Cycle Carbon Research Articles

Historic buildings to Positive Energy Buildings: a trilemma between energy efficiency, lifecycle carbon and architecture conservation.

Heritage buildings define the distinctive character of many urban areas by creating continuity with the past and serving as a visual cultural reference. To ensure their continued use, these buildings must be adapted for better performance that demands energy retrofitting strategies while satisfying indoor environmental quality. Energy retrofit reduces CO2eq emissions in the operation phase but typically entails embodied carbon and is not always applicable to historic buildings that require architectural and cultural conservation. This study phrases it as a trilemma and aims to identify an optimal balance between increased energy efficiency and decreased lifecycle carbon when architecture conservation is acknowledged. The research is applied to a traditional fisherman’s cottage in the village on Howth Head, Ireland with an aim to make it a Positive Energy Building (PEB). First, the construction method and heritage value are investigated followed by an experimental U-value calculation to identify the intervention needs. Then, a range of retrofit strategies to increase the energy efficiency of the building, but sensitive to the architectural conservation agenda, are proposed. Furthermore, using the EnergyPlus simulation engine, the study analyses the implications of different building materials for thermal insulation, building façade and window retrofit, on the building’s operational energy performance. Finally, for each scenario, a lifecycle carbon analysis was applied to identify the optimal strategy when architecture conservation is considered. The best retrofit strategies for reducing operational carbon do not always decrease embodied carbon. Similarly, the optimal materials to be used to achieve the highest level of energy efficiency and reduced life cycle carbon to become a PEB do not adhere to architectural conservation objectives. Further analysis is undertaken to achieve a balanced strategy which can be adopted in similar conservation retrofit projects.

Life Cycle Carbon Emissions and an Uncertainty Analysis of Recycled Asphalt Mixtures

The efficient recycling of road materials is an effective way to reduce carbon emissions. Approximately 400 million tons of waste asphalt pavement materials is generated annually in China, but the utilization rate is less than 50%. In this paper, a whole life cycle CO2 emission calculation model for recycled asphalt mixtures is established, and an uncertainty analysis is carried out on the basis of this model. The steps in the recycled asphalt mixture stage with the greatest impact on emissions are identified. The life cycle of asphalt mixtures is divided into raw material production, mixture preparation, material transportation and construction phases based on the carbon emission trends in the four phases. First, recycled asphalt mixtures are considered, and the carbon emissions along a two-way four-lane highway are analyzed based on the relevant carbon emission factor and other known data. The carbon dioxide emissions of each stage are also compared to identify the key links among stages. Then, the carbon emissions of hot-recycled asphalt mixtures are compared with those of ordinary asphalt mixtures and cold-recycled asphalt mixtures in each stage. Finally, an analytical uncertainty study of recycled asphalt mixtures is conducted using uncertainty modeling in different scenarios. Based on the quantitative results of the carbon emission calculations through life cycle assessment (LCA), future measures for reducing carbon emissions from recycled asphalt mixtures are proposed.

Energetic performance and life cycle carbon emission of CO2 automotive air conditioning system with an evaporative gas cooler and a dual-evaporator configuration in China

Enhanced actions on climate change have led CO2 air conditioner to take center stage in automotive field. However, its inefficient performance in hot climates limits its further application. A dual-evaporator (D-E) configuration, an evaporative gas cooler (EGC), and their combination (D-E + EGC) were first integrated with the system and experimentally studied in this paper in an attempt to alleviate this problem. Annual energy consumption and life cycle climate performance (LCCP) under four modes (baseline, D-E, EGC, and D-E + EGC) in China were estimated. Results show D-E increases evaporation pressure and EGC is able to decrease discharge pressure. D-E + EGC combines the advantages of both. Thus, improvement percentage in coefficient of performance (COP) brought by D-E + EGC is the highest, followed by those of EGC and D-E. This percentage is more significant at higher ambient temperatures, and even reaches 67.4 % at 45°C outdoor condition. In any mode, annual energy consumption and LCCP in southeast China are double or triple of those in other regions, which shows this system is of high energy consumption and high emission in southeast China. Compared with baseline mode, annual energy consumption and LCCP can be reduced by 3 ∼ 7 % for D-E, 14 ∼ 16 % for EGC, and 18 ∼ 22 % for D-E + EGC. Specifically, D-E + EGC could save up to 890 kWh of electricity and reduce carbon emission by up to 440kgCO2 per vehicle, indicating this technique is a promising way to reduce energy consumption and carbon emission for vehicles equipped with CO2 air conditioners.

Life cycle comprehensive performance assessment of the TiAlN coated tool based on surface treatment

The optimal surface treatment process can availably improve tool surface properties, and meet the requirements of low-carbon manufacturing. In this work, based on tool surface modification technology and tool life cycle carbon emission system, TiAlN coated tools are carried out micro-blasting treatment (MBT), cryogenic treatment (CT) and heat treatment (HT). The effects of surface treatment processes on the surface integrity (morphology, roughness, micro-hardness, residual stress) of the coated tool are studied. The high-speed dry finishing turning experiments of cobalt-based superalloy are carried out to investigate the tool wear morphology and wear mechanism. The carbon emissions of the tool life cycle are analyzed. Finally, the comprehensive performance of the coated tool within life cycle is evaluated. The results show that the highest level of surface integrity of coated tool is achieved by MBT, while the lowest carbon emission of environmental is impacted by HT. Compared with the untreated (UT) tool, the micro-blasted tool has the most significant improvement in surface roughness with a 28.6% reduction. The cryogenic treated tool has the greatest improvement on the surface hardness which is increased by 44.4%. The effect of HT on the surface residual stress is the most obvious. The surface stress of the heat-treated tool has increased by 59.4%. Moreover, the flank wear VB of the micro-blasted tool, cryogenic treated tool and heat-treated tool is reduced by 25.17%, 24.50% and 32.12%, respectively. The main wear mechanisms of the treated tool are adhesive wear, oxidation wear and abrasive wear. According to comprehensive performance assessment, the performance of surface treatment process during the coated tool life cycle is: HT > MBT > CT > UT.

Improving building resilience in the face of future climate uncertainty: A comprehensive framework for enhancing building life cycle performance

This research introduces an innovative resilient design framework, addressing gaps in building performance optimization by considering a holistic life cycle perspective and factoring in climate projection uncertainties from the 2020s to 2090s. The study concludes that in the case study, future climate scenarios in different Shared Socio-Economic Paths significantly impact building life cycle performance, with wall U-value, windows U-value, and wall density identified as major factors affecting building performance under future climate uncertainty. The ensemble learning model achieves high fidelity in predicting life cycle carbon emissions (LCCE), life cycle cost (LCC), and indoor discomfort hours (IDH) through input feature screening and hyperparameter optimization. Comparing optimization algorithms, Two-Archive Evolutionary Algorithm for Constrained multi-objective optimization (C-TAEA) demonstrates better convergence degree and optimization effect. Among the tested multi-criteria decision making methods, the VIKOR method selects the best building resilient design scheme from the Pareto data set, effectively reducing LCCE, LCC, and IDH, and leading to an overall improvement in building life cycle performance. Applying this framework, the finalized scheme for an office building in cold region optimizes 44.0% of LCCE, 8.2% of LCC, and 4.3% of IDH. This framework develops a new approach to improve building life cycle performance under future climate uncertainty and supports informed decision-making for resilient building design. To promote carbon neutrality in construction, it is urged that future studies incorporate additional sources of uncertainty, such as occupant behavior, into the proposed framework.

Carbon reduction potential of a rain garden: A cradle-to-grave life cycle carbon footprint assessment

With emphasis on constructing low-carbon cities, the renovation of old communities highlights the importance of renewing rainwater management facilities. Rain garden is an exceptional Nature-based Solution for rainwater management. When applying them to renovate old communities, the carbon footprint should be considered. This study focused on renovating facilities in the Greater Bay Area and utilized the Energy Expert platform to calculate rain garden carbon footprint with the Life Cycle Assessment. The carbon reduction benefits during the operation were estimated. This study accounting the life cycle carbon footprint of the 5455 m2 rain garden was 1117.42 tCO2e. The carbon footprint contribution, from highest to lowest was the end-of-life phase, materials production phase, construction phase, use and maintenance phase. Regarding carbon emission inventory, waste soil landfill, fertilizer acquisition, and waste soil recycling ranked high. Transportation also accounted for a remarkable carbon emission. The rain garden showed great potential for climate change mitigation, with a total and net carbon reduction of 1927.41 and 809.99 tCO2e, respectively. To reduce the carbon footprint of the rain garden, we should focus on waste soil treatment and transportation. Recommendations included increasing waste soil recycling, in situ recycling and green transportation.

TMET-03. REPROGRAMMING OF GLIOBLASTOMA GLUCOSE METABOLISM FUELS TUMOR GROWTH

Abstract Metabolic adaptation can promote oncogenic phenotypes in glioblastoma (GBM), but the metabolic pathways utilized by GBM and how they differ from the pathways utilized in normal cortex are poorly understood. Here, we utilize in vivo stable isotope tracing in mice and patients with GBM to define carbon fate and metabolic rewiring in cancer. We infused uniformly-labeled 13C glucose into mice bearing orthotopic GBM patient-derived xenografts or into patients undergoing surgical resection for likely GBM. Tumor and cortex were physically separated in mice by fluorescence-guided microdissection. In humans, samples of enhancing tumor, non-enhancing tumor and normal cortex were separated intraoperatively using MRI guidance. Samples were subsequently analyzed by liquid chromatography mass spectrometry to determine the downstream metabolic fates of infused 13C glucose. Of eight patients infused with 13C6-glucose, six were confirmed to have GBM while the others had non-GBM high grade gliomas. In mice and in patients, glucose-derived carbon effectively entered glycolysis and labeled glycolytic intermediates equivalently in tumor and cortex. Compared to GBM tissue, cortical tissue preferentially oxidized glucose-derived carbon in the TCA cycle and used glucose-derived carbon to synthesize neurotransmitters. Cortical tissue utilized glucose-derived carbon to synthesize the amino acid and neurotransmitter precursor serine, while GBM tissue derived serine from extracellular sources. By contrast, GBM tissue preferentially utilized glucose-derived carbon for the synthesis of purines, pyrimidines and NAD+/NADH. Using time-course isotope tracing studies in mice with GBM and a novel metabolic flux analysis framework, we quantified absolute metabolic fluxes in vivo and confirmed elevated nucleotide synthesis and serine salvage in GBM. Consistent with these results, eliminating dietary serine in mice slowed GBM PDX growth. These studies are the first measurements of numerous metabolic pathways in humans and indicate that GBMs suppress the physiologic utilization of glucose carbons to fuel biosynthesis, which represents a targetable metabolic liability.

Life cycle carbon footprint accounting of an offshore wind farm in Southeast China—Simplified models and carbon benchmarks for typhoons

Offshore wind farms are fast-spreading off the southeast coast of China to achieve carbon neutrality by 2060. However, unfavorable weather conditions in Southeast China (e.g. frequent typhoons and severe wind intermittency) may increase the carbon footprint of offshore wind energy. But typhoons have never been considered in carbon accounting before, which may affect the design decisions of stakeholders and research priority setting for academicians. (i) To determine the effect of typhoons on carbon footprint, a life cycle assessment was performed on a typical offshore wind farm using real data. The results demonstrate that typhoons can be the largest contributor to carbon footprint, and the maximum wind speed of typhoons is the most critical parameter to carbon footprint. (ii) To quantify the carbon emissions caused by typhoons, simplified models estimating carbon emission intensity under different maximum wind speeds of typhoons are established, using Monte Carlo method based on 51 historical typhoons. The models imply that wind turbines with Permanent Magnet Synchronous Generator (PMSG) are highly recommended in typhoon-prone area, because their carbon footprint is smaller than those with Doubly-Fed Induction Generator (DFIG). (iii) To set carbon benchmarks for typhoons, statistic analysis was conducted based on the simulated samples generated by Monte Carlo method. The carbon benchmarks of typhoons show that gearbox has the highest carbon emission intensity (mean=4.35g/kW, 95th percentile=7.00g/kW) among all components, resulting DFIG with gearbox not suitable in typhoon-areas. The site selection of offshore wind farms in Southeast China should avoid areas where the maximum wind speed of typhoons exceeds 44.5 m/s. This study emphasizes the importance of typhoons in carbon footprint accounting for offshore wind farms in Southeast China. More significantly, the proposed simplified models and carbon benchmarks of typhoons can be applied to feasibility studies in early design stage for engineers and stakeholders.

Life cycle carbon footprint assessment of coal-to-SNG/methanol polygeneration process

The coal-to-natural gas project alleviates the shortage of natural gas in China by using the abundant coal resources, but it has the problems of single product and poor ability to deal with risks. The coal to synthetic natural gas (SNG)/methanol polygeneration process can solve this by coproducing chemicals and have the advantages of high economic benefit and energy saving. The impact of polygeneration process design on carbon emission reduction is still the key issue to be solved urgently. Therefore, for the coal-to-SNG/methanol polygeneration process, this paper explores the interactions between the polygeneration process design and carbon emissions by using life-cycle assessment method, and evaluates the environmental impact potential of the process. The fluctuations of industrial parameters are also simulated using Monte Carlo analysis, and most of the results are concentrated at ±6.5 %, which verifies the reasonableness of the results. And the carbon emission reduction effect of the polygeneration process is examined by comparing with coal-to-gas and coal-to-methanol processes. The results show that the polygeneration process will reduce carbon emission by about 7.9 % under the same output, which helps to achieve carbon emission reduction.

Mitigating carbon emissions of single-family houses: Assessing the need for a limit value

Reducing carbon emissions in the global building and construction sector is a crucial part of achieving climate targets. Laws that aim to limit the carbon emissions of new buildings have yet to be implemented on a larger scale, although some nations already have thresholds. These thresholds may not be sufficient to mitigate carbon emissions, and not all types of buildings are obliged to comply with them. In the case of Denmark, single-family houses (SFH) are not required to not comply with a limit, although they represented approximately 17% of all newly built areas from 2010 to 2022, indicating significant resource use and associated carbon emissions. This study aims to establish sufficient background data to support the need for implementing a limit value for SFHs in building regulations to ensure necessary reductions in carbon emissions. The study finds that the life cycle carbon emissions of Danish SFHs vary between 5.6 and 13.2 kg CO2e/m2/year, showing that compliance with the current limit value of larger buildings is possible and that a reduction of more than 50% in carbon emissions is possible. However, currently, there is no intentional investigation or achievement of potential carbon emissions in the construction industry. The study’s findings inform policymakers that a limit value for SFHs must be introduced no later than 2025 to initiate the necessary reduction of carbon emissions.

Development of an early design tool for the sustainability assessment of positive energy districts: methodology, implementation and case-studies

The concept of Positive Energy District is one of the research ideas that embody the ambitions of decarbonization, renovation (both literal and in a wider perspective) and inclusivity for the urban environment portrayed in the EU activities. In this framework, the paper presents a modeling and simulation tool which allows for an early-design depth to be applied in the field of Positive Energy Districts renovation design and integrated performance assessment. The work aims at creating a tool for stakeholders and designers that would allow them to: a) Calculate carbon impacts along the life cycle for different technical systems and materials used for retrofitting; b) Compute use stage carbon emissions, including import-export of electricity; c) Computations of PED carbon emission balances, along the expected useful life of the district computing both embodied and the use stage carbon emissions. The tool has been created as a spreadsheet including typical profiles of energy use per building archetype, with the inclusion of available and free Life Cycle Assessment data within the life cycle carbon assessment and aims at jointly developing use stage and life cycle considerations. It was tested on a district case studies in the EU.

Aquatic Carbon Export and Dynamics in Mountain Headwater Streams of the Western U.S.

AbstractMountain headwater streams actively cycle carbon, receiving it from terrestrial landscapes and exporting it through downstream transport and gas exchange with the atmosphere. Although their importance is now widely recognized, aquatic carbon fluxes in headwater streams remain poorly characterized. In this study, aquatic carbon fluxes were measured in 15 mountain headwater streams and were used in a geostatistical analysis to determine how landscape characteristics influence aquatic carbon fluxes. In‐stream sensors were used to measure fluorescent dissolved organic matter (fDOM) (a surrogate for dissolved organic carbon (DOC)) at a subset of sites to characterize dynamic responses to hydroclimatic events. Wetlands have a positive influence on aquatic carbon fluxes, whereas perennial snow/ice has the opposite effect, reflecting differences in soil organic matter content in these landscapes. Mean annual temperature (MAT) has a complex influence on DOC, with peak DOC exports in basins with MAT of 0–2°C. Precipitation has a strong positive influence on aquatic carbon fluxes, and declining snowpacks in the western United States may reduce future aquatic carbon exports. fDOM (and by implication DOC) and showed strong dynamic responses to snowmelt and rain events, with fDOM increasing and decreasing during events. Combining results from this study with those from a companion study on CO2 exchange yielded total aquatic carbon fluxes of 7.2–15.7 g C m−2 yr−1 (median = 12.22), similar to those from forests and peatlands. Given net ecosystem production (NEP) of similar magnitude, NEP calculations that do not account for losses via the aquatic pathway can substantially overestimate terrestrial carbon sequestration.

Carbon budgets at the component scale and their impacts on design choices: the façade as a case study

In accordance with the Paris agreement, the Swiss Climate Strategy (SCS) defines the net-zero target to be reached before 2050, which demands for a thoughtful carbon budget allocation between the different contributors. Ongoing normalization tasks are currently defining life cycle carbon budgets at the building scale aligned with the SCS. While recent research has provided promising methodologies to break down a whole building’s carbon budget, SCS-aligned budgets cannot be calculated at the component scale yet. Having the ability to define carbon budgets at the components’ level could support a carbon-responsible design process by reducing the scope of the design problem: the idea is to ensure that the cumulative impact of all the building components (calculated per building energy reference area) remains below the allowed building carbon budget based on SCS targets. This would provide a straightforward link between SCS and carbon budgets at the component scale, a scale at which many decisions need to be taken during the design process. Moreover, based on the set SCS net-zero objectives to be reached by 2050, the carbon budget, whether for buildings or for their components, will have to decrease annually, thereby affecting design flexibility, i.e. the number of design solutions that can still comply with the building’s carbon budget on any specific year. The research presented in this paper aims to provide a framework able to set carbon budgets at the components’ scale and start discussing the consequences of such carbon budgets on façade design flexibility until 2050.

Carbon footprint of a conventional wastewater treatment plant: An analysis of water-energy nexus from life cycle perspective for emission reduction

Reducing greenhouse gas (GHG) emissions is of far-reaching implications for the sustainable development of a conventional domestic wastewater treatment plant (WWTP). GHG emissions of the WWTP in different working loads were monitored to quantify the influence of critical processes on GHG emissions and shed light on the relations between direct and indirect GHG emissions with the water-energy nexus. The life cycle carbon footprint of the WWTP was assessed to find the most critical impact factor. A conceptual model of direct and indirect GHG emissions was established based on the water-energy nexus and life cycle assessment (LCA). Results showed that direct GHG emissions were highest in medium working load in May. While high indirect GHG emissions were in February, with the highest working load. Methane (CH4) emission rates, from 44.39 ± 42.49 to 4.94 ± 2.29 kg CO2e·d−1, decreased along the treatment processes due to oxidation. Dissolved CH4 in wastewater mainly came from the influent that was 0.08 ± 0.04 kg CH4·d−1. The increase of nitrous oxide (N2O) emissions and dissolved N2O occurred in the secondary treatment stage and was affected by the C/N ratio. The operation and maintenance phase had the most significant carbon footprint due to 86.4% of indirect GHG emissions from electricity usage through LCA. Electricity usage and glucose dosing were significantly correlated with N2O emissions but had no contribution to CH4 emissions. The conceptual model qualitatively demonstrated that direct and indirect GHG emissions reduced as electricity usage decreased based on the water-energy nexus. This study provided new insight into the analysis of GHG emissions from WWTPs.

Decoupling economic growth from building embodied carbon emissions in China: A nighttime light data-based innovation approach

The contribution of the construction sector is indispensable for the realization of China's carbon peaking and carbon neutrality goals. However, existing studies have focused on the decoupling relationship between GDP and building life cycle carbon emissions, neglecting the utilization of Night Time Light data (NTL). The research question of this research is how to describe the decoupling relationship between Economic Growth (EG) and Building Embodied Carbon emissions (BECs) by introducing NTL. To tackle this question, the carbon emission coefficient approach is used to calculate BECs first. Then, both GDP and NTL are selected to reflect EG. The Tapio model is utilized to examine the regional and temporal evolution of China's inter-provincial decoupling performance. The main findings are as follows: 1) the number of provinces that achieved decoupling status in China is increasing, and progress has been made in BECs reduction. 2) There are significant regional differences in the decoupling of China's BECs. Particularly, most of the provinces in the south of the Hu Huanyong line show a negative decoupling for the year 2020 due to the impact of COVID-19. 3) The long-term decoupling results of GDP and NTL are consistent, while the short-term decoupling results obtained via NTL are more accurate. The study can enrich the application of NTL in the field of BECs, and provide a basis for the Government to set effective carbon reduction targets and pathways.

Building information modelling-enabled multi-objective optimization for energy consumption parametric analysis in green buildings design using hybrid machine learning algorithms

Green buildings (GB) have been widely promoted in various nations. However, the post occupancy evaluation suggests many GB cannot well fulfill the expected targets. To overcome the mismatch among GB’s multi-objectives, this paper develops an efficient and intelligent hybrid method using BIM-DesignBuilder (BIM-DB), Grey wolf optimization (GWO), random forest (RF) and non-dominated sorting genetic algorithm II (NSGA-II) to achieve the optimization of design parameters. The BIM model and DB simulation tool were used to obtain data samples of envelope and air conditioning system design parameters, and their life cycle carbon emission (LCCE), economic cost (EC) and predicted mean vote (PMV). The RF model was used to achieve high precision prediction. The GWO was used in the hyper-parameter optimization. The NSGA-II algorithm was applied to multi-objective optimization to obtain optimal design parameters. A building case shows: (1) The RF model had an excellent prediction performance for LCCE, EC and PMV. (2) BIM-DB can be used to obtain low error and high reliability building simulation data sets. (3) The RF-NSGA-II intelligent algorithm can reduce the LCCE of the building in the entire cycle by 16.6%, reduce the EC per square meter by 2.0%, and greatly improve the thermal comfort by 18.3%, representing good application value. This research provides a way of thinking for the multiobjective optimization of green buildings from the perspective of data mining and guidance for the parameter selection of the envelopes and air conditioning systems of new and existing buildings to more scientifically and effectively design green buildings.

Analysis of the Impact of Photovoltaic Curtain Walls Replacing Glass Curtain Walls on the Whole Life Cycle Carbon Emission of Public Buildings Based on BIM Modeling Study

The construction industry plays a crucial role in achieving global carbon neutrality. The purpose of this study is to explore the application of photovoltaic curtain walls in building models and analyze their impact on carbon emissions in order to find the best adaptation method that combines economy and carbon reduction. Through a carbon emissions calculation and economic analysis of replacing photovoltaic curtain walls on a large public building in Zhenjiang, China, the results showed that after replacing glass curtain walls with photovoltaic curtain walls, the carbon emissions during the construction operation stage decreased by 30.74%, but the carbon emissions during the production and transportation stage of building materials increased by 10.48%. The carbon emissions throughout the entire life cycle of the building have been reduced by 20.99%. This indicates that photovoltaic curtain wall technology has the potential to reduce building carbon emissions. Further promoting the development of production technology and sales routes for photovoltaic curtain walls and accelerating the improvement of carbon trading systems can further improve the carbon emission reduction effect of buildings. This study provides practical reference for public buildings in similar areas and guidance for reducing carbon emissions in the future.

Air source assisted ground source composite heat pump system: life cycle carbon emissions and simulation analysis

ABSTRACT Air source assisted ground source composite heat pump (DSHP) system is a combination of ground source heat pump (GSHP) and air source heat pump (ASHP) that makes use of both underground and outdoor temperatures to ensure long-term stability and reliability. The development of a carbon emission model for DSHP system involved a life-cycle assessment (LCA). This model was used to analyze the energy savings of DSHP in two different areas of China Nanjing and Hohhot. In both cases, an office building with an area of 3040 m2 was used as the subject of the study. The evaluation of energy savings using TRNSYS dynamic simulations revealed that the operation stage accounts for about 75%-85% of the carbon emission in the entire life cycle assessment of DSHP systems, Among them, refrigerant leakage produces a carbon footprint of more than 20%. The installation stage accounts for about 10% of the emissions, while the adjustment of the power energy structure during operation is crucial in achieving energy savings and emission reductions. A comparison study shows that DSHP can lower emissions by up to 23% when compared to traditional air conditioning systems like gas boiler and chiller system (BLR-CH). The use of DSHP is therefore a highly effective alternative for organizations committed to reducing their carbon footprint.

Life cycle carbon assessment of decarbonising UK’s hard-to-treat homes: A comparative study of conventional retrofit vs EnerPHit, heat pump first vs fabric first and ecological vs petrochemical retrofit approaches

Life cycle carbon assessment of decarbonising UK’s hard-to-treat homes: A comparative study of conventional retrofit vs EnerPHit, heat pump first vs fabric first and ecological vs petrochemical retrofit approaches

Ecological Burden of Modern Surgery: An Analysis of Total Knee Replacement's Life Cycle.

It is estimated that surgical procedures account for 20%-30% of the greenhouse gases emissions from health-care systems. Total knee replacements (TKR) are one of the most frequently performed procedures in orthopaedics. The aim of this study was to identify and quantify the environmental impacts generated by TKRs, the factors that generate the most emissions, and those that can be easily modified. To calculate the life cycle carbon footprint of a posterior stabilized cemented TKR performed in a single orthopaedic surgery department, 17 TKRs performed between October 12 and 20, 2020 by 4 senior surgeons were analysed. The analysis of the life cycle included the manufacture of the implant, from raw materials to distribution; the journey made by patients and staff; and the surgery including all consumables required to facilitate the procedure. The overall life cycle carbon footprint of a single TKR was 190.5 kg of CO2. This consisted of 53.7 kg CO2 (28%) for the manufacture of the prosthesis, 50.9 kg CO2 (27%) for travel, 57.1 kg CO2 (30%) for surgery, and 28.8 kg CO2 (15%) for waste management. This is comparable to a New York-Detroit direct flight. The production of a total knee prosthesis, throughout its life cycle, generates emissions with important consequences on the environment and therefore on our health. Although much data are currently missing to make precise estimates, and especially regarding benefits in terms of patient function and its impact on carbon emissions, these data serve as a starting point for other more detailed or comparative studies.