Equivalent Emissions Research Articles

The impact of climate change on variations in rutting resilience of asphalt pavement across the climate zones in China

This study aims to investigate resilience differences of asphalt pavements across China's climate zones in response to climate change. The impacts of climate change on rutting depth (RD), influence degree on rutting resilience, and Greenhouse Gas emissions in various climate zones were evaluated, and adaptation measures were proposed. The findings indicate that the warmer climate zones will be significantly affected. Freeways in these zones, serving for 10 years under projected climate conditions 40 years ahead, are expected to have RD increments exceeding 2 mm. Carbon dioxide equivalent emissions could increase by 23.1 million tons (a 39.4% increase) compared to current conditions. The degree of influence of climate change on rutting resilience will significantly differentiate among the climate zones. Four potential adaptation measures have been proposed to urgently enhance rutting resilience in response to climate change.

A novel life cycle assessment methodology for transitioning from nZEB to ZEB. Case-study

This study analyzes the CO2 equivalent emissions of a LEED-certified nearly Zero Energy Building (nZEB) using a simplified Life Cycle Assessment (LCA) methodology, aligned with EN 15978. Focusing on the building's energy performance across its life cycle, the study demonstrates that in 2022, 95 % of the energy used for heating came from renewable sources, which decreases to 86 % by 2050 due to milder winters. However, the need for cooling increases by 9 % over the same period due to hotter summers. By 2050 and 2080, if the EU transitions to renewable electricity, the operational Global Warming Potential (GWP) could approach zero. The study highlights that embodied emissions (69 %) outweigh operational emissions (31 %) in 2022, emphasizing the need to reduce embodied GWP through material reuse and recycling. Notably, concrete and aluminum were found to contribute the most to embodied emissions. The research also shows that nZEBs can exceed the EU's 2030 energy targets, with renewable energy contributing 67 % of the building's total consumption. As climate change favors nZEB performance, the operational emissions will trend towards zero, but embodied emissions will become increasingly significant. To achieve the EU's zero-emission goals, it is crucial to prioritize reducing embodied GWP in future nZEBs. This study underscores the importance of nZEBs in mitigating climate change impacts, offering a pathway toward sustainable construction and energy efficiency.

Complacency in the quantification and reporting of climate impacts as carbon dioxide equivalent emissions

PurposeThe choice of characterization model has the potential to profoundly influence LCA results and conclusions. It is therefore a requirement of ISO 14044:2006 that the selection of characterization model shall be both justified and consistent with goal and scope. The purpose of this article was to examine current practices regarding the characterization of GHG emissions and reporting as CO2 equivalent emissions.MethodsA survey of practice was conducted across articles recently published in the International Journal of Life Cycle Assessment. Each article was examined using seven predetermined questions covering reporting of CO2 equivalent emissions and justification of climate metric used, interpretation of results in relation to climate measures or goals, and the implications of choosing an alternative climate metric.Results and discussionOf the sample of 85 articles, more than half reported GHG emissions as CO2 equivalent emissions. Of these, 81% unambiguously reported the climate metric used. Most often, there was no justification for the choice of a characterization model. Where a justification was given, the most common reason was alignment with the requirements of a program or PCR document. In some cases, the choice of characterization model was determined by the choice of impact assessment method (e.g., CML, ReCiPe). In other cases, the choice of characterization model was based on the desire to compare results to other studies. It is noted that none of the abovementioned reasons is scientific justification related to a stated climate objective. Not surprisingly, most studies made no attempt to interpret results reported as CO2 equivalent emissions in relation to climate measures or goals, and most did not discuss the potential implications of alternative climate metrics. For almost half of the articles, the choice of climate metric was assessed as potentially having major implications for decision-making or comparison to alternative systems.ConclusionsBased on this survey, it is evident that key aspects of ISO 14044:2006 are routinely not being followed. When GHG emissions are aggregated into a single impact category indicator result, there is a loss of transparency about climate impacts over time and the potential to unknowingly trade short-term climate benefits against the exacerbation of the difficulties of achieving long-term climate stabilization. As such, whenever GHG emissions are reported as CO2 equivalent emissions, it is imperative that the choice of characterization model is unambiguously reported and justified, that results are interpreted in relation to environmental outcomes, and that the potential implications of selecting alternative models are discussed.Graphical

Beyond 4 × 4: Paramotoring a novel approach to accelerate plant exploration in challenging environments

Societal Impact StatementAddressing the burning environmental crisis, we explore how the ‘extreme sport’ of paramotoring can enhance and accelerate scientific exploration with minimal environmental impact compared to off‐road vehicles. Our study demonstrates the scientific potential of paramotoring to access fragile desert ecosystems and investigate unrecorded habitats and species. Comparisons with 4 × 4s showed significant reductions in CO2‐eq emissions for longer missions and ninefold faster travel times. Unlike off‐road vehicles, which can damage the equivalent of over one football pitch in area per linear kilometre driven, paramotors cause minimal damage. Integrating extreme sports and science can accelerate data and specimen collection for more effective habitat conservation. This has the potential to spark discoveries and engagement across diverse communities.Summary In the face of an urgent climate and environmental crisis, we explore the potential of paramotoring to expand scientific reach and collection capability without the environmental harm associated with off‐road vehicles. In Peru's fog oasis desert, we brought together paramotor experts and scientists to conduct missions involving monitoring, plant sampling, surveying, sensor placement and transportation. We compared the environmental impact and time taken by paramotoring with surveys conducted using off‐road vehicles and walking. Shorter paramotor missions showed small differences in CO2 equivalents and time efficiency compared to off‐road vehicles. However, longer missions (28 km from base camp) revealed up to nine times faster travel and two thirds less CO2 equivalent emissions. Notably, off‐road vehicles left a substantial environmental footprint (700 to 8000 m2 per km), whilst paramotors had a minimal impact, with a tiny surface ‘footprint’ of just a few square metres, representing orders of magnitude (1000 to 10,000) less environmental impact. With basic training in identification and sampling, paramotorists collected plant specimens that are invaluable for ongoing and future scientific study. Whilst logistical and safety challenges in transporting scientists via paramotors need further investigation, the benefits, especially compared to surface travel, are evident. Integrating extreme sports into scientific endeavour promises wider and more comprehensive exploration, new discoveries and increased engagement across diverse communities—and in summary—offers significant potential to address urgent environmental challenges.

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.

Quantifying benefits of renewable investments for German residential Prosumers in times of volatile energy markets

The COVID-19 pandemic and the Russian invasion of Ukraine have led to unseen disruptions in the global energy markets since the end of 2021. Residential renewable investments like photovoltaic systems, battery home storage systems, and heat pumps are therefore gaining traction. However, the benefits of those technologies during the energy crisis and beyond have not been fully quantified yet. Therefore, in this study, we benchmark renewable investments for a broad variety of single-family homes by evaluating potential cost savings and emission reductions. In addition, the study considers the influence of recent political incentives and subsidies. The results show that photovoltaic systems are a no-regret investment decision, both economically and environmentally. At the climax of the energy crisis, a typical German household with a heat pump could save 1850 € and reduce equivalent CO2 emissions by 250 g/kWh annually. Politically introduced price breaks on electricity and natural gas do not reverse this advantage. Furthermore, when owning an electric vehicle renewable investments are often more beneficial.

Energy Hub Model for the Massive Adoption of Hydrogen in Power Systems

A promising energy carrier and storage solution for integrating renewable energies into the power grid currently being investigated is hydrogen produced via electrolysis. It already serves various purposes, but it might also enable the development of hydrogen-based electricity storage systems made up of electrolyzers, hydrogen storage systems, and generators (fuel cells or engines). The adoption of hydrogen-based technologies is strictly linked to the electrification of end uses and to multicarrier energy grids. This study introduces a generic method to integrate and optimize the sizing and operation phases of hydrogen-based power systems using an energy hub optimization model, which can manage and coordinate multiple energy carriers and equipment. Furthermore, the uncertainty related to renewables and final demands was carefully assessed. A case study on an urban microgrid with high hydrogen demand for mobility demonstrates the method’s applicability, showing how the multi-objective optimization of hydrogen-based power systems can reduce total costs, primary energy demand, and carbon equivalent emissions for both power grids and mobility down to −145%. Furthermore, the adoption of the uncertainty assessment can give additional benefits, allowing a downsizing of the equipment.

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

Toward a dynamic national transportation noise map: Modeling temporal variability of spectral traffic noise emission levels.

The National Transportation Noise Map predicts time-averaged road traffic noise across the continental United States (CONUS) based on annual average daily traffic counts. However, traffic noise can vary greatly with time. This paper outlines a method for predicting nationwide hourly varying source traffic sound emissions called the Vehicular Reduced-Order Observation-based Model (VROOM). The method incorporates three models that predict temporal variability of traffic volume, predict temporal variability of different traffic classes, and use Traffic Noise Model (TNM) 3.0 equations to give traffic noise emission levels based on vehicle numbers and class mix. Location-specific features are used to predict average class mix across CONUS. VROOM then incorporates dynamic traffic class mix data to obtain dynamic traffic class mix. TNM 3.0 equations then give estimated equivalent sound level emission spectra near roads with up to hourly resolution. Important temporal traffic noise characteristics are modeled, including diurnal traffic patterns, rush hours in urban locations, and weekly and yearly variation. Examples of the temporal variability are depicted and possible types of uncertainties are identified. Altogether, VROOM can be used to map national transportation noise with temporal and spectral variability.

Thermodynamic, economic, and environmental analyses and multi-objective optimization of an organic flash regenerative cycle with an ejector for geothermal heat utilization

Based on the existing organic flash regenerative cycle (OFRC), this paper presents a novel OFRC system incorporating an ejector (E-OFRC). The ejector replaces the high-pressure throttle valve for initial flash evaporation and utilizes a low-pressure throttle valve for the second flash evaporation of saturated liquid separated from the first flash. The gaseous working fluid from the second flash is employed as the ejecting fluid. The E-OFRC system employs an ejector to mitigate irreversible losses associated with high-pressure throttle and to drive gaseous working fluids from secondary flash to circulate to enhance overall system performance. Thermodynamic, economic, and environmental models are established, and the impacts of flash pressure (P4), endothermic pressure (P3), and geothermal water temperature (THS,in) on system performance are analyzed and compared with those of the OFRC system. Multi-objective optimization using the Dragonfly algorithm is conducted, while the TOPSIS method is utilized to determine optimal operating parameters for the E-OFRC system. The findings indicate that, in comparison to the OFRC system, the thermal efficiency of the E-OFRC system is only lower under P3, while its thermodynamic, economic, and environmental performance is enhanced under other considered conditions. This underscores the advantages of the E-OFRC system. The optimal operating parameters for the E-OFRC system are THS,in = 423.53 K, P3 = 1.89 MPa, P4 = 0.96 MPa; yielding a net output power of 84.75 kW, a specific investment cost of 2833.54$/kW, and an annual CO2 equivalent emission reduction of 0.807 × 106kg − providing valuable technical support for engineering applications.

Research on carbon emission accounting and carbon emission reduction path of coal preparation plant

“Peak carbon dioxide emissions、Carbon neutrality” is the two stage goal of carbon emission reduction proposed by China. Carbon emission accounting is the basic premise for effectively carrying out various carbon emission reduction work and promoting the green transformation of the economy. The coal industry is one of the key objects of carbon emission reduction. Taking Zhenneng Coal Preparation Plant as the research object, this paper studies the carbon emission in the production process of the coal preparation plant and the selection of carbon emission factors, and constructs the carbon emission accounting model of the coal preparation plant. It is calculated that the carbon dioxide equivalent emission per 1 t of coal products produced by the coal preparation plant in 2018–2022 is 15.4391 kgCO2e. Based on the carbon emission reduction path at home and abroad, the development suggestions for carbon emission reduction in coal preparation plants are put forward. It is of great significance to establish a unified and standardized carbon emission accounting system for the coal industry, achieve the goal of “double carbon” and promote the comprehensive green and low-carbon transformation of economic and social development.

Seawater Mixed with One Part Alkali Activated Material: An Environmental and Cost Evaluation.

Concrete production is associated with extensive energy consumption and significant CO2 emissions. In addition, tremendous amounts of freshwater are used as a mixing agent. Urgency is increasing to develop sustainable cementitious materials and promote freshwater-saving strategies. An environmentally friendly alternative binder, seawater mixed with one part alkali activated material, is studied. In this work, a cradle-to-gate life cycle assessment was applied to study the equivalent CO2 emission and cost properties of the clinker-free binder. The seawater mixed mortar possesses comparable mechanical properties to Portland cement, with 3 d flexural and compressive strengths of 5.3 MPa and 25.2 MPa. In addition, the mortar developed in this work is of similar cost as commercial cement, but reduces CO2 emissions by 44.8%.

Selection of track form in railway tunnel from a life cycle analysis perspective

AbstractThe use of greenhouse gas (GHG) emissions as a criterion for decision-making within the rail industry is increasing. The demand for considering this criterion affects the type of decision models acceptable by railway infrastructure managers in the planning, construction, and maintenance of railway assets. The total amount of GHG emitted from a track solution in tunnels during its service life depends on the track form (i.e., ballasted track or ballastless track), the type of construction, maintenance machines used, current traffic profile, and tunnel length. However, the development in the design of ballastless track systems during recent decades to make them environmentally friendly motivates infrastructure managers to rethink and consider the use of the system. This study examines the effect of several design and maintenance factors not adequately addressed in previous research. These factors are (i) the modulus of elasticity of track support affecting the design of track forms, (ii) differences in maintenance and renewal required for track forms in the corresponding line condition, and (iii) recent developments in optimizing the environmental impact of ballastless tracks. The GHG emissions, represented by life cycle carbon dioxide equivalent (CO2e) emissions, are calculated using the climate impact software developed by the Swedish Transport Administration Trafikverket. The result is compared with the estimated emission from the conventional ballasted tracks. The method proposed in this paper is applied in a case study to study the effect of applying the optimized ballastless track system Rheda 2000® in a railway tunnel (the Hallsberg-Stenkumla tunnel) as part of a new line project in Sweden. The model applied in the study is an integral part of an integrated decision support system for effectively selecting track solutions from a lifecycle perspective. The study´s findings are: (i) the life cycle CO2 equivalent emissions by a ballastless track during its life cycle are 10% lower than that of the ballasted track, (ii) the primary total emission driver for both track form solutions is the emissions generated at the manufacturing of rails. (iii) the second important emission factor for the ballasted track solution is the emission from the renewal of the track form during its life cycle, and (iv) the second important emission factor for the ballastless track solution is concrete manufacturing.

Biomethane and Green Hydrogen Production Potential from Municipal Solid Waste in Cape Coast, Ghana.

Biomethane and hydrogen are promising elements in the transition towards sustainable energy, due to their capacity to mitigate greenhouse gas emissions. In Ghana, efforts to promote sustainable waste valorization for energy production are underway; however, organic waste conversion into biomethane and hydrogen still needs to be expanded. This study aims to evaluate the potential of producing biomethane and hydrogen from the municipal solid waste in Cape Coast, and their injection into the national gas grid. The upgrading biogas obtained from anaerobic digestion of food/organic wastes was used to generate biomethane. The modified Buswell Equation and data from literature were used to estimate the amount of biomethane and hydrogen. The environmental impact was assessed using the CO2 equivalent emissions. The findings reveal that Cape Coast generated approximately 6,400 tons of food waste in 2021, with a projection to 11,000 tons by 2050. Biomethane and hydrogen quantities was estimated at 3,700,000 m³ and 784,000 kg in 2021, respectively. Their projection reaches to 6,600,000 m³ and 1,400,000 kg by 2050. Converting waste into biomethane and hydrogen is an eco-friendly method of their management and use for renewable energy in Ghana. Strategies can be integrated into Ghana national energy policies to encourage waste-to-energy projects.

A dual methodology employing ion-pair chromatography and built-in UV spectrophotometry for quantifying recently approved combination of mometasone and indacaterol in a novel combined metered dose inhaler: assessing the greenness, carbon footprint, blueness, and whiteness

Developing analytical techniques that align with green and sustainable chemistry principles is crucial in today's scientific landscape. This work introduces two innovative approaches for the simultaneous quantification of indacaterol (IND) and mometasone (MOM), a recently approved combination therapy for chronic obstructive pulmonary disease. These methods—rapid isocratic ion pair chromatography (IPC) and UV–visible spectrophotometry—demonstrate improved environmental sustainability, cost-effectiveness, and versatility compared to existing techniques. The optimized 4-min IPC method achieved excellent resolution (retention times 2.18 ± 0.1 min for IND and 3.95 ± 0.1 min for MOM), peak symmetry, and sensitivity. It utilizes a low-cost ion pair mobile phase of acetonitrile and acidified water containing 0.025% sodium dodecyl sulfate (50:50% v/v), making it suitable for laboratories with standard chromatographic instruments. The spectrophotometric approach offers two procedures: first derivative and ratio derivative methods. These serve as simplified, low-cost alternatives for resource-limited laboratories without access to advanced instruments. Both techniques feature simplified protocols that minimize extraction and fractionation steps. Comprehensive validation confirmed outstanding accuracy (98–102%) and precision (%2 <). Sustainability assessments using ComplexGAPI, AGREE, carbon footprint, BAGI, and RGB12 tools demonstrated enhanced environmental performance compared to existing methods. The IPC and spectrophotometry methods achieved greenness scores of 0.81 and 0.85, respectively, surpassing the 0.63–0.67 range of reported techniques. Additionally, they showed lower carbon footprints of 0.035 and 0.022 kg CO2 equivalent emissions per sample, compared to 0.079–0.092 kg for conventional procedures. The application of novel "blueness" and "whiteness" concepts using BAGI and RGB12 algorithms further confirmed superior sustainability, with scores of 87.5 & 90 for blueness and 88.1 & 89.8 for whiteness. Successfully applied to quantify IND and MOM in combined capsules, this work provides a model for eco-friendly pharmaceutical analysis that maintains high analytical reliability while improving sustainability metrics.

Environmental impacts from traffic on highway construction work zones: Framework and simulations

Emissions from internal combustion engine vehicles on highways are the major contributors to global warming in the United States. Transportation sector pavement-related emissions come from gasolines and diesel use in vehicles from pavement-vehicle interaction, which is affected by pavement conditions, and by the trucking of new pavement materials and demolition. The objective of this study was to develop a framework for determining the fuel use resulting in environmental impacts caused by construction work zones (CWZs) on a range of vehicles and to produce initial calculations of these impacts by modeling traffic closure conditions for highway maintenance and rehabilitation activities. The study included two common highway categories—freeways/multi-lane highways and two-lane highways. The framework was demonstrated using three CWZ operations under different traffic congestion levels. In the simulation results for a freeway with a CWZ and heavy congestion, fuel consumption increased by 85% and the carbon-dioxide equivalent emissions increased by 86%. Changing CWZ traffic congestion from heavy (average speed 5 mph) to medium (average speed 25 mph for a freeway section) reduced fuel consumption by 40% on a freeway. This study also included use of a pilot car in a CWZ on a two-lane road typical of lower traffic volume state highways and county roads to compare with the drive cycles in MOVES used for the scenarios. The pilot-car operation scenario results indicate that a one-lane closure with pilot-car operation on a two-lane road might consume 13% excess fuel because of idling time and the slow movement of vehicles following the pilot car.

Study on radiation heat transfer characteristics of aeroengine combustion chamber

The thermal radiation of gaseous combustion products in an aero-engine combustion chamber has obvious non-ash-body characteristics. In this paper, based on the OpenFOAM platform, a numerical study on multi-field coupled turbulence-combustion-radiation radiative heat transfer was carried out for a certain type of aero-engine combustion chamber using the mean weighted sum of grey gas (WSGG) gas radiation model, which can accurately describe the non-ash characteristics of the gas. The results show that the radiation heat transfer characteristics are influenced by several factors such as equivalent ratio, combustion pressure and wall emissivity, among which the equivalent ratio is dominant. Increasing the equivalence ratio from 0.11 to 0.4 resulted in a 189% increase in average incident radiation at the combustion chamber wall and a 233% increase in average incident radiation at the exit. Increasing the equivalent ratio, combustion pressure or wall emissivity will increase the average radiation intensity in the combustion chamber and the inhomogeneity of radiation distribution at the exit of the combustion chamber. The radial radiation distribution factor (RRDF) also increases with the increase of equivalent ratio, combustion pressure and wall emissivity.

A life cycle carbon dioxide equivalent emissions assessment of zero carbon building in hot semi-arid climate region: Case study

As societies are shifting toward carbon neutral environments, they are beginning to account for their carbon emissions. One of the primary contributors of greenhouse gas emissions and global warming is the building industry; therefore, Life Cycle Assessment (LCA) is one of the instruments that allows an assessment of the energy and the energy-related environmental impacts of the buildings from cradle to grave, according to ISO 14040. In this context, the aim of this research study is to assess the Life Cycle carbon dioxide (LC CO2eq) emissions over a 50-year-lifespan of a zero-carbon solar-powered earth-based building, built with carbon-free adobe bricks, in the hot semi-arid climate of Morocco. While research on the carbon dioxide equivalent (CO2eq) emissions across the life cycle is crucial to determine the energy-intensive stages, this study looks into global tendencies of CO2eq emissions arising during the cradle-to-gate embodied (A1-3) and operational (B6) phases of a Zero Carbon Building (ZCB) case study, and which should be offset by carbon-free energy in order to abide by the ZCB definition. Results show that the LC CO2eq emissions of the eco-friendly zero-carbon residential building falls in 48.62 Kg CO2eq/m2.y., with an operational phase that has a share of around 93 % of global LC CO2eq emissions. In addition, when conventional construction materials such as concrete, bricks, and insulation materials are used as an alternative, embodied carbon emissions accounts for 6.3 kg CO2eq/m2.y. and is 85 % higher than the eco-friendly building, and it constitutes approximately 12.5 % of the overall carbon footprint. Moreover, the annual embodied and operational CO2eq emissions are offset by the 3.3-kWc-building-added-photovoltaic system. Hence, the conducted case study offers valuable insight into the good practices for decarbonization of Morocco's building stock.Through that case study, we aim to generate knowledge of net zero carbon buildings within the African continent, promoting the perks of decentralized solar energy in leaping forward a carbon-free electrified continent and valorizing the local construction techniques and knowhow in the building sector.

The carbon footprint of French hospital ophthalmology consultations.

France carbon footprint, with 604 million tons of CO2 equivalent (CO2eq) annual emissions, far exceeds the worldwide scientific specifications to not exceed 2 °C of warming in 2100. The healthcare sector is one of the biggest contributors to greenhouse gas emissions. The aim of this study is to quantify and evaluate the carbon footprint of the consultation activity of an ophthalmology department at a single institution in France. The perimeter of the investigation included consultations and excluded the surgeries and the hospitalisation. We calculated the carbon footprint of a single day of practice in our scope of investigation. We included consumption of energy, patient travel, staff travel, pharmaceutics and medical devices purchases, computer hardware, biomedical equipment/exam materials, and waste. We used the official French public database of emission factors: Base Empreinte® of the Environmental and Energy Management Agency of France. The carbon footprint of a single day of our department was estimated at 1 688.65 kgCO2eq. It represents an average of 9.28 kgCO2eq per patient. Energy consumption contributed for 114.80 kgCO2eq (6.8%), travel for 1324.76 kgCO2eq (78.4%), pharmaceutics and medical devices for 208.33 kgCO2eq (12.3%), equipment for 14.38 kgCO2eq (0.9%) and waste for 26.38 kgCO2eq (1.6%). This study highlights the importance of patient travels, and possibly pharmaceutics, in the carbon footprint of hospital ophthalmology practice in France. More studies are needed to establish it at the national or international scale, as well as more carbon footprint analyses on products, especially those of high prices, to increase the accuracy of these studies.

Eco-efficient ultra-high-performance concrete formulation utilizing electric arc furnace slag and recycled glass powder–advanced analytics and lifecycle perspectives

Ultra-high-performance concrete (UHPC) is a promising material for sustainable and resource-efficient construction, but its high Portland Cement content poses environmental challenges. This research proposes an optimized UHPC blend that significantly reduces the Portland Cement dosage by incorporating industrial waste materials [i.e., Recycled Glass Powder (RGP) and Electric Arc Furnace Slag (EAFS)]. The integration of these waste materials in UHPC formulation addresses critical waste management issues and aligns with sustainable construction practices. Utilizing a tri-variable Design of Experiments methodology in conjunction with the Andreasen & Andersen theory, the research aims to reduce Portland Cement in UHPC without compromising its compressive strength and rheological behavior. The optimized blend incorporates RGP and EAFS, achieving the threshold compressive strength established by ACI-239 (150 MPa) while maintaining a self-compacting performance in the fresh state. This mixture features low cement (621 kg/m³) and silica fume (100 kg/m³) content. Life cycle assessments (LCA) were conducted to examine the environmental efficiency of the optimized blend. A comparative LCA demonstrates that the optimized UHPC mixture developed in this study surpasses a control mixture with higher cement and silica fume contents while maintaining comparable mechanical and rheological properties. Notably, this improvement is highlighted by a nearly 20% reduction in CO2 equivalent emissions. The scientific significance of this study lies in its demonstration of a viable pathway to producing UHPC with reduced environmental impact, contributing to the advancement of sustainable building practices, and offering a practical solution to waste management issues.