Renewable electricity policies,heterogeneity, and cost effectiveness

Renewable electricity policies promote investment in renewable electricity generators and have become increasingly common around the world. Because of intermittency and the composition of other generators in the power system, the value of certain renewable – particularly wind and solar – varies across locations and technologies. This paper investigates the implications of this heterogeneity for the cost effectiveness of renewable electricity policies. A simple model of the power system shows that renewable electricity policies cause different investment mixes. Policies also differ according to their effect on electricity prices, and both factors cause the cost effectiveness to vary across policies. We use a detailed, long-run planning model that accounts for intermittency on an hourly basis to compare the cost effectiveness for a range of policies and alternative parameter assumptions. The differences in cost effectiveness are economically significant, where broader policies, such as an emissions price, outperform renewable electricity policies.     

Landholder Profiling and Typologies for Natural Resource–Management Policy and Program Support: Potential and Constraints

The use of landholder typologies to aid the development, implementation, and monitoring natural-resource management (NRM) policies and programs has increased considerably during the past decade. This article explores the potential for using such typologies for a variety of NRM and rural and regional development applications. Review of typology use further suggests that there is potential to refine the way that typologies are developed and applied to better aid NRM, farming systems analyses, and rural and regional development. Before typologies will be adopted more widely, a number of theoretical and methodologic issues must be addressed. These include the following questions: (1) Which criteria and methods should or can be used to classify landholders? (2) How should studies across spatial and temporal scales be integrated? (3) How should multiple and single industry studies be integrated to gain the most value from research? We argue that quantitative research techniques are well suited to provide an underlying structure for landholder typologies, and qualitative research techniques are useful for developing understanding of the nature of variation within and between landholder types. We argued further that because of the potential utility and breadth for the application of landholder typologies, a nested set of landholder typologies could be developed that are coordinated at the national, regional, and local geographic levels, with repeated measures used to track the evolution with time of landholder practices, management values, and socioeconomic characteristics.     

The distribution of benefits from improvements in urban air quality

This paper analyzes the distribution of benefits from an air pollution control strategy for the Boston metropolitan area. Average benefits to seven income groups are measured by physical improvements in air quality and by dollar values, using housing value and health damage approaches to estimate willingness to pay. Benefits include those in the work environment as well as at home. Physical benefits at home are found to be greater for the poor rather than for the rich; when measured in monetary terms with workplace benefits included, however, the distribution is much less pro-poor.     

Seabird predation on the sea-skater Halobates sericeus (Heteroptera: Gerridae)

Regurgitated food samples were collected from 18 species of seabirds on 8 of the Northwestern Hawaiian Islands between February 1978 and February 1981. Sea-skaters (Halobates sericeus) was found in the diets of 9 species, but can be considered to be an important food item for only 4 species: the blue-gray noddy Procelsterna cerulea; the Bonin petrel Pterodroma hypoleuca; the gray-backed tern Sterna lunata; and Bulwer's petrel, Bulweria bulwerii. The blue-gray noddy, by far the most important avian predator of Halobates spp., may at times feed exclusively on this food item and may appreciably reduce the populations of sea-skaters within their foraging territories.     

Perceptions of Species Abundance,Distribution, and Diversity: Lessons from Four Decades of Sampling on a Government-Managed Reserve

/ We examined data relative to species abundance, distribution, anddiversity patterns of reptiles and amphibians to determine how perceptionschange over time and with level of sampling effort. Location data werecompiled on more than one million individual captures or observations of 98species during a 44-year study period on the US Department of Energy's(DOE) Savannah River Site National Environmental Research Park (SRS-NERP) inSouth Carolina. We suggest that perceptions of herpetofaunal speciesdiversity are strongly dependent on level of effort and that land managementdecisions based on short-term data bases for some faunal groups could resultin serious errors in environmental management. We provide evidence thatacquiring information on biodiversity distribution patterns is compatiblewith multiyear spatially extensive research programs and also provide aperspective of what might be achieved if long-term, coordinated researchefforts were instituted nationwide.To conduct biotic surveys on government-managed lands, we recommend revisionsin the methods used by government agencies to acquire and report biodiversitydata. We suggest that government and industry employees engaged inbiodiversity survey efforts develop proficiency in field identification forone or more major taxonomic groups and be encouraged to measure the status ofpopulations quantitatively with consistent and reliable methodologies. Wealso suggest that widespread academic cooperation in the dissemination ofinformation on regional patterns of biodiversity could result byestablishment of a peer-reviewed, scientifically rigorous journal concernedwith status and trends of the biota of the United States. KEY WORDS: Abundance; Amphibian; Biodiversity; Distribution; Landmanagement; Reptile     

A life-cycle inventory model of municipal solid waste combustion

Evaluation of alternate strategies for municipal solid waste (MSW) management requires models to calculate environmental emissions as a function of both waste quantity and composition. A methodology to calculate waste component-specific emissions associated with MSW combustion is presented here. The methodology considers emissions at a combustion facility as well as those avoided at an electrical energy facility because of energy recovered from waste combustion. Emission factors, in units of kg pollutant per metric ton MSW entering the combustion facility, are calculated for CO2-biomass, CO2-fossil, SOx, HCl, NOx, dioxins/furans, PM, CO, and 11 metals. Water emissions associated with electrical energy offsets are also considered. Reductions in environmental emissions for a 500-metric-ton-per-day combustion facility that recovers energy are calculated.     

Assessment of natural components of PM10 at UK urban and rural sites

Proposals from the European Commission have raised the possibility that Member States may be able to subtract the concentrations of natural components of airborne particulate matter from measured concentrations when evaluating compliance with EU Limit Values. By applying the pragmatic mass closure model [Harrison et al., 2003. A pragmatic mass closure model for airborne particulate matter at urban background and roadside sites. Atmospheric Environment 37, 4927–4933] to chemical composition data for PM₁₀, it has been possible to estimate the concentrations of natural sea salt, strongly bound water and secondary organic carbon (which is assumed wholly biogenic) to the measured mass of PM₁₀. Because of the difficulty in distinguishing between natural and anthropogenic crustal dusts, the contribution of natural windblown dust and soil has not been accounted for. When the natural components are estimated for two urban and one rural site in the UK, the long-term mean PM₁₀ concentration is reduced by between 5.2 and 7.3 μg m⁻³. The number of exceedences of the 50 μg m⁻³ 24-h limit value falls dramatically from 54 to 21 (from a total of 291 days) at an urban street canyon site, 7 to 3 (n=292 days) at an urban background site and from 8 to 0 (n=241 days) at a rural site when using gravimetric PM₁₀ concentrations. The calculations have also been performed using PM₁₀ concentrations measured by TEOM increased by a factor of 1.3 as recommended by the European Commission as an interim means of estimating gravimetric equivalency, and the number of exceedences of the 24-h limit value fell from 92 to 47 (from a total of 291 days) at the urban street canyon site, from 11 to 3 (n=292 days) at the urban background site and from 6 to 3 (n=241) at the rural site. Clearly, therefore, application of this proposed measure would make a very major difference to the likelihood of compliance or otherwise with the 24-h limit value for PM₁₀.     

Development and evaluation of an impactor for a PM2.5 speciation sampler

A conventional impactor for a particle speciation sampler was developed and validated through laboratory and field tests. The speciation sampler consists of the following components: a PM2.5 conventional impactor that removes particles larger than 2.5 microns, an all-glass, coated honeycomb diffusion denuder, and a 47-mm filter pack. The speciation sampler can operate at two different sampling rates: 10 and 16.7 L/min. An experimental characterization of the impactor's performance was conducted. The impactor's collection efficiency was examined as a function of critical design parameters such as Reynolds number, the distance from the nozzle exit to the impaction plate, and the impaction substrate coating method. The bounce of particles larger than the cut point was successfully minimized by using a greased surface as the impaction substrate. Additionally, a series of field intercomparison experiments were conducted at both 10 and 16.7 L/min airflow. PM2.5 mass and SO4(2-) concentrations were measured and compared with the Federal Reference Method (FRM) and found to be in good agreement. Results of the laboratory chamber tests also indicated that the impactor's performance was in good agreement with the FRM.     

Dioxins and polychlorinated biphenyls (PCDD/Fs and PCBs) in food from farms close to foot and mouth disease animal pyres

To control the outbreak of foot and mouth disease, which occurred in the UK in early 2001, a large number of farm animals were slaughtered. Where it was not possible to render or landfill the carcasses, they were destroyed by burning on open pyres, with wood, coal and other materials. Uncontrolled combustion such as this is known to produce small quantities of dioxins and an investigation was made into whether, as a result of the burning, there was an elevation in the concentrations of these compounds in food produced in the areas close to the pyres. With few exceptions, concentrations of PCDD/Fs and PCBs were within the expected ranges as predicted by reference data. No accumulation over time was evident from a repeat milk sampling exercise. Where elevated concentrations of PCDD/Fs and PCBs were found in chickens and eggs, they were in samples not destined for the food chain. Elevated levels in some samples of milk from Dumfries and Galloway were not found in earlier or later samples and may have been found as a result of a temporary feeding regime. Elevated concentrations in lamb from Carmarthenshire were from very young animals which would not have entered the food chain. There was no evidence of any significant increase in dietary exposure to PCDD/Fs and PCBs as a result of the FMD pyres.     

Comparison of methods for the analysis of dissolved urea in seawater

A comparison between the diacetyl monoxime and urease methods for measuring dissolved concentrations of urea in seawater was conducted in artificial seawater, phytoplankton-culture filtrate and both natural and ureaspiked field samples from coastal and oceanic enviroments during 1984. The urease technique underestimated urea concentrations in unbuffered photoplankton-culture filtrate as a result of the inhibition of the urease enzyme, causing the incomplete hydrolysis of urea in these samples. Factors responsible for inhibiting urease included pH, seawater ions, and possibly extracellular metabolites produced in unialgal cultures. Seawater type and time of sample collection were important variables affecting urea measurement by the urease method, and recovery of internal standards ranged from 40 to 100%. Increasing the heating time of the urease assay, or the concentration of urease added to the seawater samples increased the amount of urea determined by the urease method. However, measured values were still less than the concentration of the urea internal standards. The diacetyl monoxime method was suitable for urea determinations in all the seawater samples we examined; it was easily automated, and the results were accurate and reproducible. This modified technique is recommended for measuring disolved concentrations of urea in seawater.