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Cement and concrete are essential for global development. However, cement manufacture is responsible for around 7–8% of global greenhouse gas emissions, with significant growth anticipated. Beyond efficiencies in cement manufacturing, other strategies for using less cement in construction through applying the principles of efficient design, circular economy and reuse also have the potential to reduce emissions. A further option is to move towards cements with different compositions and inherently lower embodied carbon dioxide. This paper focuses on these materials and the challenges to their widespread adoption, drawing mainly on applied research, trials and standardisation activities conducted in the UK and the EU. In addition to modification of standards, basic technical and practical information such as strength development curves, durability, site considerations and a shared broad body of evidence are key for specifiers to consider when using any new cement. The paper describes the role of standards and specifications and the underpinning information (applied research, published case studies and experience) essential in getting any new cement adopted. It also shows how a range of evidence from research and application can feed into a simple conceptual model and evidence base. [ABSTRACT FROM AUTHOR]

The roles digital media-technologies play in raising public issues relating to emerging technologies and their potential for engaging publics with science and policy assessments is a lively field of inquiry in Science and Technology Studies (STS). This paper presents an analysis of controversies over proposals for the large-scale removal of atmospheric carbon dioxide (CDR). The study combines a digital method (web-querying) with document analysis to map debates about two CDR approaches: bioenergy with carbon capture and storage (BECCS) and afforestation. In the first step, we locate actors using the web to engage with BECCS and afforestation and map their alignments in relation to competing framings of CDR. In a second step, we examine the devices deployed by UK-based actors to evidence and contest the feasibility of BECCS and afforestation. Our analysis shows that policy distinctions between "natural" and "engineered" CDR are used flexibly in practice and do not map neatly onto actor engagement with BECCS and afforestation. We highlight the predominance of cross-cutting techno-economic expertise and argue that framings of CDR as a solution to governing climate change may contribute to public disengagement from climate policy processes. The paper reflects on methods for studying controversies, publics, and issues emerging around processes of technoscientific assessment. [ABSTRACT FROM AUTHOR]

Thousands of clinical trials are conducted globally each year. Yet, little is known about their environmental impact. This paper presents the results of a high-level literature review of the carbon footprint of clinical trials. Five papers were identified and their contents summarised qualitatively. All papers were authored by UK researchers. Carbon footprint metrics from 14 trials were presented in carbon dioxide equivalents (CO2e). Emissions were broken down by three broadly defined clinical trial activities: operations, travel, and supplies. Recommen - dations for carbon reduction are discussed. The review showed a dearth of publications on greenhouse gas emissions generated by clinical trials. More work in this area is needed to achieve sustainable, low carbon clinical research. [ABSTRACT FROM AUTHOR]

This paper analysed operational CO2 emissions from electricity grid interaction in photovoltaic prosumer dwellings in South Wales, UK. Operational CO2 emissions were quantified in four prosumer dwellings aiming to analyse (1) the differences in the result when time-varying data and static emission factors are used, and (2) the association of load-matching indicators to the results. Electricity balance data were obtained through monitoring (April 2020 to March 2021), and three sources for the grid's CO2 intensity were considered: (1) UK nationwide average time-varying values (UK), (2) South Wales (SW) average time-varying values and (3) the UK Government's official CO2 emissions factor (EF) for the study period. UK and SW grid CO2 intensity were obtained as dynamic data flows in a 30 min resolution, whereas EF was a year constant. Gross CO2 emissions calculated using SW data reached the highest emissions results: between 67.5% and 69.3% higher than the results obtained using the UK time-varying data, and between 41.1% and 45.1% higher than using the EF. The differences between the obtained yearly net emissions using dynamic data and the EF in each studied dwelling ranged between 6.2% and 294%. Results also show that the definition of geographic boundaries for location-based approach calculations can significantly affect the obtained emissions values. [ABSTRACT FROM AUTHOR]

The year 2020 has seen the world gripped by the effects of the COVID‐19 pandemic. It is not the first time, nor will it be last, that our increasingly globalized world has been significantly affected by the emergence of a new disease. In much of the Northern Hemisphere, the academic year begins in September, and for many countries, September 2020 marked the return to full schooling after some period of enforced closure due to COVID‐19. In this paper, we focus on the airborne spread of disease and investigate the likelihood of transmission in school environments. It is crucial to understand the risk airborne infection from COVID‐19 might pose to pupils, teachers, and their wider social groups. We use monitored CO2 data from 45 classrooms in 11 different schools from within the UK to estimate the likelihood of infection occurring within classrooms regularly attended by the same staff and pupils. We determine estimates of the number of secondary infections arising via the airborne route over pre/asymptomatic periods on a rolling basis. Results show that, assuming relatively quiet desk‐based work, the number of secondary infections is likely to remain reassuringly below unity; however, it can vary widely between classrooms of the same school even when the same ventilation system is present. Crucially, the data highlight significant variation with the seasons with January being nearly twice as risky as July. We show that such seasonal variations in risk due to changes in ventilation rates are robust and our results hold for wide variations in disease parameterizations, suggesting our results may be applied to a number of different airborne diseases. [ABSTRACT FROM AUTHOR]

Nuclear power has the potential to provide significant amounts of reliable electricity generation without carbon dioxide emissions. Disposing of radioactive waste is, however, an ongoing challenge, and if it is to be buried, the characterisation of the regional groundwater system is vital to protect the anthroposphere. This aspect is understudied in comparison to the engineered facility; yet, selecting a suitable groundwater setting can ensure radionuclide isolation hundreds of thousands of years beyond that provided by the engineered structure. This paper presents a multi-faceted scoping tool to quantitatively assess, and directly compare, the regional hydrogeological prospectivity of different groundwater settings for disposal at an early stage of the site selection process. The scoping tool is demonstrated using geological data from three distinct UK groundwater settings as a case study. Results indicate a significant difference in the performance potential of different regional groundwater settings to ensure long-term waste containment. [ABSTRACT FROM AUTHOR]

The UK government is committed to reducing carbon dioxide emission levels by 80%, comparative to the 1990 baseline, by 2050. 'Nearly-zero-energy buildings' (nZEBs) were introduced by the Energy Performance Building Directive (recast) in 2010 as a realistic solution to the intrinsic environmental debt associated with most existing buildings. This paper aims to carry out a life-cycle cost (LCC) analysis to identify what is a cost-optimal level and how best to achieve this by examining and focusing on the exploration of realistically applicable energy-efficient measures and retrofit scenarios for a typical UK dwelling. A sensitivity analysis is used to identify uncertainty and provide the expected economic benefits and losses of the applied scenarios over their respective lifetimes. It was established that the total LCCs of all the retrofit scenarios were in fact lower than that of the baseline scenario (i.e. not retrofitting the property) over the 30-year study period. Furthermore, it was found that the cost-optimal level for the retrofit of a typical UK residential dwelling is 75 (kWh/m2)/year; meanwhile, the UK's current nZEB target stands at 44 (kWh/m2)/year, meaning that there is a gap between the current nZEB target and the calculated cost-optimal level. [ABSTRACT FROM AUTHOR]

There is currently great interest in the creation of sustainable and liveable cities, both in the UK and globally. While it can be argued that good progress is being made in thinking about the needs of future cities, meeting these needs and aspirations in practice poses major challenges of understanding and measurement (what is meant by these terms and how can progress towards their achievement be measured?), complexity (cities are complex systems of systems with many interacting parts) and resilience (will interventions made today be relevant and effective in the future?). The Liveable Cities research programme created a systematic decision-making method for improving urban sustainability and liveability: the Liveable Cities Method (LCM). The LCM prioritises four criteria – individual and societal well-being, resource security, resource efficiency and carbon dioxide emissions as a proxy for environmental harm – in an interconnected framework and assesses the need for, and the resilience of, interventions designed to move cities towards improved sustainability and liveability. This paper illustrates the LCM through an example intervention made to the city of Birmingham, UK, and highlights how addressing sustainability and liveability in this way offers unique opportunities for the UK civil engineering profession to lead thinking among urban professionals. [ABSTRACT FROM AUTHOR]

Passive solar systems are often designed primarily with efficiency in mind, and research efforts are concentrated towards gaining an increase in performance. However, due to the multiple materials used, their manufacturing processes, a lifespan that is usually shorter than that of buildings that these systems are applied to and the waste generated when they have reached the end of their useful life, a more holistic approach to the design and performance of these systems should be adopted. This paper reports on the environmental impact of a unique integrated collector–storage solar water heater design, experimentally tested under Scottish weather conditions, considering circular economy and reuse potential. As such, the material flows and components used are mapped against the life-cycle stages of existing European standards while ensuring an optimal efficiency. End-of-life considerations and design for disassembly and reuse are assessed and discussed. Energy payback times of 4·5 and 4·6 years can be realised for a circular and a linear approach, respectively. Operational carbon dioxide savings, which far outstrip the embodied carbon dioxide, demonstrate carbon dioxide payback times of just 7 months, when replacing an electric system. The results show that a holistic design, which promotes circular economy principles, does not compromise efficiency and economic viability. [ABSTRACT FROM AUTHOR]

This paper quantifies the impacts of policy objectives on the composition of an optimum new passenger vehicle fleet. The objectives are to reduce individually absolute energy use and associated emissions of CO 2 , NO x and PM 2.5 . This work combines a top down, diversity-led approach to fleet composition with bottom-up models of 23 powertrain variants across nine vehicle segments. Changing the annual distance travelled only led to the smallest change in fleet composition because driving less mitigated the need to shift to smaller vehicles or more efficient powertrains. Instead, managing activity led to a ‘re-petrolisation’ of the fleet which yielded the largest reductions in emissions of NO x and PM 2.5 . The hybrid approach of changing annual distance travelled and increasing willingness to accept longer payback times incorporates management of vehicle activity with consumers’ demand for novel vehicle powertrains. Combining these changes in behaviour, without feebates, allowed the hybrid approach to return the largest reductions in energy use and CO 2 emissions. Introducing feebates makes low-emitting vehicles more affordable and represents a supply side push for novel powertrains. The largest reductions in energy use and associated emissions occurred without any consumer behaviour change, but required large fees (£79–99 per g CO 2 /km) on high-emitting vehicles and were achieved using the most specialised fleets. However, such fleets may not present consumers with sufficient choice to be attractive. The fleet with best diversity by vehicle size and powertrain type was achieved with both the external incentive of the feebate and consumers modifying their activity. This work has a number of potential audiences: governments and policy makers may use the framework to understand how to accommodate the growth in vehicle use with pledged reductions in emissions; and original equipment manufacturers may take advantage of the bottom-up, vehicle powertrain inputs to understand the role their technology can play in a fleet under the influence of consumer behaviour change, external incentives and policy objectives. [ABSTRACT FROM AUTHOR]

Carbon Capture, Utilisation and Storage (CCUS) is a key element in the United Kingdom Government strategy for reducing carbon dioxide (CO 2) emissions. The UK aims to capture and store 10 million tonnes of CO 2 each year by 2030. At each stage in the CCUS infrastructure, accurate measurement of the CO 2 flow rate is required, over a range of temperatures, pressures, flow rates and fluid phases, where the flow measurement must be validated through a credible traceability chain. The traceability chain provides the underpinning confidence required to verify meter performance, financial and fiscal transactions, and environmental compliance. The UK equivalent of the EU Emissions Trading System (EU ETS) specifies a maximum uncertainty value for CO 2 flow measurement. Accordingly, the provision of accurate and traceable flow measurement of CO 2 is a prerequisite for an operational CCUS scheme. However, there are currently no CO 2 flow measurement facilities, nationally or internationally, providing traceable flow calibrations of gas phase, liquid/dense phase and supercritical phase CO 2 that replicate real-world CCUS conditions. This lack of traceable CO 2 gas and liquid flow measurement facilities and associated flow measurement standards is a significant barrier to the successful implementation of CCUS projects worldwide. This paper presents an overview of the traceability chain required for CO 2 flow measurement in the UK and globally. Current challenges are described along with potential solutions and opportunities for the flow measurement community. • Presents an overview of the measurement challenge arising from the physical properties of CO 2. • Discusses the role of flow measurement in enabling CCUS. • Identifies the flow measurement technologies for CCUS. • Highlights the current traceability chain and regulations with respect to CO 2. [ABSTRACT FROM AUTHOR]

The UK's 2050 net-zero emission target is one of the most ambitious goals in the world. Organisations should play a vital role by communicating a sufficient level of carbon emission information with the stakeholders. Motivated by the necessity of measuring the level of carbon disclosure, this paper provides a unique carbon emission disclosure measurement based on a sample of UK firms from 2013 to 2019. We apply different methods to assess the validity and reliability of our developed measurement. The results suggest that our measurement captures the actual CO2 emission, including scope 1, scope 2, and also captures the environmental, social and governance (ESG) score. Additionally, we explore the association between capital expenditure, corporate governance and the level of carbon emission disclosure. Further, the results show a positive relationship between capital expenditure and carbon emission disclosure. Also, there is a significant positive relationship between internal governance and carbon emission disclosure. Moreover, the analysis suggests that internal governance strengthen the relationship between capital expenditure and carbon emission disclosure. We also use quantile regression, and the findings show that capital expenditure and internal governance have a positive impact on carbon emission disclosure under all quantiles. Our data suggest that capital expenditure declines within the UK by around 53% over the last six years. Following the reduction in capital expenditure, the results demonstrate 39% decline in the CO2 emission level. The results also indicate that for every $1 million capital expenditure, approximately 2.75 Metric tons of carbon dioxide (MtCO2) emissions increase. Business investment is around 70% of the UK's total investment. Therefore, the reduction in capital expenditure is one of the primary reasons that might explain the decrease in the UK's overall CO2 emission level. The unique findings of this paper are relevant to the government, management and standard-setters. • Novel measurement of corporate carbon emission disclosure. • Our novel carbon disclosure measurement encapsulates actual CO2 emission. • This measure also captures Environmental, Social and Governance (ESG) score. • Capital expenditure is positively related with carbon emission disclosure. • Internal governance moderates this relationship. [ABSTRACT FROM AUTHOR]

Over the past decade there has been significant pressure to minimise emissions and safety risks related to commercial driving. This pressure to meet the triple bottom line of cost, environment, and society has often resulted in the rapid application of vehicle technologies designed to mitigate undesired effects. Often the cognitive and behavioural effects of technologies on the commercial driver have not received in-depth analysis to determine comprehensive viability. As such, this paper aims to identify a timescale for implementation for future technologies for UK road freight, and likely associated human factors issues, improving upon the currently employed 'trial-and-error' approach to implementation which may carry high economic, environmental, safety-related risk. Thought experiments are carried out to broadly explore these future systems. Furthermore, this work aims to examine whether technology alone will be enough to meet future CO2 reduction targets, and assess the role of behavioural and systems interventions for future research. [ABSTRACT FROM AUTHOR]

There is a growing body of evidence concerning the energy efficiency performance of domestic buildings in the UK, driven by policy-based agendas, such as the need for zero carbon dioxide homes by 2016 for new build homes, and the prior Green Deal and energy company obligation for sustainable refurbishment. While there have been a number of studies funded and results presented in this area, little work has been done to understand the drivers, practices and issues of data collection and analysis. There are a number of major building performance evaluation (BPE) studies in the UK, yet behind many of these research projects are practical issues of data loss, experimental error, data analysis variances and resident issues that are common when studies move from the actual to the living lab. In this paper the issues of domestic energy are addressed by leading BPE practitioners in the UK. They identify issues of client demands, technical failure, costs and implementation. This work provides insights of both academic and industry-based practitioners and considers, not only the practicalities of building performance studies, but also issues for these types of studies in the future. [ABSTRACT FROM AUTHOR]

Carbon Capture and Storage (CCS) is an essential tool in the fight against climate change. Any prospective storage site must meet various criteria that ensure the effectiveness, safety and economic viability of the storage operations. Finding the most suitable site for the storage of the captured CO 2 is an essential part of the CCS chain of activity. This work addresses the site selection of a second site for the Acorn CCS project, a project designed to develop a scalable, full-chain CCS project in the North Sea (offshore northeast Scotland). This secondary site has been designed to serve as a backup and upscaling option for the Acorn Site, and has to satisfy pivotal project requirements such as low cost and high storage potential. The methodology followed included the filtering of 113 input sites from the UK CO 2 Stored database, according to general and project-specific criteria in a multi-staged approach. This criteria-driven workflow allowed for an early filtering out of the less suitable sites, followed by a more comprehensive comparison and ranking of the 15 most suitable sites. A due diligence assessment was conducted of the top six shortlisted sites to produce detailed assessment of their storage properties and suitability, including new geological interpretation and capacity calculations for each site. With the new knowledge generated during this process, a critical comparison of the sites led to selection of East Mey as the most suitable site, due to its outstanding storage characteristics and long-lasting hydrocarbon-production history, that ensure excellent data availability to risk-assess storage structures. A workshop session was held to present methods and results to independent stakeholders; feedback informed the final selection criteria. This paper provides an example of a criteria-driven approach to site selection that can be applied elsewhere. • CO 2 storage site selection for the Acorn CCS project in the North Sea. • Criteria-driven approach based on geological, economic, and safety aspects. • Multi-staged methodology including filtering, comparison and ranking of sites. • East Mey selected thanks to its storage characteristics and hydrocarbon history. [ABSTRACT FROM AUTHOR]

• Assessed CO 2 shipping as a global decarbonisation strategy for future developments. • Identified technical and safety challenges encountered during in CO 2 shipping chain. • Evaluated the environmental impact of shipping emissions in the transport chain. • Summarised emission control technologies as a key enabler in the CO 2 shipping chain. Carbon Capture, Utilisation and Storage (CCUS) can reduce greenhouse gas emissions for a range of technologies which capture CO 2 from a variety of sources and transport it to permanent storage locations such as depleted oil fields or saline aquifers or supply it for use. CO 2 transport is the intermediate step in the CCUS chain and can use pipeline systems or sea carriers depending on the geographical location and the size of the emitter. In this paper, CO 2 shipping is critically reviewed in order to explore its techno-economic feasibility in comparison to other transportation options. This review provides an overview of CO 2 shipping for CCUS and scrutinises its potential role for global CO 2 transport. It also provides insights into the technological advances in marine carrier CO 2 transportation for CCUS, including preparation for shipping, and in addition investigates existing experience and discusses relevant transport properties and optimum conditions. Thus far, liquefied CO 2 transportation by ship has been mainly used in the food and brewery industries for capacities varying between 800 m3 and 1000 m3. However, CCUS requires much greater capacities and only limited work is available on the large-scale transportation needs for the marine environment. Despite most literature suggesting conditions near the triple-point, in-depth analysis shows optimal transport conditions to be case sensitive and related to project variables. Ship-based transport of CO 2 is a better option to decarbonise dislocated emitters over long distances and for relatively smaller quantities in comparison to offshore pipeline, as pipelines require a continuous flow of compressed gas and have a high cost-dependency on distance. Finally, this work explores the potential environmental footprint of marine chains, with particular reference to the energy implications and emissions from ships and their management. A careful scrutiny of potential future developments highlights the fact, that despite some existing challenges, implementation of CO 2 shipping is crucial to support CCUS both in the UK and worldwide. [ABSTRACT FROM AUTHOR]

A range of technology and policy actions can be put in place to reduce carbon emissions from passenger cars, this paper aims to prioritise between them, based on their likely impact and uncertainty. Formal sensitivity analysis techniques are used for the first time to determine the relative importance of factors affecting future emissions from passenger vehicles in Great Britain. The two most important actions to limit future life-cycle CO 2 emissions involve shifting to electric vehicles and limiting trends towards larger and more powerful vehicles. According to our analysis over 80% of the uncertainty in future cumulative CO 2 emissions can be attributed to uncertainty in electric vehicle uptake and vehicle size and power. These variables are a priority for transport policy makers. The analysis also highlights variables of comparatively low importance; these include the share of hybrid electric vehicles, the Rebound Effect and the utilisation factor of PHEVs. • Sensitivity analysis is used to prioritise emissions reductions from passenger cars. • Sobol indices are applied to future transport emissions for the first time. • >80% of future uncertainty in CO 2 is from the uptake of EVs and vehicle size & power. • Increasing EV uptake and limiting vehicle size and power are important priorities. [ABSTRACT FROM AUTHOR]

• B2.4E10 fuel blend both increase renewable content in fuel and reduce harmful emissions. • Drive cycles cover transient driving behaviour better than steady-state scenarios. • Biodiesel has low WTT carbon dioxide emissions, but increases harmful emissions. • Binary blends with ethanol has largest harmful emission reduction. • Future use of B2.4E10 requires investment into second generation ethanol production. Reduction in fossil fuels, contributing to greenhouse gases, and improvement of air quality from vehicle emissions is of growing concern worldwide. This has led to the introduction of several binding and non-binding agreements, such as the Renewable Energy Directive to increase the renewable content of fuel for transportation, the carbon dioxide emissions standards to limit the amount of carbon dioxide emissions from vehicles and the Euro Standards to limit the amount of emissions harmful to human health in the exhaust. However, the influence of the fuel composition on hazardous exhaust emissions is a complex, and often contradictory, relationship between factors such as the fuel properties, combustion characteristics and engine load. Therefore policy implemented to improve one aspect, such as a reduction in carbon dioxide, can have a detrimental effect on another such as increased NO x emissions. This paper analyses, in a holistic manner, the impact on carbon dioxide and harmful emissions from transient compression ignition engines when increasing the renewable content of the fuel to meet the renewable energy targets. The analysis is based on a model developed from a rigorous Design of Experiment methodology used to determine the complex relationship between renewable fuel content and exhaust emissions (carbon monoxide, carbon dioxide and nitrogen oxides). Unlike other studies, the results were collected from a transient engine cycle, the World Harmonised Light vehicle Test Procedure, rather than steady state conditions, thus the results are more applicable to the real world. The results generally show that as the amount of ethanol is increased then the NO x and CO emissions decrease compared to current pump diesel. Increasing the biodiesel content generally increases the CO and CO 2 emissions from the engine. For practical reasons a ternary blend is required to minimise the diesel engine emissions whilst meeting the UK's future renewable content target. A blend of B2.4E10 was found to be the optimum compromise between renewable content and engine emissions. However, for this to be achieved the UK will have to invest in second and third generation ethanol. [ABSTRACT FROM AUTHOR]

The Paris Agreement on climate change has calls for urgent, radical, and transformative actions in mitigation and adaptation, particularly in terms of reducing greenhouse gas (GHG) emission. There are many terms used to describe the process of reducing GHGs, including decarbonization, low carbon development (LCD) or low carbon transition (LCT). The conceptualization of these terms remains puzzling and there has not been any consensus to explain the meaning and their interrelationship. Clearer definition and conceptual boundaries are necessary to improve the coherence of overarching practices to cut CO 2 emission. The paper aims to review key concepts related to climate change mitigation related to the reduction of CO 2 and efforts toward net-zero emission in the academic literature, by (1) examining progress of the literature over time, (2) identifying geographical locus and sectoral focus of the literature, (3) determining the interrelationships between the key concepts. We use a Systematic Literature Review (SLR) method for data collection by selecting peer-reviewed literature from Scopus and analyzing the data with content analysis and bibliometric analysis. The findings are, firstly, the publications of the literature are influenced by global and national climate change policies and the interest of scholars affiliated to institutions from major emitter countries. Therefore, the literature is mostly originating from countries that emit the most CO 2 while also implement mitigations to reduce CO 2 emission. Secondly, China is the country where studies are mostly focused and also where the authors are affiliated/located. However, publications from the United Kingdom are cited the most. Thirdly, there are three clusters of literature found, namely that LCD and LCT are the terms used to identify visions for climate mitigation, while decarbonization is the actions and processes to achieve either LCD or LCT (as the visions). • The dynamic of climate change policies influence the literature trend. • The literature is mostly originating from major CO 2 emitter. • Low carbon development and low carbon transition are visional terms. • Decarbonization indicates the processes of decoupling CO 2 to achieve the visions. [ABSTRACT FROM AUTHOR]