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Urban flooding poses a significant challenge to the rapidly growing Indian cities. Low-impact development strategies such as green roofs have shown the potential to reduce urban flooding. However, their performance assessment significantly varies across different studies. Therefore, the study's primary objective is to evaluate green roofs in the Indian context. For this evaluation, the green roofs are assessed based on building-level implementation scenarios for a high-density urban area in India for 25%,50%, and 75% application rates and different rainfall intensities (2,3 and 4-h duration and 2,5,10 and 25-year frequencies). Secondly, to probe the variations in the green roof performance across studies, uncertainty contributions to the runoff reduction from different parameters are quantified. The results show that green roofs can reduce up to 62% of flood volume and 24% of runoff. However, they are reasonably effective only beyond 25% application rates. Further, rainfall intensity contributes the most to the uncertainty of runoff reduction from green roofs. This uncertainty assessment implies that localized evaluation of green roofs depending on local rainfall conditions is required for city-wide policy planning. The study has a significant contribution to building confidence in the ability of green roofs to reduce urban floods in the context of developing countries like India. • Green roof performance is assessed through building-level implementation scenarios. • Green roofs show a reduction of up to 62% in flood volume and 24% in runoff. • Green roofs are reasonably effective only at a minimum 25% application rate. • Rainfall intensity contributes the highest to the total performance uncertainties. • Uncertainty quantification can explain performance variations across studies. [ABSTRACT FROM AUTHOR]

• Sewage treatment deficits for forecasted rural and urban populations computed for India. • Scenario analysis to aid urban planners and decision-makers plan sustainable sewage treatment. • Life cycle costs computed considering land, capital, operation and maintenance cost. • Investing in land for natural treatment systems beneficial than energy-intensive treatment. • Lowered greenhouse gas emissions due to natural and hybrid treatment systems. Sewage treatment involves a trade-off of land vs. energy and the location of installing Sewage Treatment Plants (STPs) strongly impacts the decisions regarding treatment technologies. In the wake of rapid urbanization, deteriorating freshwater quality and water scarcity, it is crucial to plan adequate and low-cost sewerage infrastructure that can improve the quality of life in rural and urban areas. The present work involves a novel life cycle analysis through six scenarios generated from a holistic perspective that can aid urban planners and urban local bodies in planning the sewage treatment facilities in their cities, towns or villages. Instead of planning sewerage infrastructure for a long-term period of thirty years, it is suggested to create and operate the STPs only for the upcoming decade. Further, owing to the drawbacks of mechanized and natural treatment systems, adopting a mix of these treatment approaches in planning infrastructure is suggested and the benefits of implementing the same are quantified and discussed. Implementing these strategies results in almost 30 % cost savings and 40 % reduction in greenhouse gas emissions, hence, investing in land for natural treatment systems is suggested instead of incurring heavy electricity bills for mechanized treatment systems. The land cost significantly affects the decision-making regarding treatment technology selection; hence, the variation in the life cycle cost of different sewage treatment approaches is assessed for varying land rates in India. [Display omitted] [ABSTRACT FROM AUTHOR]

This study assesses a trade-off between mechanized treatment systems and natural treatment systems for wastewater treatment (WWT) and recycling approaches. Investigation on this trade-off is carried out using field data on operation and maintenance (O and M) costs and land requirements. It is then shown that none of them in solo are techno-economically viable and environmentally sustainable for WWT in urban areas in India. Hence, a paradigm shift in WWT in India is proposed to adopt hybrid treatment systems (HTSs) approach. HTSs involve treatment considering a combination of natural and mechanized treatment approaches. Adoption of HTSs will result in energy savings and environmental benefits and hence will help India to achieve various national and international commitments of WWT and recycling. [ABSTRACT FROM AUTHOR]

The global carbon budget, defined as the cumulative amount of permissible carbon emissions to meet the temperature targets, is widely used to study climate change. This carbon budget is rapidly decreasing, with a high probability of it getting exhausted in the coming few decades. The extensive use of non-renewable resources has resulted in a rapid depletion of the global carbon budget. Currently, there is a lack of studies assessing the long-term impact of various sectors on the rapidly decreasing global carbon budget. The recent budget estimates have further reduced by 200 GtCO 2 in the past decade, creating conflicts among the nations towards getting a higher share of the remaining budget. This study focuses on allocating the global carbon budget to a sub-sectoral level for India's iron and steel sector. First, the global carbon budget is allocated using different approaches, giving India a range of carbon budgets. Further, the allocation is done to the sectoral and sub-sectoral levels to obtain the benchmark targets between 2020 and 2050 from the national carbon budget. Projections have been made for the production capacity and the expected emissions till 2050 for India's iron and steel sector using three scenarios based on specific CO 2 emission reduction. The results indicate that the carbon emissions for the "specific CO 2 emission stagnation" scenario for 2 °C temperature target are 66% to 726% above the benchmark carbon budget allocated to the iron and steel sector using different allocation methods. The study also shows the benchmark carbon budget of the iron and steel sector for the 2 °C, 1.7 °C, and 1.5 °C temperature targets will deplete between 2023 and 2046 for the different emission scenarios. • Proposed framework for allocating global carbon budget to the sub-sectoral level. • Global to national carbon budget allocation done using four approaches. • Sub-sector emissions and production capacity projection done using three scenarios. • Year of exhaustion for sub-sector's carbon budget determined for various scenarios. [ABSTRACT FROM AUTHOR]

Management of Construction and Demolition (C&D) waste from buildings has become essential to ensure sustainable infrastructural growth across the globe. The major proportion of C&D waste comprises of debris generated from the demolition activities, and their inadequate management can lead to disruption of natural resource cycles. Hence, there is a need to develop a holistic understanding of Demolition Waste Management (DWM) to reduce the building sector's impact on resources. Through a systematic literature review of 148 original journal articles, conference proceedings, and recent review papers (between the period 2000 to 2022) extracted from a scientific database, this study has identified 33 major global strategies for DWM guided by the Circular Economy (CE) framework through a perspective of the building lifecycle. A few of the strategies identified in this review are standardization of building components, incentivization of innovation, extended producer's responsibility, pre-demolition survey and audits, blockchain technology. Furthermore, the way ahead for the DWM in the Indian construction industry is assessed, and ten major challenges in CE implementation in India are discussed. The corrective actions are proposed against each challenge, and the extent of effort required for implementation with the impact created from each measure is also highlighted in this study. The review findings are valuable for both academicians and practitioners while establishing guidelines or framing policies during any stage of construction. The life cycle perspective of DWM proposed in this paper also attempts to chart a roadmap to reach various sustainable development goals. [Display omitted] • Demolition Waste Management (DWM) in building's lifecycle was reviewed. • Construction and Demolition sector studied from a life cycle thinking perspective. • The study proposes 33 building DWM strategies using the Circular Economy framework. • Challenges and way ahead in DWM within the Indian construction sector were assessed. [ABSTRACT FROM AUTHOR]

Four municipal wastewater treatment plants ( WWTPs) in India based on different technologies are compared by conducting Life Cycle Assessment ( LCA) using field data. CML 2 baseline 2000 methodology is adopted in which eight impact categories are considered. SBRs ranked highest in energy consumption and global warming potential ( GWP) but also produced the best effluent with respect to organics and nutrients. Constructed wetlands have negligible energy consumption and negative GWP because of carbon sequestration in the macrophytes. Emissions associated with electricity production required to operate the WWTPs, emissions to water from treated effluent and heavy metal emissions from waste sludge applied to land are identified as main contributors for overall environmental impacts of WWTPs. This comparison of technologies suggests that results from LCA can be used as indicators in a multicriteria decision-making framework along with other sustainability indicators. [ABSTRACT FROM AUTHOR]

Abstract: Many technological alternatives for wastewater treatment are available, ranging from advanced technologies to conventional treatment options. It is difficult to select the most appropriate technology from among a set of available alternatives to treat wastewater at a particular location. Many factors, such as capital costs, operation and maintenance costs and land requirement, are involved in the decision-making process. Sustainability criteria must also be incorporated into the decision-making process such that appropriate technologies are selected for developing economies such as that of India. A scenario-based multiple-attribute decision-making (MADM) methodology has been developed and applied to the selection of wastewater treatment alternative. The four most commonly used wastewater treatment technologies for treatment of municipal wastewater in India are ranked for various scenarios. Six scenarios are developed that capture the regional and local societal priorities of urban, suburban and rural areas and translate them into the mathematical algorithm of the MADM methodology. The articulated scenarios depict the most commonly encountered decision-making situations in addressing technology selection for wastewater treatment in India. A widely used compensatory MADM technique, TOPSIS, has been selected to rank the alternatives. Seven criteria with twelve indicators are formulated to evaluate the alternatives. Different weight matrices are used for each scenario, depending on the priorities of the scenario. This study shows that it is difficult to select the most appropriate wastewater treatment alternative under the “no scenario” condition (equal weights given to each attribute), and the decision-making methodology presented in this paper effectively identifies the most appropriate wastewater treatment alternative for each of the scenarios. [Copyright &y& Elsevier]

Abstract: A framework for technology assessment for wastewater treatment is proposed in this work. A case study of technology selection for high rise buildings in urban centres of India is used for evaluation and to test this framework. The multiple-attribute decision-making technique is used for ranking the alternatives. The three most commonly used wastewater treatment technologies viz., activated sludge process (ASP), sequencing batch reactors (SBR) and membrane bio-reactor (MBR) are evaluated. Seven criteria having indicators derived from life cycle assessment (LCA), life cycle costing (LCC) and criteria accounting for resource constraints, robustness of the system and sustainability are used for the evaluations. The technology assessment framework used in this work will help identify appropriate wastewater treatment technologies for various decision-making situations encountered while managing wastewaters. Importantly, this study validates the theory that it is the decision situation which decides the appropriateness of the technology and not the technology itself. Hence, the definition of appropriate technology given by Murphy et al. [4] is more convincing for water and sanitation technologies. [Copyright &y& Elsevier]

There is a lack of studies on assessing long-term impacts of different sectors on shrinking global carbon budget. Present study focuses on assessing contribution of electric vehicles (EVs) with improving electricity grids' efficiency (EGs) and minimizing 'transmission and distribution' (T&D) losses in reducing carbon dioxide (CO 2) emissions and fulfilling emission targets for 2030 and 2050. Eleven different scenarios are articulated with estimated uncertainties for Mumbai Metropolitan Regions' (MMRs') passenger transportation using data extracted from MMR's Comprehensive Mobility Plan's transportation model. A novel methodology is developed to estimate local carbon budget targets from global targets between 2018 and 2050. The estimations indicate that carbon emissions in 'business as usual' scenario are 252%, 505%, and 55% above the targets for 2 °C, 1.5 °C, and Intended Nationally Determined Contributions (INDC), respectively. Study also shows that introducing EVs in MMR without simultaneously improving EGs will generate more net CO 2 emissions than BAU. EVs with EG and T&D improvements are not enough to meet the estimated targets. However, their combined contribution significantly reduces CO 2 emission by half and reaches peak emission by 2025 from post-half-century. • Developed a novel methodology to estimate local carbon budget. • Transport emissions assessment with electric vehicle, electricity grid (EG), and T&D losses. • Interventions are unable to achieve carbon budget targets of 2 °C, 1.5 °C, and INDC. • Electric vehicles are not suitable without improving EG efficiency, and T&D losses. [ABSTRACT FROM AUTHOR]

Increasing urbanization and rapid depletion of resources have forced authorities to shift from traditional linear system of take-make-use-dispose to circular system of resource conservation. Circular Economy (CE) is a sustainable development approach that works on the waste management strategy of reduce, reuse, recycle, and recover. Considerable work has been performed on CE in various sectors such as in electronic sector, construction sector, automotive sector, etc. However, CE in the water sector is gaining rapid attention, because of imbalance in water resources and the prevailing linear approach. The aim of this study is to review the world-wide growth of CE concept in the water sector from an economic, environmental, social, and technical perspective. 98 publications were selected by systematic literature review and categorized in economic, environmental, social, and technical criteria including a combination of multiple criteria. In this study, the world-wide status of CE implementation in the water sector is assessed and strategies to encourage and enhance CE implementation are proposed. The six BS8001:2017 principles and 6Rs (reduce, reuse, recycle, reclaim, recover, restore) of waste management are critically analyzed for deriving recommendations and successful implementation of CE in water sector. Finally, challenges and opportunities to implement CE in the water sector in India are discussed. Image 1 • Worldwide growth of Circular economy (CE) in the water sector is reviewed. • Confluence of 6Rs and BS8001:2017 principles is needed for CE implementation. • Challenges and opportunities to implement CE strategies in India are discussed. • Framework needs to be developed to monitor CE implementation in water sector. [ABSTRACT FROM AUTHOR]

Appropriate spatial planning and environmental management of coastal areas in cities are essential to maintain a balance of environmental quality and urban development, whereas unscientific planning practices lead to the degradation of coastal ecosystems. Coastal Regulation Zone (CRZ) guidelines are currently being used in India for management of the coast. These guidelines are difficult to implement and do not take into account the variation of physical characteristics of the coast. The alternative to this approach is a quantitative land classification in coastal areas based on geospatial and multiple criteria decision making techniques. In this work, we applied these two approaches to the three case locations of the coastal lands in Mumbai region representing areas which are i) predominantly urban, ii) rural and iii) no development areas. The classification results of the two approaches are systematically compared and contrasted to show the lacunae in the present method of CRZ classification and to highlight the advantages of using the quantitative approach in coastal land classification. The comparative analysis shows that the quantitative approach takes into account the variation of physical features along the coast and will help in conserving the coastal ecosystem more efficiently. Image 1 • Challenges are identified in current practice of coastal area classification. • Comparative assessment of quantitative and prevailing approach is carried out. • Field validation showed the advantages of new classification approach. • Quantitative approach is found better than approach of current practice. [ABSTRACT FROM AUTHOR]

Selecting appropriate locations for municipal solid waste (MSW) management facilities, such as transfer stations, is an important issue in rapidly developing regions. Multiple alternatives and evaluation attributes need to be analyzed for finalizing the locations of these facilities. Multi-attribute decision-making (MADM) approaches are found to be very effective for ranking several potential locations and hence selecting the best among them based on the identified attributes. However, conventional MADM approaches fail to find the rankings of alternatives derived from all possible combinations of these potential locations. Therefore, this study presents a two-stage MADM model that also accounts for all possible combinations of locations. This study evaluates economical, environmental, social and technical attributes based on realistic conditions of the study area, i.e., Nashik city (India). The results provide the ranks of all possible combinations along with their probabilities of rank reversibility. The mean and standard deviation of the relative closeness are further evaluated for the top-ranking locations under distinct schemes. The present study will help stakeholders in finding suitable locations for MSW management facilities while considering economic, environmental, social and technical attributes., (Copyright © 2020 Elsevier Ltd. All rights reserved.)