Intertemporal and intergenerational Pareto efficiency

Efficiency conditions are derived for both private and public goods which provide benefits over time. In deriving these conditions, the paper extends the notion of efficiency to an intertemporal Pareto-optimal concept requiring the maximization of the ith individual's utility at a point of time subject to the constancy of his utility in all future periods and that of all other individuals during the relevant time span. By permitting births and deaths, a generalization of the basic model recasts the analysis into an intergenerational setting. Additional extensions involve learning by doing and perpetual public goods. The paper concludes that several of the conventional practices in public expenditure analysis do not conform to our definition of intertemporal Pareto efficiency.     

Review of information on pesticide residues in the Canadian environment

Summary Pesticide residues in soil, water, food, wildlife and other media have been analysed in several monitoring studies. The purpose was to establish the distribution of these residues across a defined area, ascertain their trend over a specific period and use the results to assess environmental compliance and safety. In the present review the availability of information on pesticide residues in various Canadian environmental components was sought. With the possible exception of localized pesticide contamination of some private water supply wells, ground and surface water, most analyses revealed concentrations below guideline limits. Only a few cases were reported of mishandling, misuse and poisoning from pesticides. Continuing surveillance programmes and in-depth and well-organized monitoring studies, with special focus on areas that are vulnerable to contamination, by both provincial and federal governments, are largely responsible for the encouraging results. This experience in the control of pesticide use and monitoring of residues in the environment should be of particular interest in developing countries.Dr A.Y. Sangodoyin is a senior lecturer in the Department of Agricultural Engineering at the University of Ibadan. He was recently involved in a study visit to the University of Alberta, Edmonton, Alberta, Canada T6G 2G7, where his co-author Dr D.W. Smith is a member of staff in the Department of Civil-Engineering.     

Modelling nitrogen fluxes at the landscape scale

The distribution and impacts of different nitrogen pollutants are inextricably linked. To understand the problem fully, the interactions between the different pollutants need to be taken into account. This is particularly important when it comes to abatement techniques, since measures to reduce emissions of one nitrogen pollutant can often lead to an increase in another. This project represents a step towards greater understanding of these issues by linking together new and existing nitrogen flux models into a larger framework. The modelling framework has been constructed and some of the nitrogen flows between fields, farms and the atmosphere have been modelled for a UK study area for typical farm management scenarios.     

Nitrous Oxide in Agricultural Drainage Waters Following Field Fertilisation

Dissolved nitrous oxide (N₂O), nitrate (NO₃ ^-), and ammonium (NH₄ ⁺) concentrations in an agricultural field drain were intensively measured over the period of field nitrogen (N) fertilisation and for several weeks thereafter. Supersaturations of dissolved N₂O were observed in field drain waters throughout the study. On entry to an open drainage ditch, concentrations of dissolved N₂O rapidly decreased and a total N₂O-N emission via this pathway of 13.2 g over the period of study (45 days) was calculated. This compared with a predicted emission of the order of 300 g, based on measured losses of NO₃ ^- and NH₄ ⁺ in the field drainage water, and the default IPCC emission factor of 0.01 kg N₂O-N per kg Nentering rivers and estuaries. In contrast to widespread evidence of a clear relationship between the amount of N applied to agricultural land and subsequent direct N₂O emission from the soil surface, the relationship between the amount of N₂O in soil drainage waters and the amount of N applied was poor. We conclude that the complexity, both spatially and temporally, of the processes ultimately responsible for the amount of N₂O in agricultural drainage waters make a straightforward relationship between N₂O concentration and N application rate unlikely in all but the simplest of systems.     

Sustainable land application: an overview

Man has land-applied societal nonhazardous wastes for centuries as a means of disposal and to improve the soil via the recycling of nutrients and the addition of organic matter. Nonhazardous wastes include a vast array of materials, including manures, biosolids, composts, wastewater effluents, food-processing wastes, industrial by-products; these are collectively referred to herein as residuals. Because of economic restraints and environmental concerns about land-filling and incineration, interest in land application continues to grow. A major lesson that has been learned, however, is that the traditional definition of land application that emphasizes applying residuals to land in a manner that protects human and animal health, safeguards soil and water resources, and maintains long-term ecosystem quality is incomplete unless the earning of public trust in the practices is included. This overview provides an introduction to a subset of papers and posters presented at the conference, "Sustainable Land Application," held in Orlando, FL, in January 2004. The USEPA, USDA, and multiple national and state organizations with interest in, and/or responsibilities for, ensuring the sustainability of the practice sponsored the conference. The overriding conference objectives were to highlight significant developments in land treatment theory and practice, and to identify future research needs to address critical gaps in the knowledge base that must be addressed to ensure sustainable land application of residuals.     

Spatial variability of soil phosphorus in relation to the topographic index and critical source areas: sampling for assessing risk to water quality

A measure of soil P status in agricultural soils is generally required for assisting with prediction of potential P loss from agricultural catchments and assessing risk for water quality. The objectives of this paper are twofold: (i) investigating the soil P status, distribution, and variability, both spatially and with soil depth, of two different first-order catchments; and (ii) determining variation in soil P concentration in relation to catchment topography (quantified as the "topographic index") and critical source areas (CSAs). The soil P measurements showed large spatial variability, not only between fields and land uses, but also within individual fields and in part was thought to be strongly influenced by areas where cattle tended to congregate and areas where manure was most commonly spread. Topographic index alone was not related to the distribution of soil P, and does not seem to provide an adequate indicator for CSAs in the study catchments. However, CSAs may be used in conjunction with soil P data for help in determining a more "effective" catchment soil P status. The difficulties in defining CSAs a priori, particularly for modeling and prediction purposes, however, suggest that other more "integrated" measures of catchment soil P status, such as baseflow P concentrations or streambed sediment P concentrations, might be more useful. Since observed soil P distribution is variable and is also difficult to relate to nationally available soil P data, any assessment of soil P status for determining risk of P loss is uncertain and problematic, given other catchment physicochemical characteristics and the sampling strategy employed.     

Integrating Media Studies of Climate Change into Transdisciplinary Research: Which Direction Should We Be Heading?

Research in the area of media coverage on climate change communication represents one of the most prolific areas of inquiry within communication and mass communication studies. This body of literature, which ranges from empirical to critical studies, continues to expand. Much research has focused on representations of climate change causes, effects, and human actions, while some has assessed the impacts of these representations. What is broadly missing from this literature, however, is a discussion of how we might integrate media analysis into transdisciplinary collaborative research aimed at creating solutions to the social, environmental, and economic issues intertwined with climate change. Given the magnitude of problems the society and science are currently grasping with, it behooves us to understand how media studies can contribute most effectively to characterizing and solving problems. We maintain that the move toward integrating media studies into transdisciplinary collaborative research marks an essential transition for environmental communication in general, but climate change communication in particular, given the urgency and magnitude of creating meaningful adaptation and mitigation strategies to address this pressing, complex challenge. Drawing on our work as part of a large transdisciplinary sustainability science team, we provide a case study for understanding what collaborations are key to moving media studies into a transdisciplinary context and the key opportunities and barriers that come along with that move. We argue that media studies must increasingly engage directly in collaboration with other researchers, stakeholders, and communities to serve on-the-ground decision-making and enhance society's ability to take action.     

“We cannot let this happen again”: reversing UK flood policy in response to the Somerset Levels floods, 2014

The Multiple Streams Framework offers a theoretical account of how policy proposals move from latent possibilities to becoming favored for implementation. We apply this framework in the context of the policy response to the 2013–2014 flooding of the Somerset Levels and Moors. Stakeholder interviews and analysis of news media coverage evidence the way in which a specific policy option that had fallen out of favor with the national Environment Agency – dredging – came to the fore and was eventually adopted during the period in which the conjunction of problem, policy, and political pressures came to a head. Local political activists mobilized a wider campaign with the help of social media and capitalized on national political sensitivities to successfully promote dredging. What is less clear is the longevity of the policy reversal, given funding constraints.     

Framing for resilience through social learning: impacts of environmental stewardship on youth in post-disturbance communities

Civic ecology practices, such as community gardening and citizen-led urban reforestation and wetland restoration, provide opportunities for social learning. Because social learning is an important component of community resilience, we suggest that civic ecology practices can be a strategy for responding to and mitigating environmental disturbances in an era threatened by climate change. Despite the links between civic ecology, social learning and community resilience, empirical research that systematically considers these connections is limited. This study addresses this gap by introducing ‘frames’ as an approach to considering social learning outcomes and process. More specifically, we provide a model for investigating the role civic ecology education programs play in shaping youths’ capacity to understand and respond to environmental disturbance. We used participant observation and cognitive mapping to assess social learning among three youth restoration programs working in the wake of Hurricane Sandy in New York, NY, and after the 2013 floods in Boulder, CO. In all three programs, youth demonstrated social learning and cognitive change by shifting their emphasis from the impacts of disturbance towards a solutions-based framing that focused on community, action, and mitigation. However, the depth of these changes was not uniform across all programs, suggesting that variations in program length, community context, social identity, and opportunities for self-defined action may shape overall impacts of programs and youth capacity for future action.     

Testing and Improving Temperature Thresholds for Snow and Rain Prediction in the Western United States

The phase of precipitation at the land surface is critical to determine the timing and amount of water available for hydrological and ecological systems. However, there are few techniques to directly observe the precipitation phase and many prediction tools apply a single temperature threshold (e.g., 0°C) to determine phase. In this paper, we asked two questions: (1) what is the accuracy of default and station optimized daily temperature thresholds for predicting precipitation phase and (2) what are the regions and conditions in which typical temperature‐based precipitation phase predictions are most suited. We developed a ground truth dataset of rain vs. snow using an expert decision‐making system based on precipitation, snow depth, and snow water equivalent observations. This dataset was used to evaluate the accuracy of three temperature‐threshold‐based techniques of phase classification. Optimizing the temperature threshold improved the prediction of precipitation phase by 34% compared to using 0°C threshold. Developing a temperature threshold based on station elevation improved the error by 12% compared with using the 0°C temperature threshold. We also found the probability of snow as a function of temperature differed among ecoregions, which suggests a varied response to future climate change. These results highlight a current weakness in our ability to predict the effects of regional warming that could have uneven impacts on water and ecological resources.