CO2e Emissions Research Articles

The sustainability impacts of a web-based outpatient booking application.

Climate change is a critical global issue, impacting ecosystems, economies and communities worldwide. The shift from paper-based to digital systems is becoming increasingly prevalent across industries, with downstream positive impacts on sustainability. In 2020, Austin Health, a public tertiary hospital in Victoria, Australia, adopted a web-based outpatient booking application, which succeeded the prior paper-based system. The application served as an integrated platform for administrative staff to access various Austin Information Technology platforms and replaced previous mail-based outpatient appointment notifications with Short Message Service-based notifications. This study aimed to assess the environmental impact and organisation-wide economic cost of a web-based outpatient booking application compared to the prior paper-based system across the same time period. A retrospective environmental and economic assessment was conducted for both the web-based booking application and the paper-based system. The evaluation covered 36,925 outpatient diagnostic imaging studies - including CT, MRI, ultrasound and mammography - performed at Austin Health from 1st July 2023 until 30th June 2024. The environmental impact was assessed by calculating the expected carbon dioxide equivalent (CO2e) emissions produced by each system. The economic cost analysis was conducted from the perspective of the hospital and included the direct costs of labour and materials/consumables. CO2e emissions were significantly reduced using the web-based outpatient booking application compared to the prior paper-based system (38.5 tonnes compared to 0.002 tonnes), predominantly attributable to the elimination of postage-related fuel emissions (27.7 tonnes). The estimated net operating cost savings across the year was at least AUD 175,000 (in 2024 Australian Dollars, adjusted for inflation). This was primarily due to labour savings from the elimination of workflow inefficiencies (at least 2342 h saved) amounting to at least AUD 85,272 in salary, followed by savings from eliminated pathology tests (AUD 57,422) and postage costs (AUD 55,193). The adoption of the web-based outpatient booking application led to a substantial reduction in carbon emissions and operating costs, alongside enhanced operational efficiency and productivity. These benefits are anticipated to be enduring, especially in the face of an ever-increasing demand for medical imaging services.

Unraveling economic-environmental coupling in China's petrochemical industry towards carbon peaking

The petrochemical industry is a (key pillar) of chemical production and has relatively stable product demand in a long term, but it faces great decarbonization challenges due to the high energy consumption and complex industrial structure. To tackle this, a flow-land-infrastructure-petrochemical (FLIP) multi-factor model is developed with integration of material and energy flow analysis and decoupling assessment, targeting industrial carbon peaking via industrial structure upgrading and production efficiency improvement of four-digit level petrochemical sub-sectors. A nationally leading petrochemical industrial park was then selected to validate the model's effectiveness and robustness. Through the model optimization, the park could achieve 19 % and 30 % of CO2e emission reductions in 2025 and 2030 respectively, compared with emissions in the scenario without intervention. The overall carbon productivity could rise by 89 % with a decoupling index of -0.15 between economic growth and carbon emissions during 2020–2030, showing a feasible carbon peaking pathway. Infrastructure with lock-in emissions needs energy system transformation and adjacent industrial symbiosis from a regional perspective, while promotion targets and entry thresholds of carbon productivity should be individually tailored for each stock and incremental manufacturing sub-industry. The model could be extended to other petrochemical clusters and emission-intensive industries, synergistically addressing the effects of structure upgrading and efficiency progress to support practical and economically sustainable carbon peaking pathway formulation.

The Royal College of Ophthalmologists' National Ophthalmology Database study of cataract surgery: report 19, a comparative study of the cost and carbon footprint of local anaesthesia techniques for cataract surgery.

Understanding the financial and environmental impact of clinical pathways is important for designing sustainable services. This study aimed to compare the cost and carbon footprint of sub-Tenon's and topical anaesthesia for cataract surgery, benchmark minimum topical anaesthesia utilisation rates, and quantify the benefits of increased topical anaesthesia usage in the United Kingdom National Health Service (NHS). The cost and carbon footprint of products and staffing for topical and sub-Tenon's anaesthesia for cataract surgery were calculated and applied to National Ophthalmology Database audit data. A mainly process-based approach was used to estimate the carbon dioxide equivalent (CO2e) of product production, usage, and waste disposal. The typical CO2e per case was 0.71 kg for topical anaesthesia and 1.19 kg for sub-Tenon's anaesthesia. Around a third of CO2e was generated by usage of unneccesary equiptment and wasteful practices. The typical cost per case was £14.60-£17.14 for topical anaesthesia, £27.74 for sub-Tenon's anaesthesia performed by an operating department practitioner and £56.15 for sub-Tenon's anaesthesia performed by a consultant anaesthetist. It is estimated that around 25,000 NHS cataract cases could annually be converted from sub-Tenon's to topical anaesthesia, which would reduce the CO2e emissions of services by 12,000 kg while saving £265,000 on product usage and between £63,500 and £773,750 on staffing. Topical anaesthesia is a cheaper and more environmentally sustainable alternative to sub-Tenon's anaesthesia for cataract surgery. Increased topical anaesthesia usage in cataract services could contribute towards the NHS aspiration of becoming "net zero" by 2040.

Energy Solutions for Decarbonization of Industrial Heat Processes

The global rise in population and advancement in civilization have led to a substantial increase in energy demand, particularly in the industrial sector. This sector accounts for a considerable proportion of total energy consumption, with approximately three-quarters of its energy consumption being used for heat processes. To meet the Paris Agreement goals, countries are aligning policies with international agreements, and companies are setting net-zero targets. Upstream emissions of the Scope 3 category refer to activities in the company’s supply chain, being crucial for achieving its net-zero ambitions. This study analyzes heating solutions for the supply chain of certain globally operating companies, contributing to their 2030 carbon-neutral ambition. The objective is to identify current and emerging heating solutions from carbon dioxide equivalent (CO2e) impact, economic, and technical perspectives, considering regional aspects. The methodology includes qualitative and quantitative surveys to identify heating solutions and gather regional CO2e emission factors and energy prices. Calculations estimate the CO2e emissions and energy costs for each technology or fuel, considering each solution’s efficiency. The study focuses on Europe, the United States, Brazil, China, and Saudi Arabia, regions or countries representative of companies’ global supply chain setups. Results indicate that heat pumps are the optimal solution for low temperatures, while biomass is the second most prevalent solution, except in Saudi Arabia where natural gas is more feasible. For medium and high temperatures, natural gas is viable in the short term for Saudi Arabia and China, while biomass and electrification are beneficial for other regions. The proportion of electricity in the energy mix is expected to increase, but achieving decarbonization targets requires cleaner energy mixes or competitive Power Purchase Agreement (PPA) projects. Brazil, with its high proportion of renewable energy sources, offers favorable conditions for using green electricity to reduce emissions. The utilization of biomethane is promising if costs and incentives align with those in the EU. Although not the objective of this study, a comprehensive analysis of CAPEX and lifecycle costs associated with equipment is necessary when migrating technologies. Policies and economic incentives can also make these solutions more or less favorable.

Using Chronic Kidney Disease as a Model Framework to Estimate Healthcare-Related Environmental Impact.

While the economic and clinical burden of chronic diseases are well documented, their environmental impact remains poorly understood. We developed a framework to estimate the environmental impact of a disease care pathway using chronic kidney disease (CKD) as an example. A life cycle assessment framework was developed for the CKD care pathway and validated by experts. Life cycle stages were characterised for resource utilisation based on a literature review and ecoinvent database inputs, in ten countries. The ReCiPe impact assessment method was used to calculate impacts across multiple environmental dimensions. At CKD stage5, kidney replacement therapies (KRT) have highest impact; emissions ranged between 3.5 and 43.9kg carbon dioxide equivalents (CO2e) per session depending on dialysis modality, and 336-2022kgCO2e for kidney transplant surgery, depending on donor type. Hospitalisations have a substantial environmental impact: a 1-day intensive care stay had highest impact (66.4-143.6kgCO2e), followed by a 1-day hospital stay (28.8-63.9kgCO2e) and an 8-h emergency room visit (14.4-27.5kgCO2e). Patient transport to and from healthcare sites was a key driver of environmental impact for all life cycle stages, representing up to 99.5% of total CO2e emissions. Full care pathways should be analysed alongside specific healthcare processes. Application of this framework enables quantification of the environmental benefits of preventative medicine and effective management of chronic diseases. For CKD, early diagnosis, and proactive management to reduce the need for KRT and hospitalisations could improve patient outcomes and reduce environmental burden.

A behaviour change strategy to reduce greenhouse gas emissions from international scientific conferences and meetings

We estimated the environmental impact and financial cost of two exemplar in-person academic events organised by the European academic society, the European Academy of Nursing Science, identified the main sources of these emissions, and then mapped them against the COM-B behaviour change framework of capability, opportunity, motivation to identify strategies that could be applied by organisers and participants to reduce this impact. These events contributed 41 tonnes and 99 tonnes of CO2e emissions per event, a per-participant mean of either 0.324 (SD 0.173) or 0.724, (SD 0.263) tonnes, representing 2 to 5.5 times the daily per-person European average. Distance from home was the largest contributor to emissions. Costs were similar for both events. Our multi-component behavioural change programme includes environmental change, enablement, education, incentivisation and persuasion, by which organisers provide participants with the opportunity for less-polluting behaviour, and enhance participants capabilities and motivation to act on the opportunities provided.

Promoting a sustainable diet among office workers in Sweden: A pilot Study

Abstract Background Society is facing multiple challenges, including lifestyle-related diseases, alongside global climate change. Actions are needed to promote sustainable lifestyles advocating for healthy and environmentally friendly diets. This study aimed to assess how a sustainable lifestyle, compared to conventional healthy lifestyle education at work, affects participants’ energy intake, nutrient consumption, and diet-related CO2e. Methods An 8 week two-armed randomized trial was conducted, comprising a sustainable lifestyle arm (n = 21) and a healthy lifestyle arm (n = 16) based on the theoretical framework of the Behavioral Change Wheel, in total (n = 33) completed the trial. The office workers participated in 6 workshops during working hours. Linear mixed-effects models and analysis of variance tests were used for data analysis. Changes over time are presented as arms combined, along with their respective mean differences. Results A significant decrease in mean diet-related CO2e was observed (p < 0.001), with a decrease on average of 0.74 and 0.71 kg CO2e/day. The mean change in daily kilocalorie intake had a significant decrease over time (p = 0.008), on average of 192 and 386 Kcal. Moreover, a significant decrease in mean protein intake was observed (p < 0.001), with a decrease on average of 16 and 18 grams, possibly explaining the decrease in CO2e. No significant differences were observed between the arms at any timepoint. Conclusions Promoting sustainable lifestyle habits has a similar impact to advocating for a conventional healthy lifestyle regarding diet. This supports the new Nordic Nutrition Recommendations 2023. Despite the small sample size, insights into facilitating sustainable behaviors can influence public health policies across Europe and the workplace as an arena for health promotion. Key messages • The promotion of sustainable and healthy lifestyle habits at work can promote both individual and planetary health by decreasing diet-related CO2e emissions. • Here we demonstrate that the workplace has the potential to act as an arena to combat climate change.

Do’s and Don’ts in Climate Impact Assessment of University Campuses: Towards Responsible, Transparent and Comprehensive Reporting

With the commitment of more and more universities to decrease greenhouse gas emissions, standardizing the modeling is now becoming urgent. To date, published climate-relevant emissions can be based on completely different and incomparable accounting methods, as shown with results between 6 and 2696 t CO2e for the use phase of the same campus. This article aims to identify, compare, and evaluate the different modeling approaches behind this. For this purpose, this article proposes basic attributes of emissions modeling and reporting. Of the three established approaches to emissions accounting, sector logic (territorial carbon accounting) produces the lowest figures. Reporting in accordance with the greenhouse gas protocol, which has become established worldwide, can also shift the responsibility outside the institutional consumer. Life-cycle assessment, instead, essentially includes provision costs triggered by the consumer. The different modeling approaches also overlap with different coverage of emission sources, for which a standard set is being proposed. Such emissions modeling should finally lead to the determination of university-specific climate performances, i.e., the CO2e emissions per capita and per m2 of gross floor area. Infrastructure and procurement expenses must be recorded in addition and converted to an annual average.

A-177 Using the Building Research Establishment Environmental Assessment Method to maximise the Environmental Social Governance benefits of building a pathology hub laboratory

Abstract Background Organisations focusing on Environmental Social Governance (ESG) factors do not just benefit society and the planet, they also enjoy better performance across key profitability metrics, driven by higher growth and productivity, lower operational costs and enhanced return on investment. SYNLAB’s new Synnovis Pathology Hub, built in partnership with the National Health Service (NHS), is a high-tech purpose-built laboratory building with construction completing in Spring 2024. It will serve more than 1.7 million people in the southeast London region delivering both routine and special diagnostics in support of a 15-year NHS pathology contract. The redevelopment of the site presented an opportunity to closely align SYNLAB company strategy with the delivery of its ESG ambitions, as well as achieve financial and operational sustainability. Methods BREEAM (Building Research Establishment Environmental Assessment Method) is a standardised framework within which SYNLAB could collaborate with the building landlord and Hub delivery partners. BREEAM assessment categories are: energy, land use and ecology, water, health and wellbeing, pollution, transport, materials, waste and management. Applying the intent of SYNLAB’s ESG strategy to the hub build programme, setting this expectation with stakeholders, and using BREEAM as a platform on which to track and report ESG benefits ensured ESG and related deliverables were high on the agenda to be captured and delivered. Results The hub is on track to achieve the BREEAM Excellent rating which means it will rank within the top 10% of commercial buildings in the UK in terms of ESG benefits. Contributors to this achievement include: Recycling over 85% of materials during construction, saving more than 500 tonnes of materials from going to waste; Incorporation of changing rooms and 56 cycle rack spaces to encourage healthy and sustainable travel, helping to keep London’s air clean and reduce CO2e emissions; An Energy Management System within the Building Management System providing detailed area by area analysis and control. Along with water metering per floor, this helps SYNLAB to understand usage and focus process improvements; An energy efficient air handling system, a key area of opportunity for laboratory energy efficiency; Conformity with EU Taxonomy for Sustainable Activities, for example by limiting the flow rate of water to prevent wastage; Reuse of materials within the building, for example by relocating seating, private call areas, glass walls; Reuse of materials externally through donations to charitable organisations, for example televisions and fridges were given to a local care home, improving the residents’ quality of life; Working with local schools and wider the community. Conclusions Incorporating BREEAM ESG criteria from the early stages of planning in construction projects provide a higher likelihood of stakeholder buy-in, adoption and delivery. Pathology networks are considered key in delivering the national ambitions set out within the Long-Term Plan for the NHS and there is increased government and social pressure driving healthcare businesses to adopt ESG. There is the opportunity within Pathology networking and Pathology new builds to harness these benefits from the outset and lay the long term foundations for ESG within healthcare for future sustainability.

Multi-objective optimisation of hybrid renewable energy systems for Colombian non-interconnected zones

Colombia’s Atlantic coast wind and solar resources could enhance energy mix and self-generation. Renewable clean energy has been studied in response to fossil fuel pollution. Wind and solar photovoltaic systems have low initial, operational, and levelized energy costs. Variable wind and sun radiation may limit availability. In this regard, hybrid renewable energy systems (HRES) and energy storage have become crucial. These systems can effectively meet load demand by utilising complementary renewable resources. This study deals with sizing a wind and photovoltaic HRES with storage, using a Particle Swarm Optimisation algorithm for yearly variable resources in a non-interconnected zone in La Guajira, Colombia. The study evaluates the LCOE, probability of load loss, and the system’s CO2 emission. It develops a sensitivity analysis to determine the importance of each objective factor. From a life cycle analysis, an HRES configuration with low LCOE and environmental emission rates is associated with the size of the wind resource; the HRES configuration with minimum LCOE values is close to obtaining higher equivalent CO2e emissions. The study highlights the configuration obtained for the Colombian context, giving more importance to the environmental factor and reaching an LCOE of 0.754 USD/kWh and emission of 18.97 tCO2e/year; this configuration also increases the wind energy generation, reaching 41 % more share, compared to the configuration obtained when the economic factor is a priority.

Reducing the carbon footprint for a 30-bed haemodialysis unit by changing the delivery of acid concentrate supplied by individual 5 L containers to a central delivery system

BackgroundHaemodialysis treatments generate greenhouse gas (GHG) emissions mainly as a result of the equipment, consumables and pharmaceuticals required. An internal audit demonstrated a 33% wastage of acid concentrate when using individual 5.0 L containers at a 1:44 dilution ratio. We therefore investigated whether changing the delivery system for acid concentrate would reduce wastage and any associated greenhouse gas emissions.MethodsWe calculated the difference for a 30-bed dialysis unit between receiving acid concentrate in single-use 5.0 L plastic containers versus bulk delivery for a central acid delivery system connected to the dialysis machines. Estimates of carbon dioxide equivalent (CO2e) emissions were made using the United Kingdom government database and other sources.ResultsA 30-station dialysis unit functioning at maximum capacity (3 shifts and 6 days/week), switching to bulk delivery and central acid delivery could realise an approximate total reduction of 33,841 kgCO2e/year; in reduced product wastage, saving 6192 kgCO2e, 5205 kgCO2e from fewer deliveries, and 22,444 kgCO2e saving from a reduction in packaging and waste generated, which equates approximately to a one tonne reduction in CO2e emissions per dialysis station/year.ConclusionsSwitching from delivering acid concentrate in individual 5.0 L containers to a central acid delivery system can result in substantial reductions in CO2e emissions within a dialysis clinic. The emission savings from reducing the single-use plastic packaging greatly outweigh any gains from eliminating wastage of acid concentrate. Dialysis companies and clinicians should consider reviewing the design of current and future dialysis facilities and policies to determine whether reductions in CO2e emissions can be made.Graphical

Variations of nitrous oxide procurement per public hospital bed between Australian states and territories: A cross-sectional analysis.

We aimed to identify variations in nitrous oxide (N2O) procurement between Australian states and territories per public hospital bed by undertaking a cross-sectional analysis of N2O procurement data for all Australian public hospitals from 1 January 2017 to 30 June 2022. Data were obtained from state and territory departments of health. All Australian public hospitals across six states and two territories were included. We obtained N2O procurement data from Department of Health representatives from all states and territories, accounting for all 697 Australian public hospitals and four public dental hospitals. The main outcome measured in this study was N2O procurement per public hospital bed by state or territory. Across the 5 years (1 January 2017 to 30 June 2022) an average of 242,054 (standard deviation (SD) 16,222) kg of N2O, equivalent to 64,144 (4299) tonnes of carbon dioxide emissions (CO2e), were procured per annum. CO2e emissions from N2O purchase varied more than threefold per public hospital bed between different states/territories (0.47-1.48 CO2e tonnes per hospital bed). There were significant variations in N2O procurement between Australian states and territories when adjusted for public hospital bed numbers. Further analysis of this variation to determine cause and to guide mitigation interventions is therefore warranted.

A Life Cycle and Economic Assessment of the Peggy Guggenheim Collection in Venice for Environmental and Economic Sustainability

This paper applies selected methodologies for the measurement of the environmental and economic sustainability of the Peggy Guggenheim Collection (PGC) in Venice with a view to assessing the PGC’s sustainability and commitment to implementing selected SDGs. To assess environmental sustainability, a life cycle assessment (LCA) has been carried out. The museum is conceptualized as a “firm” that produces several outputs and needs several inputs. The results provide the number of annual CO2e (and other pollutants) emissions linked to the regular activity of the museum. The environmental cost (in EUR), linked to the impacts obtained from LCA, has been calculated. To assess economic sustainability, a survey and econometric methods were used to value services directly generated by the museum, and input/output methods were used to compute the direct and indirect impacts on the local economy. Nonetheless, PGC visitors (those who travel to Venice with the main objective of visiting the PGC) contribute to around 1.2%/1.4% of Venice’s GDP. The results from input–output tables show that, although the final demand generated by the PGC’s own activities amounted to about EUR 620 million in 2022, the economic benefits of the PGC beyond this final demand are significant and very positive due to carry-over effects. Specifically, the PGC leads to an increase in GDP of around EUR 1.200 million, with a multiplier of 1.9. In terms of employment, around 8200 jobs are associated with the presence of the PGC. The net public finance revenue also clearly benefits, with a net income of around EUR 150 million in 2022. Comparing both the environmental and economic impacts of the PGC, one can conclude that the annual activities performed by the museum are highly sustainable, with the economic pillar strongly offsetting the costs generated using natural resources. The creation of economic value, therefore, is generated in respect of environmental boundaries, even if some minor flaws can be highlighted. The connection between museums and sustainable development goals is highly recognized. The findings show the PGC’s commitment to achieving and implementing selected SDGs, including SDG 4, SDG 11, and SDG 16, by implementing actions and strategies that are aligned with these goals.

Strategies of Automated Machine Learning for Energy Sustainability in Green Artificial Intelligence

Automated machine learning (AutoML) is recognized for its efficiency in facilitating model development due to its ability to perform tasks autonomously, without constant human intervention. AutoML automates the development and optimization of machine learning models, leading to high energy consumption due to the large amount of calculations involved. Hyperparameter optimization algorithms, central to AutoML, can significantly impact its carbon footprint. This work introduces and investigates energy efficiency metrics for advanced hyperparameter optimization algorithms within AutoML. These metrics enable the evaluation and optimization of an algorithm’s energy consumption, considering accuracy, sustainability, and reduced environmental impact. The experimentation demonstrates the application of Green AI principles to AutoML hyperparameter optimization algorithms. It assesses the current sustainability of AutoML practices and proposes strategies to make them more environmentally friendly. The findings indicate a reduction of 28.7% in CO2e emissions when implementing the Green AI strategy, compared to the Red AI strategy. This improvement in sustainability is achieved with a minimal decrease of 0.51% in validation accuracy. This study emphasizes the importance of continuing to investigate sustainability throughout the life cycle of AI, aligning with the three fundamental pillars of sustainable development.

On CO2 efficiency and trade-offs between sustainability, safety, economy and resilience in infrastructure developments

The escalating crisis of climate change underscores the pressing need to reduce global CO2e emissions substantially. At the same time, a major increase is expected in global demand for infrastructure systems. In meeting this challenge, we here provide and illustrate a novel modeling framework that affords decision support in pursuit of sustainable developments of infrastructure systems. Based on this framework, for the case of roadway traffic infrastructure systems, it is shown that different strategies for the development of roadway traffic infrastructure systems, yielding approximately the same economic benefits to society, can differ in their embedded carbon footprint by up to a factor of three. This knowledge has the potential to contribute significantly to sustainable developments in general and mitigation of climate change in particular. Our models and results may readily assist decision-makers in the construction industry, at national and supra-national scales, in identifying optimal strategies for infrastructure developments. Furthermore, our work may straightforwardly support regulatory bodies and code writers in defining requirements for material and structural performances for the next generation of standards and codes.

A new strategy to produce calcium carbide-acetylene from integrated multi-level low carbon construction driven by biomass

A highly efficient and clean biomass energy-based calcium carbide-acetylene production system, including low-carbon energy supply, solid waste recycling and cascade utilization of waste heat, has been developed for the conventional energy-intensive and highly polluting fossil fuel-dependent calcium carbide industry. This system supplies the carbide-acetylene production plant with energy from the gasification of biomass and converts the plant's solid waste carbide slag into the calcium feedstock required by the plant. The waste heat from the plant's high-temperature exhaust gases is recycled and used via the multi-stage heat exchange, so that the energy cascade conversion and utilization is achieved. A simulation model of the plant is created in Aspen Plus, and a mathematical model for the biomass gasification process and cycle compensation of the calcium source through the Fortran language is written and embedded. When calculating the carbon consumption and CO2e emissions of the system, it was found that the carbon consumption and CO2e emissions of the conventional process were 5.43 t Coal·t−1C2H2 and 2.25 t CO2e·t−1C2H2, respectively. However, the carbon consumption of the new process was reduced by 65.19%, and carbon emissions by 27.24% in comparison. The energy analysis shows that the energy efficiency of the system is 36.21% for the conventional process and 44.82% for the new processes. The exergy analysis of the effective energy shows that the exergy efficiency of the new process is 73.20%, which is 52.98% better than that of the conventional process. Introduction of an index, the levelized income of acetylene product (LIOA), to characterize the product income of the system. When the price of acetylene is between 2.23 $/kg and 4.19 $/kg, the LIOA for the conventional and the new processes are 1.41 $/kg to 3.38 $/kg and − 1.28 $/kg to 0.68 $/kg, respectively. It is worth noting that the critical price (PCC2H2) for products generating net revenue from the new process is 3.17 $/kg. This study is of great importance for the development of a low-carbon biomass-coupled calcium carbide-acetylene process.

Double Counting of Emission Reductions Undermines the Credibility of Corporate Mitigation Claims.

Companies are increasingly relying on emission reductions attributable to their adoption of renewable electricity to achieve net-zero emission targets. However, there is a risk of double counting of emission reductions threatening the credibility of corporate climate actions due to defective accounting rules of GHG emissions related to electricity consumption and the overlap between different market-based instruments, including carbon credit markets, renewable power purchase agreements, and renewable energy certificates. Using data of 63 major Chinese companies in seven sectors, we quantitatively assess the risks of double counting related to corporate sourcing of renewables and their consequent influences on the alignment of corporate emission trajectories with the 1.5 °C goal of the Paris Agreement. Results show that 7.1% of the electricity consumed by sample companies in 2021 was from renewable energy procurement and deployment, with which they reported 8.27 Mt of CO2e emission reductions compared to the scenario with no renewable electricity consumption. However, emission reductions that could be double counted are predicted to be 0.9-1.3 times as many as emission reductions that companies will report during 2021-2030. After adjustment of the reported emissions that might be underestimated due to double counting, the overall emission trajectories of sample companies are no longer aligned with the 1.5 °C goal. Our findings suggest that it is urgently needed to improve the corporate carbon accounting rules and increase the transparency of corporate carbon disclosures.

Renovation Wave in Europe: Low-Carbon Design for the Refurbishment of Social Housing in Southern Italy

The public housing stock, called social housing, in Italy was developed between the 1950s and the 1980s. As of today, the first residential developments are almost nearing their end-of-life age and are in need of urgent and intensive renovation. The European Commission, with the Renovation Wave, has set a goal of doubling the rate of building renovation over the next 10 years, reducing emissions, improving energy performance, and promoting decarburization. Renovation interventions, including structural, functional, energy, and plant upgrading interventions, etc., are to be preferred over integral demolition and reconstruction interventions, which have significant repercussions in terms of managerial and social discomfort. The case studies examined concern renovation interventions aimed at energy efficiency, functional adaptation of housing, as well as façade restyling. The design variants analyzed were evaluated in terms of CO2e emissions, according to life cycle inventory (LCI) and Environmental Product Declaration (EPD) approaches. This approach has a twofold purpose: to propose design guidelines, with low CO2e emissions, through hypotheses of variants in the case studies, and to propose, to the economic operators, economically advantageous bidding scenarios in the procurement process.

Reduced travel emissions through a carbon calculator with accessible environmental data: a case study in Madison, Wisconsin

The echoing environmental toll of the transportation system calls for a drastic need to move beyond carbon-intensive modes of transportation into more sustainable ones. With the rise of emerging modes of transportation, this transition is more promising than ever. In this work, we take a travel-centric approach to promoting and accelerating the transition away from carbon-intensive modes of transportation by informing travelers about their emissions. A carbon calculator—as a function of trip distance and Well-to-Wheel (WTW) Life Cycle Assessment (LCA)—was developed and embedded on a website platform. Users would input their trip distance, and the calculator outputs the carbon footprint (CO2e) of the trip if it was to be done through seven different modes: car (gasoline), car (hybrid), car (electric), bus, electric bike, bike, and walking. In addition, the calculator outputs the equivalent of CO2e as cheeseburgers for a more intuitive display. The overall goal of this work is to understand how travelers respond to being exposed to carbon footprint information. This serves as a step forward in realizing a sustainable transportation system. We make available the calculator online through this link. Study results indicated that trip distance, environmental awareness, age, income, and mode of transportation used were the most influential features in predicting modal shifts. Importantly, the majority of modal shifts resulted in reduced CO2e emissions.

Energy flexibility in aerospace manufacturing: The case of low carbon intensity production

In this paper, the prospects of energy flexibility in mitigating the environmental impact of aerospace manufacturing are explored. In collaboration with a UK-based aerospace manufacturing enterprise, demand response, in particular production time, is explored under different stochastic scenarios. This is done through a decision-support framework that consists of a stochastic discrete-event simulation model that tests different scenarios under a full factorial design of experiments framework. The simulation model tests various improvement strategies pertaining to prioritisation rules, production start-up rules, and operating hours. The model aids in scheduling energy-intensive processes, so the time of performing such processes can coincide with times of the day when the energy’s carbon intensity is at its lowest. The use case constitutes a family of aluminium structural aerospace components that are characterised by high production rate. Results demonstrate promising potential of the proposed approach, with the best-case scenario resulting in a 7% reduction in CO2e emissions. Analysis of the results demonstrate that operational decisions that do not require infrastructural changes or capital expenditures can contribute favourably to achieving net-zero targets. This research offers useful insights on leveraging operational short-term decisions to meet the aerospace manufacturing’s sector decarbonisation targets.