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The utilization of geological formations, distinguished by natural porosity and permeability and protected by low-permeability caprock, has emerged as an effective strategy for carbon dioxide (CO2) storage. This method significantly contributes to mitigating anthropogenic greenhouse gas emissions and addressing the challenges of climate change. Recent research has unveiled the potential of CO2 to enhance geothermal heat energy extraction in geothermal reservoirs by acting as a subsurface heat exchange fluid. This review paper explores the viability of CO2 in augmenting geothermal heat energy extraction, comparing it to conventional water-based geothermal systems. Special emphasis is placed on CO2 plume geothermal (CPG) systems, characterized by rapid deployment and long-term utilization of geothermal energy resources. With the overarching objective of establishing net-zero energy communities, the analysis of such systems offers a comprehensive understanding of their features, providing a fresh perspective on extracted energy within the context of energy supply in integrated, sustainable energy in built systems. Notably, these systems demonstrate efficacy in meeting the power requirements of an energy community, spanning both distinct heating and electricity needs. However, the key challenge lies in selecting suitable locations. This scientific review aims to comprehend the characteristics of CPG under specific temperature and pressure conditions while optimizing subsurface permeability. This insight is pivotal for identifying future locations for CPG operations with the intent of powering small energy communities. [ABSTRACT FROM AUTHOR]

Nowadays, global climate change is likely the most compelling problem mankind is facing. In this scenario, decarbonisation of the chemical industry is one of the global challenges that the scientific community needs to address in the immediate future. Catalysis and catalytic processes are called to play a decisive role in the transition to a more sustainable and low-carbon future. This critical review analyses the unique advantages of structured reactors (isothermicity, a wide range of residence times availability, complex geometries) with the multifunctional design of efficient catalysts to synthesise chemicals using CO2 and renewable H2 in a Power-to-X (PTX) strategy. Fine-chemistry synthetic methods and advanced in situ/operando techniques are essential to elucidate the changes of the catalysts during the studied reaction, thus gathering fundamental information about the active species and reaction mechanisms. Such information becomes crucial to refine the catalyst's formulation and boost the reaction's performance. On the other hand, reactors architecture allows flow pattern and temperature control, the management of strong thermal effects and the incorporation of specifically designed materials as catalytically active phases are expected to significantly contribute to the advance in the valorisation of CO2 in the form of high added-value products. From a general perspective, this paper aims to update the state of the art in Carbon Capture and Utilisation (CCU) and PTX concepts with emphasis on processes involving the transformation of CO2 into targeted fuels and platform chemicals, combining innovation from the point of view of both structured reactor design and multifunctional catalysts development. [ABSTRACT FROM AUTHOR]

Energy is crucial to economic and social development and improves quality of life. However, fossil fuel energy produces greenhouse gases (GHGs) and cannot be sustained for a long time. It is essential to tackle these problems by moving towards renewable and sustainable energy. Some countries, including those in the Arabian Gulf region, are still in the appraisal stage of adopting different forms of renewable energy. This paper reviews the business potential and likely GHG reductions associated with adopting renewable energy in Oman. It is revealed that 1·9 Mt of annual carbon dioxide emissions could be cut by producing 10% of the country's electricity from renewables. The paper further discusses the global sustainable energy commitment under the UN Framework Convention on Climate Change and reviews the 2030 targets of some countries that are high producers of GHGs. It is anticipated that if all these planned targets are achieved, the total sustainable energy contribution could grow by nearly 11 000 TWh by 2030. These plans provide guidance for those countries still preparing to submit their plans to the UN. [ABSTRACT FROM AUTHOR]

This paper estimates the efficiency of the power generation sector in the USA by using Window Data Envelopment Analysis (W-DEA). We integrate radial and non-radial efficiency measurements in DEA using the hybrid measure while we extend the proposed model by considering good and undesirable outputs as separable and non separable. Then in the second stage, we perform parametric and non-parametric econometric techniques in order to model the relationship between the calculated environmental efficiencies and economic growth in attaining sustainability. Our empirical findings indicate a stable N-shape relationship between environmental efficiency and regional economic growth in the case of global and total pollutants but an inverted N-shape in the case of local pollutants. This implies that attention is required when considering local and global pollutants and the extracted environmental efficiency scores. A clear message to policy makers and government officials is that climate change which calls for economic, environmental and social concern should be analyzed according to its dispersion and regional dimension. [ABSTRACT FROM AUTHOR]

This paper reports the pros and cons of co-management (i.e. concerted actions towards climate change and air quality management) through local sustainability initiatives using three case studies, each encompassing the planning and management issues at local government levels. Case study I is policy-based and reports the outcome of a consultation exercise while case studies II and III have greater scientific bearing. These case studies pave the way for development of a more integrated Climate Change Strategy Action Plan at local scales, specifically regarding policies on emissions sources from transportation and decentralised energy. They highlight the merits and the trade-offs of implementing local scale co-management practices, using a more integrated planning framework than what is currently under offer. We recognise that delivery of such ambitious, cross-cutting agenda may be impeded, primarily owing to limited expertise in assessing the synergies and the expected outcomes from cross-fertility between these two arenas. This calls for a step-change through more cohesive, cross-disciplinary policy frameworks, going beyond the local administrative spheres to maximise the co-management potentials while mitigating the wider environmental impacts. [ABSTRACT FROM AUTHOR]

Climate change seems to have had a notable effect on the environment. Natural disasters such as flooding are occurring more frequently but the human effect on the built environment and transportation is the greatest single cause of greenhouse gas emissions. The construction industry consumes a large amount of energy and natural resources, especially in construction materials. Hence, action is needed to reduce carbon dioxide emissions, increase recycling and the reuse of materials and reduce water consumption. In this paper, the negative effect of the construction industry on climate is examined and remedial actions are proposed. A review of construction-related effects on climate change and sustainable construction is followed by a presentation of the authors' research on low-carbon dioxide concrete. Some examples of actions taken in Algeria to mimimise the effects of the industry on climate through research and practice are given. This mainly includes the use of cement replacement materials, recycling and efficient utilisation of resources. [ABSTRACT FROM AUTHOR]

Civil infrastructure, including the highway maintenance sector, is under increasing pressure to deliver 'low-carbon' services. Reducing this sector's 'carbon footprint' can help to meet targets set under the Kyoto Protocol. Carbon dioxide emissions reduction is now a legal requirement under the UK's Climate Change Act; infrastructure clients therefore require their supply chains to provide carbon footprint information. A new, more holistic, project-specific carbon footprinting approach is urgently needed to account for carbon in an integrated manner, identifying areas of carbon hot spots and developing a reduction hierarchy to support business decision making. In this paper a process-based carbon footprinting framework based on the PAS2050:2011 protocol is adopted. Results of case studies (focusing on the carbon footprint) of 'typical' UK highway maintenance processes are provided, namely pavement resurfacing, pavement marking, bulk lamp changing and grass cutting. These processes were selected across urban, semi-urban and rural site locations to investigate the significance of these locations on the carbon footprint. The results indicate the robustness of the PAS2050-compliant framework for highway maintenance carbon footprinting; areas of carbon hotspots and related reduction opportunities can be identified to inform the reduction hierarchy across the processes value chain. The research presented can be used as a framework to plan, evaluate and manage highway maintenance programmes and carbon budgets over the maintenance processes value chain. [ABSTRACT FROM AUTHOR]

Estimation of emissions of greenhouse gases (GHG) is becoming an established part of assessing sustainability within environmental impact assessment (EIA). However, a comparative study of 25 environmental impact statements (EISs) to analyse the practice of accounting for emissions during the EIA process suggests that consideration of the effects of development on emissions of GHG is poorly understood. The extent to which assessment is actually carried out is also inconsistent and sporadically implemented. A key indicator appears to be the varying and sometimes contradictory use of technical terminology, particularly of the term ‘carbon’ and its similar phraseology. This paper provides a critical evaluation of the differing terminology that is applied to GHG assessments undertaken as part of EIA process and explores the effect that misuse of these terms could have on an impact EIS. [ABSTRACT FROM PUBLISHER]

Abstract: At present, the cement industry generates approximately 5% of the world’s anthropogenic CO2 emissions. This share is expected to increase since demand for cement based products is forecast to multiply by a factor of 2.5 within the next 40years and the traditional strategies to mitigate emissions, focused on the production of cement, will not be capable of compensating such growth. Therefore, additional mitigation strategies are needed, including an increase in the efficiency of cement use. This paper proposes indicators for measuring cement use efficiency, presents a benchmark based on literature data and discusses potential gains in efficiency. The binder intensity (bi) index measures the amount of binder (kgm−3) necessary to deliver 1MPa of mechanical strength, and consequently express the efficiency of using binder materials. The CO2 intensity index (ci) allows estimating the global warming potential of concrete formulations. Research benchmarks show that bi ∼5kgm−3 MPa−1 are feasible and have already been achieved for concretes >50MPa. However, concretes with lower compressive strengths have binder intensities varying between 10 and 20kgm−3 MPa−1. These values can be a result of the minimum cement content established in many standards and reveal a significant potential for performance gains. In addition, combinations of low bi and ci are shown to be feasible. [ABSTRACT FROM AUTHOR]

This section presents abstracts of papers on city planning published from 2007 to 2008, including "Streets, Sounds and Identity in Inter-war Harlem," by Clare Corbould, "(Re)making the Other, Heterosexualising Everyday Space," by Kath Browne, and "Rankings and Reactivity: How Public Measures Recreate Social Worlds," by Wendy Nelson Espeland and Michael Sauder.