Indirect GHG Emissions Research Articles

ORGANISATION CARBON FOOTPRINT ASSESSMENT AND GREENHOUSE GAS REDUCTION EMISSION OF YALA RAJABHAT UNIVERSITY, THAILAND

This research aims to study carbon footprint assessment and the guidelines for reducing greenhouse gas emissions at the Yala Rajabhat University in southern Thailand. Data was collected from January to December 2020 for evaluating greenhouse gas emissions. The methodology followed the guidelines of the Thailand Greenhouse Gas Management Organisation (Public Organisation). The greenhouse gas emissions can be classified into three categories: (1) Direct GHG emissions, (2) electricity indirect GHG emissions, and (3) other indirect GHG emissions. The results showed that Scope 2 indirect greenhouse gas emissions from energy consumption had the highest amount of greenhouse gas emissions at 1,625,941.82 kilogrammes of carbon dioxide equivalent (kgCO2 e/year). Amount of greenhouse gas emissions were 182,144.76 and 28,545.71 kgCO2 e/year for Scope 3 and Scope 1, respectively. Guidelines for reducing greenhouse gas emissions electricity consumption of the Yala Rajabhat University urgently needed. To reduce the amount of carbon footprint. This can be done in the form of (1) energy management, including reducing electricity use, (2) solid waste management using the 3Rs (Reduce, Reuse, Recycle) principle, and (3) fuel efficiency and renewable energy adoption.

Indicator-based environmental and social sustainability assessment of hospitals: A literature review

The healthcare sector's direct and indirect GHG emissions account for 4%–5% of global net emissions. Hospitals face the challenge of sustainable transformations and need to measure, monitor, and report on their sustainability performance. While indicator-based assessments of hospital sustainability have received increased attention over the last years, they are heterogenous in their terminologies, categories, and included indicators. This study reviews taxonomies and included indicators in hospital sustainability assessments, laying the foundation for future developments of consistent indicator-based assessments. The objective is to (1) critically review existing assessments of hospitals; (2) identify relevant sustainability topics in a hospital context and derive a best-practice categorization; (3) highlight thematical gaps. Based on the PRISMA method, we identify 88 relevant articles. First, 47 articles (comprehensive hospital sustainability assessments with extensive indicator sets) are reviewed, forming the basis for deriving a best-practice categorization. Second, considering an additional 41 articles (proposing indicators for specific hospital aspects), we collect all indicators and compile a consolidated indicator pool. We find substantial variations in the taxonomies and terminologies of the reviewed articles; most notably, there is a disagreement about what constitutes an indicator. 73% of all consolidated indicators are qualitative, and 78% are site-specific. Thematical gaps relate to sustainability along upstream and downstream value chains (esp. food and pharmaceuticals) and quantitative social indicators in general. The developed best-practice taxonomy and the compiled indicator pool serve as a comprehensive basis for future sustainability assessments of hospitals.

Adapting the marine stewardship council's risk-based framework to assess the impact of towed bottom fishing gear on blue carbon habitats.

Wild capture fisheries are of economic and social importance, providing a primary source of protein to people globally. There is a broad research base on the environmental impacts of fishing gears and processing methods yet, the impact on the global CO2 budget is less well studied. Evaluating the risk that wild capture fisheries pose to ecosystem health is vital to sustainably managing fishing practices to meet increasing global nutritional needs and reverse declines in marine biodiversity. At the same time meeting net-zero ambitions by reducing direct and indirect GHG emissions is vital. Ecological risk assessments, trait-based assessments, and vulnerability assessments have long supported fisheries management systems globally but do not yet provide any representation regarding the impacts that fishing gears have on the ability of the habitat to capture and store carbon. Considering the importance of accessibility and transparency in approaches necessary for fisheries sustainability certifications, this paper describes a method to integrate habitat carbon capacity attributes into the Marine Stewardship Council (MSC) Consequence and Spatial Analysis (CSA) framework. Applying the CSA carbon extension developed herein produces different CSA risk scores compared to the MSC CSA that does not account for carbon. This has potential consequences for certification schemes as carbon becomes more important in the fisheries sustainability conversation. The CSA carbon extension tool developed here is an important first step in incorporating carbon indicators into evaluations of fisheries that consider fishery carbon impacts.

Navigating the “performing-organizing” paradox: tensions between supply chain transparency, coordination, and scope 3 GHG emissions performance

PurposeDrawing on paradox theory and the category of the “performing-organizing” paradox, the study investigates the tensions firms experience in the context of organizing the processes involved in managing their indirect GHG emissions.Design/methodology/approachThe authors develop hypotheses to explain why the paradox elements of supply chain transparency and supply chain coordination affect firms' ability to reduce their indirect supply chains GHG emissions. Using a two-stage method based on data from Refinitiv and CDP for 2002 to 2021, the authors test this study’s hypotheses through panel regression analyses.FindingsWhile greater transparency experience with scope 3 emissions disclosure, GSCM practices and broader supply chain engagement are all associated with higher levels of scope 3 emissions levels, both long-term transparency experience and GSCM practices are also associated with relative reductions in scope 3 emissions over time.Practical implicationsGiven growing pressures on firms to demonstrate both transparency and legitimacy regarding their scope 3 emissions, firms must understand the characteristics of this paradox as this has implications for how emissions performance is perceived and managed. This study's results suggested that firms need to take both a long-term perspective and effectively communicate the differences involved in reporting their emissions performance to avoid unwarranted criticism.Originality/valueFilling a gap in sustainable OSCM studies by providing large-scale quantitative insights into the relationships between organizing and performing, the authors demonstrate that the processes involved in firms' efforts of measuring and managing their indirect scope 3 emissions are paradoxically affected by whether performance outcomes are specified as annual absolute levels of scope 3 emissions, or relative changes over time.

Adressing Energy Demand and Climate Change through the Second Law of Thermodynamics and LCA towards a Rational Use of Energy in Brazilian Households.

This study focuses on a typical Brazilian household through the lens of sustainable development, regarding energy demand and GHG emissions. The analysis encompasses both the direct and indirect energy, exergy consumption, and GHG emissions (quantified by life cycle assessment) associated with the usual routine of a household. The household is modeled as a thermodynamic system to evaluate inputs (food, electricity, fuels for transportation) and outputs (solid and liquid residues). The hypothesis is that each input and output contains CO2,eq emissions and exergy derived from its physical-chemical characteristics or production chains. Each household appliance is modeled and tested as a function of external parameters. The contribution of several industries was obtained to the total GHG emissions and exergy flows entering and exiting the household (e.g., fuels for transportation, food, gas, electricity, wastewater treatment, solid waste). It was verified that urban transportation was the flow with the highest GHG and exergy intensity, ranging between 1.49 and 7.53 kgCO2,eq/day and achieving 94.7 MJ/day, almost five times higher than the calculated exergy demand due to electricity. The second largest flow in GHG emissions was food due to the characteristics of the production chains, ranging from 1.6 to 4.75 kgCO2,eq/day, depending on the adopted diet. On the other hand, the electricity presented low GHG emissions due to the main energy sources used to generate electricity, only 0.52 kgCO2,eq/day. Moreover, the chemical exergy of the solid waste was 9.7 MJ/day, and is not irrelevant compared to the other flows, representing an interesting improvement opportunity as it is entirely wasted in the baseline scenario.

A systems perspective analysis of an increased use of forest bioenergy in Canada: Potential carbon impacts and policy recommendations

The Government of Canada aims at reducing overall greenhouse gas emissions by 30% by 2030 (compared to 2005) and reaching net-zero GHG emissions by 2050. Several of the climate actions under development would incentivize an increased use of forest biomass for energy. However, lessons learned from bioenergy policies worldwide have shown that increasing the use of bioenergy can impact the forest sector as a whole and that the carbon impacts of bioenergy should be assessed holistically to limit unintended negative consequences. This study aims to summarize and present existing data in a manner that enables the Canadian government and stakeholders to identify bioenergy pathways that can contribute to Canada's decarbonization targets. Firstly, we synthetize existing statistical datasets on wood removals and uses into a holistic picture of wood flows across Canada's economy. We find that, in 2017, a minimum of 77.7 Mm3 of wood were used for energy in Canada, and that reported quantities of wood used exceeded the amount of wood removals by 14–33 Mm3 annually. Thus, while 72% of wood used for energy in 2017 derived from secondary industry residues, the origin of 26% of wood for energy cannot be identified, seriously hindering any consideration on the sustainability of the current forest bioenergy use in Canada. Secondly, we assess that the amount of wood used for energy might increase by 5.5–20.4 Mm3 by 2030. In order to identify the potential impacts of this extra bioenergy demand on GHG emissions, we reviewed relevant literature based on our qualitative analysis of the system dynamics of the forest sector in response to such an increased demand. Our results show that unless targeted measures are defined to stimulate the use of residues, it is possible that direct and indirect biogenic GHG emissions from increased use of forest bioenergy will undermine Canada's decarbonization goals. We recommend several measures to avoid this, including: discouraging the dedicated harvest of logs for bioenergy, prioritizing the collection and use of logging residues which are usually burned at roadside, and favoring the recovery and use of post-consumer wood. In addition, we recommend improving the consistency among statistical datasets on Canada's forestry sector.

Indirect GHG emissions in hydropower plants: a review focused on the uncertainty factors in LCA studies

Although Life Cycle Assessment (LCA) is standardized, there is a wide range of approaches and discussions of the methodology evaluating of environmental impacts in different contexts in energy production. This review aims to present some findings, and highlight and discuss factors that influence the Life cycle Assessments (LCAs) of Hydropower Plants (HPPs) such as: indirect emissions; different stages of HPPs (construction, operation and decommissioning), the scale/productivity of HPPs; types of projects (reservoir and run-of-river), and land use. This study presents the comparison of different energy sources through the LCA and the comparison between several HPP with their different characteristics. Most of the results obtained by HPP LCAs indicate that the construction phase is the most influential phase for indirect emissions due to the use of steel and concrete. There is an important relationship between impact and production, since plants with higher productivity will have their impacts diluted during their lifetime. The comparison of the LCA results of HPPs with the LCA of other energy sources indicates that, for the category analyzed (Global Warming Potential- GWP), HPPs have a good environmental performance considering the emissions quantified. The object of this study is indirect emissions and not direct emissions, which are important, but require another approach. This review also indicates some uncertainties related to the LCA of the HPPs and the need to conduct future studies on the environmental impacts of UHEs. We also present suggestions that should contribute to improve the use of the LCA methodology.

Greenhouse gas emissions and carbon footprint of cucumber, tomato and lettuce production using two cropping systems

Vegetable intercropping is an alternative to the conventional system and characterised by a greater efficiency of land use and inputs. For this reason, it is a more sustainable and low greenhouse gas emission (GHG) cultivation model. Thus, the objective is to estimate direct and indirect GHG emissions and the carbon footprint per kilogram of vegetables produced using the intercropping and monoculture systems in a protected environment. For this, based on published studies on agronomic efficiency of these crop systems, intercropping systems of cucumber-lettuce and tomato-lettuce were compared with cucumber, tomato and lettuce monocultures. Two functional units were selected to estimate the impacts (GHG emissions) of each system (intercropping and monoculture) per 1 kg of vegetables produced and 1 ha of cultivation. The total GHG emitted for each cropping system was converted as CO2 equivalent (CO2eq), using the IPCC methodology and specific factors (Tier 2). The GHG emissions in both intercropping configurations (16,368 kg CO2eq ha−1) were about 35% lower than the total emitted in monocultures (25,273 kg CO2eq ha−1). Infrastructure and synthetic fertilisers were the main contributing sources. The carbon footprint to produce 1 kg of intercropped vegetables (0.105 kg CO2eq kg−1) was about five times lower than that in the monoculture (0.516 kg CO2eq kg−1), mainly because of the differences in crop productivities. Our results confirm that the intercropping of cucumber-lettuce and tomato-lettuce should be promoted to mitigate GHG emissions.

Using IO Table in Analyzing the Environmental Burden of PET Plastic Packaging Industry in Vietnam

Plastic industry plays an important role in the economic development. The PET plastic packaging industry is the largest segment of the plastic industry, accounting for 37.43% of GDP of Vietnam's plastic industry. However, the current production and consumption of PET in Vietnam are having significant environmental impacts. This study uses input-output tables (IO tables) in 2007, 2012 and updated for 2018 to determine the current status of plastic production and plastic consumption (by economic sectors) in Vietnam during the period of 2007 - 2018. At the same time, the research integrates IO tool and LCI to identify the environmental burden in the PET plastic packaging life cycle through PET’s demand of other economic sectors. The results show that the two biggest PET plastic consumers are food processing sectors and electronics sectors, and these industries are also responsible for the highest indirect GHG emissions. This result can form the basis for developing a sustainable plastic packaging production and consumption strategy for Vietnam.

Prediction of future carbon footprint and ecosystem service value of carbon sequestration response to nitrogen fertilizer rates in rice production

There is concern for variations of the carbon footprint (CF) and ecosystem service value of carbon sequestration (ESVCS) related to nitrogen (N) fertilizer rate in rice production under future climate change. To explore possible future ecological effects of N fertilizer rate, a DeNitrification–DeComposition (DNDC) model combined with Representative Concentration Pathway (RCP) projections (RCP 4.5 and RCP 8.5) were used to predict the CF and ESVCS of rice production. The model was validated by a two-year field experiment, and then seven N fertilizer levels (0, 75, 150, 190, 225, 300, and 375 kg N/ha) were set for prediction from 2015 to 2050. The validation results indicated a good fit between the DNDC-simulated and observed data of GHG emission and rice yield. Under RCP 8.5, the mean CF was 4.5–8.7% higher and the average ESVCS was 3.6–7.4% lower than those under RCP 4.5. The effects of N fertilizer rate on CF and ESVCS were consistent between the two climate change scenarios. In both RCPs, it was found that CF and ESVCS were mainly influenced by N fertilizer rate due to the latter's effect on CH4 emissions and crop carbon fixation. CH4 was the main contributor to CF during 2015–2050, accounting for 43.9–58.3% of the total CF. Agricultural inputs were also large contributors to CF, and N fertilizer increased the indirect GHG emissions by 24.6–122.2% compared with no N fertilization treatment. Among the studied N fertilizer rates, 190 kg N/ha was the optimal rate, obtaining the lowest CF and highest ESVCS. These results indicate that, under future climate change, an N fertilizer rate of 190 kg N/ha could achieve a trade-off between high yield, reduction of CF, and improvement of ESVCS in rice production.

Huella de carbono: emisiones de GEI por uso del sistema de iluminación de la Facultad de Ingeniería Ambiental de la Universidad Nacional de Ingeniería, Lima-Perú

El objetivo general de este estudio de investigación es contribuir a establecer parcialmente la Línea Base de la Huella de Carbono por el uso de los Sistemas de Iluminación en los ambientes de las edificaciones de la Facultad de Ingeniería Ambiental (FIA) de la Universidad Nacional de Ingeniería (UNI), en el desarrollo de las actividades académicas, gestión y de apoyo. Para lo cual se establecieron los objetivos específicos: Identificar las fuentes de emisión indirecta de GEI, estimar las emisiones indirectas de GEI que provienen de la generación de electricidad de origen externo (Alcance 2.) y preparar el informe del inventario de GEI correspondientes. Las universidades y en especial las Facultades relacionadas a la Ingeniería Ambiental tienen la responsabilidad relevante de contribuir a la sostenibilidad ambiental a través de la formación académica de profesionales, con investigaciones y acciones directas al respecto; las cuales servirán académicamente para replicar las buenas prácticas en otras facultades, universidades y sectores. Esta contribución está alineada con las acciones de mitigación conformantes de las ‘Contribuciones Nacionalmente Determinadas’ (NDC), que constituyen el compromiso del Perú para reducir sus emisiones de gases de efecto invernadero al año 2030, en el marco del Acuerdo de París. La sociedad moderna desarrolla gran cantidad de actividades con el uso de los sistemas eléctricos, según la IEEE a nivel mundial el 66% de la electricidad es generada por combustibles fósiles y el 16% de la electricidad mundial es consumida en sistemas de iluminación; en el Perú según el Ministerio de Energía y Minas (MINEM), aproximadamente el 35% de la energía primaria (después de la transformación y/o descontadas las pérdidas) es destinada a la generación eléctrica, de la cual el consumo energía por la iluminación en los hogares es de 19% del total de la factura eléctrica, en el sector público este porcentaje se eleva al 20% y en el sector comercial hasta el 25%. El informe del inventario de GEI se ha realizado según la Norma ISO 14064-1. La metodología de cuantificación aplicada es la combinación de medición y cálculo. Los cálculos basados en datos de las actividades de GEI, datos de las horas de consumo de energía eléctrica y las mediciones directas de consumo intermitente de energía por los sistemas de iluminación, multiplicado por el Factor de Emisión (FE) de GEI. El año base considerado es 2018, determinándose el inventario de emisiones indirectas de GEI que provienen de la generación de electricidad de origen externo (Alcance 2) por uso del Sistema de iluminación de la Facultad de Ingeniería Ambiental de la Universidad Nacional de Ingeniería, en las actividades académicas, de gestión y apoyo, de 63.169 tonCO2e. Siendo el mayor consumo por la actividad académica directa (aulas, laboratorios y biblioteca) 41.18 %. Una emisión per cápita de 0.061 tonCO2e/estudiante y 0.052 tonCO2e/usuario, así como un promedio de 0.042 tonCO2e/lámpara.

The service-stock trap: analysis of the environmental impacts and productivity of the service sector in Hungary

Urbanization and the emerging share of the service sector in economic output may support the sustainability transition due to lower material input and emissions, while further accelerating the economic growth at the same time. Nevertheless, there are significant barriers to the transition. In this study, the service sector of Hungary and its four commercial sub-sectors have been analyzed with regard to their material requirement (input flows and stock) and greenhouse gas emissions (GHG) emissions utilizing EXIOBASE v3. General policy implications are also provided with special regard to costs, possible taxes and productivity of resources. The share of direct and indirect GHG emissions and material input generated by the sector was stable and moderate. A permanently improving trend is present in GHG, and material input intensity. Material stock accumulation in the service sector (capital stock), however, shows an ascending trend, and it has increased from 42% in 1995 to be 55% in 2015. Material input productivity of investments into services has increased until the economic crisis, then it starts to decline or stagnate; while overall stock productivity has decreased in two sub-sectors, and slow improvement was observable in sub-sectors of transportation and information and communication technology (ICT). Stock productivity of ICT and machinery capital stock was decreased dramatically in all sub-sectors. Four economic sub-sectors of the commercial services analyzed in this study have increased their capital stock from 130 to 288 Mt between 2000 and 2015. The exponential trend in material stock accumulation is an environmental issue with rising scientific concern and awareness, since it constitutes the basis of crucial waste management, resource scarcity and resource use challenges in the future. The current study indicates general reinforcement of the environmental pressure of material stock accumulation by the service sector. This phenomena was defined as the ‘service-stock trap’, which refers to the sign of a trade-off between the descending flow-type environmental impacts and ascending impacts of capital stock accumulation during the economic transition towards a service-based economy. As a promising way out of the trap, the resource tax was discussed in detail, which seems to be suitable for forming investment decisions of the business actors.

The development of a carbon footprint model for the calculation of GHG emissions from highways: the case of Egnatia Odos in Greece

Global transport demand is increasing and the associated emissions of GHGs are becoming a key factor in the environmental planning of networks and the actual operational management stage. We describe the development of a novel methodology for the calculation of the carbon footprint of a major motorway (Egnatia Odos) in Northern Greece. Total GHG emissions were calculated for 2014 as the base year, from all corporate activities, including stationary and mobile combustion, fugitive gases, purchased electricity, personnel travel, waste disposal and contractor (third party) emissions. End user vehicle emissions constitute a significant part of the carbon footprint and are estimated from annual traffic data supplied by Egnatia Odos S.A., combined with emission factors extracted from the TREMOVE model, for different vehicle categories and fuel types. The emissions model developed uses additional input data, concerning fuel and electricity consumption, fugitive gases from a/c equipment, personnel commuting and travel, waste disposal, and contractor data, also provided by Egnatia Odos S.A., for the calculation of direct and indirect GHG emissions for all three Scopes of the GHG Protocol. The final product was developed in the form of a specialized electronic platform, which is user-friendly and can be updated with the most recent input data available, in order to be used by highways’ personnel for the calculation of their carbon footprint in future years. The overall carbon footprint of Egnatia Odos S.A. in 2014 has been estimated at 770 ktCO2e, with 91% of emissions sourced by the end user category (i.e. vehicle emissions).

The Sustainability Price: expanding Environmental Life Cycle Costing to include the costs of poverty and climate change

This study develops the Sustainability Price (SP) to include social and environmental costs in the price of goods and to move towards a sustainable economy, as recommended by the UN Global Sustainability Panel. The SP addresses research gaps for integrating social and environmental values as well as computational methods in Environmental Life Cycle Costing (ELCC). A detailed case study is used to identify data sources, develop the method and consider policy applications for product labelling. An Interdisciplinary Research (IDR) methodology is used to provide a framework for methods for calculating costs to meet minimum sustainability values. Values are based on UN sustainability goals with a focus on climate change and poverty. Costs for climate change are based on the International Panel on Climate Change (IPCC) carbon price paths to avoid dangerous climate change. Costs for poverty are based on Anker’s method, which follows the UN cost of basic needs approach which is used by international institutions, national governments and ethical trade organisations. The costs are expressed as changes in value added and tracked through the supply chain using the Leontief price model. The case study uses a scoping analysis to identify important variables which are the focus of data collection and a hybrid modelling approach. Existing economic and social surveys in India captured regional and production variables for the SP. Hotspots in the production process included indirect GHG emissions for spinning and knitting processes and absolute poverty in cotton farming regions such as Gujarat. Despite wage increases of up to 200% to address absolute poverty, the SP of a T-shirt produced in India is only about 2% more than the existing price when retailed in the USA. The SP clearly communicates the costs to address poverty and climate change in global supply chains and demonstrates the use of economic methods and data sources in ELCC. The SP identifies hotspots in the supply chain and can inform labelling for ethical trade products. The SP is limited to minimum values for sustainability and does not consider optimisation. Expanding the scope to other minimum values such as planetary boundaries is recommended for further research.

Global warming potential from maize and maize-soybean as affected by nitrogen fertilizer and cropping practices in the North China Plain

Nitrogen fertilizer is required to meet grain targets, but the fossil fuel consumption and greenhouse gas emissions resulting from its use are a barrier to achieve low C agriculture. The objective of this study is to evaluate the net global warming potential (GWP) of maize and soybean monoculture and maize-soybean intercrop systems with an ecosystem-level C budget and determine the optimal N fertilizer requirement of maize-soybean intercrop based on the GWP in CO2 -eq during cropping season. The field experiment had five treatments: maize and soybean monoculture receiving 240 kg N ha−1 and maize-soybean intercrop receiving 120, 180 and 240 kg N ha−1 for three years (2012, 2013, and 2014). Considering greenhouse gas (GHG: CO2, CH4 and N2O) emissions from the field plots, indirect GHG emissions from agricultural inputs (e.g., fertilizer, diesel and pesticides) and CO2 fixation by crops, soybean monoculture was the net C source due to its lower net primary production, while all maize monoculture and intercrop treatments were net C sinks except for the maize-soybean intercrop receiving 240 kg N ha−1 in 2013. Maize monoculture was the largest C sink due to its higher net primary production, even though it had significantly (p < 0.05) greater direct and indirect GHG emission than of the maize-soybean intercrop treatments with lower N rates. Nitrogen fertilizer contributed to direct and indirect GHG emissions, with peak N2O fluxes from field plots up to two weeks after N fertilization and 26%–74% of indirect emission attributable to N fertilizer use. Higher N fertilizer rates did not improve yield in the maize-soybean intercrop, and the nitrogen-scaled GWP showed that maize-soybean intercrops fertilized with 150–182 kg N ha−1 had a comparable C fixation potential to maize monoculture receiving 240 kg N ha−1. In conclusion, we demonstrate the ability of maize-soybean intercrop to function as a C sink, similar to maize monoculture, in the North China Plain.

Comparing a territorial-based and a consumption-based approach to assess the local and global environmental performance of cities

In the framework of pressing local and global environmental challenges it is essential to understand that cities are complex systems dependent on and linked to the rest of the world through global supply chains that embody an array of environmental flows. Cities are thus a complex articulation that intertwine local and global challenges which rely at their extended hinterland for their resource use and pollution emission. To assess the environmental sustainability of an urban area in a comprehensive manner, it is not only necessary to measure its local and direct environmental performance but also to understand and take into account its global and indirect environmental counterparts. This paper presents a comparative analysis of a territorial-based and a consumption-based approach to estimate both direct and embodied resource use and pollution flows for the case of Brussels Capital Region (Belgium). The territorial-based approach is based on local energy, water and material consumption measured data as well as measured data on waste generation and pollution emissions. The estimation of indirect resource use and pollution emissions (or consumption-based approach) is based on the regional IO-tables of the city-region of Brussels extended with multi-region input-output tables, taking into account the global flows of consumption. The comparison of these two approaches is particularly relevant in the case of cities that have limited productive activities and limited or no extraction of materials as the impact on the hinterland is often underestimated or neglected by local (environmental) policies which are only based on territorial-based figures. The results show that the indirect primary energy use, GHG emissions and material use estimated by the consumption-based approach is more than three times higher than local measures indicate. The embodied water use, estimated via IOA, was over 40 times higher than the local water consumption. These results show that territorial-based approach using local data underestimate the resource needs and pollution emissions of a city and can therefore be insufficient or even be misguiding. By mapping the origin of embodied flows it is in fact possible to illustrate the open character of an urban economy and its dependence on the global hinterland. Finally, this paper discusses the possibility and relevance to combine these two approaches to create a hybrid framework that measures the full environmental performance of cities both accurately and comprehensively.

Water and the political ecology of urban metabolism: the case of Mexico City

Today, 52% of the world's population live in urban areas and this number is expected to rise to 64-69% by 2050. Cities consume most of the world's energy and materials, and are responsible of about three quarters of direct and indirect GHG emissions. Consumption patterns, however, are asymmetrical among cities and citizens. Urban metabolism, or the analysis of energy and material flows and stocks (infrastructure) that shape settlements, allows the identification not only of the dimensions of these flows and stocks, but also their main technical and socio-ecological features. These can also be evaluated from an urban political ecology perspective, that is, in terms of power relationships that define who gets access to, or control over, natural resources and other components of urban space. This article opens with a general introduction to urbanization trends, followed by a presentation of urban metabolism and urban political ecology approaches as useful analytical tools for assessing the access, management and usufruct of water in Mexico City's Metropolitan Area. A general description of the hydropolitan region of study is then offered in order to analyze urban water flows and their socioecological implications for the water-energy nexus and climate. The article concludes with a call for a paradigm change in order to transform urban settlements towards more livable, sustainable and equitable ones; a process that demands not only paying attention to the form but also to the function of urban territories within capitalist productive relationships. In this context the design and execution of public policies needed for transforming the current trend of constructing, operating, managing, and living in cities must be proactive, imaginative, and based on an integral metabolic planning that allows the adjustment of planning and policy tools to overarching contextual changes and to historical trends and socially desirable futures. Specific recommendations include the bottom-up management of water infrastructure and the guarantee of human rights to water, sanitation and a healthy environment; these are components of the 'right to the city.'Key words: urban metabolism, water, water-energy nexus, climate change, urban political ecology, Mexico City

Socio-technological impact analysis using an energy IO approach to GHG emissions issues in South Korea

Through energy input–output (E-IO) analyses from 1985 to 2005, the changes in three factors affecting GHG emissions in South Korea were analyzed. Based on the E-IO results, the changes in the direct and total (embodied) GHG emissions from the pertinent sectors were decomposed into three factors—the energy consumption effect, the social effect, and the technological effect—using the Sato-Vartia index for the three periods of 1985–1995, 1995–2000, and 2000–2005. The decomposition analysis demonstrated that a total emission matrix including both direct and indirect GHG emissions showed an evolution pattern that was very similar to the changes in direct GHG emissions; however, ripple effects were observed in the case of emissions from sector #-59 (Synthetic resins, synthetic rubber-p). The results showed that national energy policies such as those pertaining to the diversification of energy sources, shifts in the energy consumption structure (social effect), and the transformation to a low-carbon energy economy (technology effect) were effective. Finally, several limitations of the Divisia decomposition analysis were pointed out.

Low-carbon assessment for ecological wastewater treatment by a constructed wetland in Beijing

Presented in this paper is a low-carbon assessment for wastewater treatment by a constructed wetland as ecological engineering. Systems accounting by combining process and input–output analyses is applied to track both direct and indirect GHG emissions associated with the wastewater treatment. Based on the detailed assessment procedures and the embodied GHG emission intensity database for the Chinese economy in 2007, the GHG emissions embodied in both the construction and operation stages of a pilot constructed wetland in Beijing are investigated in concrete detail, with parallel calculations carried out for a cyclic activated sludge plant as a typical conventional wastewater treatment system for comparison. With the overall embodied GHG emissions taken into account, the constructed wetland is shown to be remarkably less carbon intensive than the conventional wastewater treatment system, and the contrast in GHG emission structure is also revealed and characterized. According to the results, the ecological engineering of the constructed wetland is considered to be favorable for achieving the low-carbon goal.

Monetary value of the environmental and health externalities associated with production of ethanol from biomass feedstocks

This research is aimed at monetizing the life cycle environmental and health externalities associated with production of ethanol from corn, corn stover, switchgrass, and forest residue. The results of this study reveal current average external costs for the production of 1 l of ethanol ranged from $0.07 for forest residue to $0.57 for ethanol production from corn. Among the various feedstocks, the external costs of PM 10, NO X , and PM 2.5 are among the greatest contributors to these costs. The combustion of fossil fuels in upstream fertilizer and energy production processes is the primary source of these emissions and their costs, especially for corn ethanol. The combined costs of emissions associated with the production and use of nitrogen fertilizer also contribute substantially to the net external costs. For cellulosic ethanol production, the combustion of waste lignin to generate heat and power helps to keep the external costs lower than corn ethanol. Credits both for the biogenic carbon combustion and displacement of grid electricity by exporting excess electricity substantially negate many of the emissions and external costs. External costs associated with greenhouse gas emissions were not significant. However, adding estimates of indirect GHG emissions from land use changes would nearly double corn ethanol cost estimates.