Cause, conseguenze e strategie di mitigazione Proponiamo il primo di una serie di articoli in cui affronteremo l’attuale problema dei mutamenti climatici. Presentiamo il documento redatto, votato e pubblicato dall’Ipcc - Comitato intergovernativo sui cambiamenti climatici - che illustra la sintesi delle ricerche svolte su questo tema rilevante.

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Climate Change 2007: The Physical Science Basis.

National Institute of Standards and Technology における超伝導研究及び生活

The rapid rise of shale gas development through horizontal drilling and high volume hydraulic fracturing has expanded the extraction of hydrocarbon resources in the U.S. The rise of shale gas development has triggered an intense public debate regarding the potential environmental and human health effects from hydraulic fracturing. This paper provides a critical review of the potential risks that shale gas operations pose to water resources, with an emphasis on case studies mostly from the U.S. Four potential risks for water resources are identified: (1) the contamination of shallow aquifers with fugitive hydrocarbon gases (i.e., stray gas contamination), which can also potentially lead to the salinization of shallow groundwater through leaking natural gas wells and subsurface flow; (2) the contamination of surface water and shallow groundwater from spills, leaks, and/or the disposal of inadequately treated shale gas wastewater; (3) the accumulation of toxic and radioactive elements in soil or stream sediments near disposal or spill sites; and (4) the overextraction of water resources for high-volume hydraulic fracturing that could induce water shortages or conflicts with other water users, particularly in water-scarce areas. Analysis of published data (through January 2014) reveals evidence for stray gas contamination, surface water impacts in areas of intensive shale gas development, and the accumulation of radium isotopes in some disposal and spill sites. The direct contamination of shallow groundwater from hydraulic fracturing fluids and deep formation waters by hydraulic fracturing itself, however, remains controversial.

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A Critical Review of the Risks to Water Resources from Unconventional Shale Gas Development and Hydraulic Fracturing in the United States

Annual Energy Outlook

This review summarizes and organizes the literature on life cycle assessment (LCA), life cycle energy analysis (LCEA) and life cycle cost analysis (LCCA) studies carried out for environmental evaluation of buildings and building related industry and sector (including construction products, construction systems, buildings, and civil engineering constructions). The review shows that most LCA and LCEA are carried out in what is shown as “exemplary buildings”, that is, buildings that have been designed and constructed as low energy buildings, but there are very few studies on “traditional buildings”, that is, buildings such as those mostly found in our cities. Similarly, most studies are carried out in urban areas, while rural areas are not well represented in the literature. Finally, studies are not equally distributed around the world.

Life cycle assessment (LCA) and life cycle energy analysis (LCEA) of buildings and the building sector: A review

Sustainability assessments of bio-based polymers

Design and construction industries, along with owners, have an increasing interest in and responsibility for the environmental impacts of buildings. Since the environmental impacts of a building’s life cycle are considerable, quantification of all phases is important, especially the construction phase, which is often glossed over. This research focuses on the construction phase of a building project. Generally, the life-cycle inventory created in performing a life-cycle assessment (LCA) is developed using either a process or input–output approach; however, both techniques have distinct advantages and disadvantages. A hybrid approach combining both methods’ advantages has been proposed and will be demonstrated. Existing hybrid models are reviewed, along with a recommendation of a hybrid model for construction. A preliminary case study of a precast concrete parking garage’s construction using hybrid LCA methodology is presented. Preliminary investigations indicate transportation, equipment activity, and sup...

Example of a Hybrid Life-Cycle Assessment of Construction Processes

Several studies suggest green construction can result in significant economic savings by improving employee productivity, increasing benefits from improvements in health and safety, and providing savings from energy, maintenance, and operational costs. This article quantifies these benefits by establishing a set of measurable performance and building attribute variables, collecting longitudinal data, statistically analyzing the results, and performing sensitivity analyses for a precast concrete manufacturing facility located near Pittsburgh, Pennsylvania. Productivity, absenteeism, energy, and financial data are presented and an engineering economic analysis is reported. Results show that in the new facility manufacturing productivity increased by about 25%; statistically significant absenteeism results varied; and energy usage decreased by about 30% on a square foot basis. Considering all aspects, the economic analysis showed that the company made the correct decision to build a new green facility.

The Economic Benefits of Green Buildings: A Comprehensive Case Study

The healthcare sector is a driver of economic growth in the U.S., with spending on healthcare in 2012 reaching $2.8 trillion, or 17% of the U.S. gross domestic product, but it is also a significant source of emissions that adversely impact environmental and public health. The current state of the healthcare industry offers significant opportunities for environmental efficiency improvements, potentially leading to reductions in costs, resource use, and waste without compromising patient care. However, limited research exists that can provide quantitative, sustainable solutions. The operating room is the most resource-intensive area of a hospital, and surgery is therefore an important focal point to understand healthcare-related emissions. Hybrid life cycle assessment (LCA) was used to quantify environmental emissions from four different surgical approaches (abdominal, vaginal, laparoscopic, and robotic) used in the second most common major procedure for women in the U.S., the hysterectomy. Data were collected from 62 cases of hysterectomy. Life cycle assessment results show that major sources of environmental emissions include the production of disposable materials and single-use surgical devices, energy used for heating, ventilation, and air conditioning, and anesthetic gases. By scientifically evaluating emissions, the healthcare industry can strategically optimize its transition to a more sustainable system.

Environmental Impacts of Surgical Procedures: Life Cycle Assessment of Hysterectomy in the United States

This paper uses a dynamic life cycle assessment (DLCA) approach and illustrates the potential importance of the method using a simplified case study of an institutional building. Previous life cycle assessment (LCA) studies have consistently found that energy consumption in the use phase of a building is dominant in most environmental impact categories. Due to the long life span of buildings and potential for changes in usage patterns over time, a shift toward DLCA has been suggested. We define DLCA as an approach to LCA which explicitly incorporates dynamic process modeling in the context of temporal and spatial variations in the surrounding industrial and environmental systems. A simplified mathematical model is used to incorporate dynamic information from the case study building, temporally explicit sources of life cycle inventory data and temporally explicit life cycle impact assessment characterization factors, where available. The DLCA model was evaluated for the historical and projected future environmental impacts of an existing institutional building, with additional scenario development for sensitivity and uncertainty analysis of future impacts. Results showed that overall life cycle impacts varied greatly in some categories when compared to static LCA results, generated from the temporal perspective of either the building's initial construction or its recent renovation. From the initial construction perspective, impacts in categories related to criteria air pollutants were reduced by more than 50 % when compared to a static LCA, even though nonrenewable energy use increased by 15 %. Pollution controls were a major reason for these reductions. In the future scenario analysis, the baseline DLCA scenario showed a decrease in all impact categories compared with the static LCA. The outer bounds of the sensitivity analysis varied from slightly higher to strongly lower than the static results, indicating the general robustness of the decline across the scenarios. These findings support the use of dynamic modeling in life cycle assessment to increase the relevance of results. In some cases, decision making related to building design and operations may be affected by considering the interaction of temporally explicit information in multiple steps of the LCA. The DLCA results suggest that in some cases, changes during a building's lifetime can influence the LCA results to a greater degree than the material and construction phases. Adapting LCA to a more dynamic approach may increase the usefulness of the method in assessing the performance of buildings and other complex systems in the built environment.

Melissa M. Bilec

Papers

Sustainability assessments of bio-based polymers

Example of a Hybrid Life-Cycle Assessment of Construction Processes

The Economic Benefits of Green Buildings: A Comprehensive Case Study

Environmental Impacts of Surgical Procedures: Life Cycle Assessment of Hysterectomy in the United States

Dynamic life cycle assessment: framework and application to an institutional building