River Basin models to inform planning decisions have continued to evolve, largely based on predominant planning paradigms and progress in the sciences and technology. From the Industrial Revolution to the first quarter of the 21st century, such modeling tools have shifted from supporting water resources development to integrated and adaptive water resources management. To account for the increasing complexity and uncertainty associated with the relevant socioecological systems in which planning should be embedded, river basin models have shifted from a supply development focus during the 19th century to include, by thes 2000s–2020s, demand management approaches and all aspects of consumptive and non-consumptive uses, addressing sociocultural and environmental issues. With technological and scientific developments, the modeling has become increasingly quantitative, integrated and interdisciplinary, attempting to capture, more holistically, multiple river basin issues, relevant cross-sectoral policy influences, and disciplinary perspectives. Additionally, in acknowledging the conflicts around ecological degradation and human impacts associated with intensive water resource developments, the modeling has matured to embrace the need for adequate stakeholder engagement processes that support knowledge-sharing and trust-building and facilitate the appreciation of trade-offs across multiple types of impacts and associated uncertainties. River basin models are now evolving to anticipate uncertainty around plausible alternative futures such as climate change and rapid sociotechnical transformations. The associated modeling now embraces the challenge of shifting from predictive to exploratory tools to support learning and reflection and better inform adaptive management and planning. Managing so-called deep uncertainty presents new challenges for river basin modeling associated with imperfect knowledge, integrating sociotechnical scales, regime shifts and human factors, and enabling collaborative modeling, infrastructure support, and management systems.
1-20 of 342 Results
Article
A Century of Evolution of Modeling for River Basin Planning to the Next Generation of Models, Methods, and Concepts
Caroline Rosello, Sondoss Elsawah, Joseph Guillaume, and Anthony Jakeman
Article
Adding Biodiversity to Agricultural Landscapes Through Ecology and Biotechnology
David Still
Agriculture is practiced on 38% of the landmass on Earth, and having replaced natural ecosystems, it is the largest terrestrial biome on Earth. Agricultural biomes are typically focused on annual crops that are produced as a succession of genetically uniform monocultures. Compared to the ecosystems they replaced, agroecosystems provide fewer ecosystem functions and contain much less biodiversity. The large-scale conversion from natural lands to agriculture occurred centuries ago in the Old World (Africa, China, Europe, and India), but in many areas during the latter 20th and early 21st centuries, especially tropical areas with rich biodiversity, agriculture is an emerging industry. Here, displacement of natural ecosystems is also a late 20th-century occurrence, and much of it is ongoing. Regardless of where or when agriculture was established, biodiversity declined and ecosystem services were eroded.
Agricultural practices are the second largest contributor to biodiversity loss, due to the loss of habitat, competition for resources, and pesticide use. Most (~96%) of the land used to produce crops is farmed using conventional methods, while smaller percentages are under organic production (~2%) or are producing biotech crops (~4%). Regardless of how agriculture is practiced, it exacts a toll on biodiversity and ecosystem services. While organic agriculture embraces many ecological principals in producing food, it fails to recognize the value of biotechnology as a tool to reduce the environmental impact of agriculture. Herbicide- and/or insect-resistant crops are the most widely planted biotech crops worldwide. Biotech crops in general, but especially insect-resistant crops, reduce pesticide use and increase biodiversity. The widespread adoption of glyphosate-resistant crops increased the use of this herbicide, and resistance evolved in weeds. On the other hand, glyphosate has less environmental impacts than other herbicides. Because of the limited scale of biotech production, it will not have large impacts on mitigating the effects of agriculture on biodiversity and ecosystem services. To have any hope of reducing the environmental impact of agriculture, agro-ecology principals and biotechnology will need to be incorporated. Monetizing biodiversity and ecosystem services through incorporation into commodity prices will incentivize producers to be part of the biodiversity solution. A multi-level biodiversity certification is proposed that is a composite score of the biodiversity and ecosystem services of an individual farm and the growing region were the food is produced. Such a system would add value to the products from farms and ranches proportionate to the level by which their farm and region provides biodiversity and ecosystem services as the natural ecosystem it replaced.
Article
Addressing Climate Change Through Education
Tamara Shapiro Ledley, Juliette Rooney-Varga, and Frank Niepold
The scientific community has made the urgent need to mitigate climate change clear and, with the ratification of the Paris Agreement under the United Nations Framework Convention on Climate Change, the international community has formally accepted ambitious mitigation goals. However, a wide gap remains between the aspirational emissions reduction goals of the Paris Agreement and the real-world pledges and actions of nations that are party to it. Closing that emissions gap can only be achieved if a similarly wide gap between scientific and societal understanding of climate change is also closed.
Several fundamental aspects of climate change make clear both the need for education and the opportunity it offers. First, addressing climate change will require action at all levels of society, including individuals, organizations, businesses, local, state, and national governments, and international bodies. It cannot be addressed by a few individuals with privileged access to information, but rather requires transfer of knowledge, both intellectually and affectively, to decision-makers and their constituents at all levels. Second, education is needed because, in the case of climate change, learning from experience is learning too late. The delay between decisions that cause climate change and their full societal impact can range from decades to millennia. As a result, learning from education, rather than experience, is necessary to avoid those impacts.
Climate change and sustainability represent complex, dynamic systems that demand a systems thinking approach. Systems thinking takes a holistic, long-term perspective that focuses on relationships between interacting parts, and how those relationships generate behavior over time. System dynamics includes formal mapping and modeling of systems, to improve understanding of the behavior of complex systems as well as how they respond to human or other interventions. Systems approaches are increasingly seen as critical to climate change education, as the human and natural systems involved in climate change epitomize a complex, dynamic problem that crosses disciplines and societal sectors.
A systems thinking approach can also be used to examine the potential for education to serve as a vehicle for societal change. In particular, education can enable society to benefit from climate change science by transferring scientific knowledge across societal sectors. Education plays a central role in several processes that can accelerate social change and climate change mitigation. Effective climate change education increases the number of informed and engaged citizens, building social will or pressure to shape policy, and building a workforce for a low-carbon economy. Indeed, several climate change education efforts to date have delivered gains in climate and energy knowledge, affect, and/or motivation. However, society still faces challenges in coordinating initiatives across audiences, managing and leveraging resources, and making effective investments at a scale that is commensurate with the climate change challenge. Education is needed to promote informed decision-making at all levels of society.
Article
Aerosols and Their Impact on Radiation, Clouds, Precipitation, and Severe Weather Events
Zhanqing Li, Daniel Rosenfeld, and Jiwen Fan
Aerosols (tiny solid or liquid particles suspended in the atmosphere) have been in the forefront of environmental and climate change sciences as the primary atmospheric pollutant and external force affecting Earth’s weather and climate. There are two dominant mechanisms by which aerosols affect weather and climate: aerosol-radiation interactions (ARIs) and aerosol-cloud interactions (ACIs). ARIs arise from aerosol scattering and absorption, which alter the radiation budgets of the atmosphere and surface, while ACIs are connected to the fact that aerosols serve as cloud condensation nuclei and ice nuclei. Both ARIs and ACIs are coupled with atmospheric dynamics to produce a chain of complex interactions with a large range of meteorological variables that influence both weather and climate. Elaborated here are the impacts of aerosols on the radiation budget, clouds (microphysics, structure, and lifetime), precipitation, and severe weather events (lightning, thunderstorms, hail, and tornadoes). Depending on environmental variables and aerosol properties, the effects can be both positive and negative, posing the largest uncertainties in the external forcing of the climate system. This has considerably hindered the ability to project future climate changes and make accurate numerical weather predictions.
Article
Agricultural Dispersals in Mediterranean and Temperate Europe
Aurélie Salavert
Along with ceramics production, sedentism, and herding, agriculture is a major component of the Neolithic as it is defined in Europe. Therefore, the agricultural system of the first Neolithic societies and the dispersal of exogenous cultivated plants to Europe are the subject of many scientific studies. To work on these issues, archaeobotanists rely on residual plant remains—crop seeds, weeds, and wild plants—from archaeological structures like detritic pits, and, less often, storage contexts. To date, no plant with an economic value has been identified as domesticated in Western Europe except possibly opium poppy. The earliest seeds identified at archaeological sites dated to about 5500–5200 bc in the Mediterranean and Temperate Europe. The cultivated plants identified were cereals (wheat and barley), oleaginous plant (flax), and pulses (peas, lentils, and chickpeas). This crop package originated in the Fertile Crescent, where it was clearly established around 7500 bc (final Pre-Pottery Neolithic B), after a long, polycentric domestication process. From the middle of the 7th millennium bc, via the Balkan Peninsula, the pioneer Neolithic populations, with their specific economies, rapidly dispersed from east to west, following two main pathways. One was the maritime route over the northwestern basin of the Mediterranean (6200–5300 bc), and the other was the terrestrial and fluvial route in central and northwestern continental Europe (5500–4900 bc). On their trajectory, the agropastoral societies adapted the Neolithic founder crops from the Middle East to new environmental conditions encountered in Western Europe.
The Neolithic pioneers settled in an area that had experienced a long tradition of hunting and gathering. The Neolithization of Europe followed a colonization model. The Mesolithic groups, although exploiting plant resources such as hazelnut more or less intensively, did not significantly change the landscape. The impact of their settlements and their activities are hardly noticeable through palynology, for example. The control of the mode of reproduction of plants has certainly increased the prevalence of Homo sapiens, involving, among others, a demographic increase and the ability to settle down in areas that were not well adapted to year-round occupation up to that point. The characterization of past agricultural systems, such as crop plants, technical processes, and the impact of anthropogenic activities on the landscape, is essential for understanding the interrelation of human societies and the plant environment. This interrelation has undoubtedly changed deeply with the Neolithic Revolution.
Article
Agricultural Energy Demand and Use
David Roland-Holst
This overview article examines the historical and technical relationship between agrifood supply chains and energy services. Because agriculture is the original environmental science, all technological change in food production has environmental implications, but these are especially serious in the context of conventional energy use. Agrifood sustainability is of paramount importance to us all, and this will require lower carbon pathways for agriculture.
Article
Agricultural Innovation and Dispersal in Eastern North America
Kandace D. Hollenbach and Stephen B. Carmody
The possibility that native peoples in eastern North America had cultivated plants prior to the introduction of maize was first raised in 1924. Scant evidence was available to support this speculation, however, until the “flotation revolution” of the 1960s and 1970s. As archaeologists involved in large-scale projects began implementing flotation, paleoethnobotanists soon had hundreds of samples and thousands of seeds that demonstrated that indigenous peoples grew a suite of crops, including cucurbit squashes and gourds, sunflower, sumpweed, and chenopod, which displayed signs of domestication. The application of accelerator mass spectrometry (AMS) dating to cucurbit rinds and seeds in the 1980s placed the domestication of these four crops in the Late Archaic period 5000–3800 bp. The presence of wild cucurbits during earlier Archaic periods lent weight to the argument that native peoples in eastern North America domesticated these plants independently of early cultivators in Mesoamerica. Analyses of DNA from chenopods and cucurbits in the 2010s definitively demonstrated that these crops developed from local lineages.
With evidence in hand that refuted notions of the diffusion of plant domestication from Mesoamerica, models developed in the 1980s for the transition from foraging to farming in the Eastern Woodlands emphasized the coevolutionary relationship between people and these crop plants. As Archaic-period groups began to occupy river valleys more intensively, in part due to changing climatic patterns during the mid-Holocene that created more stable river systems, their activities created disturbed areas in which these weedy plants thrive. With these useful plants available as more productive stands in closer proximity to base camps, people increasingly used the plants, which in turn responded to people’s selection. Critics noted that these models left little room for intentionality or innovation on the part of early farmers.
Models derived from human behavioral ecology explore the circumstances in which foragers choose to start using these small-seeded plants in greater quantities. In contrast to the resource-rich valley settings of the coevolutionary models, human behavioral ecology models posit that foragers would only use these plants, which provide relatively few calories per time spent obtaining them, when existing resources could no longer support growing populations. In these scenarios, Late Archaic peoples cultivated these crops as insurance against shortages in nut supplies.
Despite their apparent differences, current iterations of both models recognize humans as agents who actively change their environments, with intentional and unintentional results. Both also are concerned with understanding the social and ecological contexts within which people began cultivating and eventually domesticating plants.
The “when” and “where” questions of domestication in eastern North America are relatively well established, although researchers continue to fill significant gaps in geographic data. These primarily include regions where large-scale contract archaeology projects have not been conducted. Researchers are also actively debating the “how” and “why” of domestication, but the cultural ramifications of the transition from foraging to farming have yet to be meaningfully incorporated into the archaeological understanding of the region. The significance of these native crops to the economies of Late Archaic and subsequent Early and Middle Woodland peoples is poorly understood and often woefully underestimated by researchers. The socioeconomic roles of these native crops to past peoples, as well as the possibilities for farmers and cooks to incorporate them into their practices in the early 21st century, are exciting areas for new research.
Article
Agricultural Methanogenesis
Alexander N. Hristov
Agriculture is a significant source of methane, contributing about 12% of the global anthropogenic methane emissions. Major sources of methane from agricultural activities are fermentation in the reticulo-rumen of ruminant animals (i.e., enteric methane), fermentation in animal manure, and rice cultivation. Enteric methane is the largest agricultural source of methane and is mainly controlled by feed dry matter intake and composition of the animal diet (i.e., fiber, starch, lipids). Processes that lead to generation of methane from animal manure are similar to those taking place in the reticulo-rumen. Methane emissions from manure, however, are greatly influenced by factors such as manure management system and ambient temperature. Systems that handle manure as a liquid generate much more methane than systems in which manure is handled as a solid. Low ambient temperatures drastically decrease methane emissions from manure. Once applied to soil, animal manure does not generate significant amounts of methane. Globally, methane emissions from rice cultivation represent about 10% of the total agricultural greenhouse gas emissions. In the rice plant, methane dissolves in the soil water surrounding the roots, diffuses into the cell-wall water of the root cells, and is eventually released through the micropores in the leaves. Various strategies have been explored to mitigate agricultural methane emissions. Animal nutrition, including balancing dietary nutrients and replacement of fiber with starch or lipids; alternative sinks for hydrogen; manipulation of ruminal fermentation; and direct inhibition of methanogenesis have been shown to effectively decrease enteric methane emissions. Manure management solutions include solid-liquid separation, manure covers, flaring of generated methane, acidification and cooling of manure, and decreasing manure storage time before soil application. There are also effective mitigation strategies for rice that can be categorized broadly into selection of rice cultivars, water regime, and fertilization. Alternate wetting and drying and mid-season drainage of rice paddies have been shown to be very effective practices for mitigating methane emissions from rice production.
Article
Agricultural Nitrogen and Phosphorus Pollution in Surface Waters
Marianne Bechmann and Per Stålnacke
Nutrient pollution can have a negative impact on the aquatic environment, with loss of biodiversity, toxic algal blooms, and a deficiency in dissolved oxygen in surface waters. Agricultural production is one of the main contributors to these problems; this article provides an overview of and background for the main biogeochemical processes causing agricultural nutrient pollution of surface waters. It discusses the main features of the agricultural impact on nutrient loads to surface waters, focusing on nitrogen and phosphorus, and describes some of the main characteristics of agricultural management, including processes and pathways from soil to surface waters. An overview of mitigation measures to reduce pollution, retention in the landscape, and challenges regarding quantification of nutrient losses are also dealt with. Examples are presented from different spatial scales, from field and catchment to river basin scale.
Article
Agricultural Origins and Their Consequences in Southwestern Asia
Alan H. Simmons
Despite millennia of success as hunters and gatherers, some human groups made a monumental transition to agricultural economies and more sedentary lifeways, broadly referred to as the “Neolithic.” This major tipping point in human history first occurred around 12,000 years ago in Southwest Asia and the eastern Mediterranean, where it is also the best documented. Much research has focused on the origins of agriculture, asking questions about why this event occurred after so much success at hunting and gathering. While early investigations concentrated on the economic significance of the Neolithic, studies in the late 20th century and continuing into the early 21st century also address what are perhaps more significant issues related to social, ritual, political, and ecological aspects of the Neolithic. Equally important is a focus on not only why the Neolithic first occurred, but also its consequences. These often are addressed in relation to the subsequent development of so-called civilizations and the environmental and social impacts that these had, but increasingly there are investigations of the consequences of the Neolithic within itself.
These consequences refer to Neolithic societies on both the Near Eastern mainlands and adjacent Mediterranean islands. These include not only economic consequences but also ones related to social organization and complexity, trade, and health and disease. What is apparent is that consequential events during the Neolithic were not linear, following a predictable path. For example, there is strong evidence for substantial environmental deterioration during the Neolithic at sites such as ‘Ain Ghazal in Jordan, where adaptive responses may have included divisions of domestic animal and plant resources. However, in Cyprus, where the Neolithic is now known to be as early as it was on the mainlands, evidence is limited for severe ecological degradation throughout the period. Thus, Neolithic consequences must be examined from a broad perspective, considering both successes and failures.
Article
Agricultural Practices and Environmental Impacts of Aztec and Pre-Aztec Central Mexico
Deborah L. Nichols
The Basin of Mexico is a key world region for understanding agricultural intensification and the development of ancient and historic cities and states. Archaeologists working in the region have had a long-standing interest in understanding the dynamics of interactions between society and environment and their research has been at the forefront of advances in both method and theory. The Basin of Mexico was the geopolitical core of the Aztec empire, the largest state in the history of Mesoamerica. Its growth was sustained by a complex economy that has been the subject of much research.
Two themes underlie a broad interest in the pre-Hispanic agriculture of the Basin of Mexico. First, how with a Neolithic technology did the Aztecs and their predecessors sustain the growth of large cites, dense rural populations, and the largest state system in the history of pre-Hispanic Mesoamerica? Second, what is the relationship of agricultural intensification and urbanization and state formation? Mesoamerica is the only world region where primary civilizations developed that lacked domestic herbivores for either food or transportation. Their farming depended entirely on human labor and hand tools but sustained large cities, dense populations, and complex social institutions. Intensive agriculture began early and was promoted by risk, ecological diversity, and social differentiation, and included irrigation, terracing, and drained fields (chinampas). Most farming was managed by smallholder households and local communities, which encouraged corporate forms of governance and collective action. Environmental impacts included erosion and deposition, but were limited compared with the degradation that took place in the colonial period.
Article
Agricultural Subsidies and the Environment
Heather Williams
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.
Article
Consequences of Agriculture in Mesopotamia, Anatolia, and the Levant
John M. Marston
The ancient Near East was one of the earliest centers of agriculture in the world, giving rise to domesticated herd animals, cereals, and legumes that today have become primary agricultural staples worldwide. Although much attention has been paid to the origins of agriculture, identifying when, where, and how plants and animals were domesticated, equally important are the social and environmental consequences of agriculture. Shortly after the advent of domestication, agricultural economies quickly replaced hunting and gathering across Mesopotamia, the Levant, and Anatolia. The social and environmental context of this transition has profound implications for understanding the rise of social complexity and incipient urbanism in the Near East.
Economic transformation accompanied the expansion of agriculture throughout small-scale societies of the Near East. These farmsteads and villages, as well as mobile pastoral groups, formed the backbone of agricultural production, which enabled tradable surpluses necessary for more expansive, community-scale economic networks. The role of such economies in the development of social complexity remains debated, but they did play an essential role in the rise of urbanism. Cities depended on agricultural specialists, including farmers and herders, to feed urban populations and to enable craft and ritual specializations that became manifest in the first cities of southern Mesopotamia. The environmental implications of these agricultural systems in the Mesopotamian lowlands, especially soil salinization, were equally substantial. The environmental implications of Mesopotamian agriculture are distinct from those accompanying the spread of agriculture to the Levant and Anatolia, where deforestation, erosion, and loss of biodiversity can be identified as the hallmarks of agricultural expansion.
Agriculture is intimately connected with the rise of territorial empires across the Near East. Such empires often controlled agricultural production closely, for both economic and strategic ends, but the methods by which they encouraged the production of specific agricultural products and the adoption of particular agricultural strategies, especially irrigation, varied considerably between empires. By combining written records, archaeological data from surveys and excavation, and paleoenvironmental reconstruction, together with the study of plant and animal remains from archaeological sites occupied during multiple imperial periods, it is possible to reconstruct the environmental consequences of imperial agricultural systems across the Near East. Divergent environmental histories across space and time allow us to assess the sustainability of the agricultural policies of each empire and to consider how resulting environmental change contributed to the success or failure of those polities.
Article
The Agriculture of Early India
Charlene Murphy and Dorian Q. Fuller
South Asia possesses a unique Neolithic transition to agricultural domestication. India has received far less attention in the quest for evidence of early agriculture than other regions of the world traditionally recognized as “centers of domestication” such as southwest Asia, western Asia, China, Mesoamerica, South America, New Guinea, and Africa. Hunter-gatherers with agricultural production appeared around the middle of the Holocene, 4000 to 1500 bce, with the cultivation of domesticates and a correspondingly more sedentary lifestyle emerging at this time. Two thousand years ago South Asia was inhabited by farmers, with densely populated river valleys, coastal plains, urban populations, states, and even empires. While some of the crops that supported these civilizations had been introduced from other regions of the world, a large proportion of these crops had local origins from wild plants native to the subcontinent.
As a case study for the origins of agriculture, South Asia has much to offer archaeologists and environmental scientists alike for understanding domestication processes and local transitions from foraging to farming as well as the ways in which early farmers adapted to and transformed the environment and regional vegetation. Information exchange from distant farmers from other agricultural centers into the subcontinent cannot be ruled out. However, it is clear that local agricultural origins occurred via a series of processes, including the dispersal of pastoral and agro-pastoral peoples across regions, the local domestication of animals and plants and the adoption by indigenous hunter-gatherers of food production techniques from neighboring cultures. Indeed, it is posited that local domestication events in India were occurring alongside agricultural dispersals from other parts of the world in an interconnected mosaic of cultivation, pastoralism, and sedentism. As humans in South Asia increasingly relied on a more restricted range of plant species, they became entangled in an increasingly fixed trajectory that allowed greater food production levels to sustain larger populations and support their developing social, cultural and food traditions.
Article
Agroecology: Principles and Practices for Diverse, Resilient, and Productive Farming Systems
Miguel A. Altieri
Agroecology is a science that applies ecological concepts and principles to the design and management of sustainable agricultural ecosystems. Inspired by the diversified models of traditional agriculture, agroecologists promote crop diversification (polycultures, crop-livestock combinations, rotations, agroforestry systems, etc.) as an effective agroecological strategy for introducing more biodiversity into agroecosystems, which in turn provides a number of ecological services to farmers, such as natural soil fertility, pest regulation, pollination, and others. The agroecological approach involves the application of blended agricultural and ecological sciences with indigenous knowledge systems. A variety of agroecological and participatory approaches have shown in many rural areas very positive outcomes, even under adverse environmental and socioeconomic conditions. Potentials include raising crop yields and total farm output, increasing stability of production through diversification, enhancing resilience of farms to climate change, improving diets and income, and conservation of the natural resource base and biodiversity. Agroecological principles can also be applied to break the monoculture nature of modern mechanized farms. Strategies include complex crop rotations, cover cropping in vineyards and fruit orchards, strip intercropping, and so on. The ultimate goal is to develop integrated diversified and resilient agroecosystems with minimal dependence on external, off-farm inputs.
Article
Agroforestry and Its Impact in Southeast Asia
Christopher Hunt
Research during the late 20th and early 21st centuries found that traces of human intervention in vegetation in Southeast Asian and Australasian forests started extremely early, quite probably close to the first colonization of the region by modern people around or before 50,000 years ago. It also identified what may be insubstantial evidence for the translocation of economically important plants during the latest Pleistocene and Early Holocene. These activities may reflect early experiments with plants which evolved into agroforestry. Early in the Holocene, land management/food procurement systems, in which trees were a very significant component, seem to have developed over very extensive areas, often underpinned by dispersal of starchy plants, some of which seem to show domesticated morphologies, although the evidence for this is still relatively insubstantial. These land management/food procurement systems might be regarded as a sort of precursor to agroforestry. Similar systems were reported historically during early Western contact, and some agroforest systems survive to this day, although they are threatened in many places by expansion of other types of land use. The wide range of recorded agroforestry makes categorizing impacts problematical, but widespread disruption of vegetational succession across the region during the Holocene can perhaps be ascribed to agroforestry or similar land-management systems, and in more recent times impacts on biodiversity and geomorphological systems can be distinguished. Impacts of these early interventions in forests seem to have been variable and locally contingent, but what seem to have been agroforestry systems have persisted for millennia, suggesting that some may offer long-term sustainability.
Article
Air Pollution and Weather Interaction in East Asia
Aijun Ding, Xin Huang, and Congbin Fu
Air pollution is one of the grand environmental challenges in developing countries, especially those with high population density like China. High concentrations of primary and secondary trace gases and particulate matter (PM) are frequently observed in the industrialized and urbanized regions, causing negative effects on the health of humans, plants, and the ecosystem.
Meteorological conditions are among the most important factors influencing day-to-day air quality. Synoptic weather and boundary layer dynamics control the dispersion capacity and transport of air pollutants, while the main meteorological parameters, such as air temperature, radiation, and relative humidity, influence the chemical transformation of secondary air pollutants at the same time. Intense air pollution, especially high concentration of radiatively important aerosols, can substantially influence meteorological parameters, boundary layer dynamics, synoptic weather, and even regional climate through their strong radiative effects.
As one of the main monsoon regions, with the most intense human activities in the world, East Asia is a region experiencing complex air pollution, with sources from anthropogenic fossil fuel combustion, biomass burning, dust storms, and biogenic emissions. A mixture of these different plumes can cause substantial two-way interactions and feedbacks in the formation of air pollutants under various weather conditions. Improving the understanding of such interactions needs more field measurements using integrated multiprocess measurement platforms, as well as more efforts in developing numerical models, especially for those with online coupled processes. All these efforts are very important for policymaking from the perspectives of environmental protection and mitigation of climate change.
Article
Air Pollution, Science, Policy, and International Negotiations
Willemijn Tuinstra
In the course of time, the framing of the air pollution issue has undergone a transformation. It is no longer viewed as either a local health issue or a transboundary problem affecting ecosystems but as a global issue that manifests at various levels and has links to various problems. This poses a challenge for processes fostering data collection, international cooperation, and science and policy networking to deal with the issue in its various manifestations. The experience at the Air Convention, officially the Convention on Long-range Transboundary Air Pollution (CLRTAP) of the United Nations Economic Commission for Europe (UN-ECE), shows that interaction between science and policymaking at various levels of scale can enhance each other if certain conditions are met. Alignment of, for example, air policy, climate policy, nitrogen policy, health policy, and biodiversity policy not only asks for cooperation at different scales (i.e., at the local, national, regional, and global levels) but also between different arenas of decision-making and negotiation. This means that joint processes of science and policy development are needed to identify where problem formulations meet, how procedures for data collection match or which indicators are comparable, and what is possible with regard to aligning sequence and focus of policymaking. These do not necessarily need to be, or even should be, processes leading to full integration of policymaking or scientific assessment. However, successful joint processes make clear to decision-makers what the (co-)benefits of certain emission reduction measures are for various policy problems while providing a more complete picture of the cost-effectiveness of these measures. History has shown that decision-makers start acting when they can see the benefits of certain policy options or when the costs of inaction exceed those of action. Policy options might range from emission reduction measures to investments in scientific infrastructure and international cooperation. It also helps when problems are viewed as relevant by those who have the power and resources to act. Observations, measurements, and scientific assessment have the potential to point to this relevance but so does informed, critical public opinion. Current international cooperation is aimed at maintaining a network of experts and continuing efforts in capacity building in countries. Also in cities, capacity building is crucial, which is more and more supported by citizen-led air quality monitoring initiatives.
Article
The Allocation of Groundwater: From Superstition to Science
Burke W. Griggs
Groundwater is a critical natural resource, but the law has always struggled with it. During the 19th and early 20th centuries, the common law developed several doctrines to allocate groundwater among competing users. The groundwater revolution of the mid-20th century produced an explosive growth in pumping worldwide—and quickly exposed the flaws of these doctrines. Legal rules predicated on land and on surface waters could not meet the challenges posed by the common-pool groundwater resource: those of understanding groundwater dynamics, quantifying the impacts of pumping on other water rights, and devising satisfactory remedies. Unfettered by received property restraints, pumping on an industrial, aquifer-wide scale depleted and contaminated aquifers, regardless of doctrine.
The groundwater revolution motivated significant legal developments. Starting in the 1970s, the Supreme Court of the United States adapted its methods for resolving interstate water disputes to include the effects of groundwater pumping. This jurisprudence has fundamentally influenced international groundwater law, including the negotiation of trans-boundary aquifer agreements. Advances in hydrogeology and computer groundwater modeling have enabled states and parties to evaluate the effects of basin-wide pumping. Nonetheless, difficult legal and governance problems remain. Which level of government—local, state, or national—should exercise jurisdiction over groundwater? What level of pumping qualifies as “safe yield,” especially when the aquifer is overdrawn? How do the demands of modern environmental law and the public trust doctrine affect groundwater rights? How can governments satisfy long-neglected claims to water justice made by Indigenous and minority communities? Innovations in groundwater management provide promising answers. The conjunctive management of surface and groundwater can stabilize water supplies, improve water quality, and protect ecosystems. Integrated water resources management seeks to holistically manage groundwater to achieve social and economic equity. Water markets can reward water conservation, attract new market participants, and encourage the migration of groundwater allocations to more valuable uses, including environmental uses.
The modern law of groundwater allocation combines older property doctrines with 21st-century regulatory ideals, but the mixture can be unstable. In nations with long-established water codes such as the United States, common-law Anglophone nations, and various European nations, groundwater law has evolved, if haltingly, to incorporate permitting systems, environmental regulation, and water markets. Elsewhere, the challenges are extreme. Long-standing calls for groundwater reform in India remain unheeded as tens of millions of unregulated tube wells pump away. In China, chronic groundwater mismanagement and aquifer contamination belie the roseate claims of national water law. Sub-Saharan nations have enacted progressive groundwater laws, but poverty, racism, and corruption have maintained grim groundwater realities. Across the field, experts have long identified the central problems and reached a rough consensus about the most effective solutions; there is also a common commitment to secure environmental justice and protect groundwater-dependent ecosystems. The most pressing legal work thus requires building practical pathways to reach these solutions and, most importantly, to connect the public with the groundwater on which it increasingly depends.
Article
Legal Regimes for Sharing Transboundary Water
Mara Tignino
The law applicable to transboundary waters is a corpus juris that dates back to the 19th century. It originally focused on regulating the uses of transboundary watercourses for navigation and commercial transport. It was crafted primarily on the European and North American continents, and it has gradually become universally applicable, thereby taking a new shape. The regulation of transboundary waters was rooted in a strict dynamic of coexistence between sovereign entities: each acted as it saw fit with respect to “its” portion of the watercourse, which was treated at the same time as the image of the territory to which it is attached.
The need for regulation only arose when uses affected the riparian states’ exercise of their “sovereign rights.” Since the 1990s, the law has tried to break away from this “classical” logic to make room for more community-based and even “ecosystem” notions based on aspects of joint management, and sometimes even pool of shared resources.
A number of treaties have been negotiated and adopted by states bordering transboundary watercourses in Europe, Asia, Africa, and the Americas. They reflect, and sometimes even develop, some of the principles and rules enacted in broader forums, such as the United Nations (UN) or its Economic Commission for Europe, or the European Union. These efforts show the steps taken in the field of transboundary waters management, but they also reveal some of its limits, as they do not always comprehend all facets of water management and protection.
