Perceptions of climate change risks in primary resource use industries: a survey of the Canadian mining sector

A survey documenting how climate change is perceived, experienced, and responded to in the Canadian mining sector was administered to industry practitioners at the Prospectors & Developers Association of Canada annual meeting. Nine key findings from the survey are discussed: (1) The Canadian mining sector is sensitive to climate-related conditions. (2) Climate change is perceived to be having a negative impact on mining operations. (3) Companies are taking action to manage the current impacts. (4) Cost and uncertainty are commonly identified barriers to adapting to current climate change. (5) Future climate change is expected to have impacts for the industry. (6) Climate change projections are perceived as threats by the majority of respondents. (7) Despite the perceived threat, companies are not currently taking action to plan for future impacts. (8) Cost and uncertainty are commonly identified barriers to adapting to future climate change impacts. (9) The mining sector is currently making efforts to reduce greenhouse gas emissions. The survey is exploratory in nature, establishing a baseline for targeted research to assess in greater detail the vulnerability of mining to climate change.     

Estimating the effect of nitrogen fertilizer on the greenhouse gas balance of soils in Wales under current and future climate

The Welsh Government is committed to reduce greenhouse gas (GHG) emissions from agricultural systems and combat the effects of future climate change. In this study, the ECOSSE model was applied spatially to estimate GHG and soil organic carbon (SOC) fluxes from three major land uses (grass, arable and forest) in Wales. The aims of the simulations were: (1) to estimate the annual net GHG balance for Wales; (2) to investigate the efficiency of the reduced nitrogen (N) fertilizer goal of the sustainable land management scheme (Glastir), through which the Welsh Government offers financial support to farmers and land managers on GHG flux reduction; and (3) to investigate the effects of future climate change on the emissions of GHG and plant net primary production (NPP). Three climate scenarios were studied: baseline (1961–1990) and low and high emission climate scenarios (2015–2050). Results reveal that grassland and cropland are the major nitrous oxide (N₂O) emitters and consequently emit more GHG to the atmosphere than forests. The overall average simulated annual net GHG balance for Wales under baseline climate (1961–1990) is equivalent to 0.2 t CO₂e ha^?1 y^?1 which gives an estimate of total annual net flux for Wales of 0.34 Mt CO₂e y^?1. Reducing N fertilizer by 20 and 40 % could reduce annual net GHG fluxes by 7 and 25 %, respectively. If the current N fertilizer application rate continues, predicted climate change by the year 2050 would not significantly affect GHG emissions or NPP from soils in Wales.     

Groundwater Level Trends and Drivers in Two Northern New England Glacial Aquifers

We evaluated long‐term trends and predictors of groundwater levels by month from two well‐studied northern New England forested headwater glacial aquifers: Sleepers River, Vermont, 44 wells, 1992‐2013; and Hubbard Brook, New Hampshire, 15 wells, 1979‐2004. Based on Kendall Tau tests with Sen slope determination, a surprising number of well‐month combinations had negative trends (decreasing water levels) over the respective periods. Sleepers River had slightly more positive than negative trends overall, but among the significant trends (p < 0.1), negative trends dominated 67 to 40. At Hubbard Brook, negative trends outnumbered positive trends by a nearly 2:1 margin and all seven of the significant trends were negative. The negative trends occurred despite generally increasing trends in monthly and annual precipitation. This counterintuitive pattern may be a result of increased precipitation intensity causing higher runoff at the expense of recharge, such that evapotranspiration demand draws down groundwater storage. We evaluated predictors of month‐end water levels by multiple regression of 18 variables related to climate, streamflow, snowpack, and prior month water level. Monthly flow and prior month water level were the two strongest predictors for most months at both sites. The predictive power and ready availability of streamflow data can be exploited as a proxy to extend limited groundwater level records over longer time periods.     

Evaluation of Dynamically Dimensioned Search Algorithm for Optimizing SWAT by Altering Sampling Distributions and Searching Range

The primary advantage of Dynamically Dimensioned Search (DDS) algorithm is that it outperforms other optimization techniques in both convergence speed and searching ability for parameter sets that satisfy statistical guidelines while requiring only one algorithm parameter (perturbation factor) in the optimization process. Conventionally, a default value of 0.2 is used as the perturbation factor, where a normal distribution is applied with mean sampling distribution of zero and variance of one. However, the perturbation factor sensitivity to the performance of DDS for watershed modeling is still unknown. The fixed‐form sampling distribution may result in finding parameters at the local scale rather than global in the sampling space. In this study, the efficiency of DDS was evaluated by altering the perturbation factor (from 0.05 to 1.00) and the selection of sampling distribution (normal and uniform) on hydrologic and water quality predictions in a lowland agricultural watershed in Texas, United States. Results show that the use of altered perturbation factor may cause variations in convergence speed or the ability to find better solutions. In addition, DDS results were found to be very sensitive to sampling distribution selections, where DDS‐N (normal distribution) outperformed DDS‐U (uniform distribution) in all case scenarios. The choice of sampling distributions could be the potential major factor to be attributed for the performance of auto‐calibration techniques for watershed simulation models.     

Autonomy and the Politics of Food Choice: From Individuals to Communities

Individuals use their capacity for autonomy to express preferences regarding food choices. Food choices are fundamental, universal, and reflect a diversity of interests and cultural preferences. Traditionally, autonomy is cast in only epistemic terms, and the social and political dimension of it, where autonomy obstruction tends to arise, is omitted. This reflects problematic limits in the Cartesian notion of the individual. Because this notion ignores context and embodiment, the external and internal constraints on autonomy that extend from social location are not considered. Therefore, reconceptions of the individual and autonomy which emphasize social location and relational interdependency are needed. To combat autonomy obstruction, individuals can appeal to community and community autonomy as a social mechanism. Communities are social groups characterized by people living in places with shared goals. Recognizing their interdependency, individuals can organize as communities in order to accomplish objectives that they cannot on their own. While community autonomy is valuable unto itself, it can also enhance individual autonomy.     

Emissions of PCDD/Fs, PCBs, and PAHs from legacy on-road heavy-duty diesel engines

Exhaust emissions of seventeen 2,3,7,8-substituted polychlorinated dibenzo-p-dioxin/furan (PCDD/F) congeners, tetra-octa PCDD/F homologues, 12 WHO 2005 polychlorinated biphenyl (PCB) congeners, mono-nona chlorinated biphenyl homologues, and 19 polycyclic aromatic hydrocarbons (PAHs) from three legacy diesel engines were investigated. The three engines tested were a 1985 model year GM 6.2 J-series engine, a 1987 model year Detroit Diesel Corporation 6V92 engine, and a 1993 model year Cummins L10 engine. Results were compared to United States’ mobile source inventory for on-road diesel engines, as well as historic and modern diesel engine emission values. The test fuel contained chlorine at 9.8 ppm which is 1.5 orders of magnitude above what is found in current diesel fuel and 3900 ppm sulfur to simulate fuels that would have been available when these engines were produced. Results indicate PCDD/F emissions of 13.1, 7.1, and 13.6 pg International Toxic Equivalency (I-TEQ) L⁻¹ fuel consumed for the three engines respectively, where non-detects are equal to zero. This compares with a United States’ mobile source on-road diesel engine inventory value of 946 pg I-TEQ L⁻¹ fuel consumed and 1.28 pg I-TEQ L⁻¹ fuel consumed for modern engines equipped with a catalyzed diesel particle filter and urea selective catalytic reduction. PCB emissions are 2 orders of magnitude greater than modern diesel engines. PAH results are representative of engines from this era based on historical values and are 3-4 orders of magnitude greater than modern diesel engines.     

Metal ion and other key water quality constituent attenuation in soil columns

A set of soil columns was constructed to simulate discharge of disinfected tertiary treated wastewater to a river via nearby land application or indirect discharge. The system was primarily designed to observe the fate of metal ions and nutrients. The following three experiments were conducted: (1) flow through saturated soils only, which simulates indirect discharge where water is directly applied to groundwater; (2) flow through unsaturated soil followed by saturated flow, which simulates vadose then saturated zone transport; and (3) saturated flow only using ethylene diamine tetraacetic acid-metal chelates, which determined effects of metal organic complexes on metal mobility through the soil. Metal ion attenuation was substantial but not complete in experiments 1 and 2 (removal: 68% Cu2+, 43% Ni2+, 98% Pb2+, and 96% Hg2+), which was somewhat contrary to modeling results. Cyanide attenuation was also monitored (92% removal). In experiment 3, lead attenuation was somewhat reduced (92% removal) and delayed (requiring additional residence time); copper attenuation was significantly reduced (38% removal) and delayed; and nickel concentrations were higher in the 28-day sample (> 80 microg/L) than in the column feed water (58 microg/L). Near-complete denitrification and total phosphorus attenuation were observed. For the water quality constituents studied, unsaturated (vadose zone) transport did not appear to add additional benefit.     

Treatment Optimization Through Refinement of a Conceptual Site Model Using Compound Specific Isotope Analysis

Two adjacent automotive component manufacturers in Japan had concentrations of trichloroethene (TCE) and perchloroethene (PCE) in soils and groundwater beneath their plants. One of the manufacturers extensively used these solvents in its processes, while the adjacent manufacturer had no documentation of solvent use. The conceptual site model (CSM) initially involved a single source that migrated from one building to under the adjacent building. Further, because low concentrations of daughter products (e.g., cis‐1,2‐dichloroethene; 3.6 to 840 micrograms per liter [μg/L]) were detected in groundwater, the CSM did not consider intrinsic degradation to be a significant fate mechanism. With this interpretation, the initial remedial design involved both source treatment and perimeter groundwater control to prevent offsite migration of the solvents in groundwater. Identifying whether intrinsic degradation was occurring and could be quantified represented a means of eliminating this costly and potentially redundant component. Further, incorporating intrinsic degradation into the remediation design would also allow for a more focused source treatment, resulting in further cost savings. Three rounds of sampling and data interpretation applying compound specific isotope analysis (CSIA) were used to refine the CSM. The first sampling round involved three‐dimensional CSIA (¹³C, ³⁷Cl, and ²H), while the second two rounds involved ¹³C only, focusing on degradation over time. For the May 2012 sampling, δ¹³C for PCE ranged from –31‰ to –29.6 ‰ and for TCE ranged from –30.4‰ to –28.3‰; showing similar values. δ²H for TCE ranged from 581‰ to 629‰, indicating a manufactured TCE rather than that resulting from dehalogenation processes from PCE. However, mixing of manufactured TCE with that resulting from degraded PCE cannot be ruled out. Because of the similar δ¹³C ratios for PCE and TCE, and ³⁷Cl data for PCE and TCE, fractionation and enrichment factors could not be relied upon. Fractionation patterns were evaluated using graphical methods to trace TCE to the source location to better focus the locations for steam injection. Graphical methods were also used to define the degradation mechanism and from this, incorporate intrinsic degradation processes into the remedial design, eliminating the need for a costly perimeter pump and treat system. ©2015 Wiley Periodicals, Inc.     

Metabolism of nC11 fatty acid fed to Trichoderma koningii and Penicillium janthinellum II: Production of intracellular and extracellular lipids

Abstract

Little is known about the fungal metabolism of nC₁₀ and nC₁₁ fatty acids and their conversion into lipids. A mixed batch culture of soil fungi, T. koningii and P. janthinellum, was grown on undecanoic acid (UDA), a mixture of UDA and potato dextrose broth (UDA+PDB), and PDB alone to examine their metabolic conversion during growth. We quantified seven intracellular and extracellular lipid classes using Iatroscan thin-layer chromatography with flame ionization detection (TLC-FID). Gas chromatography with flame ionization detection (GC-FID) was used to quantify 42 individual fatty acids. Per 150 mL culture, the mixed fungal culture grown on UDA+PDB produced the highest amount of intracellular (531 mg) and extracellular (14.7 mg) lipids during the exponential phase. The content of total intracellular lipids represented 25% of the total biomass-carbon, or 10% of the total biomass dry weight produced. Fatty acids made up the largest class of intracellular lipids (457 mg/150 mL culture) and they were synthesized at a rate of 2.4 mg/h during the exponential phase, and decomposed at a rate of 1.8 mg/h during the stationary phase, when UDA+PDB was the carbon source. Palmitic acid (C_16:0), stearic acid (C_18:0), oleic acid (C_18:1), linoleic acid (C_18:2) and vaccenic acid (C_18:1) accounted for >80% of the total intracellular fatty acids. During exponential growth on UDA+PDB, hydrocarbons were the largest pool of all extracellular lipids (6.5 mg), and intracellularly they were synthesized at a rate of 64 μg/h. The mixed fungal species culture of T. koningii and P. janthinellum produced many lipids for potential use as industrial feedstocks or bioproducts in biorefineries.