Meat,Dairy and Climate Change: Assessing the Long-Term Mitigation Potential of Alternative Agri-Food Consumption Patterns in Canada

We use a newly developed model of the entire Canadian energy system (TIMES-Canada) to assess the climate change mitigation potential of different agri-food consumption patterns in Canada. For this, our model has been extended by disaggregating the agricultural demand sector into individual agri-food demands to allow for a more in-depth analysis. Besides a business-as-usual (baseline) scenario, we have constructed four different agri-food scenarios to assess the viability of reducing Canadian meat and dairy consumption in order to diminish Canada’s agricultural sector energy consumption and greenhouse gas (GHG) emissions. Our policy scenarios progressively restrict the consumption of different meat and dairy agricultural products until the year 2030. Our results suggest that the implementation of a meat and dairy consumption reduction policy would lead to a 10 to 40 % reduction in agricultural GHG emissions, depending on the severity of the scenario. This translates to a 1 to 3 % decrease in total Canadian GHG emissions by the year 2030. Besides these environmental benefits, health benefits associated with a reduction in meat and dairy consumption (as inferred from other studies) are presented as an additional source of motivation for implementing such a policy in Canada.     

Exposure of insects and insectivorous birds to metals and other elements from abandoned mine tailings in three Summit County drainages, Colorado

Concentrations of 31 metals, metalloids, and other elements were measured in insects and insectivorous bird tissues from three drainages with different geochemistry and mining histories in Summit Co., Colorado, in 2003, 2004, and 2005. In insect samples, all 25 elements that were analyzed in all years increased in both Snake and Deer Creeks in the mining impacted areas compared to areas above and below the mining impacted areas. This distribution of elements was predicted from known or expected sediment contamination resulting from abandoned mine tailings in those drainages. Element concentrations in avian liver tissues were in concordance with levels in insects, that is with concentrations higher in mid-drainage areas where mine tailings were present compared to both upstream and downstream locations; these differences were not always statistically different, however. The lack of statistically significant differences in liver tissues, except for a few elements, was due to relatively small sample sizes and because many of these elements are essential and therefore well regulated by the bird's homeostatic processes. Most elements were at background concentrations in avian liver tissue except for Pb which was elevated at mid-drainage sites to levels where delta-aminolevulinic acid dehydratase activity was inhibited at other mining sites in Colorado. Lead exposure, however, was not at toxic levels. Fecal samples were not a good indication of what elements birds ingested and were potentially exposed to.     

Heavy metals and couple fecundity, the LIFE Study

The effect of heavy metals at environmentally relevant concentrations on couple fecundity has received limited study despite ubiquitous exposure. In 2005-2009, couples (n = 501) desiring pregnancy and discontinuing contraception were recruited and asked to complete interviews and to provide blood specimens for the quantification of cadmium (μg L⁻¹), lead (μg dL⁻¹) and mercury (μg L⁻¹) using inductively coupled plasma-mass spectrometry. Couples completed daily journals on lifestyle and intercourse along with menstruation and pregnancy testing for women. Couples were followed for 12 months or until pregnant. Fecundability odds ratios (FORs) and 95% confidence intervals (CIs) were estimated adjusting for age, body mass index, cotinine, and serum lipids in relation to female then male exposures. FORs <1 denote a longer time to pregnancy. In adjusted models, reduced FORs were observed for both female cadmium (0.78; 95% CI 0.63-0.97) and male lead (0.85; 95% CI 0.73-0.98) concentrations. When jointly modeling couples’ exposures, only male lead concentration significantly reduced the FOR (0.82; 95% CI 0.68, 0.97), though the FOR remained <1 for female cadmium (0.80; 95% CI 0.64, 1.00). This prospective couple based cohort with longitudinal capture of time to pregnancy is suggestive of cadmium and lead’s reproductive toxicity at environmentally relevant concentrations.     

PCB remediation in schools: a review

Growing awareness of polychlorinated biphenyls (PCBs) in legacy caulk and other construction materials of schools has created a need for information on best practices to control human exposures and comply with applicable regulations. A concise review of approaches and techniques for management of building-related PCBs is the focus of this paper. Engineering and administrative controls that block pathways of PCB transport, dilute concentrations of PCBs in indoor air or other exposure media, or establish uses of building space that mitigate exposure can be effective initial responses to identification of PCBs in a building. Mitigation measures also provide time for school officials to plan a longer-term remediation strategy and to secure the necessary resources. These longer-term strategies typically involve removal of caulk or other primary sources of PCBs as well as nearby masonry or other materials contaminated with PCBs by the primary sources. The costs of managing PCB-containing building materials from assessment through ultimate disposal can be substantial. Optimizing the efficacy and cost-effectiveness of remediation programs requires aligning a thorough understanding of sources and exposure pathways with the most appropriate mitigation and abatement methods.     

Can’t See the (Bamboo) Forest for the Trees: Examining Bamboo’s Fit Within International Forestry Institutions

Over the centuries, governments and international agencies have developed a wide range of institutions to manage timber resources and conserve values provided by treed lands. Concerns regarding the sustainable supply of timber have provided opportunities for the development of substitute resources; however, bamboo and other non-timber forest resources have not been a part of the development of these institutions. Bamboo is a unique Non-Timber Forest Product, as it is often classified as forest or timber, and therefore must adhere to the same regulations as timber. Given the recent global expansion of bamboo, it is timely to examine the interplay between bamboo and the traditional institutions of forest governance. This paper aims to contribute to debates regarding cognitive institutional constraints on the development of substitute natural resources using bamboo as a case study, with specific focus on the applicability of Forest Stewardship Council certification, timber legality verification and Reducing Emissions from Deforestation and Forest Degradation to bamboos.     

Examining the Impact of Expert Voices: Communicating the Scientific Consensus on Genetically-modified Organisms

Scholars are divided over whether communicating to the public the existence of scientific consensus on an issue influences public acceptance of the conclusions represented by that consensus. Here, we examine the influence of four messages on perception and acceptance of the scientific consensus on the safety of genetically modified organisms (GMOs): two messages supporting the idea that there is a consensus that GMOs are safe for human consumption and two questioning that such a consensus exists. We found that although participants concluded that the pro-consensus messages made stronger arguments and were likely to be more representative of the scientific community’s attitudes, those messages did not abate participants’ concern about GMOs. In fact, people’s pre-manipulation attitudes toward GMOs were the strongest predictor of of our outcome variables (i.e. perceived argument strength, post-message GMO concern, perception of what percent of scientists agree). Thus, the results of this study do not support the hypothesis that consensus messaging changes the public’s hearts and minds, and provide more support, instead, for the strong role of motivated reasoning.     

Managing water services in tropical regions: From land cover proxies to hydrologic fluxes

Watershed investment programs frequently use land cover as a proxy for water-based ecosystem services, an approach based on assumed relationships between land cover and hydrologic outcomes. Water flows are rarely quantified, and unanticipated results are common, suggesting land cover alone is not a reliable proxy for water services. We argue that managing key hydrologic fluxes at the site of intervention is more effective than promoting particular land-cover types. Moving beyond land cover proxies to a focus on hydrologic fluxes requires that programs (1) identify the specific water service of interest and associated hydrologic flux; (2) account for structural and ecological characteristics of the relevant land cover; and, (3) determine key mediators of the target hydrologic flux. Using examples from the tropics, we illustrate how this conceptual framework can clarify interventions with a higher probability of delivering desired water services than with land cover as a proxy.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-014-0578-8) contains supplementary material, which is available to authorized users.     

The horizontal reactive media treatment well (HRX Well®) for passive in situ remediation: Design,implementation, and sustainability considerations

A new in situ remediation concept termed a Horizontal Reactive Media Treatment Well (HRX Well^®) is presented that utilizes a horizontal well filled with reactive media to passively treat contaminated groundwater in situ. The approach involves the use of a large‐diameter directionally drilled horizontal well filled with solid reactive media installed parallel to the direction of groundwater flow. The engineered contrast in hydraulic conductivity between the high in‐well reactive media and the ambient aquifer hydraulic conductivity results in the passive capture, treatment, and discharge back to the aquifer of proportionally large volumes of groundwater. Capture and treatment widths of up to tens of feet can be achieved for many aquifer settings, and reductions in downgradient concentrations and contaminant mass flux are nearly immediate. Many different types of solid‐phase reactive treatment media are already available (zero valent iron, granular activated carbon, biodegradable particulate organic matter, slow‐release oxidants, ion exchange resins, zeolite, apatite, etc.). Therefore, this concept could be used to address a wide range of contaminants. Laboratory and pilot‐scale test results and numerical flow and transport model simulations are presented that validate the concept. The HRX Well can access contaminants not accessible by conventional vertical drilling and requires no aboveground treatment or footprint and requires limited ongoing maintenance. A focused feasibility evaluation and alternatives analysis highlights the potential cost and sustainability advantages of the HRX Well compared to groundwater extraction and treatment systems or funnel and gate permeable reactive barrier technologies for long‐term plume treatment. This paper also presents considerations for design and implementation for a planned upcoming field installation.     

Comparative study of transport processes of nitrogen, phosphorus, and herbicides to streams in five agricultural basins, USA

Agricultural chemical transport to surface water and the linkage to other hydrological compartments, principally ground water, was investigated at five watersheds in semiarid to humid climatic settings. Chemical transport was affected by storm water runoff, soil drainage, irrigation, and how streams were linked to shallow ground water systems. Irrigation practices and timing of chemical use greatly affected nutrient and pesticide transport in the semiarid basins. Irrigation with imported water tended to increase ground water and chemical transport, whereas the use of locally pumped irrigation water may eliminate connections between streams and ground water, resulting in lower annual loads. Drainage pathways in humid environments are important because the loads may be transported in tile drains, or through varying combinations of ground water discharge, and overland flow. In most cases, overland flow contributed the greatest loads, but a significant portion of the annual load of nitrate and some pesticide degradates can be transported under base-flow conditions. The highest basin yields for nitrate were measured in a semiarid irrigated system that used imported water and in a stream dominated by tile drainage in a humid environment. Pesticide loads, as a percent of actual use (LAPU), showed the effects of climate and geohydrologic conditions. The LAPU values in the semiarid study basin in Washington were generally low because most of the load was transported in ground water discharge to the stream. When herbicides are applied during the rainy season in a semiarid setting, such as simazine in the California basin, LAPU values are similar to those in the Midwest basins.