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Abstract Chemical contamination has impaired ecosystems, reducing biodiversity and the provisioning of functions and services. This has spurred a movement to restore contaminated ecosystems and develop and implement national and international regulations that require it. Nevertheless, ecological restoration remains a young and rapidly growing discipline and its intersection with toxicology is even more nascent and underdeveloped. Consequently, we provide guidance to scientists and practitioners on when, where, and how to restore contaminated ecosystems. Although restoration has many benefits, it also can be expensive, and in many cases systems can recover without human intervention. Hence, the first question we address is: “When should we restore contaminated ecosystems?” Second, we provide suggestions on what to restore—biodiversity, functions, services, all 3, or something else—and where to restore given expected changes to habitats driven by global climate change. Finally, we provide guidance on how to restore contaminated ecosystems. To do this, we analyze critical aspects of the literature dealing with the ecology of restoring contaminated ecosystems. Additionally, we review approaches for translating the science of restoration to on-the-ground actions, which includes discussions of market incentives and the finances of restoration, stakeholder outreach and governance models for ecosystem restoration, and working with contractors to implement restoration plans. By explicitly considering the mechanisms and strategies that maximize the success of the restoration of contaminated sites, we hope that our synthesis serves to increase and improve collaborations between restoration ecologists and ecotoxicologists and set a roadmap for the restoration of contaminated ecosystems. Integr Environ Assess Manag 2016;12:273–283. © 2015 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of SETAC Key Points We merge insights from ecological and economic theory and on-the-ground restoration activities to provide guidance on what endpoints should be targeted for restoration in contaminated ecosystems and when, where, and how to restore ecosystems degraded by contaminants. We encourage practitioners to consider restoration as early as possible (i.e., before injury or before remediation) and to restore both structural and functional endpoints. We also promote consideration of broader landscape and seascape contexts and new ideas and approaches that can overcome the scientific and financial limitations of restoration. We urge more reciprocal transfer of knowledge among theorist and practitioners and academics, industry, government, tribal organizations, NGOs and the public to improve the science of restoration.

The production of biofuel from cellulosic residues can have both environmental and financial benefits. A particular benefit is that it can alleviate competition for land conventionally used for food and feed production. In this research, we investigate greenhouse gas (GHG) emissions associated with the production of ethanol, biomethane, limonene and digestate from citrus waste, a byproduct of the citrus processing industry. The study represents the first life cycle-based evaluations of citrus waste biorefineries. Two biorefinery configurations are studied—a large biorefinery that converts citrus waste into ethanol, biomethane, limonene and digestate, and a small biorefinery that converts citrus waste into biomethane, limonene and digestate. Ethanol is assumed to be used as E85, displacing gasoline as a light-duty vehicle fuel; biomethane displaces natural gas for electricity generation, limonene displaces acetone in solvents, and digestate from the anaerobic digestion process displaces synthetic fertilizer. System expansion and two allocation methods (energy, market value) are considered to determine emissions of co-products. Considerable GHG reductions would be achieved by producing and utilizing the citrus waste-based products in place of the petroleum-based or other non-renewable products. For the large biorefinery, ethanol used as E85 in light-duty vehicles results in a 134% reduction in GHG emissions compared to gasoline-fueled vehicles when applying a system expansion approach. For the small biorefinery, when electricity is generated from biomethane rather than natural gas, GHG emissions are reduced by 77% when applying system expansion. The life cycle GHG emissions vary substantially depending upon biomethane leakage rate, feedstock GHG emissions and the method to determine emissions assigned to co-products. Among the process design parameters, the biomethane leakage rate is critical, and the ethanol produced in the large biorefinery would not meet EISA’s requirements for cellulosic biofuel if the leakage rate is higher than 9.7%. For the small biorefinery, there are no GHG emission benefits in the production of biomethane if the leakage rate is higher than 11.5%. Compared to system expansion, the use of energy and market value allocation methods generally results in higher estimates of GHG emissions for the primary biorefinery products (i.e., smaller reductions in emissions compared to reference systems).

Some empirical findings are presented on the relationship between urban form and work trip commuting efficiency, drawn from the analysis of 1986 work trip commuting patterns in the greater Toronto area. Work trip commuting efficiency is measured with respect to the average number of vehicle kilometers traveled (VKT) per worker in a given zone. Preliminary findings include VKT per worker increases as one moves away from both the central core of the city and from other high-density employment centers within the region; job-housing balance, per se, shows little impact on commuting VKT; and population density, in and of itself, does not explain variations on commuting VKT once other urban structure variables have been accounted for.

Reducing carbon dioxide (CO2) emissions has become a global consensus in response to global warming and climate change, especially to China, the largest CO2 emitter in the world. Most studies have focused on CO2 emissions from the production sector, however, the household sector plays an important role in the total energy-related CO2 emissions. This study formulates an integrated model based on logarithmic mean Divisia index methodology and a system dynamics model to dynamically simulate household energy consumption and CO2 emissions under different conditions. Results show the following: (1) the integrated model performs well in calculating the contribution of influencing factors on household CO2 emissions and analyzing the options for CO2 emission mitigation; (2) the increase in income is the dominant driving force of household CO2 emissions, and as a result of the improved standard of living in China a sustained increase in household CO2 emissions can be expected; (3) with decreasing energy intensity, CO2 emissions will decrease to 404.26 Mt-CO2 in 2020, which is 9.84% lower than the emissions in 2014; (4) the reduction potential by developing non-fossil energy sources is limited, and raising the rate of urbanization cannot reduce the household CO2 emission under the comprehensive influence of other factors.

This paper is Part II of a two-part series in which the risks associated with unrestrained greenhouse-gas emissions, and with measures to limit emissions, are reviewed. A sustained limitation of global CO2 emissions requires global population stabilization, a reduction in per capita emissions in the developed world, and a limitation of the increase in per capita emissions in the developing world. Reducing or limiting per capita emissions requires a major effort to improve the efficiency with which energy is transformed and used; urban development which minimizes the need for the private automobile and facilitates district heating, cooling, and cogeneration systems; and accelerated development of renewable energy. The following risks associated with these efforts to limit CO2 emissions are reviewed here: (i) resources might be diverted from other urgent needs; (ii) economic growth might be reduced; (iii) reduction measures might cost more than expected; (iv) early action might cost more than later action; (v) reduction measures might have undesired side effects; (vi) reduction measures might require heavy-handed government intervention; and (vii) reduction measures might not work. With gradual implementation of a diversified portfolio of measures, these risks can be greatly reduced. Net risk is further reduced by the fact that a number of non-climatic benefits would result from measures to limit CO2 emissions. Based on the review of risks associated with measures to limit emissions here, and the review of the risks associated with unrestrained emissions presented in Part I, it is concluded that a reasonable near-term (20–30 year) risk hedging strategy is one which seeks to stabilize global fossil CO2 emissions at the present (early 1990's) level. This in turn implies an emission reduction of 26% for industrialized countries as a whole and 40–50% for Canada and the USA if developing country emissions are to increase by no more than 60%, which in itself would require major assistance from the industrialized countries. The effectiveness of global CO2-emission stabilization in slowing down the buildup of atmospheric CO2 is enhanced by the fact that the airborne fraction (ratio of annual atmospheric CO2 increase to total annual anthropogenic emissions) decreases if emissions are stabilized, whereas it increases if emissions continue to grow exponentially. The framework and conclusions presented here are critically compared with so-called optimization frameworks.

This article explores the complex, “contact zone” nature of museums within the context of the current environmental crisis threatening our planet. Historically and even today, museums have engaged in a practice of “monocultural” thinking which is mired in a pretext to neutrality that has advanced the patriarchal capitalist neoliberal status quo and maintained a vision of a human/non-human binary of power, dominance, and control. However, there is also growing evidence that museums are shifting their approaches. Focusing on examples from Canada, we discuss how museums are using exhibitions and pedagogical and community outreach strategies to render visible deeply problematic and global “technofossil” practices, encourage activism through aesthetic engagement, encourage dialogue between community and industry as well as engage in imaginative decolonising initiatives that remap our understandings of who we are and where we need to go. We argue that in taking up environmental issues in politically intentional ways, museums create “oppositional views” that act as pedagogical sites of resistance.

taken into consideration: mandatory use of solar energy in new state and federal buildings, and mandatory use of solar energy in new dwellings when technically feasible. To increase the effectiveness of the solar energy program nationally and to assure its rapid implementation, the following steps should be taken: faster development of new photovoltaic cell technologies, an acceleration of the demonstration program for small-scale solar thermal power and wind plants, an acceleration of the biomass program, more aggressive research on energy storage means, and an intensification of the program of synthetic fuels production. In addition, emphasis in the building industry on the advantage of passive solar systems and hybrid systems seems necessary in order to reduce the use of fossil fuels and to make a place for solar energy as one of the major energy sources it deserves to be.

We examined life cycle environmental and economic implications of two near-term scenarios for converting cellulosic biomass to energy, generating electricity from cofiring biomass in existing coal power plants, and producing ethanol from biomass in stand-alone facilities in Ontario, Canada. The study inventories near-term biomass supply in the province, quantifies environmental metrics associated with the use of agricultural residues for producing electricity and ethanol, determines the incremental costs of switching from fossil fuels to biomass, and compares the cost-effectiveness of greenhouse gas (GHG) and air pollutant emissions abatement achieved through the use of the bioenergy. Implementing a biomass cofiring rate of 10% in existing coal-fired power plants would reduce annual GHG emissions by 2.3 million metric tons (t) of CO2 equivalent (7% of the province's coal power plant emissions). The substitution of gasoline with ethanol/gasoline blends would reduce annual provincial lightduty vehicle fleet emissions between 1.3 and 2.5 million t of CO2 equivalent (3.5-7% of fleet emissions). If biomass sources other than agricultural residues were used, additional emissions reductions could be realized. At current crude oil prices ($70/barrel) and levels of technology development of the bioenergy alternatives, the biomass electricity cofiring scenario analyzed is more cost-effective for mitigating GHG emissions ($22/t of CO2 equivalent for a 10% cofiring rate) than the stand-alone ethanol production scenario ($92/t of CO2 equivalent). The economics of biomass cofiring benefits from existing capital, whereas the cellulosic ethanol scenario does not. Notwithstanding this result, there are several factors that increase the attractiveness of ethanol. These include uncertainty in crude oil prices, potential for marked improvements in cellulosic ethanol technology and economics, the province's commitment to 5% ethanol content in gasoline, the possibility of ethanol production benefiting from existing capital, and there being few alternatives for moderate-to-large-scale GHG emissions reductions in the transportation sector.