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We present the results of a study on the climate forcing effects of replacing coal for power generation in the United Kingdom (UK) with wood pellets produced in northern Ontario, Canada. Continuous wood pellet production from two biomass sources were considered: fiber from increased harvesting of standing live trees (stemwood scenario) and from harvest residue provided by ongoing harvesting operations (residue scenario). In both scenarios, biomass was collected from harvesting operations in two forest management units (FMUs) with contrasting harvest residue treatments: natural decay of slash piles in the Hearst FMU and slash pile burning in the Kenora FMU. Life cycle emissions associated with wood pellets were assessed for production, transportation, and combustion to replace coal at a hypothetical power generating station in the UK. Greenhouse gas (GHG) emissions and removals in wood pellet and coal scenarios were assessed using two methods: global warming potential (GWP)-based mass balance and dynamic life cycle assessment (LCA) approaches. In the stemwood scenario, climate change mitigation from replacing coal with wood pellets was not achieved within the study timeline (2020–2100). In the residue scenario, immediate climate change mitigation was achieved with fiber sourced from the Kenora FMU where the current practice is to burn slash piles; for the Hearst FMU, where slash is allowed to decompose in the forest, climate change mitigation occurred 11.6 and 3.1 years after biomass collection began, as assessed by the mass balance and dynamic LCA methods, respectively. Factors affecting mitigation potential in the studied scenarios are discussed. [ABSTRACT FROM AUTHOR]

Maximising resource‐use efficiency, productivity and environmental sustainability are all fundamental requirements to raise global food production by ~70 per cent in order to feed a world population of ~9.7 billion people by 2050. Perhaps the most vital resource within our capacity to achieve this goal is our soil. Broadly, the fundamental question concerns whether or not satisfying this production demand will accelerate soil degradation, climate change, and the loss of soil carbon stocks. This paper builds upon the outputs of the UK Charity 'Food & Farming Futures' (chaired by Lord Curry of Kirkharle) virtual workshop held on 23 March 2021, entitled 'Capturing the Potential of Soil'. The event focussed on the link between soil health, primarily soil organic carbon (SOC), and agricultural productivity. Supported with commentaries by Professor Pete Smith (University of Aberdeen and Science Director of the Scottish Climate Change Centre of Expertise) and Professor Steve McGrath (Head of Sustainable Agricultural Sciences at Rothamsted Research), specific focus will be given to the research challenges within the UK's ability to improve soil health and functionality, the implementation priorities that must be held in order to improve soil management by 2050 and what the potential co‐benefits could be. These co‐benefits were scattered across environmental, economic, social and political issues, yet they may be summarised into six primary co‐benefits: developing natural capital, climate change mitigation, carbon trading, improvements in crop yield, animal performance and human health (nutrition). Additionally, the main barriers to improved soil management practices are centred on knowledge exchange‐regarding agri‐environmental techniques—whilst the most impactful solutions rely on soil monitoring, reporting and verification. [ABSTRACT FROM AUTHOR]

Universities and research centers are major producers of greenhouse gas emissions. There are growing calls from within the university sector for more proactive approaches to reducing the emissions associated with research and teaching and to contribute more to climate change mitigation. These debates have considered both the campus-based emissions of universities with large estates and the travel-related emissions associated with international staff and student communities. There is therefore an increasingly acute tension between universities' imperative to foster international networks and expand research and teaching on the one hand and their moral obligations to decarbonize on the other hand. In this article, we consider how academic departments can navigate this challenging paradox. Our study is based on an analysis of the Department of Geography at Durham University in the United Kingdom. We examine the major sources of emissions associated with this department and find that by far the largest contribution comes from air travel for staff research and student field trips. We then explore student perspectives and consider potential pathways toward a low-carbon model of research and teaching. Overall, we find a high level of support for decarbonization in the academy and potential for significant emissions reductions with minimal impact on quality of research and teaching. [ABSTRACT FROM AUTHOR]

Food systems contribute 23–42% of global greenhouse gas emissions. Reducing food system emissions is an essential component of climate change mitigation, and a system-wide approach, including production, processing, trade and demand-side transformations, will be needed. Long-term analysis of greenhouse gas (GHG) emissions of food supply is crucial for informing this transformation, and understanding the processes contributing to existing trends can reveal opportunities for future mitigation strategies. To address these needs we used data on food supply, trade and emission intensity to quantify changes in GHG emissions between 1986 and 2017 resulting from food supply in the United Kingdom (UK). Uniquely, the relative contributions of supply-side and demand-side changes to historical trends in food emissions were assessed, and the gap between current UK food consumption and EAT-Lancet recommended diets was used to estimate the additional GHG emission reductions that could be achieved by shifting to the Planetary Health Diet (PHD). It was estimated that in the UK, per-capita GHG emissions from food fell by 32% (from 4.6 tCO 2 eq/capita to 3.1 tCO 2 eq/capita) between 1986 and 2017. Of this 32% reduction, 21% was due to supply-side changes (a fall in emission intensity per unit of production due to increased efficiency of farming practices), 10% was due to demand-side changes (including dietary change and waste reduction), and 2% was due to changing trade patterns. Relative to the PHD, however, the average UK citizen still greatly over-consumes beef, lamb and pork, tubers and starchy vegetables and dairy products, and under-consumes vegetables, nuts, and legumes. It was estimated that by adopting the PHD, UK per capita food emissions could be reduced by a further 42% to 1.8 tCO 2 eq/capita. These results expose the historic contributions of both supply- and demand-side changes to reductions in GHG emissions from food, and highlight the underutilised potential of dietary change in contributing to mitigation of GHG emissions from food. [Display omitted] • UK per-capita food emissions fell by 32% between 1986 and 2017. • Supply and demand-side changes contributed to this reduction. • Adopting the Planetary Health Diet could reduce emissions of UK food supply by 42%. • This reveals the underutilised potential of dietary change as a mitigation strategy. [ABSTRACT FROM AUTHOR]

Highlights: [•] Presents time series of embodied emissions in UK construction from 1997 to 2011. [•] Contends that mitigation requires greater focus on material efficiency. [•] Identifies barriers to uptake of alternative materials, technologies and practices. [ABSTRACT FROM AUTHOR]

Countries' emission reduction commitments under the Paris Agreement have significant implications for lifestyles. National planning to meet emission targets is based on modelling and analysis specific to individual countries, whereas global integrated assessment models provide scenario projections in a consistent framework but with less granular output. We contribute a novel methodology for translating global scenarios into lifestyle implications at the national and household levels, which is generalisable to any service or country and versatile to work with any model or scenario. Our 5Ds method post-processes Integrated Assessment Model projections of sectoral energy demand for the global region to derive energy-service-specific lifestyle change at the household level. We illustrate the methodology for two energy services (mobility, heating) in two countries (UK, Sweden), showing how effort to reach zero carbon targets varies between countries and households. Our method creates an analytical bridge between global model output and information that can be used at national and local levels, making clear the lifestyle implications of climate targets. [ABSTRACT FROM AUTHOR]

Anaerobic digestion (AD) is at the interface of biowaste management, energy generation, food production and land-based carbon dioxide removal. Strategic deployment of AD requires careful scoping of interactions with prospective alternative biowaste management, energy generation technologies and land uses to ensure effective delivery of climate neutrality and circularity. There remains a need to assess the greenhouse gas (GHG) mitigation efficacy of AD in the context of future alternative (counterfactual) processes associated with differential rates of decarbonisation across energy, waste management and land (including agriculture) sectors. To address this gap, prospective life cycle assessment (LCA) is applied to AD deployment scenarios across three decarbonisation contexts, using the UK as an example. Food waste prevention and diversion to animal feed always achieve more GHG mitigation than AD, even with sustainable intensification of food and feed production. Compared with maize- or grass-biomethane transport fuel, solar electricity generation can avoid 16 times more fossil energy and afforestation can mitigate six times more GHG per hectare of land occupied. Transport biomethane is currently the most effective biogas use for GHG mitigation, but large-scale combustion of biogas for electricity or industrial heat generation is the most effective long-term option as transport is electrified and bioenergy carbon capture & storage (BECCS) is deployed. Prioritising waste prevention and diversion to animal feed (including via insect meal) instead of maximising AD deployment could simultaneously: offset an additional 10–15% of national GHG emissions; meet an additional 2–4% of national energy demand; free enough arable land to provide 20–21% of national recommended protein and kcal intake. However, AD is likely to remain the best option to manage substantial volumes of residual food wastes and manures that will remain available even if ambitious projections on waste prevention and diet change are realised. [Display omitted] • Consequential LCA of anaerobic digestion (AD) in future decarbonisation contexts • GHG mitigation efficacy of AD declines as energy & transport systems decarbonise • AD-crop cultivation is a highly inefficient land use for energy generation and GHG mitigation • Carbon capture & storage could maintain effective mitigation from large-scale biogas use • Sustainable niche for waste-AD alongside waste prevention & diversion to animal feed [ABSTRACT FROM AUTHOR]

Tourism results in the emission of climate-changing greenhouse gases. There has been limited destination-focused quantitative analysis of how tourism might be reshaped to reduce these emissions. This paper uses an extended tourism environmental satellite account methodology to examine the case of tourism in Wales, a United Kingdom region. It shows how an estimate of the emissions associated with trips to, and in, the region – internally, from the rest of the UK and from abroad – can contribute to regional aspirations to reduce greenhouse gas emissions. The analysis suggests that substantial emissions cuts are dependent upon technical developments outside of tourism itself. Four potential scenarios are devised and analysed. Scenario 1 shows the value of low carbon electricity production in cutting tourism-related emissions. Scenario 2 analyses a possible 50% fall in international arrivals and 10% increase in UK domestic arrivals – maintaining employment but reducing emissions. Scenario 3 shows the effects of switch from private to public transport modes for 50% of UK resident arrivals. Scenario 4 examines the outcomes of reducing ground transport emissions by using electric, biofuel and hybrid technologies. All scenarios cut emissions, none are highly effective and most are dependent on changes in society and governance. [ABSTRACT FROM AUTHOR]

Current economic instruments aimed at climate change mitigation focus mainly on CO2 emissions, but efficient climate mitigation needs to focus on other greenhouse gases as well as CO2. This study investigates the distributional effects of climate change taxes on households belonging to different income and lifestyle groups; and it compares the effects of a CO2 tax with a multiple GHG tax in the UK in terms of cost efficiency and distributional effects. Results show that a multi GHG tax is more efficient than a CO2 tax due to lower marginal abatement costs, and that both taxes are regressive, with lower income households paying a relatively larger share of their income for the taxes than higher income households. A shift from a CO2 tax to a GHG tax will reduce and shift the tax burden between consumption categories such as from energy-intensive products to food products. Consumers have different abilities to respond to the tax and change their behavior due to their own socio-economic attributes as well as the physical environment such as the age of the housing stock, location, and the availability of infrastructure. The housing-related carbon emissions are the largest component of the CO2 tax payments for low income groups and arguments could be made for compensation of income losses and reduction of fuel poverty through further government intervention. [ABSTRACT FROM AUTHOR]

Abstract: Carbon capture and storage (CCS) technology has been endorsed by the IPCC and the UK government as a key mitigation option but remains on the cusp of wide-scale commercial deployment. Here we present a technology roadmap for CCS, depicted in terms of external factors and short- and long-term pathways for its development, moving from a demonstration to commercialisation era. The roadmap was been developed through a two-phase process of stakeholder engagement; the second phase of this, a high level stakeholder workshop, is documented here. This approach has provided a unique overview of the current status, potential and barriers to CCS deployment in the UK. In addition to the roadmap graphics and more detailed review, five consensus conclusions emerging from the workshop are presented. These describe the need for a monetary CO2 value and the financing of carbon capture and storage schemes; the lack of technical barriers to the deployment of demonstration scale CCS plant; the role of demonstration projects in developing a robust regulatory framework; key storage issues; the need for a long-term vision in furthering both the technical and non-technical development of CCS. [Copyright &y& Elsevier]

• Timing of ecosystem restoration can influence its resilience to climate change. • This study quantifies the opportunity cost of delaying restoration-based GHG mitigation. • Delaying mitigation substantially decreases the economic benefits of peatland restoration. • Climate change beliefs explain variation in benefits of increased peatland resilience. • Results provide economic arguments for early investments in nature-based solutions. Ecosystem restoration and, in particular, peatland restoration, are considered a promising greenhouse gas (GHG) mitigation strategy to move towards net zero emissions. To remain within acceptable limits for projected warming scenarios, inaction with respect to GHG mitigation in the short term implies a need for even larger removals of GHGs in the longer term, which can be conceptualized as a 'mitigation debt'. This paper explores the economic implications of delaying GHG mitigation through ecosystem restoration using data of a large survey (N = 1377) that included a choice experiment to elicit the public's willingness to pay (WTP) for peatland restoration in Scotland, UK. The valuation specifically considers the interaction between the timing of restoration action and long-term ecosystem resilience. We find that respondents have a substantial WTP for peatland restoration. Importantly, we find considerable benefits for early restoration action (up to £191 million annually in our case study), which is linked to an increased resilience of peatlands under future climate change. This demonstrates that delaying restoration and thus accumulating a mitigation debt has an important opportunity cost that substantially decreases the related economic benefits. Attitudes towards climate change and climate change beliefs are found to explain variation in the public's WTP. Our research strengthens the economic argument for not delaying climate change mitigation through ecosystem restoration, demonstrating that the mitigation debt also translates into a welfare loss. To fully realise the potential benefits associated with immediate mitigation using peatland restoration, however, more needs to be understood about the mechanisms that facilitate large-scale implementation in practice. [ABSTRACT FROM AUTHOR]

Although the food service sector is a major user of water, the potential for heat recovery from commercial kitchens' drain water remains largely unexplored. For the first time, we compare the life cycle environmental burdens of producing and installing a heat recovery system with the environmental credits arising from energy savings for a restaurant case study, and for the entire UK food service sector. Life Cycle Assessment was applied to determine the impacts of heat recovery systems made from different materials and comprising a heat exchanger in the shape of a concentric double-walled pipe, pipework and fittings. The design option with the smallest environmental footprint combined a heat exchanger made out of polypropylene-graphite (PP-GR) with polyethylene pipework, exhibiting 80–99% less environmental impact compared with components made out of (35% recycled) copper. Contrasting the environmental impacts of two heat recovery set-ups with energy savings shows that a PP-GR based system pays back all burdens of the seven assessed environmental impact categories, within two years, while payback times for the copper-based system vary depending on the replaced energy source, and can exceed the 10 year operational lifetime of the system. When looking at typical flow-rates in UK food outlets, net environmental savings can be realised across all analysed impact categories above a threshold water consumption of 555 L/day, using current technology. Extrapolation to the UK food service sector indicates annual greenhouse gas emission mitigation potential of about 500 Gg CO 2 equivalent. Image 1 • LCA on equipment for recovering heat from commercial kitchen's drain water. • Heat recovery from kitchen drain water could reduce UK GHG emissions. • Trade-off between climate change mitigation and resource depletion. • Heat exchanger from polypropylene-graphite preferable to copper device. • Full environmental payback achievable from 300 m3 water consumption per year. [ABSTRACT FROM AUTHOR]