Operational Framework to Quantify "Quality of Recycling" across Different Material Types.

Many pledges and laws are setting recycling targets without clearly defining quality of recycling. Striving to close this gap, this study presents an operational framework to quantify quality of recycling. The framework comprises three dimensions: the Virgin Displacement Potential (VDP); In-Use Stocks Lifetime (IUSL); and Environmental Impact (EI). The VDP indicates to what extent a secondary material can be used as a substitute for virgin material; the IUSL indicates how much of a certain material is still functional in society over a given time frame, and the EI is a measure of the environmental impact of a recycling process. The three dimensions are aggregated by plotting them in a distance-to-target graph. Two example calculations are included on poly(ethylene terephthalate) (PET) and glass. The results indicate that the recycling of bottle and container glass collected via a deposit-refund system has the lowest distance-to-target, at 1.05, and, thus, the highest quality of recycling. For PET bottles, the highest quality of recycling is achieved in closed-loop mechanical recycling of bottles (distance to optimal quality of 0.96). Furthermore, sensitivity analysis indicates that certain parameters, e.g., the collection rate for PET bottles, can reduce the distance-to-target to 0.75 when all bottles are collected for recycling.

Evaluating the Ecological Footprint of Landfills: A Framework and Case Study of Fargo, North Dakota.

There is growing interest in better understanding the environmental impacts of landfills and optimizing their operation. Accordingly, we developed a holistic framework to calculate a landfill's Ecological Footprint (EF) and applied that to the Fargo, North Dakota, landfill. Parallelly, the carbon footprint and biocapacity of the landfill were calculated. We calculated the EF for six scenarios (i.e., cropland, grazing land, marine land, inland fishing ground, forest land, and built land as land types) and six operational strategies typical for landfills. Operational strategies were selected based on the variations of landfill equipment, the gas collection system, efficiency, the occurrence of fugitive emissions, and flaring. The annual EF values range from 124 to 213,717 global hectares depending on land type and operational strategy. Carbon footprints constituted 28.01-99.98% of total EF, mainly driven by fugitive emissions and landfill equipment. For example, each percent increase in Fargo landfill's fugitive emissions caused the carbon footprint to rise by 2130 global hectares (4460 tons CO2e). While the landfill has biocapacity as grazing grass in open spaces, it remains unused/inaccessible. By leveraging the EF framework for landfills, operators can identify the primary elements contributing to a landfill's environmental impact, thereby minimizing it.

Estimating the impact on water scarcity due to coffee production, trade, and consumption worldwide and a focus on EU.

Coffee consumption is concentrated in the "Global North", while production is mainly located in the "Global South". This trade-driven dependency leads to the exploitation of natural resources. As an export-oriented cash crop, such dependency jeopardizes the existence of a fair distribution of the risks and revenues among all the actors taking part in its globalized supply chain. Coffee trees are mainly rain-fed and only partly irrigated. However, the increasing global coffee demand led to higher consumption of freshwater, which can exacerbate the stressed condition of already stressed water basins. This study quantifies the impact of global coffee consumption on water scarcity, considering the larger system made of producer and consumer countries. The global displacement of such impact is driven by consumer preferences. We found that the US, EU and Asian countries' coffee consumption create impact on water scarcity mostly in African and South American countries, which is also representative of the economic disparities existing behind the global trade flows. Climate change will likely affect the varieties currently preferred by global consumers. Therefore, immediate environmental sustainability actions including water resource preservation are necessary to face current and future challenges.

Estimating crop coefficients and actual evapotranspiration in citrus orchards with sporadic cover weeds based on ground and remote sensing data.

Accurate estimations of actual crop evapotranspiration are of utmost importance to evaluate crop water requirements and to optimize water use efficiency. At this aim, coupling simple agro-hydrological models, such as the well-known FAO-56 model, with remote observations of the land surface could represent an easy-to-use tool to identify biophysical parameters of vegetation, such as the crop coefficient Kc under the actual field conditions and to estimate actual crop evapotranspiration. This paper intends, therefore, to propose an operational procedure to evaluate the spatio-temporal variability of Kc in a citrus orchard characterized by the sporadic presence of ground weeds, based on micro-meteorological measurements collected on-ground and vegetation indices (VIs) retrieved by the Sentinel-2 sensors. A non-linear Kc(VIs) relationship was identified after assuming that the sum of two VIs, such as the normalized difference vegetation index, NDVI, and the normalized difference water index, NDWI, is suitable to represent the spatio-temporal dynamics of the investigated environment, characterized by sparse vegetation and the sporadic presence of spontaneous but transpiring soil weeds, typical of winter seasons and/or periods following events wetting the soil surface. The Kc values obtained in each cell of the Sentinel-2 grid (10 m) were then used as input of the spatially distributed FAO-56 model to estimate the variability of actual evapotranspiration (ETa) and the other terms of water balance. The performance of the proposed procedure was finally evaluated by comparing the estimated average soil water content and actual crop evapotranspiration with the corresponding ones measured on-ground. The application of the FAO-56 model indicated that the estimated ETa were characterized by root-mean-square-error, RMSE, and mean bias-error, MBE, of 0.48 and -0.13 mm d-1 respectively, while the estimated soil water contents, SWC, were characterized by RMSE equal to 0.01 cm3 cm-3 and the absence of bias, then confirming that the suggested procedure can produce highly accurate results in terms of dynamics of soil water content and actual crop evapotranspiration under the investigated field conditions.

Effects of different Danish food consumption patterns on Water ScarcityFootprint.

Food production and consumption have been recognized as a major source of environmental impacts. To ensure food security and a sustainable food system, dietary changes have been identified as one of the valuable strategies to reduce impacts on the environment while promoting human health. The vast majority of scientific literature has been focused on the effects of food consumption on climate change while neglecting to assess the degree of water scarcity impacts due to water consumption embodied in food. The research paper investigates the nexus between food consumption and impacts on water consumption adding important findings to a more recent growing body of studies estimating the water footprint (WF) of different dietary scenarios. This study uses the Water Footprint Network methodology and the AWARE (Available Water REmaining) characterization model to assess both the WF and the blue WSF (water scarcity footprint), respectively, of four Danish diets: standard, carnivore, vegetarian and vegan. In order to make them comparable, a total intake of 2000 kcal person-1 day-1 was set as energetic reference for all the diet scenarios considered. Using detailed trade and production data of agri-foods, we were able to assess the location of primary production and consequently to reveal countries mainly affected by water scarcity associated with import to satisfy Danish diets consumption. We found that while the vegan scenario scored the best environmental profile requiring 1489 L/cap/day calculated with the volumetric WF approach, it has the largest potential impacts on blue WSF of 10,477 LH20-eq/cap/day. This study has shown that more than 90% of impacts on water consumption occur outside the national borders, as a consequence of large quantities of fruits and nuts imported by countries already threatened by high water scarcity conditions such as USA and Mediterranean regions. This methodological approach may be used to compare environmental performances of recommended dietary guidelines and to assess impact scenarios of new trade policies, protecting local water scarcity levels.

Emissions of non-CO2 greenhouse gases from livestock in China during 2000-2015: Magnitude, trends and spatiotemporal patterns.

Livestock production, an important source for non-CO2 greenhouse gases (GHGs) including methane (CH4) and nitrous oxide (N2O) in China, has changed remarkably over the past decades due to economic development and demand for livestock product. However, the variation of non-CO2 GHGs from China's livestock have not received sufficient attention in existing literature. Here, we examine the spatiotemporal patterns of emissions of CH4 and N2O from main livestock in China as well as their long-term trends during the period 2000-2015. Results suggest that the livestock sourced emissions of non-CO2 GHGs in China experienced three phases: a rapid increase from 2000 to 2006, followed by a sharp drop in 2007 and then a slow increase at a lower level from 2008 to 2015. The 2007 drop reflects the impact of macro-control policies on livestock development and extensive measures taken on livestock to control the flu outbreak that year, and the slower increase from 2008 to 2015 with respect to the period 2000-2006 reflects the changes in livestock categories and a general improvement in production efficiency. Spatiotemporal patterns demonstrate that traditional livestock provinces including Henan, Sichuan, Inner Mongolia, Shandong, Yunnan and Hunan stood out as top six provinces in emission of non-CO2 GHGs in 2015. On the other hand, provinces like Jiangxi, Hubei, Hunan, Yunnan, Inner Mongolia, Liaoning and Xinjiang, identified as the emerging provinces, demonstrate the highest growth rates over the last decades. We find that different livestock categories dominated the difference in pattern of non-CO2 GHG emissions in both provinces with high emissions and those with high growth rates. Mitigation measures and policies suggestions should not only focus on high non-CO2 GHG emissions provinces, but also pay attention to the emerging new sources.

Biceps femoris muscle-tendon strain during an entire overground sprint acceleration: a biomechanical explanation for hamstring injuries in the acceleration phase.

The objectives of this study were to analyse the peak muscle-tendon (MT) strain of the hamstring during an entire acceleration sprint overground and examine their relationship with relative joint angles and segment orientation in the sagittal plane, which are the direct causes of MT strain. Kinematic data were recorded using a 3D inertial motion capture system in 21 male semi-professional soccer players during 40-metre overground sprint. Scaled musculoskeletal models were used to estimate peak MT strain in the hamstring over 16 steps. Biceps femoris long head (BFLH) exhibited the largest peaks in MT strain compared to semitendinosus (ST) and semimembranosus (SM) muscles across all the steps, with its overall strain decreased as the number of steps and maximum speed increased. Hip flexion angle was found to be a strong predictor (p < 0.001) of joint angles, being the orientation of the pelvis in the sagittal plane of the segment with the greatest influence (p < 0.001) on the peak MT strain of BFLH during sprinting. The current study provides a biomechanical explanation for the high proportion of hamstring injuries in the acceleration phase of sprinting.

Management of excavated soil and dredging spoil waste from construction and demolition within the EU: Practices, impacts and perspectives.

Excavated soil and rock (ESR) and dredging spoils (DDS) account for 23 % of the total EU waste generation in 2020. This study performs a life cycle assessment and life cycle costing to quantify the potential environmental and cost savings resulting from increasing the level of ESR and DDS prepared for reuse and recycled in comparison to the business-as-usual practice. Scenarios for the waste management pathways based on the status quo, technical feasibility or normative impositions are assessed, including the potential contribution to achieving the European Green Deal goals. Results show that promoting preparing for reuse and recycling could lead to non-negligible GHG reductions (up to 3.6 Mt. CO2 eq.) and economic savings (EUR 12.3 billion) annually. Depending upon the scenario, 0.2 % to 1 % of the net annual GHG emissions reductions sought by the European Green Deal could be facilitated by scaling up improved circular management of ESR and DDS at the EU level. Finally, the study highlights the main barriers to scaling up to more circular (i.e., preparing for reuse and recycling) and better performing management options in Europe. The results provide new insights for the European Green Deal and circular economy policymaking for CDW.

Exploring the potential of circular solutions to replace inorganic fertilizers in the European Union.

The use of inorganic fertilizer in agriculture is linked to the consumption of finite mineral resources. The demand of inorganic fertilizer is unsustainable since the current practices mostly follow a linear economy pathway incurring in a significant loss of nutrients. Accordingly, circular solutions to close the nutrient loop should be implemented to increase the sustainability of agriculture. However, the implementation of circular solutions is neither straightforward nor always beneficial. The present analysis investigates the circular solutions to replace inorganic fertilizers currently available considering the type of feedstock required, the technology implied, and the specific crop response. A major element of novelty is that accounting for the specific crop response allows the present study to capture the actual potential of circular solutions revealing that unspecific law-enforced figures can remarkably underestimate such potential, likely inducing further loss of nutrients and environmental impact. This paper reveals a set of available solutions discussing their feasibility and limitations and analyzing their efficiencies compared to traditional fertilizers. The flaws affecting the current practices, which are hampering the exploitation of the full potential of such solutions are highlighted. By means of the illustrative example of the EU pork industry, a qualitative assessment of the potential to substitute the use of inorganic fertilizers with efficient and feasible solutions is provided. The example focuses on barley, maize, and wheat, as the main domestically sourced feed crops. The proposed novel, more comprehensive, approach to the problem of circular nutrients flows opens the pathway to future policy-oriented quantitative analyses.

The environmental footprints of the feeds used by the EU chicken meat industry.

Chicken meat production in the European Union (EU) causes environmental pressures within and beyond the EU, mostly due to feed consumption. The expected dietary shift from red to poultry meat will drive changes in the demand for chicken feeds and the associated environmental impacts, calling for a renewed attention on this supply chain. By performing a break-down analysis based on material flow accounting, this paper assesses the annual environmental burden caused within and outside of the EU by each single feed consumed by the EU chicken meat industry from 2007 to 2018. The increased feed demand required to support the growth of the EU chicken meat industry over the analyzed period caused a 17 % increase in cropland use - 6.7 million hectares in 2018. Instead, CO2 emissions linked to feed demand decreased by ~45 % over the same period. Despite an overall improvement in resource and impact intensity, chicken meat production was not decoupled from environmental burden. In 2018, 0.40 Mt. of nitrogen, 0.28 Mt. of phosphorous, and 0.28 Mt. of potassium inorganic fertilizers were implied. Our findings indicate that the sector is not yet compliant with the EU sustainability targets defined in the Farm To Fork Strategy, calling for an urgent need to fill existing policy implementation gaps. The EU chicken meat industry's environmental footprints were driven by endogenous factors such as the feed use efficiency at the chicken farming stage and the feed cultivation efficiency within the EU, as well as by exogenous factors such as the import of feed via international trade. Limitations on the use of alternative feed sources, as well as the exclusion of the imports from the EU legal framework constitute a crucial gap, which hamper fully leveraging existing solutions.

Management practices for compostable plastic packaging waste: Impacts, challenges and recommendations.

The EU Green Deal aims at solving the challenges related to plastic production, (mis-)use, and pollution. While the bioplastic industry is identified as one of the possible avenues to tackle the problem, bioplastic waste collection and management practices are still far from full-development and harmonisation. To inform policy makers on the best practices and their feasibility, this study quantifies environmental and economic impacts of compostable plastic packaging (CPP) waste management schemes by means of Life Cycle Assessment and Costing. Results show that, with respect to climate change and financial costs, the scheme leading to the highest benefits is collecting CPP with conventional plastic waste followed by mechanical sorting and recycling (saving ca. 306 kg CO2eq. t-1 at a net income of 3.7 EUR t-1). The second best option is collecting CPP with bio-waste followed by biological treatment (saving ca. 69 kg CO2eq. t-1 at a cost of 197 EUR t-1). Collecting CPP with conventional plastics followed by sorting and biological treatment is to be avoided. The trend on the other impact categories generally follows climate change. Ideally, closed loop is therefore preferred, but conditioned by (i) having high share of CPP in municipal waste (else sorting is economically unfeasible), (ii) good citizen's behaviour at source-segregation, and (iii) an established market for secondary material. Currently, overall benefits are limited by the low amounts, suggesting that the management choice could ultimately be based on rather simple technical and economic feasibility criteria while regulatory and management efforts should be focused on other waste streams with greater implications on environment.

EU-27 ecological footprint was primarily driven by food consumption and exceeded regional biocapacity from 2004 to 2014.

The European Union (EU) plans to decarbonize the region by 2050. As highlighted by the Green Deal and Farm to Fork Strategy, food systems are essential for this transition. Here we investigate the resource dependence and carbon emissions of the EU-27's food systems from 2004 to 2014 via an ecological footprint (EF)-extended multi-regional input-output approach, accounting for demand and supply (including trade), and considering multiple externalities. Food contributes towards almost a third of the region's EF, and appropriates over half of its biocapacity. Average reliance on biocapacity within national borders decreased, while reliance on intra-EU biocapacity increased; yet a quarter of the biocapacity for food consumption originates from non-EU countries. Despite a reduction in both total EF and food EF over the study period, EU-27 residents demand more from nature than the region's ecosystems can regenerate-highlighting the need for new or strengthened food and trade policies to enable a transformation to sustainable EU food systems.

Decrease in life expectancy due to COVID-19 disease not offset by reduced environmental impacts associated with lockdowns in Italy.

The consequence of the lockdowns implemented to address the COVID-19 pandemic on human health damage due to air pollution and other environmental issues must be better understood. This paper analyses the effect of reducing energy demand on the evolution of environmental impacts during the occurrence of 2020-lockdown periods in Italy, with a specific focus on life expectancy. An energy metabolism analysis is conducted based on the life cycle assessment (LCA) of all monthly energy consumptions, by sector, category and province area in Italy between January 2015 to December 2020. Results show a general decrease (by ∼5% on average) of the LCA midpoint impact categories (global warming, stratospheric ozone depletion, fine particulate matter formation, etc.) over the entire year 2020 when compared to past years. These avoided impacts, mainly due to reductions in fossil energy consumptions, are meaningful during the first lockdown phase between March and May 2020 (by ∼21% on average). Regarding the LCA endpoint damage on human health, ∼66 Disability Adjusted Life Years (DALYs) per 100,000 inhabitants are estimated to be saved. The analysis shows that the magnitude of the officially recorded casualties is substantially larger than the estimated gains in human lives due to the environmental impact reductions. Future research could therefore investigate the complex cause-effect relationships between the deaths occurred in 2020 imputed to COVID-19 disease and co-factors other than the SARS-CoV-2 virus.

Quality of recycling: Urgent and undefined.

Quality of recycling is a concept used by many authors in the scientific literature and the EU legislator. However, a clear definition of what is intended for quality of recycling and a framework for operationalising it is lacking. Most studies, while proposing indicators reflecting quality, leave the concept of quality largely undefined. Such lack of clarity is an obstacle to the conception of robust policies addressing recycling and circular economy. In this article, we review the available studies investigating on recycling quality, synthetize the approaches available and conclude suggesting a way forward for research to operationalise the definition to support circular economy policy measures and monitoring. Essentially, quality is not an on/off criterion. The definition of quality of recycling should consider that quality depends on technical characteristics of the recyclate, which determine if it is adequate (thus functional) for a certain end application or not. Furthermore, it should consider that the recyclate can be used in different end applications over different markets and that can be adequate for substitution of primary resources in certain applications, but less or not in others. At system-wide level, this results in a certain degree of virgin resource substitution. To this end, preserving functionality, i.e. minimising the recyclate loss of functions via functional recycling, is key. Drawing upon studies on waste management, life cycle assessment and resource dissipation, we link the concept of functionality to substitutability of virgin resources and broader suitability in the circular economy, striving to show the linkages between different perspectives.

Assessing the multiple resource use associated with pig feed consumption in the European Union.

Feed consumption is responsible for the largest shares of resource use required for producing pork. In the European Union (EU), a meat consumption decrease is expected in combination with a growth of meat production driven by foreign demand. This paper presents a multiple environmental assessment of the resource use linked to EU pig feed by performing a material flow analysis of each single feed item constituting the EU pig diet. The global relevance and the trade-driven interlinkages are disclosed by considering the country-specific resource efficiencies of 254 territories. Our analysis reveals that in 2017 a total resource use of 14.5 Mha of land, 51.9 Gm3 of green water, 3.9 Gm3 of blue water, 1.23 Mtonnes of nitrogen, 0.35 Mtonnes of phosphorous, and 0.34 Mtonnes of potassium was required to satisfy the EU demand of pig feed. Wheat-based products accounted for the largest share of land use (32%), green water (35%), nitrogen and phosphorous from fertilizer use (44% and 28%, respectively). Also soybean accounted for a significant share of land use (15%), green water (20%) and phosphorous from fertilizer use (25%). Moreover, soybean-related feed items contributed the most to the potassium use (24%). While the domestic production of cereals satisfied the demand, protein-based ingredients such as soybean were largely imported, mainly from South America, outsourcing the related environmental burden. Moreover, most of the feed from extra-EU countries resulted with higher resource use intensities than EU implying a potential resource saving if feed was domestically produced. Results obtained are discussed in relation to the many constraints that limit the possibility of increasing the EU feed production and promising alternative solutions. In particular, while some solutions seem promising in terms of savings, the current EU regulation needs to be redesigned to allow their implementation and the achievement of ambitious EU targets.

Impact of COVID-19 outbreak measures of lockdown on the Italian Carbon Footprint.

Stringent lockdown measures implemented in Italy to mitigate the spread of COVID-19 are generating unprecedented economic impacts. However, the environmental consequences associated with the temporary shutdown and recovery of industrial and commercial activities are still not fully understood. Using the well-known carbon footprint (CF) indicator, this paper provides a comprehensive estimation of environmental effects due to the COVID-19 outbreak lockdown measures in Italy. Our aim was to quantify the CF associated with the consumption of energy by any economic activity and region in Italy during the lockdown, and then compare these environmental burdens with the CF calculated for analogous periods from 2015 to 2019 (~March and April). Complementarily, we also conducted a scenario analysis to estimate the post-lockdown CF impact in Italy. A consumption-based approach was applied according to the principles of the established Life Cycle Assessment method. The CF was therefore quantified as a sum of direct and indirect greenhouse gases (GHGs) released from domestically produced and imported energy metabolism flows, excluding the exports. Our findings indicate that the CF in the lockdown period is ~-20% lower than the mean CF calculated for the past. This means avoided GHGs in between ~5.6 and ~10.6 Mt CO2e. Results further suggest that a tendency occurs towards higher impact savings in the Northern regions, on average ~230 kt CO2e of GHGs avoided by province (against ~110-130 kt CO2e in central and Southern provinces). Not surprisingly, these are the utmost industrialized areas of Italy and have been the ones mostly affected by the outbreak. Despite our CF estimates are not free of uncertainties, our research offers quantitative insights to start understanding the magnitude generated by such an exceptional lockdown event in Italy on climate change, and to complement current scientific efforts investigating the relationships between air pollution and the spread of COVID-19.

Can atmospheric pollution be considered a co-factor in extremely high level of SARS-CoV-2 lethality in Northern Italy?

This paper investigates the correlation between the high level of Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) lethality and the atmospheric pollution in Northern Italy. Indeed, Lombardy and Emilia Romagna are Italian regions with both the highest level of virus lethality in the world and one of Europe's most polluted area. Based on this correlation, this paper analyzes the possible link between pollution and the development of acute respiratory distress syndrome and eventually death. We provide evidence that people living in an area with high levels of pollutant are more prone to develop chronic respiratory conditions and suitable to any infective agent. Moreover, a prolonged exposure to air pollution leads to a chronic inflammatory stimulus, even in young and healthy subjects. We conclude that the high level of pollution in Northern Italy should be considered an additional co-factor of the high level of lethality recorded in that area.

The new fertilizer regulation: A starting point for cadmium control in European arable soils?

Bioaccumulation of cadmium (Cd) in the agricultural soil constitutes a dangerous risk for the health of both the environment and humans. Especially in the European Union, a large amount of Cd in agricultural topsoil originates from mineral fertilizer application. In this context, the EU has recently adopted the Regulation (EU) 2019/1009 with the aim to establish stricter limits for Cd presence in fertilizer products and to promote a higher use of fertilizers from organic sources. This paper discusses the future implications of the new regulation to limit the presence of cadmium (Cd) in agricultural soils and food products. The Regulation (EU) 2019/1009 represents an important step of the EU circular economy action plan with its aim to encourage the production of low cadmium content fertilizers. This paper focuses on the limits of the Regulation (EU) 2019/1009 and on the need for complementary policy instruments to protect and conserve agricultural soil health. We highlight the recently proposed, and subsequently withdrawn, EU Soil Framework Directive (SFD) as a meaningful complementary policy tool in the context of a renewed effort to pursue protection and conservation of soil health.

Different characteristics of greenhouse gases and ammonia emissions from conventional stored dairy cattle and swine manure in China.

Livestock manure emits considerable amounts of greenhouse gases (GHGs) and ammonia (NH3), inducing climate change and air pollution. However, there remains a lack of knowledge in the literature related to GHGs and NH3 emissions from the manure of various livestock species. This study reports on a field observation we conducted to analyze GHGs and NH3 emissions of solid stored manure from dairy cattle and swine, which represent the two main livestock species raised in China. Results showed that although dairy cattle manure emitted 521.9% more methane (CH4) than swine manure, they separately emitted 50.8% and 40.9% less nitrous oxide (N2O) and carbon dioxide (CO2) emissions, respectively. With respect to their global warming potential, the GHGs emission from dairy cattle manure was similar to that from swine manure. NH3 emissions from swine manure were significantly higher, namely, greater by a factor of 2.4 compared to dairy cattle manure. Differences in gas emissions between dairy cattle and swine manure can be explained by differences in the physicochemical characteristics of their manure and their associated microbiological, chemical, and physical processes that produce gas during storage periods. Based on our results, this study highlights the necessity for prospective mitigation strategies to simultaneously decrease GHGs and NH3 emissions from livestock manure. Our findings provide useful implications for understanding GHGs and NH3 emissions, which can be used to develop corresponding mitigation strategies for livestock manure management in China.

Implications of a consumer-based perspective for the estimation of GHG emissions. The illustrative case of Luxembourg.

The Kyoto protocol has established an accounting system for national greenhouse gas (GHG) emissions according to a geographic criterion (producer perspective), such as that proposed by the IPCC guidelines for national GHG inventories. However, the representativeness of this approach is still being debated, because the role of final consumers (consumer perspective) is not considered in the emission allocation system. This paper explores the usefulness of a hybrid analysis, including input-output (IO) and process inventory data, as a complementary tool for estimating and allocating national GHG emissions according to both consumer- and producer-based perspectives. We assess the historical GHG impact profile (from 1995 to 2009) of Luxembourg, which is taken as a case study. The country's net consumption over time is estimated to generate about 28,700 Gg CO2e/year on average. Compared to the conventional IPCC inventory, the IO-based framework typically shows much higher emission estimations. This relevant discrepancy is mainly due to the different points of view obtained from the hybrid model, in particular with regard to the contribution of imported goods and services. Detailing the GHG inventory by economic activity and considering a wider system boundary make the hybrid IO method advantageous as compared to the IPCC approach, but its effective implementation is still limited by the relatively complex modeling system, as well as the lack of coordination and scarce availability of datasets at the national level.