in managing national parks, it provides a valuable tool for evaluating resource tradeoffs and for incorporating public preferences into the decision-making process, leading to greater transparency and assurance that national parks are managed for the benefit of society. Understanding the full extent of the economic benefits supported by national parks helps to further the mission of these protected areas in developed countries.
Tatiana Acevedo Guerrero
Since the late 20th century, water and sanitation management has been deeply influenced by ideas from economics, specifically by the doctrine of neoliberalism. The resulting set of policy trends are usually referred to as market environmentalism, which in broad terms encourages specific types of water reforms aiming to employ markets as allocation mechanisms, establish private-property rights and full-cost pricing, reduce (or remove) subsidies, and promote private sector management to reduce government interference and avoid the politicization of water and sanitation management. Market environmentalism sees water as a resource that should be efficiently managed through economic reforms.
Instead of seeing water as an external resource to be managed, alternative approaches like political ecology see water as a socio-nature. This means that water is studied as a historical-geographical process in which society and nature are inseparable, mutually produced, and transformable. Political ecological analyses understand processes of environmental change as deeply interrelated to socioeconomic dynamics. They also emphasize the impact of environmental dynamics on social relations and take seriously the question of how the physical properties of water may be sources of unpredictability, unruliness, and resistance from human intentions. As an alternative to the hydrologic cycle, political ecology proposes the concept of hydrosocial cycle, which emphasizes that water is deeply political and social. An analysis of the politics of water flows, drawing from political ecology explores the different relationships and histories reflected in access to (and exclusion from) water supply, sanitation, and drainage. It portrays how power inequalities are at the heart of differentiated levels of access to infrastructure.
Scott M. Moore
It has long been accepted that non-renewable natural resources like oil and gas are often the subject of conflict between both nation-states and social groups. But since the end of the Cold War, the idea that renewable resources like water and timber might also be a cause of conflict has steadily gained credence. This is particularly true in the case of water: in the early 1990s, a senior World Bank official famously predicted that “the wars of the next century will be fought over water,” while two years ago Indian strategist Brahma Chellaney made a splash in North America by claiming that water would be “Asia’s New Battleground.” But it has not quite turned out that way. The world has, so far, avoided inter-state conflict over water in the 21st century, but it has witnessed many localized conflicts, some involving considerable violence. As population growth, economic development, and climate change place growing strains on the world’s fresh water supplies, the relationship between resource scarcity, institutions, and conflict has become a topic of vocal debate among social and environmental scientists.
The idea that water scarcity leads to conflict is rooted in three common assertions. The first of these arguments is that, around the world, once-plentiful renewable resources like fresh water, timber, and even soils are under increasing pressure, and are therefore likely to stoke conflict among increasing numbers of people who seek to utilize dwindling supplies. A second, and often corollary, argument holds that water’s unique value to human life and well-being—namely that there are no substitutes for water, as there are for most other critical natural resources—makes it uniquely conductive to conflict. Finally, a third presumption behind the water wars hypothesis stems from the fact that many water bodies, and nearly all large river basins, are shared between multiple countries. When an upstream country can harm its downstream neighbor by diverting or controlling flows of water, the argument goes, conflict is likely to ensue.
But each of these assertions depends on making assumptions about how people react to water scarcity, the means they have at their disposal to adapt to it, and the circumstances under which they are apt to cooperate rather than to engage in conflict. Untangling these complex relationships promises a more refined understanding of whether and how water scarcity might lead to conflict in the 21st century—and how cooperation can be encouraged instead.
James B. London
Coastal zone management (CZM) has evolved since the enactment of the U.S. Coastal Zone Management Act of 1972, which was the first comprehensive program of its type. The newer iteration of Integrated Coastal Zone Management (ICZM), as applied to the European Union (2000, 2002), establishes priorities and a comprehensive strategy framework. While coastal management was established in large part to address issues of both development and resource protection in the coastal zone, conditions have changed. Accelerated rates of sea level rise (SLR) as well as continued rapid development along the coasts have increased vulnerability. The article examines changing conditions over time and the role of CZM and ICZM in addressing increased climate related vulnerabilities along the coast.
The article argues that effective adaptation strategies will require a sound information base and an institutional framework that appropriately addresses the risk of development in the coastal zone. The information base has improved through recent advances in technology and geospatial data quality. Critical for decision-makers will be sound information to identify vulnerabilities, formulate options, and assess the viability of a set of adaptation alternatives. The institutional framework must include the political will to act decisively and send the right signals to encourage responsible development patterns. At the same time, as communities are likely to bear higher costs for adaptation, it is important that they are given appropriate tools to effectively weigh alternatives, including the cost avoidance associated with corrective action. Adaptation strategies must be pro-active and anticipatory. Failure to act strategically will be fiscally irresponsible.
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.
What Is Public and What Is Private in Water Provision: Insights from Progressive Era Cities in the US Northeast
Gwynneth C. Malin
During the colonial period and into the mid-19th century, residents of US Northeast cities drew water for domestic uses from local ponds, rivers, and ground water sources. In these early urban settlements, procuring water was a daily activity and one linked to economic class. Water provision was often a blend of public and private efforts—if residents wanted a well or a sewer built in their neighborhood, they had to help pay for it. During the 19th and early 20th centuries, city officials in the US Northeast made the gradual transition from relying on private water companies to implementing the public management of water supply. As quickening urbanization and growing immigrant populations rendered local and privately managed water sources undersupplied, elected officials began to search for new sources of water.
Each city’s history is unique, but common themes include an increase in water pollution, the need to tap new water supplies further from city centers, disease prevention, fire extinction, and financial corruption, within both private water companies and municipal efforts to supply water. While most cities of the US Northeast transitioned to municipal operation of water supply during the 19th century, this shift was not without its challenges and complexity. Funding shortages often prevented change, but crises, such as fire, drought, and infectious disease outbreaks forced the hands of municipal officials. Philadelphia was first to transition to public water management in 1801, followed by New York in 1842, and Boston in 1848. In the late 19th century, New York experienced municipal delay, countered later by Progressive-era political forces that ultimately assured permanent public water management. The story of the emerging publicity of water management during this historical period sheds light on a larger narrative about the changing role of the state during the Gilded Age and the Progressive Era. It was during the 19th and early 20th centuries that the public management of water triumphed over private in the cities of the US Northeast.