Humans depend heavily on nature. Drylands are home to 2.5 billion people, but the extent to which nature contributes to people (NCP) in drylands has been little explored. We examined the global contribution of nature to people, aiming to compare drylands and non-drylands. We predicted a lower contribution in drylands than non-drylands, largely because of the sparser population densities (peoples’ needs) and more degraded status of natural resources (lower potential contribution). Consistent with expectation, nature’s contribution was about 30% lower in drylands, with significantly lower values for drylands in Asia, Oceania, Africa and South America, but no difference for Europe and North America. Differences were due mainly to lower contributions from material and regulating contributions, i.e., the regulation of air quality, climate, water quantity and flow, soil protection and the supply of woody material, and potentially, lower use by people in drylands. Predicted declines in rainfall and increasing temperature are likely to place increasing pressure on nature to contribute to human well-being in drylands. A better understanding of nature’s contributions to people would improve our ability to allocate limited resources and achieve sustainable development in drylands.

The literature on the impacts of transport corridors points to a tradeoff between income and environmental quality. We estimate the impacts of India's Golden Quadrilateral and North-South-East-West highways on income and environmental quality to test this tradeoff hypothesis. Applying the difference-in-difference method to district level data, we find that the highways increased both local income and particulate matter air pollution. The estimated increase in air pollution is robust to using an instrumental variables approach, while that in income is not. Examining heterogeneity in these impacts, we find that the income–environment tradeoff was less steep in districts with initially higher educational attainment rates because they experienced a smaller increase in air pollution due to the highways.

As a wide-reaching institutional reform, China's fiscal decentralization was launched in the early 1980s to encourage provincial economic growth by granting more financial autonomy to provincial governments. In this paper, the impact of fiscal decentralization on China's environmental quality is investigated both theoretically and empirically. A neoclassical model is developed based on the primary characteristics of China's fiscal decentralization. Using provincial panel data for the period 1995-2015, a two-equation regression model is employed to empirically verify the three propositions of the theoretical model: (1) there exists an inverted-U shaped relationship between fiscal decentralization and GDP per capita; (2) fiscal decentralization is positively related to GDP per capita at the steady state; (3) there is an inverted-U shaped Environmental Kuznets Curve relationship between pollution emissions and economic growth.

We investigate the interaction between environmental quality and fertility in an altruistic bequest model with pollution externalities created by the aggregate production. Despite the negative externality related to the endogenous childbearing decisions, parents may choose to have fewer children in the competitive economy than in the social optimum. To achieve optimality, positive taxes on childbearing are required even with an insufficient number of children, if the social discount factor equals the parents' degree of altruism. On the other hand, child allowances may constitute the optimal policy if the social discount factor exceeds the parents' degree of altruism.

Globalization of food trade in agricultural commodities is in some senses the antithesis of key concepts of sustainable agriculture. Global trade in food products distances the depletion of resources and environmental impacts of food production from the economic and social processes that drive consumption and increases the global risks from introduction of species that become pests. However, both supply and market value chains have emerged as major sub-systems in the larger global agro-food trade system that exert enormous importance over the potential for change in agricultural production at the farm level. This special issue presents studies of seven value chains that exhibit the breadth of research about value chains and their potential contributions to sustainable agriculture. They address value chains at different scales and dealing in various products. These studies contribute to the body of knowledge with a focus on lesser researched regions and products. Most important, they demonstrate the potential for value chains to enhance agricultural sustainability for rural populations and reduce food insecurity and inequities.

After decades of rapid economic development, China is facing severe environmental problems. In particular, smog in urban areas has recently attracted a great deal of scientific and media attention both domestically and internationally. Our focus in this article is on public perceptions of smog in the northern city of Tangshan, which is routinely ranked as one of the urban areas with the worst air quality in the nation. In this article, we present the results of qualitative interviews and quantitative surveys with 341 urban residents. We examine how these residents perceive and weigh the importance of various aspects related to quality of life, including their experience with air pollution. Study participants considered environmental quality an issue of lower priority than many others; however, they surprisingly ranked it over economic concerns such as jobs and income. Their responses suggest that, for many urban residents, environmental problems like smog are fundamentally linked to basic quality of life concerns such as physical health and family well-being. We interpret our findings in the context of literature on the rise of China's middle class, the rise of environmental consciousness, and the role of gender in mediating perceptions of pollution and family health. We also consider the implications of these findings for the control and remediation of air pollution in China today.

Extension workers are sensing pressure to use soils information and chemical characteristics data to guide farmers in selecting pesticides least prone to leach into groundwater. Our objective was to estimate differences in herbicide migration to groundwater under conditions typical for the Southeast Coastal Plain, and to consider how a farmer might be advised to use such knowledge in selecting herbicides. We used a simple computer code for microcomputers to predict persistence and migration of 17 herbicides through a hypothetical, coarse-textured soil typical of the Southeast Coastal Plain. Appropriate herbicides were selected for several common crop-weed problems, such as sicklepod in soybean and Palmer amaranth in corn. Groundwater was assumed to be 3.15 m below the soil surface. Herbicides selected covered a broad range of half-lives and organic carbon partition coefficients. Only after the first-order degradation rate constant was reduced by a factor of five did predicted soil water concentrations of several herbicides at the groundwater interface reach normal detection limits. Still, predicted concentrations were below the level established for health effects advisory purposes. Due to the large number of uncertainties and the inability to estimate practical benefits, we conclude that data relating to soil and herbicide characteristics cannot be used at this time to override cost effectiveness, efficacy, and other factors normally considered by farmers and Extension professionals in herbicides for weed control.

The 1996 Safe Drinking Water Act Amendments required that water utilities send quality reports to customers. We test whether receiving such reports of health violations increases purchases of bottled water using newly released data and disaggregate changes in demand at the intensive and extensive margins. We find that a water-quality violation makes American households 25 percent more likely to purchase bottled water and, among purchasers, expenditures increase 4–7 percent, both larger responses than found in previous studies. Consumers spend approximately $300 million per year—about 4 percent of annual national spending on bottled water—to avoid health risks associated with violations.

This study examines the relationship between urban forests and household income and population density in the 149 cities with populations over 40,000 in nine southeastern states. Our empirical results show that urban forest percentage across the cities has characteristics of the environmental Kuznets curve. We find that household income around $39,000 is a threshold that changes the relationship between income and urban forest coverage from negative to positive, whereas the impact of population density on urban forests is just the opposite, from positive to negative when population density is around 180 persons per square kilometer.

In a two-period overlapping-generations model with production, we consider the damaging impact of environmental degradation on health and consequently life expectancy. Despite the presence of social constant returns to capital, which would otherwise generate unbounded growth, when pollution is left unabated, the economy cannot achieve such a path. Instead, it converges either to a stationary level of capital per worker or to a cycle in which capital per worker oscillates permanently. The government's involvement in environmental preservation proves crucial for both short-term dynamics and long-term prospects of the economy. Particularly, an active policy of pollution abatement emerges as an important engine of long-run economic growth. Furthermore, by eliminating the occurrence of limit cycles, pollution abatement is also a powerful source of stabilization.

This paper discusses the three invited papers presented in the session titled “New Regulations Require New Solutions: Federal Provisions Governing Concentrated Animal Feeding Operations” (i.e., CAFOs). These papers provide an excellent review of current state and federal laws and an excellent summary of what has been and is currently being done with respect to CAFO regulation. The papers present three different policy approaches: i) alternative performance standards, ii) location-specific regulation, and iii) insurance-based underwriting of CAFO discharges. Each approach has its drawbacks; however, blending these suggested policies into current regulation would result in efficiency gains.

Over $1.7 billion has been spent on the Conservation Reserve Program (CRP) since 1985. The purpose of this study is to show that these expenditures have aided the environment. Rather than quantify changes in environmental variables, a spatial econometric model is used to test if CRP enrollments are greater in counties with poorer environmental quality. In seven of nine regions, CRP enrollments are higher in counties with an environmental concern. This positive finding justifies past expenditures by the CRP and supports continued funding as an environmental program. The CRP is targeting current environmental concerns that will lead to future improvement.

Pollution from fossil fuel use is a global problem. Studies have shown that a worsening of environmental quality has adverse effects on worker productivity and health. In this study, there is an inexhaustible natural resource that deteriorates environmental quality and affects productivity. There also exists a perfect substitute clean backstop, which is initially too costly to operate and whose costs can be reduced through investments in knowledge. Depending on the endowment of environmental quality, the optimal solution shows that the planner should only use the resource or only the backstop until a constant steady state is reached in which the polluting resource and backstop are used in fixed proportions. We show that investments in alternative technologies from the very beginning can help an economy make the eventual switch to clean energy sources, thereby attaining better environmental quality.

This paper studies optimal fiscal policy, in the form of taxation and the allocation of tax revenues between infrastructure and environmental investment, in a general-equilibrium growth model with endogenous subjective discounting. A green spending reform, defined as a reallocation of government expenditures toward the environment, can procure a double dividend by raising growth and improving environmental conditions, although the environment does not impact the production technology. Also, endogenous Ramsey fiscal policy eliminates the possibility of an “environmental and economic poverty trap.” In contrast to the case of exogenous discounting, green spending reforms are the optimal response of the Ramsey government to a rise in the agents' environmental concerns.

Landscape is important in determining the composition of aquatic assemblage, and benthic invertebrates, particularly Chironomidae, are often used as bioindicators of environmental quality because their occurrence and distribution are influenced by different land uses. The objective of this study was to evaluate the influence of different land uses, considering three landscape scales (drainage basins, riparian buffer and streams), on chironomid assemblage. We sampled streams located in an agricultural matrix by collecting chironomid larvae and water samples and performed a landscape analysis using Geographical Information System techniques. The drainage basins had a high percentage of agricultural land use; in all of the drainage basins studied, 79% of the riparian buffer was not in accordance with Brazilian law. Cricotopus proved to be a good indicator of the agricultural conditions, whereas Thienemanniella and Rheotanytarsus proved to be indicators of exposed soil. Lopescladius was more sensitive to disturbance and was positively correlated with the presence of riparian vegetation. Although the variables at the local scale (stream) were responsible for a major change in the assemblage, the landscape attributes at large scales (drainage basin and riparian buffer) generated significant effects on Chironomidae fauna. Our results suggest the importance of the conservation of two larger landscape scales to support the equilibrium and maintenance of aquatic assemblage.

The present study was undertaken in order to analyse whether macrobenthic communities can or not be used in monitoring programmes of the environmental quality of fish ponds. Functional community analysis and biotic metrics were analysed aiming at the assessment of their effectiveness in discriminating potential impacts of fish production in these systems. The macrofaunal patterns in earthen fish ponds of the Ria Formosa lagoon showed to be influenced by the input of fish food during the production cycle and by changes in abiotic parameters caused by seasonality and fish production. Polychaetes were generally dominant considering the number of taxa and abundance. The trophic functional analysis of the benthic communities showed that the deposit-feeding functional group dominated in both areas of the ponds but within water entrance areas there was an increase of suspension-feeding, carnivory and herbivory feeding modes. The presence of less trophically mixed communities within feeding areas may be related to the relative high disturbance levels of these areas. From the biotic indicators that show a differential response to organic input in fish earthen ponds, the abundance of Capitella spp. as well as the diversity (Shannon–Wiener and Margalef species richness), evenness (Pielou) and AMBI indices seem to be the best indicators to be used in monitoring studies in similar systems. Managers should pay particular attention when Capitella spp. taxa are observed within the feeding areas. Nevertheless, manipulative experiments are needed in order to test the dominance levels of Capitella spp. and the values of those indices that are of concern.

Artificial Neural Network models (ANNs) were used to predict habitat suitability for 12 macroinvertebrate taxa, usingenvironmental input variables. This modelling technique was applied to a dataset of 102 measurement series collected in 31sampling sites in the Greek river Axios. The database consisted of seven physical-chemical and seven structural variables, as wellas abundances of 90 macroinvertebrate taxa. A seasonal variable was included to allow the description of potential temporalchanges in the macroinvertebrate communities. The induced models performed well for predicting habitat suitability of themacroinvertebrate taxa. Senso-nets and sensitivity analyses revealed that dissolved oxygen concentration and the substratecomposition always played a crucial role in predicting habitat suitability of the macroinvertebrates. Although ANNs are oftenreferred to as black box prediction techniques, it was demonstrated that ANNs combined with sensitivity analyses can provideinsight in the relationship between river conditions and the occurrence of macroinvertebrates, and thus deliver new ecologicalknowledge. Consequently, these models can be useful in decision-making for river restoration and conservation management.

Environmental risks and costs associated with insecticide applications in Maine potato farming have been characterized and estimated using an Aroostook producer survey. The results of this study allow for comparison of pest management strategies based on producer concern for various aspects of the environment, including water quality, human health and animal safety. ‘Willingness to pay’ survey methodology was used to acquire an environmental cost range for insecticide use. Maine potato producers are willing to pay between $1.00 acre−1 (one acre = 0.4047ha) and $26.80acre−1 to avoid or reduce environmental risk associated with a single insecticide application. The Aroostook producer survey indicates that producers with small farms are generally willing to pay more to avoid or reduce environmental risk than producers with large farms. Mean Maine potato farm size has more than tripled over the past 40 years; therefore, concern for environmental quality on Maine potato farms could be decreasing.