Estimation of greenhouse gas emissions from municipal wastewater treatment systems in India

Greenhouse gas (GHG) emissions generated from municipal wastewater treatment plants in India is estimated in this study. The emissions from the wastewater treatment process as well as from the electricity used during the treatment process are estimated by using the methodology of Intergovernmental Panel on Climate Change. The present treatment plants of capacity 15 997 million litres per day (MLD) contributes towards GHG emissions of 7.3 Mt of CO₂‐eq/year. The future GHG emissions would depend upon the treatment technology used for treating 34 109 MLD of untreated wastewater. The highest GHG emissions would occur if all new wastewater treatment plants are based on upflow anaerobic sludge blanket technology, 19.66 Mt CO₂‐eq/year and lowest if sequential batch reactor technology is adopted, 2.93 MtCO₂‐eq/year.     

Setting limits and targets for greenhouse gas emissions at local level:a case study based on the District of Winchester,UK

We introduce climate change and those aspects of global warming that are required to understand the rationale behind the setting of emissions targets. We then review recent evidence that indicates that immediate and substantial action needs to be taken globally to cut emissions of carbon dioxide in order to keep its atmospheric concentration at a ‘safe’ level. This limit implies a range of cumulative carbon dioxide emissions budgets for the UK from now until 2050. We adopt a figure at the low end of the range to derive a comparable budget for Winchester, UK. Given Winchester's consumption emissions of 1.52 million tonnes of carbon dioxide in 2004, we calculate an emissions pathway until 2050 consistent with this budget. This suggests annual reductions of 6.7% are required. Our methodology can be applied to other local authority areas provided relevant statistics are available.     

Sustainability assessment of cities: SDGs and GHG emissions

ABSTRACT

The United Nations’ (UN) sustainable development goals (SDGs), the core of the 2030 Agenda for Sustainable Development and the UN Paris Agreement, were adopted in 2015. Involvement of not only national governments but also all other stakeholders including local governments is important to promote sustainable development and to achieve the goals. The question arises, therefore, of what methods should be used to best implement and assess sustainability issues at a local level. In this light, a new version of Comprehensive Assessment System for Built Environment Efficiency (CASBEE), CASBEE for Cities, is introduced for assessing the sustainability of cities and communities around the world based on SDG indicators and greenhouse gas (GHG) emissions. The tool allows users to understand the sustainability of cities and communities based on quality (Q) and environmental load (L) perspectives. The sustainability assessments show that cities in developed countries tend to have good grades for Q, but bad grades for L, while cities in developing countries tend to have the opposite trend. This will assist cities and communities in both developed and developing countries to understand urgent problems and to identify effective solutions for sustainable development.     

Climate impacts on European agriculture and water management in the context of adaptation and mitigation—The importance of an integrated approach

We review and qualitatively assess the importance of interactions and feedbacks in assessing climate change impacts on water and agriculture in Europe. We focus particularly on the impact of future hydrological changes on agricultural greenhouse gas (GHG) mitigation and adaptation options. Future projected trends in European agriculture include northward movement of crop suitability zones and increasing crop productivity in Northern Europe, but declining productivity and suitability in Southern Europe. This may be accompanied by a widening of water resource differences between the North and South, and an increase in extreme rainfall events and droughts. Changes in future hydrology and water management practices will influence agricultural adaptation measures and alter the effectiveness of agricultural mitigation strategies. These interactions are often highly complex and influenced by a number of factors which are themselves influenced by climate. Mainly positive impacts may be anticipated for Northern Europe, where agricultural adaptation may be shaped by reduced vulnerability of production, increased water supply and reduced water demand. However, increasing flood hazards may present challenges for agriculture, and summer irrigation shortages may result from earlier spring runoff peaks in some regions. Conversely, the need for effective adaptation will be greatest in Southern Europe as a result of increased production vulnerability, reduced water supply and increased demands for irrigation. Increasing flood and drought risks will further contribute to the need for robust management practices.The impacts of future hydrological changes on agricultural mitigation in Europe will depend on the balance between changes in productivity and rates of decomposition and GHG emission, both of which depend on climatic, land and management factors. Small increases in European soil organic carbon (SOC) stocks per unit land area are anticipated considering changes in climate, management and land use, although an overall reduction in the total stock may result from a smaller agricultural land area. Adaptation in the water sector could potentially provide additional benefits to agricultural production such as reduced flood risk and increased drought resilience.The two main sources of uncertainty in climate impacts on European agriculture and water management are projections of future climate and their resulting impacts on water and agriculture. Since changes in climate, agricultural ecosystems and hydrometeorology depend on complex interactions between the atmosphere, biosphere and hydrological cycle there is a need for more integrated approaches to climate impacts assessments. Methods for assessing options which “moderate” the impact of agriculture in the wider sense will also need to consider cross-sectoral impacts and socio-economic aspects.     

Fuel-price reform to achieve climate and energy policy goals in Saudi Arabia: A multiple-scenario analysis

Saudi Arabia experiences annual growth of 6% in its power demand. Generation expansion has been driven by low domestic retail fuel prices leading to a power generation mix based on fossil fuels only. In light of current climate change discussions, this research assesses future generation expansion under different potential fuel-price reforms by an enhanced OSeMOSYS model. Results demonstrate that domestic retail fuel price levels >20% [>60%] of expected international wholesale fuel prices¹ are necessary to minimize emissions when considering emissions penalties [without pricing for emissions]. By 2030 renewables can reach 70% penetration by capacity and 30% by energy.     

The contribution of CO2 emissions to environmental stress in the Middle East: challenges and potential solutions

The increasing demand for water and electricity in the Middle East causes environmental stress. Along with the industrial sector, desalination and power plants are linked to fossil fuel combustion, which is chiefly responsible for increased carbon dioxide emissions. The magnitude of certain sustainable development indicators (such as the ecological footprint) has led to growing concern. This paper presents some of the challenges facing the transition to sustainable development.     

New Urban and Standard Suburban Subdivisions: Evaluating Psychological and Social Goals

Residents living in a New Urbanist subdivision (NUS) and a more standard suburban subdivision (SSS) near Salt Lake City, UT, were interviewed to test whether residents of a New Urbanist setting experience a stronger sense of community, greater sociability and outdoor use, and stronger preferences for New Urbanist site designs and housing diversity. Results validated several, but not all, New Urbanist claims. The NUS had gridded streets, smaller lots, homes with front porches, and back alleys with accessory apartments over detached garages; the SSS lacked these and had cul-de-sacs and 47% larger lots. After controlling for two sociodemographic variables, the two groups of residents reported similar levels of sense of community. NUS residents reported more neighboring behaviors, outdoor use, and more positive reactions to alleys and apartments; SSS residents were more satisfied with their larger front yard setbacks and front-loaded attached garages. Design and management improvements used elsewhere were suggested to alleviate complaints about the rental apartments and alleys, particularly of too many cars in the alleys.     

Thermal upgrades of existing homes in Germany: The building code, subsidies, and economic efficiency

One of the cheapest ways to reduce CO₂ emissions is thermal renovation of existing homes. Germany is a world leader in this project, with a strict building code, generous state subsidies, and an advanced renovation infrastructure. The effects of its policies are here explored in the light of progressive tightening of the building code, and the strict criteria for subsidies. Data on costs and outcomes of residential building renovations are presented from published reports on renovation projects, and cross-checked with projects investigated directly. Comparisons are made in terms of euros invested for every kilowatt hour of heating energy saved over the lifetime of the renovations, for standards ranging from 150 kWh (the lowest standard) to 15 kWh (the highest) of primary energy use per square metre of floor area per year. It is found that the lowest standard is an order of magnitude more cost-effective than the highest, in terms of both energy saved per euro invested, and return on investment over the lifetime of the renovations, regardless of fuel prices. It is argued that this throws into question Germany's policy of progressively regulating for higher renovation standards, and offering subsidies only for projects that go beyond the minimum standard.     

Life cycle primary energy use and carbon emission of an eight-storey wood-framed apartment building

In this study the life cycle primary energy use and carbon dioxide (CO₂) emission of an eight-storey wood-framed apartment building are analyzed. All life cycle phases are included, including acquisition and processing of materials, on-site construction, building operation, demolition and materials disposal. The calculated primary energy use includes the entire energy system chains, and carbon flows are tracked including fossil fuel emissions, process emissions, carbon stocks in building materials, and avoided fossil emissions due to biofuel substitution. The results show that building operation uses the largest share of life cycle energy use, becoming increasingly dominant as the life span of the building increases. The type of heating system strongly influences the primary energy use and CO₂ emission; a biomass-based system with cogeneration of district heat and electricity achieves low primary energy use and very low CO₂ emissions. Using biomass residues from the wood products chain to substitute for fossil fuels significantly reduces net CO₂ emission. Excluding household tap water and electricity, a negative life cycle net CO₂ emission can be achieved due to the wood-based construction materials and biomass-based energy supply system. This study shows the importance of using a life cycle perspective when evaluating primary energy and climatic impacts of buildings.     

Embodied and operational carbon dioxide emissions from housing: A case study on the effects of thermal mass and climate change

A 100-year lifecycle carbon dioxide (CO₂) emissions analysis is reported for a two-bedroom, 65 m² floor area, semi-detached house in south-east England. How the balance between the embodied (ECO₂) and operational CO₂ emissions of the building are affected by the inclusion of thermal mass and the impacts of climate change is quantified. Four ‘weights’ of thermal mass were considered, ranging from lightweight timber frame to very heavyweight concrete construction. For each case, total ECO₂ quantities were calculated and predictions for operational CO₂ emissions obtained from a 100-year dynamic thermal modelling simulation under a medium-high emissions climate change scenario for south-east England. At the start of the lifecycle, the dwellings were passively cooled in summer, but air conditioning was installed when overheating reached a certain threshold. The inclusion of thermal mass delayed the year in the lifecycle when this occurred, due to the better passive control of summertime overheating. Operational heating and cooling energy needs were also found to decrease with increasing thermal mass due to the beneficial effects of fabric energy storage. The calculated initial ECO₂ was higher in the heavier weight cases, by up to 15% (4.93 t) of the lightweight case value, but these difference were offset early in the lifecycle due to the savings in operational CO₂ emissions, with total savings of up to 17% (35.7 t) in lifecycle CO₂ found for the heaviest weight case.     

Feasibility study of capturing carbon credit benefits in an academic institution: A case study

The CDM potential in an academic institution hosting 2500 students is analyzed through the introduction of renewable energy technologies (Solar Water Heater, Solar Steam Cooking) and adoption of energy efficient technologies (Compact Fluorescent Lighting, Energy Efficient Air Conditioners). The baseline emission has been calculated for each technology. A detail investment analysis has been carried out for each of these measures. The impact of revenue generated by selling carbon credits through the clean development mechanism (CDM), on the economic viability of the project activity is analyzed along with sensitivity analysis.Out of the four cases analyzed, energy efficient lighting and energy efficient air conditioners do not require CDM benefits for their viability hence they fail to prove the additionality. Solar steam cooking having negative value of IRR does not pass the additionality criterion for CDM. The solar water heater generating 48.13 tCO₂/year is identified as the candidate CDM project. The total amount of CO₂ that can be saved from emitting to the atmosphere by employing the renewable and energy efficient technologies is 311.34 tCO₂/year. The CERs generated by this project are insufficient to cover the validation/ verification and registration expenses. For converting the CDM potential into reality, bundling of the similar activities with nearby academic institutes can be considered.