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Ordinary Portland cement (OPC) is produced through energy-intensive processes and contributes to approximately 8% of global carbon dioxide emissions. As one of the most consumed materials after water, cement's environmental impact is substantial. Decarbonizing emissions in the intensive processes of cement production requires a sustainable supply of low-carbon resources. The purpose of this study is to explore the potential of agricultural waste ashes as supplementary cementitious materials (SCMs) to reduce the carbon footprint of OPC. In Africa, where agricultural waste is abundant, these residues could offer a sustainable solution for cement manufacturing. This study employed a multi-criteria decision analysis methodology to identify and select relevant literature for analysis. The review reveals that incorporating agricultural-based SCMs, such as rice husk ash, coffee husk ash, sugarcane bagasse ash, and palm oil fuel ash, into cement production can significantly reduce clinker requirements, thereby lowering carbon dioxide emissions while maintaining performance standards of OPC. The review found that locally sourced waste materials can reduce the carbon footprint of cement by up to 40%. Transitioning from a clinker-dependent sector to a bio-based one presents several opportunities as well as challenges for the African cement industry, but it is critical for reducing carbon emissions and improving sustainability. This approach not only decreases emissions but also supports sustainable construction, aligning with global climate goals and sustainable development goals (SDGs) 12 (responsible consumption and production) and 13 (climate action). Adopting green cement could revolutionize the African cement industry, promoting resource efficiency and sustainable development across the continent. Article highlights Agricultural supplementary cementitious materials can reduce clinker reliance, lowering carbon emissions and promoting sustainable construction. Variability in material quality, processing infrastructure, and supply chains limits large-scale adoption in Africa. Policy support, cost-efficient processing, and market awareness are critical for scaling up agricultural supplementary cementitious materials use.

We investigate the potential in producing biodegradable bio-plastics to support the emergent 'net-zero' greenhouse gas (GHG) emissions targets in the UK. A 'cradle to grave' life cycle assessment was developed to evaluate GHG mitigation potentials of bio-based polybutylene succinate plastics produced from wheat straw-only (single feedstock) or wheat straw plus Miscanthus (mixed feedstocks) agricultural supply systems. For scenarios using mixed feedstocks, significant carbon mitigation potentials were identified at catchment and national levels (emission reduction of 30 kg CO2eq kg−1 plastic compared to petroleum-based alternatives), making the system studied a significant net carbon sink at marginal GHG abatement costs of £0.5-14.9 t−1 CO2eq. We show that an effective 'net-zero' transition of the UK's agricultural sector needs spatially explicit, diversified and integrated cropping strategies. Such integration of perennial bio-materials into food production systems can unlock cost-effective terrestrial carbon sequestration. Research & Development and scale-up will lower costs helping deliver a sustainable bioeconomy and transition to 'net-zero'.

The transportation sector significantly contributes to global greenhouse gas emissions, with heavy-duty vehicles (HDVs) and buses accounting for approximately a quarter of transportation emissions. This paper explores the life cycle assessment of these vehicle types, assessing their environmental impacts in Qatar during production, operation, and end-of-life stages leveraging a cradle-to-grave system boundary from the year 2022 until 2050. Additionally, the study investigates their potential roles in decarbonizing the transport sector through emerging technologies and policy interventions. The key findings highlight the importance of electrification, alternative fuels, and efficiency improvements in reducing emissions, emphasizing the critical role of HDVs and buses in achieving sustainable transport systems. The results indicate that transitioning from internal combustion engine vehicles (ICEV) to battery electric vehicles (BEV) can lead to reductions in global warming potential (BEV HDVs and Buses reflecting 33.5% and 32.8% reduction) and particulate matter emissions (from 3.09E-04 kg PM2.5-eq/km in 2022 to 2.15E-04 kg PM2.5-eq/km in 2050 for HDVs). The decline in PM2.5 emissions will improve urban air quality and reducing public health risks. However, the shift to BEVs increases mineral resource depletion due to battery production, necessitating improved recycling strategies and sustainable raw material sourcing. This study provides critical insights for policymakers and industry stakeholders, highlighting the need for integrated approaches, including renewable energy investments, battery recycling initiatives, and electrification incentives. The transition to sustainable transportation is essential for achieving Qatar’s National Vision 2030, reducing dependence on fossil fuels, and mitigating environmental impacts.

We hypothesize that Fashion brands’ demand for organic agroforestry cotton (OAC) may foster more sustainable supply chains in the cotton industry. However, to realize the potential of the OAC market, a better understanding of the market demand for OAC, as well as the quality and production standards under which the brands operate, the institutional frameworks, and the market mechanisms that underpin its commercialization, is needed. We evaluated the existing organic markets in Brazil using an interview-based methodology with key stakeholders throughout the organic cotton supply chain in 2022. Our study revealed that some brands are willing to pay prices ranging from USD $ 2.57 to USD$4.61 per kg of cotton lint depending on the brand. These brands require suppliers to meet quality specifications for the cotton fiber; for example, they require average to long fibers and specify harvesting practices that influence fiber quality. There are also social and environmental criteria that prioritize vulnerable communities of family farmers and women groups planting cotton based on established sustainable practices. The institutional framework includes different stakeholders throughout the organic cotton supply chain, which is fundamentally driven by private demand for cotton, counts on the support of agents connecting brands to farmers, and is indirectly supported by public policies. Existing markets for organic cotton are established via contracts that provide farmers with guarantees to invest in planting cotton and have different certification systems used by the brands that monitor and verify adherence to the standards. Market demand for OAC may, therefore, potentially lead to new markets that promote sustainable supply chains and farming practices. However, existing markets for organic cotton reveal complex requirements that must be addressed, such as the need for supporting agents connecting brands to farmers, and market mechanisms, such as complex contracts and certification.

KCERT 2050 is a modelling tool designed to assist in the identification and evaluation of synergies and trade-offs within sectoral decarbonization pathways for Kenya. KCERT 2050 is positioned as a user-friendly and dynamic tool that bridges complex energy systems and emissions models with integrated impact assessment tools, aimed at aiding decision making towards carbon neutrality in both public and private sectors. The tool considers greenhouse gas emissions from various economic sectors and is validated through a collaborative process involving experts from diverse backgrounds. This study uses KCERT 2050 to examine the prospects of achieving a net−zero emissions pathway by 2050. In the baseline scenario, a significant emission trajectory is observed, with the transport sector emerging as the largest contributor. Transitioning to the net−zero pathway reveals substantial reductions across key sectors, such as transport, industry, and land use, driven by strategies including electrification, waste reduction, and afforestation. The sensitivity analysis underscores the potential for emission mitigation through various levers, including land use optimization and the adoption of cleaner transportation modes. In conclusion, our findings emphasize the potential and feasibility of Kenya’s ambitious net−zero emissions target. To attain this goal, it is imperative to prioritize sustainable land use and innovative waste management strategies.

Energy supply for clean cooking is a priority for Sub-Saharan Africa (SSA). Liquefied petroleum gas (LPG, i.e., propane or butane or a mixture of both) is an economically efficient, cooking energy solution used by over 2.5 billion people worldwide and scaled up in numerous low- and middle-income countries (LMICs). Investigation of the technical, policy, economic and physical requirements of producing LPG from renewable feedstocks (bioLPG) finds feasibility at scale in Africa. Biogas and syngas from the circular economic repurposing of municipal solid waste and agricultural waste can be used in two groundbreaking new chemical processes (Cool LPG or Integrated Hydropyrolysis and Hydroconversion (IH2)) to selectively produce bioLPG. Evidence about the nature and scale potential of bioLPG presented in this study justifies further investment in the development of bioLPG as a fuel that can make a major contribution toward enabling an SSA green economy and universal energy access. Techno-economic assessments of five potential projects from Ghana, Kenya and Rwanda illustrate what might be possible. BioLPG technology is in the early days of development, so normal technology piloting and de-risking need to be undertaken. However, fully developed bioLPG production could greatly reduce the public and private sector investment required to significantly increase SSA clean cooking capacity.

Sugarcane is an economically important crop in Fiji as it has considerable impact on the gross domestic product and around 22% (200,000) of the population is directly or indirectly dependent on the sugarcane industry. Considering the importance of this crop, a life cycle assessment (LCA) was performed in order to understand environmental impacts. In this paper, Fijian sugarcane production was assessed to produce a set of LCA results for defined impacts. The results can be used in subsequent assessments of sugarcane-related products and provide significant insights into the current impacts. Life cycle impact assessment results were generated using CML, ReCiPe and Impact 2002 + models running in Open LCA software using the Ecoinvent database. This connected the system flows and process flow to the product systems in order to calculate the life cycle impact assessment results to be based on local data for comparable and accurate evaluation. Previous analysis revealed that sugarcane production has a considerable impact on global warming potential because of the significant use of fossil fuels in farm machineries and transportation, and the production and use of agrochemicals. Results from this study show that sugarcane production has least impact on ozone layer depletion. Fertilizer production and usage was found to be one of the key issues affecting various impact categories. These results will assist further assessments on the sugarcane products and systems. However, in order to further develop the LCA tool for Fijian agricultural systems, development and testing of life cycle impact assessment models is necessary for Fijian conditions. This will ensure further accuracy of model outputs and supply more realistic and real-time results on emissions.

Purpose This study compares the environmental impacts of transitioning from a business-as-usual (BaU) internal combustion engine vehicles (ICEVs) pathway to one adopting battery electric vehicles (BEVs) in Qatar from 2022 to 2050. The analysis is based on geographically representative empirical data, focusing exclusively on the light-duty, personal vehicle sector. The research explores environmental performance trends, uncertainties, and potential implications of transitioning from ICEVs to BEVs within the Qatar National Vision (QNV) 2030 framework. Methods Utilising the ReCiPe method, this time-dynamic life cycle assessment (LCA) assessed a range of relevant environmental impact categories: global warming potential, particulate matter, human toxicity, acidification and resource depletion. This analysis incorporates different light-duty vehicle (LDV) types such as sedans, sport utility vehicle (SUVs) and sport vehicles. The impacts of potential technological advancements, such as in fuel efficiency for ICEVs and charging electricity supply and/or battery technology for the BEVs, were included to provide a more encompassing view of the environmental implications of both vehicle types. Results and discussion Decreasing environmental impact for ICEVs and BEVs is observed, with BEVs’ greater potential in reducing Qatar’s transport sector’s carbon footprint. Uncertainties emerged as this potential decrease was not seen in all impact categories, nor vehicle technology or timeframe. This stresses the BEV’s transition importance of production location and energy sources. This was observed for the carbon footprint and overarching environmental impact of battery production, exacerbated in regions reliant on fossil fuel electricity. Qatar, endowed with substantial fossil fuel reserves, relies on natural gas for electricity provision; therefore, the potential benefits of introducing BEVs are limited without strong shifts to renewables. Further research in vehicle production, disposal and technological advancements will prove essential, especially in a maturing sector like electric vehicle production and processing. Conclusions BEVs have the potential to reduce the environmental impacts of Qatar’s transport sector. Yet, the short payback period for newer BEVs is linked with the greenhouse gas intensity of electricity production, emphasising the dual challenge for Qatar with its reliance on fossil fuels. Considering environmental, economic and societal facets, a transition taking into account all facets of sustainability and not purely the introduction of BEVs is imperative in aligning with Qatar’s 2030 sustainable vision. Recommendations A clear understanding of the socio-economic and environmental aspects of the ICEV-BEV transition is urgently required, emphasising production, disposal and technological innovations. Exploring alternative batteries and recycling methods can offer pathways to mitigate environmental concerns associated with BEVs. Regions like Qatar are underrepresented in the available literature, yet should be part of the research on sustainable transitions to provide insights on the opportunity and co-benefits that arise from the development of relevant sustainability transition planning.

The role of life cycle assessment (LCA) in informing the development of a sustainable and circular bioeconomy is discussed. We analyse the critical challenges remaining in using LCA and propose improvements needed to resolve future development challenges. Biobased systems are often complex combinations of technologies and practices that are geographically dispersed over long distances and with heterogeneous and uncertain sets of indicators and impacts. Recent studies have provided methodological suggestions on how LCA can be improved for evaluating the sustainability of biobased systems with a new focus on emerging systems, helping to identify environmental and social opportunities prior to large R&D investments. However, accessing economies of scale and improved conversion efficiencies while maintaining compatibility across broad ranges of sustainability indicators and public acceptability remain key challenges for the bioeconomy. LCA can inform, but not by itself resolve this complex dimension of sustainability. Future policy interventions that aim to promote the bioeconomy and support strategic value chains will benefit from the systematic use of LCA. However, the LCA community needs to develop the mechanisms and tools needed to generate agreement and coordinate the standards and incentives that will underpin a successful biobased transition. Systematic stakeholder engagement and the use of multidisciplinary analysis in combination with LCA are essential components of emergent LCA methods. This article is part of the theme issue ‘Bio-derived and bioinspired sustainable advanced materials for emerging technologies (part 1)’.

Continuous incorporation of rice straw has caused significant CH4 emissions from the paddy field production system in East China. Anaerobic digestion (AD) of the rice straw has been considered as a promising approach that could not only mitigate the land-based CH4 emissions, but also generate low-carbon electricity and high-quality organic fertilizer. However, this approach, in many circumstances, is unable to be cost-competitive with other straw treatment processes or power sources. To understand the potential incentives that recently launched carbon trading schemes, the China Carbon Emission Trade Exchange (CCETE) and Chinese Certified Emission Reduction (CCER), could bring to the rice straw utilization value chain, we conducted a cradle-to-factory gate life cycle assessment and economic analysis of a small-scale AD system with rice straw as the main feedstock in East China. The results indicate that, depending on the choice of allocation method, the climate change impact of the bioenergy generated through the studied small-scale AD system is 0.21 to 0.28 kg CO2eq./kWh, and the digester fertilizer produced is 6.88 to 22.09 kg CO2eq./kg N. The economic analysis validates the financial sustainability of such small-scale AD projects with rice straw feedstock under carbon trading mechanisms. The climate mitigation potential could be achieved at the marginal reduction cost of 13.98 to −53.02 USD/t CO2eq. in different carbon price scenarios.