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While bioenergy plays a key role in strategies for increasing renewable energy deployment, studies assessing greenhouse gas (GHG) emissions from forest bioenergy systems have identified a potential trade-off of the system with forest carbon stocks. Of particular importance to national GHG inventories is how trade-offs between forest carbon stocks and bioenergy production are accounted for within the Agriculture, Forestry and Other Land Use (AFOLU) sector under current and future international climate change mitigation agreements. Through a case study of electricity produced using wood pellets from harvested forest stands in Ontario, Canada, this study assesses the implications of forest carbon accounting approaches on net emissions attributable to pellets produced for domestic use or export. Particular emphasis is placed on the forest management reference level (FMRL) method, as it will be employed by most Annex I nations in the next Kyoto Protocol Commitment Period. While bioenergy production is found to reduce forest carbon sequestration, under the FMRL approach this trade-off may not be accounted for and thus not incur an accountable AFOLU-related emission, provided that total forest harvest remains at or below that defined under the FMRL baseline. In contrast, accounting for forest carbon trade-offs associated with harvest for bioenergy results in an increase in net GHG emissions (AFOLU and life cycle emissions) lasting 37 or 90 years (if displacing coal or natural gas combined cycle generation, respectively). AFOLU emissions calculated using the Gross-Net approach are dominated by legacy effects of past management and natural disturbance, indicating near-term net forest carbon increase but longer-term reduction in forest carbon stocks. Export of wood pellets to EU markets does not greatly affect the total life cycle GHG emissions of wood pellets. However, pellet exporting countries risk creating a considerable GHG emissions burden, as they are responsible for AFOLU and bioenergy production emissions but do not receive credit for pellets displacing fossil fuel-related GHG emissions. Countries producing bioenergy from forest biomass, whether for domestic use or for export, should carefully consider potential implications of alternate forest carbon accounting methods to ensure that potential bioenergy pathways can contribute to GHG emissions reduction targets. [ABSTRACT FROM AUTHOR]

Conventional cost-effectiveness calculations ignore the implications of greenhouse gas ( GHG) emissions timing and thus may not properly inform decision-makers in the efficient allocation of resources to mitigate climate change. To begin to address this disconnect with climate change science, we modify the conventional cost-effectiveness approach to account for emissions timing. GHG emissions flows occurring over time are translated into an 'Equivalent Present Emission' based on radiative forcing, enabling a comparison of system costs and emissions on a consistent present time basis. We apply this 'Present Cost-Effectiveness' method to case studies of biomass-based electricity generation (biomass co-firing with coal, biomass cogeneration) to evaluate implications of forest carbon trade-offs on the cost-effectiveness of emission reductions. Bioenergy production from forest biomass can reduce forest carbon stocks, an immediate emissions source that contributes to atmospheric greenhouse gases. Forest carbon impacts thereby lessen emission reductions in the near-term relative to the assumption of biomass 'carbon neutrality', resulting in higher costs of emission reductions when emissions timing is considered. In contrast, conventional cost-effectiveness approaches implicitly evaluate strategies over an infinite analytical time horizon, underestimating nearer term emissions reduction costs and failing to identify pathways that can most efficiently contribute to climate change mitigation objectives over shorter time spans (e.g. up to 100 years). While providing only a simple representation of the climate change implications of emissions timing, the Present Cost-Effectiveness method provides a straightforward approach to assessing the cost-effectiveness of emission reductions associated with any climate change mitigation strategy where future GHG reductions require significant initial capital investment or increase near-term emissions. Timing is a critical factor in determining the attractiveness of any investment; accounting for emissions timing can better inform decisions related to the merit of alternative resource uses to meet near-, mid-, and long-term climate change mitigation objectives. [ABSTRACT FROM AUTHOR]

Replacement of fossil fuels with sustainably produced biomass crops for energy purposes has the potential to make progress in addressing climate change concerns, nonrenewable resource use, and energy security. The perennial grass Miscanthus is a dedicated energy crop candidate being field tested in Ontario, Canada, and elsewhere. Miscanthus could potentially be grown in areas of the province that differ substantially in terms of agricultural land class, environmental factors and current land use. These differences could significantly affect Miscanthus yields, input requirements, production practices, and the types of crops being displaced by Miscanthus establishment. This study assesses implications on life cycle greenhouse gas ( GHG) emissions of these differences through evaluating five Miscanthus production scenarios within the Ontario context. Emissions associated with electricity generation with Miscanthus pellets in a hypothetically retrofitted coal generating station are examined. Indirect land use change impacts are not quantified but are discussed. The net life cycle emissions for Miscanthus production varied greatly among scenarios (−90-170 kg CO2eq per oven dry tonne of Miscanthus bales at the farm gate). In some cases, the carbon stock dynamics of the agricultural system offset the combined emissions of all other life cycle stages (i.e., production, harvest, transport, and processing of biomass). Yield and soil C of the displaced agricultural systems are key parameters affecting emissions. The systems with the highest potential to provide reductions in GHG emissions are those with high yields, or systems established on land with low soil carbon. All scenarios have substantially lower life cycle emissions (−20-190 g CO2eq kWh−1) compared with coal-generated electricity (1130 g CO2eq kWh−1). Policy development should consider the implication of land class, environmental factors, and current land use on Miscanthus production. [ABSTRACT FROM AUTHOR]

To support more sustainable development of a region, decision support tools must consider local and global systems level impacts on the economy, environment, and society. Through the development and application of "economic input–output water resources" models for Beijing, China for the years 1985, 1990, and 1992, historical trends related to the economy structure and its water use are investigated. The study finds that the economy of Beijing and water use are highly concentrated in agriculture and heavy industry, but this intensive water use is indirectly reflected in the production of most other goods and services throughout the economy because of the interrelationships among various sectors of the economy. In spite of progress during the time period observed (e.g., between 1985 and 1990 the output of the economy doubled, but water consumption increased only 12% partly because of a significant increase in the price of water in 1988) and given the seriousness of water resources issues in the region, it is critical that future regional development make progress toward a more water-efficient economic system. [ABSTRACT FROM AUTHOR]

Objectives This article examines demographic and socio-economic factors associated with breastfeeding among women aged 15 to 55 in 2003 who had had a baby in the previous five years. Data sources The data are from Statistics Canada's 2003 Canadian Community Health Survey (CCHS). Supplementary information is from earlier national and regional surveys. Analytical techniques The analysis is based on information provided by 7,266 women aged 15 to 55 who had had a baby in the previous five years. Cross-tabulations were used to estimate the proportions who breastfed their most recent child and those who did so exclusively for at least six months, by age, marital status, education, household income, rural/urban residence, immigrant status and province. Multiple logistic regression was used to estimate the association of these characteristics with the prevalence and duration of breastfeeding and of exclusive breastfeeding. Main results In 2003, an estimated 85% of mothers reported that they had attempted to breastfeed, up markedly from around 25% in the mid-1960s. However, 17% had breastfed exclusively for at least six months. The likelihood of exclusive breastfeeding varied substantially by province. It rose with the mother's age and tended to be more common among those who lived in urban areas and who were college/university graduates. [ABSTRACT FROM AUTHOR]

An integrated fuel performance model for coated particle fuel has been developed to comprehensively study the behavior of TRISO-coated fuel. Modeling of both pebble-bed and prismatic configurations is possible. In the case of the pebble-bed concept, refueling of pebbles is simulated to account for the nonuniform environment in the reactor core and history-dependent particle behavior Monte Carlo sampling of particles is employed in fuel failure prediction to capture the statistical features of dimensions; material properties; and, in the case of the pebble-bed concept, the statistical nature of the refueling process. An advanced fuel failure model has been developed based on a probabilistic fracture mechanics approach. The mechanical analysis includes effects of anisotropic irradiation-induced dimensional changes and isotropic irradiation-induced creep, and the fluence-dependent Poisson ratio in irradiation creep. The stress analysis is benchmarked against the calculations of Japanese High Temperature Test Reactor (HTTR) first-loading fuel and finite element result on one case performed by the Idaho National Engineering and Environmental Laboratory. The failure model predictions are compared with NPR1, NPR2, and NPR1A capsule irradiation data. The model results compare very favorably with postirradiation examination results both in terms of failure probability, number of failed particles, and Kr85m R/B evolution during irradiation. [ABSTRACT FROM AUTHOR]

• Material intensities within single-family dwellings have coefficients of variation ranging from 13% to 160%. • Concrete basements are the largest driver of material use by mass and building envelope by volume. • Zoning ordinances incentivize high MI construction. • Understanding the variability in MI facilitates communication of its impacts on LCA findings, bottom-up MFA or circular economy studies, and similar. The need to reduce resource use in the built environment is widely recognized, but quantitative understanding of material use in buildings is limited, especially at neighbourhood and city scales. Existing bottom-up material inventories largely rely on typology-based methods, using representative buildings with little quantification of variability in material use. They also typically focus on advancing material replacement or recycling with less attention to reducing material use. This paper quantifies the material intensity of 40 single-family wood framed dwellings in Toronto, Canada. Design and construction drawings from the Toronto Committee of Adjustment and local building codes were used to estimate material quantities for each building. The variability in material use and intensity is explored per building, floor area and number of bedrooms and the largest drivers determined to identify opportunities for building design modifications to meaningfully reduce material intensity. Variability in the quantities of construction materials used within the single-family dwellings studied is large, with coefficients of variation ranging from 13% up to 160%. Concrete basements are the largest driver of material use by mass (mean 56% of total material mass) and building envelope insulation by volume (37%). This paper advances our understanding of the range of material intensities within a single building type in one city and the largest drivers of material use within single-family dwellings. This provides valuable information for including variability in typology approaches to bottom-up urban material intensity and insights for policy/design pathways for reducing material use in single-family dwellings. [ABSTRACT FROM AUTHOR]

Large scale, low cost, and low carbon intensity hydrogen production is needed to reduce emissions in the energy and transportation sectors. We present a techno-economic analysis and life cycle assessment of natural gas pyrolysis technologies for hydrogen production, with carbon black (CB) as a co-product. Four designs were considered based on the source of heat to the pyrolysis system, the combustion medium, and use of carbon capture (CC) technology. The oxygen-fired-CB design with CC is the most attractive from financial and environmental perspectives, superior to a conventional steam methane reformer (SMR) process with CC. The estimated pre-tax minimum hydrogen selling prices for the pyrolysis technologies range between $1.08/kg and $2.43/kg when natural gas (NG) costs $3.76/GJ. Key advantages include near-zero onsite GHG emissions of the oxygen-fired-CB design with CC and up to 41% lower GHG emissions compared to the SMR + CC process. The results indicate that natural gas pyrolysis may be a feasible pathway for hydrogen production. • Commercial scale hydrogen production via natural gas pyrolysis pathways is explored. • Options for handling the carbon black product are examined. • Low-carbon hydrogen of $1.7/kgH 2 outperforms the SMR hydrogen at similar conditions. • Cradle to gate GHG emissions between 1.8 and 4.6 kgCO 2 eq/kgH 2 is computed. [ABSTRACT FROM AUTHOR]

• This study integrates LCA and energy simulation on a visual programming interface. • 16,128 envelope variants are studied exploring passive EEMs on walls, windows, and roofs. • This study considers projected future climate and GHG intensity of energy sources. • The application of energy efficiency measures may increase total GHG emissions. • Studying embodied emissions is critical when highly efficient HVAC systems are used. The building industry has been developing measures for reducing operational emissions in the fight against climate change. Some of these well-intentioned measures may result in higher embodied emissions, potentially more than offsetting reductions achieved during operation. This research evaluates the effectiveness of different levels of application of five passive energy efficiency measures to reduce life cycle greenhouse gas (GHG) emissions in high-rise residential buildings in Toronto, Canada, while considering projected future climate and GHG intensity of energy sources. Through combining and automating life cycle assessment and energy simulation on a visual programing interface, the study evaluates 16,128 envelope variants, examining 56 wall, 12 roof, 6 window assemblies and 4 window-to-wall ratios (WWRs). Decreasing the WWR is found to be the most effective measure to reduce total envelope related GHG emissions (by about 28%). Increasing wall and roof insulation with GHG intensive materials (e.g., extruded polystyrene [XPS]), and increasing spandrel wall insulation potentially augment total emissions, depending on the scenario. Higher trade-offs between embodied and operational emissions are found when highly efficient electric HVAC systems are implemented (e.g., heat pumps). Results demonstrate it is imperative to assess both embodied and operational emissions during the design process of building envelopes to effectively reduce GHG emissions. [ABSTRACT FROM AUTHOR]

Addressing the "slum challenge" is essential for urban sustainability and the capacity of cities to provide a minimum quality of life to their residents. To present policy-makers with data to inform strategies to improve the lives of marginalized urban residents, this paper reviews quantitative indicators on slum infrastructure, and demonstrates analyses they can facilitate. First, we review 122 studies on slum infrastructure and report frequently assessed quantitative indicators; access to municipal services is among the most prevalent appearing in 25%–50% of the studies. We then assess how these indicators can increase our understanding of slum settlements, analysing access to services in slums vs the remaining urban population for a subset of cities (Sao Paulo, Rio, Lima, Johannesburg, Mumbai, and Hyderabad). Significant gaps exist between the communities, especially when per capita indicators are compared. Finally, we analyse how these indicators can be used to scope the challenges of achieving universal access to basic services (e.g. water, electricity, and water collection) by 2030. The results show that large infrastructure investments or conservation efforts are needed, especially for solid waste collection and water provision in Mumbai and Hyderabad. Additional work is needed to address data gaps to enable informed policy-making. • Systematic review of quantitative studies of slum infrastructure across the globe. • Access to municipal services among most prevalent indicators in slum infrastructure literature. • Lack of data on consumption patterns and other urban infrastructure indicators for slums. • Huge gap in basic infrastructure access and use patterns between slums and non-slums. • Developing cities require large infrastructure investments to attain universal access to services in 2030. [ABSTRACT FROM AUTHOR]

We present a dynamic perspective to quantify the air quality–related health impacts of the electrification of light-duty vehicles in the United States between 2022 and 2050. Using a fleet turnover model and future electricity generation mix scenarios, we compare ambitious vehicle electrification to fleet renewal relying on newer internal combustion engine vehicles, without electric vehicles. The model includes vehicle-level pollutant emission factors and a reduced complexity air quality and valuation model and covers direct (tailpipe, brake wear, and tire wear) and indirect (production of electricity and liquid fuels) emissions of NOx, SO2, PM2.5, NH3, and VOCs, with a breakdown at the county level to identify geographical disparities in the distribution of health impacts. Short-term health benefits are mostly generated by reductions in NOx emissions from newer gasoline vehicles, while fleet electrification generates further benefits in the long term. The electricity mix plays a crucial role in the success of electrification policies. With continued grid decarbonization, electrification would reduce harmful air quality– related health impacts cumulatively by 84 to 188 billion USD over the study period, compared with fleet renewal without electric vehicles. In contrast, artificially freezing the 2022 grid would make electrification responsible for 32 to 71 billion USD additional health disbenefits compared with fleet renewal. Finally, we show that while fleet electrification achieves most of its benefits over fleet renewal in the long term, delaying the implementation of such policies would sacrifice meaningful cumulative benefits. [ABSTRACT FROM AUTHOR]