Oracle-based optimization applied to climate model calibration

In this paper, we show how oracle-based optimization can be effectively used for the calibration of an intermediate complexity climate model. In a fully developed example, we estimate the 12 principal parameters of the C-GOLDSTEIN climate model by using an oracle-based optimization tool, Proximal-ACCPM. The oracle is a procedure that finds, for each query point, a value for the goodness-of-fit function and an evaluation of its gradient. The difficulty in the model calibration problem stems from the need to undertake costly calculations for each simulation and also from the fact that the error function used to assess the goodness-of-fit is not convex. The method converges to a ‘best fit’ estimate over 10 times faster than a comparable test using the ensemble Kalman filter. The approach is simple to implement and potentially useful in calibrating computationally demanding models based on temporal integration (simulation), for which functional derivative information is not readily available.     

On the horizontal homogeneity of mass-related aerosol properties

We studied the mass-related aerosol properties, simultaneously attwo sites at the urban roof top level in the same city. Nosystematic influence of the wind vector on the difference in theaerosol concentrations between the two locations could be found.These results are compared with results from a second, similarexperiment over a larger distance including one urban and onerural site. Surprisingly, we could not detect a tendency whichwould indicate that sampling air at distance in the order of 1 kmwould be less affected by the heterogeneity than samplingdistanced in the order of 10 km apart. On the contrary, theresults suggest that mass-related properties at two sites in thesame city are not necessarily more similar than at an urban and arural site outside the city. These results stress the limitedhorizontal homogeneity of urban atmospheric aerosol. As aconclusion it is suggested that single-site measurements of mass-related aerosol properties should be considered to berepresentative for an area smaller than 1 km² on size.     

Use of significance thresholds to integrate cumulative effects into project-level socio-economic impact assessment in Canada

A longstanding critique of project-level environmental assessment is that it is weak at addressing cumulative effects, and because of this many argue that cumulative effects are best managed at a regional scale. However, in the absence of regional management it is important that project-level assessment supports cumulative effects management as best as possible. In this paper we present case study socio-economic impact assessments of liquefied natural gas development on Aboriginal groups on Canada's west coast. The case studies use an analytical structure modified from typical Canadian practice including unambiguous and non-arbitrary significance thresholds grounded in stakeholder values to focus baselines, impact assessment, and significance determination on cumulative effects. This approach is found to be more capable of informing decision-makers on cumulative effects as well as more rigorous and transparent than typical assessments. Much of this approach is not conceptually new, but at least in western Canada such an approach is not typically used or meaningfully implemented by practitioners. As such, the case studies serve to illustrate how practice can bolster project-level assessment.     

Long-term environmental monitoring for assessment of change: measurement inconsistencies over time and potential solutions

The importance of long-term environmental monitoring and research for detecting and understanding changes in ecosystems and human impacts on natural systems is widely acknowledged. Over the last decades, a number of critical components for successful long-term monitoring have been identified. One basic component is quality assurance/quality control protocols to ensure consistency and comparability of data. In Norway, the authorities require environmental monitoring of the impacts of the offshore petroleum industry on the Norwegian continental shelf, and in 1996, a large-scale regional environmental monitoring program was established. As a case study, we used a sub-set of data from this monitoring to explore concepts regarding best practices for long-term environmental monitoring. Specifically, we examined data from physical and chemical sediment samples and benthic macroinvertebrate assemblages from 11 stations from six sampling occasions during the period 1996–2011. Despite the established quality assessment and quality control protocols for this monitoring program, we identified several data challenges, such as missing values and outliers, discrepancies in variable and station names, changes in procedures without calibration, and different taxonomic resolution. Furthermore, we show that the use of different laboratories over time makes it difficult to draw conclusions with regard to some of the observed changes. We offer recommendations to facilitate comparison of data over time. We also present a new procedure to handle different taxonomic resolution, so valuable historical data is not discarded. These topics have a broader relevance and application than for our case study.     

A synthesis of variability in nearshore Alaskan marine populations

One of the primary goals of any monitoring program is to detect anthropogenic changes; however natural variability can be so high that it prevents detection of human-induced effects. This project synthesized existing data to identify patterns of temporal variation within nearshore marine habitats in the Gulf of Alaska and was motivated by the need for monitoring in this environment vulnerable to oil spills, such as the Exxon Valdez. I collected 786 time series that were greater than 2 years in length from unimpacted (control) sites for 226 species. Temporal variability (CV) varied widely from 1% to 447%, averaged 89%, and was not significantly different among marine populations of birds, mammals, fish, algae and invertebrates. Temporal variability of invertebrates and algae were not significantly different when abundance was measured as biomass, percent cover or density. Both invertebrates and algae showed higher variability in low intertidal habitat compared to high intertidal habitat. For invertebrates, populations on bedrock substrates had greater temporal variability than those on cobble or soft sediment substrates, while there was not a significant difference for algae on either cobble or bedrock substrates. Many of these results are surprising, given differences in movement patterns, survey methods, life histories, and so forth. These results suggest that no single group, measure or habitat will be better or worse for monitoring and detecting change. Understanding variability is a difficult task, but until we tackle it, we will likely not understand or have predictive capabilities in ecological populations and communities.     

X-ray diffraction spectrometric analysis of nickel refinery aerosols,process materials and particulates isolated from worker lung tissues

Results are reported of X-ray diffraction analysis of extracts derived from lungs of two nickel refinery workers and of three stationary air samples collected inside a nickel refinery. Since environmental samples from the 1950s and 1960s do not exist, two archived production control samples from that period were also analyzed. Because nickel has been found in respiratory tissue of workers retired for more than twenty years, it was likely that the residual nickel compounds must be rather insoluble. Preliminary surveys showed that sulfur was not present in the lung tissue deposits and thus water-soluble and sulfidic nickel were therefore extracted from the ten process samples before the X-ray analysis. A common compound that was found in all 10 samples was trevorite. This is a spinel-type mineral, much like magnetite where the divalent iron is replaced by nickel. It may be formed when trivalent iron reacts with nickel at 1100 degrees C. It has magnetic properties and is very insoluble. Samples from the lungs were obtained by burning off the organic tissue at 630 degrees C. Due to a relatively high detection limit for the X-ray diffraction technique, we were initially not able to detect any mineral nickel compound. But when particles extracted with a magnet were analyzed, a very clear diffraction pattern of trevorite was identified. The main residue after the magnetic separation had a low concentration of nickel (4 microg g(-1)), which suggests that trevorite was the dominating, if not the only, nickel compound present. In addition, chemical analyses were performed on 13 tissue samples from one single lung; one from each main bronchus, two from each lobe, and an additional one from the lower right lobe. Statistical testing showed a highly significant correlation between the five elements determined: Ni, Co, Cu, Fe and Cr. This suggests that these metals are isomorphous and substitute for each other in the mineral structure. These results may indicate that the nickel left in the lungs some years after exposure is trevorite, and may be biologically inert. However, further speciation of nickel compounds in the lungs seems warranted, and trevorite should be tested for its potential toxic effects.     

Optimal Environmental Policy for a Polluting Monopoly with Abatement Costs: Taxes Versus Standards

In this paper, we characterize the optimal environmental policy for a polluting monopoly that devotes resources to abatement activities when damages are caused by a stock pollutant. With this aim, we calculate the stagewise feedback Stackelberg equilibrium of a (differential) policy game where the regulator is the leader and the monopolist is the follower. Our analysis shows that the first-best policy consists of applying a Pigouvian tax and a subsidy on production equal to the difference between the price and the marginal revenue. However, for a stock pollutant, the Pigouvian tax is not equal to the marginal damages but is given by the difference between the social and private valuation of the pollution stock. On the other hand, if a second-best emission tax is used, the tax is lower than the Pigouvian tax and the difference decreases with the price elasticity of the demand. Finally, we find that taxes and standards are equivalent in a second-best setting. In the second part of the paper, we solve a linear-quadratic differential game and we obtain that the first-best tax increases with the pollution stock whereas the subsidy decreases. Moreover, the tax is negative for low values of the pollution stock, i.e., for low values of the pollution stock, we obtain that the social valuation of the stock is lower than the private valuation. Furthermore, when a second-best policy is applied, the steady-state pollution stock is lower than the steady-state pollution stock associated with the efficient outcome.     

Heavy metal concentration in fish tissues inhabiting waters of “Buško Blato” reservoar (Bosnia and Herzegovina)

Heavy metals concentration (mercury, lead, cadmium, arsenic, copper, zinc and chromium) in tissues (muscles, liver, kidney and gonads) of Dalmatian barbelgudgeon, the nase, the souffie and brown trout, inhabiting waters of Busko Blato reservoir in Bosnia and Herzegovina, has been determined by atomic absorption spectrophotometry. The meat of the tested fish sorts does not contain elevated concentration of most analyzed heavy metals with exception of lead (higher than MAC in Italy, Germany and Denmark) and mercury (in muscles of brown trout higher than MAC in most countries). The lowest level of all heavy metals is always detected in gonads, with higher values in fry compared to milt for copper, zinc, chromium and arsenic. The highest copper concentration is observed in the liver from the souffie which is suggested as a suitable biomonitor for copper intoxication. In muscles of all fish sorts, lead was always present in much higher concentration than cadmium, while in kidneys of most fish sorts, lead and cadmium concentrations were similar. We showed that bioaccumulation of some heavy metals in the fish sorts analyzed is tissue and sex dependent. Also, we concluded that the small water exchange in reversible shallow reservoir does not induce elevated concentration of heavy metals in fish tissues inhabiting Busko Blato.     

Recovery of Francisella tularensis from soil samples by filtration and detection by real-time PCR and cELISA

The aim of this study was to develop a specific and highly sensitive method able to detect very low concentrations of Francisella tularensis in soil samples by real-time PCR (qPCR) with SYBR Green I. tul4 gene, which encodes the 17-kDa protein (TUL4) in F. tularensis strains, was amplified using a LightCycler (LC) device. We achieved a detection limit of 0.69 fg of genomic DNA from F. tularensis subp. holarctica live vaccine strain (LVS), corresponding to a value less than 3.4 genome equivalents per reaction. The qPCR was shown to be specific, highly sensitive and reproducible. In addition, we evaluated 2 new methods for recovering bacteria from soil based on 1-step filtration using glass fiber filters and PVDF filters. These filtration methods enabled us to recover F. tularensis efficiently from soil samples. As few as 50 CFU per 0.5 g of soil were detected by qPCR. Capture enzyme-linked immunosorbent assay (cELISA) allowed us to detect and quantify the amount of bacteria recovered from soil by an immunological method. Although qPCR was more sensitive than cELISA, we did not observe substantial differences in the amount of bacteria quantified by both methods.     

Analysing Seasonal Differences between a Soil Water Balance Model and in Situ Soil Moisture Measurementsat Nine Locations Across Europe

We compared soil moisture from the soil water balance model for European Water Accounting (swbEWA) with in situ observations from nine locations in three European climatic zones (continental, Mediterranean and maritime temperate), for different periods between 2003 and 2011. Despite the simplicity of the swbEWA model, the patterns of temporal changes in soil moisture content are well represented at all locations. Annual averages show that the model overestimates the soil moisture content, and that overestimations are the smallest when measurements are obtained from more than one depth. These results suggest that the relationship between simulated and observed soil moisture also depends on the number of measurements and the depth over which they are taken. In the continental climate, where snow cover and frozen soil influence soil moisture, we observe higher root mean square error values in winter months. However, in the Mediterranean and maritime temperate climates, we do not observe clear common seasonal patterns in the soil moisture profile, which makes it difficult to relate the model’s accuracy to climate. With the percentage of correctness and probability of detection measures, we tested the model performance in simulating dry versus non-dry events. The percentage of the correctly classified dry and non-dry events is higher than 84 % at all locations, whereas the probability to detect dry events is significantly lower, exceeding 50 % at only four out of nine stations. The frequency distribution of consecutive days with dry soil (CDDS) confirms the model performance: higher number of short dry periods (with less than 20 days of soil moisture near wilting point) are reproduced and observed in continental climates, whereas long dry periods (longer than 50 days) are noted in the Mediterranean climate. Overall, the statistical measures suggest that the model produces the highest accuracy in summer months at the stations in continental climates, whereas in the Mediterranean climate, the accuracy is slightly higher in the colder seasons.     

When speed matters: The importance of flight speed in an avian collision risk model

Renewable energy continues to grow globally, and the number of offshore wind farms is set to increase. Whilst wind energy developments provide energy security and reduced carbon budgets, they may impact bird populations through collision mortality, habitat modification and avoidance. To date, avian collision mortality has received the most attention and collision risk models have been developed to estimate the potential mortality caused by wind turbines. The utility of these models relies not only on their underlying assumptions but also on the data available to ensure the predictions are informative. Using a stochastic collision risk model (sCRM; based on the Band collision risk model) as an example, we explore the importance of bird flight speed and consider how the assumptions of the model influence the sensitivity to flight speed. Furthermore we explore the consequences of using site-specific GPS-derived flight speed rather than a standard generic value, with Lesser Black-backed Gulls Larus fuscus as an example, and consider how this generic value is currently used. We found that the model was most sensitive to the parameters of bird density, non-avoidance rate and percentage of birds at collision risk height, as well as bird flight speed. Using site-specific flight speed data derived from GPS tags rather than a standard value reduced the predicted number of collisions. We highlight that within the model, both the estimation of the probability of collision (PColl) and the flux of birds are sensitive to the bird flight speed; this sensitivity acts in opposite directions but the two do not necessarily balance out. Therefore, when the sCRM is used as generally done, there is little difference in collision estimates if airspeeds (bird flight speed relative to air through which it is moving) are used rather than groundspeeds (bird flight speed relative to ground). Estimates of seabird collision rates in relation to offshore wind farms are impacting future offshore wind development. By using site specific flight speed estimates and, accounting for different speeds in relation to wind direction, we demonstrate that cumulative collision estimates can be affected, highlighting the need for more representative flight speed data and where possible site-specific data.     

Modeling the effect of land use/land cover on nitrogen,phosphorous and dissolved oxygen loads in the Velhas River using the concept of exclusive contribution area

Non-point source water pollution is a major problem in most parts of the world, but is also very difficult to quantify and control since it is not easily separated from point sources and can theoretically originate from the whole watershed. In this article, we evaluate the relationship between land use and land cover and four water pollution parameters in a watershed in Southeast Brazil. The four parameters are nitrate, total ammonia nitrogen, total phosphorous, and dissolved oxygen. To help concentrate on non-point source pollution, only data from the wet seasons of the time period (2001–2013) were analysed, based on the fact that precipitation causes runoff which is the main cause of diffuse pollution. The parameters measured were transformed into loads, which were in turn associated with an exclusive contribution area, so that every measuring station could be considered independent. Analyses were also performed on riparian zones of different widths to verify if the effect of the land cover on the water quality of the stream decreases with the increased distance. Pearson correlation coefficients indicate that urban areas and agriculture/pasture tend to worsen water quality (source). Conversely, forest and riparian areas have a reducing effect on pollution (sink). The best results were obtained for total ammonia nitrogen and dissolved oxygen using the whole exclusive contribution areas with determination coefficients better than R²≈0.8. Nitrate and total phosphorous did not produce valid models. We suspect that the transformation delay from total ammonia nitrogen to nitrate might be an important factor for the poor result for this parameter. For phosphorous, we think that the phosphorous sink in the bottom sediment might be the most limiting factor explaining the failure of our models.     

Comparative study of the sensitivity to cadmium of two populations of Gambusia affinis from two different sites

This study aims to demonstrate the influence of animals' origin on their sensitivity toward heavy metals. For this purpose, we compared LC(50) of cadmium in two populations of Gambusia affinis captured in two geographically isolated environments in the east of Tunisia; Oued El Gsil in the city of Monastir (S2) and Oued Chenini in the region of Gabes (S1). Although physicochemical parameters of the water (pH, dissolved oxygen and salinity) are similar in the two studied sites, cadmium concentrations in water, sediments and fish tissues from S1 are significantly higher (P < 0.01) than those from S2, 48-h and 96-h LC(50) of the (S1) population are significantly higher than those from S2. In the same way, the offspring of the polluted site (S1) population exhibit 48-h and 96-h LC(50) values much higher than those of the reference site (S2) population. These results show that the population of the Gabes region is more resistant to cadmium than that of the Monastir region and that this resistance could have a genetic basis. These results indicate the influence of the origin of animals that has to be taken into account not only in laboratory toxicity tests, but also in field ecotoxicological studies.     

Monitoring of Pathogenicity of Effluents from the UASB Based Sewage Treatment Plant

We researched the behavior of pathogenic microbes in a treated wastewater reuse system to acquire knowledge for establishing new standards for the reuse of treated wastewater. Based on the results that showed occasional growth of total coliforms but barely any growth of Escherichia coli in the supply tank, we found that the total coliform, which includes bacteria that also breed in the soil, etc., is not necessarily suitable as the index bacteria for indicating pollution by excrement. We also clarified that it is possible to decrease the heterotrophic plate count to a specified level in cases where combined residual chlorine is more than 0.3 mg/l, and that the standard value for residual chlorine should be set at 0.3 mg/l or more. At the same time, we found that applying sand filtration treatment to water used for toilet flushing, sprinkling and landscaping, and sand filtration treatment plus coagulation treatment to water for recreational use lowers the annual risk of infection by Cryptosporidium to less than 10⁻⁴. The standard for viruses must be examined in the future because Noroviruses were sometimes detected even in the reclaimed water, although we could not establish the standard at this time due to problems with the virus detection method.     

Climate Damage on Production or on Growth: What Impact on the Social Cost of Carbon?

Recent articles have investigated with integrated assessment models the possibility that climate damage bears on productivity (TFP) growth and not on production. Here, we compare the impact of these alternative representations of damage on the social cost of carbon (SCC). We ask whether damage on TFP growth leads to higher SCC than damage on production ceteris paribus. To make possible a controlled comparison, we introduce a measure of aggregate damage, or damage strength, based on welfare variations. With a simple climate-economy model, we compare three damage structures: quadratic damage on production, linear damage on growth and quadratic damage on growth. We show that when damage strength is the same, the ranking of SCC between a model with damage on production and a model with damage on TFP growth is not unequivocal. It depends on welfare parameters such as the utility discount rate or the elasticity of marginal social utility of consumption.     

Comparison of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in feathers in bald eagle (Haliaeetus leucocephalus), and comparison with common eider (Somateria mollissima), glaucous-winged gull (Larus glaucescens), pigeon guillemot (Cepphus columba), and tufted puffin (Fratercula cirrhata) from the Aleutian Chain of Alaska

There is an abundance of field data for levels of metals from a range of places, but relatively few from the North Pacific Ocean and Bering Sea. In this paper we examine the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in feathers from common eiders (Somateria mollissima), glaucous-winged gulls (Larus glaucescens), pigeon guillemots (Cepphus columba), tufted puffins (Fratercula cirrhata) and bald eagles (Haliaeetus leucocephalus) from the Aleutian Chain of Alaska. Our primary objective was to test the hypothesis that there are no trophic levels relationships for arsenic, cadmium, chromium, lead, manganese, mercury and selenium among these five species of birds breeding in the marine environment of the Aleutians. There were significant interspecific differences in all metal levels. As predicted bald eagles had the highest levels of arsenic, chromium, lead, and manganese, but puffins had the highest levels of selenium, and pigeon guillemot had higher levels of mercury than eagles (although the differences were not significant). Common eiders, at the lowest trophic level had the lowest levels of some metals (chromium, mercury and selenium). However, eiders had higher levels than all other species (except eagles) for arsenic, cadmium, lead, and manganese. Levels of lead were higher in breast than in wing feathers of bald eagles. Except for lead, there were no significant differences in metal levels in feathers of bald eagles nesting on Adak and Amchitka Island; lead was higher on Adak than Amchitka. Eagle chicks tended to have lower levels of manganese than older eagles.     

Contaminants in American alligator eggs from Lake Apopka,Lake Griffin,and Lake Okeechobee,Florida

Residues of organochlorine pesticides, polychlorinated biphenyls (PCBs), and 16 elements were measured in American alligator (Alligator mississippiensis) eggs collected in 1984 from Lakes Apopka, Griffin, and Okeechobee in central and south Florida. Organochlorine pesticides were highest in eggs from Lake Apopka. None of the elements appeared to be present at harmful concentrations in eggs from any of the lakes. A larger sample of eggs was collected in 1985, but only from Lakes Griffin, a lake where eggs were relatively clean, and Apopka, where eggs were most contaminated. In 1985, hatching success of artificially incubated eggs was lower for Lake Apopka, and several organochlorine pesticides were higher than in eggs from Lake Griffin. However, within Lake Apopka, higher levels of pesticides in chemically analyzed eggs were not associated with reduced hatching success of the remaining eggs in the clutch. Therefore, it did not appear that any of the pesticides we measured were responsible for the reduced hatching success of Lake Apopka eggs.     

Monitoring for Lead Pollution using Feathers of Feral Pigeons (Columba livia) from Korea

We investigated lead exposure conditions using unwashed feathers of feral pigeons as a monitor for lead pollution from rural, central urban, and four industrial complex areas in Korea with different ambient lead concentrations. Overall, the lead levels in the feathers increased when the atmospheric lead levels increased, so that the lead levels in the feathers from urban and industrial areas were two to four times greater than those in the rural area. However, there are no significant differences in the liver lead concentrations between rural and the other areas, suggesting that the lead originated from ingestion are not differences in locations. A positive correlation was found between the concentration of lead in livers and feathers from rural, indicating that the feather lead concentrations in this area seem to mainly reflect the internal tissue lead through the metabolic process. However, there are no significant correlations in the other areas, and we observed a relatively higher lead accumulation ratio of feathers to livers. It, therefore, indicates that external contamination onto the feather surface may be an important source for lead levels in feathers rather than transfer from internal tissue lead.     

Risk perception in Northeast Asia

Multi-country surveys of the public's perception of risk using the same questionnaire were sequentially implemented from April to December 2006 in Japan, China, and South Korea. Statistical analyses, such as traditional mean tests, rank order tests, two-step cluster analysis, and principal component analysis were used to analyze the survey data. The results revealed that Chinese tend to be more tolerant of risk than Japanese and South Koreans. In all three countries, the threats of global warming, cancer, traffic accidents, and fire were perceived as higher-order risks, while infectious diseases and threats from high technology were perceived as lower-order risks. Looking across the entire multi-country sample, we found that Chinese participants perceived greater risk in typhoons, SARS, and drugs; Japanese saw greater risk from gas explosions and potential threats coming over the Internet; while people in all three countries identified earthquakes as a primary risk. These differences in risk perception reflect the natural and socioeconomic conditions in the three countries. Although the study did not emphasize differences in risk perception within countries based on demographic factors such as education, age, and gender, we found that differences based on education and age tended to be greater in China and South Korea than in Japan. We also found that men perceived greater risks than women in China and South Korea, while in Japan it was the opposite with women perceiving greater risks. A comparison of these results with previous studies reveals a bias in past studies toward student samples and indicates the need for more representative samples in multi-country surveys.     

Metal Levels in Tissues of Florida Gar (Lepisosteus Platyrhincus) from Lake Okeechobee

There is considerable concern about the effects of contaminants on organisms at higher trophic levels, as well as interest in developing bioindicators of ecological health. In this article we examine the levels of arsenic, cadmium, chromium, lead, manganese, mercury, and selenium in the gonads, liver and muscle of Florida gar (Lepisosteus platyrhincus) from Lake Okeechobee in south-central Florida. Gar are top-level predators in freshwater ecosystems. We expected that there would be differences in metal levels as a function of tissue, and predicted differences as a function of sex, size, and location around the lake. There were significant differences among tissues for all metals, but there were few differences as a function of size and gender, which may relate to the generally low levels of metals. Mercury levels were significantly higher in gar collected from the north, and arsenic levels were significantly higher in the gar collected from the south. All metal levels in the muscle of gar collected from Lake Okeechobee were similar to, or lower than those generally reported from other areas of the United States. Thus, although the levels of mercury from the Everglades to the south of Lake Okeechobee are sufficiently high to result in human fish consumption advisories, there are none for Lake Okeechobee. The mercury levels in fish muscle from Lake Okeechobee are lower than from many waters in the U.S. and do not pose a problem for humans. However, liver levels average over the 0.5 microg g(-1) level considered safe for human consumption, and might pose a problem for non-human consumers that eat the fish whole.