Sustainable supply chain and life cycle assessment (LCA): summary 2016-2025

Our overarching research questions for the sustainable supply chain and life cycle assessment (LCA) part of Theme 4 are, essentially: 

• Can we create a global EW sustainable supply chain capable of accelerating CO₂ reduction through the 21st century?
• To what extent could EW, and other carbon removal options, play a role in climate change mitigation policy for transitioning society towards a zero carbon future? 

Jump to key headings:

• Major research goals and objectives
• Research design and methods
• Cross-theme integrations
• 2016-2017
• 2017-2018
• 2018-2019
• 2019-2020
• 2020-2021
• 2021-2022
• 2022-2023
• 2023-2024
• 2024-2025
• Papers featuring our LCA work

Major research goals and objectives

• To assess the environmental, social and economic impacts of the EW supply chain.
• To develop a set of plausible future pathways involving EW, and associated policy options, together with their natural-socio-economic implications, and relative likelihoods of different outcomes.
• To build a global, sustainable, integrated EW supply chain framework for analysing and understanding long-term environmental, social and economic impacts.
• To undertake a full ‘cradle-to-cradle’ environmental impact assessment of EW using a combination of primary supply chain/operational process data and secondary Life Cycle Inventory databases. 

Research design and methods 

Our plan for this part of the project is to develop a comprehensive global sustainable supply chain framework through life-cycle assessment with uncertainty-perturbation scenario analyses. This will involve analysing the entire EW supply chain and using hybrid LCA of mining, grinding, transporting and spreading of crushed rocks needed to support EW strategies at meaningful scales for CDR (Theme 1) to enable integrated environmental assessment of the EW supply chain. 

Modelling will be undertaken by extending the Supply Chain Environmental Analysis Tool, SCEnAT, developed in Sheffield, which integrates Traditional/Process LCA with Environmental Input-Output LCA. Impacts assessments will be made using environmental (e.g. GHG emissions, protection of coral reefs, climate change), social (e.g. job creation, quality of life) and economic (e.g., growth of low carbon technology sector) indicators to measure EW sustainability performance at micro- and macro-levels. This will be achieved by integrating the hybrid LCA methodology in SCEnAT with macro econometrics, policy and technology development analysis from IAM activities . Integration is needed to model the evolution of interactions in the EW supply chain at multiple scales. Consideration of uncertainty and perturbation (e.g., CO₂ and climate trajectories) in affecting the EW supply chain is key to building a resilient model. 

We will consider political, economic and social uncertainties and perturbations, e.g. technology innovation, to mitigate risk and attempt to monetise potential resource revenues, direct and indirect, that can be generated from EW.

Cross-theme integration 

Supply-chain analysis and integrated assessment modelling will be directly, quantitatively informed by the lab and field experiments of Themes 2 and 3, and the detailed numerical Earth system modelling (Theme 1).

2016-2017

Building on the proposed sustainable supply chain framework presented at the launch of LC3M, our research in 2016-17 was focused on theorising an underpinning framework, exploring the methodologies required and initial testing. Theory work is ongoing with literature review and data identification exploring the role of evolutionary and life cycle thinking and methodology for sustainable supply chain framework to help define and categorise indicators involved including biogeochemical, environmental, economic and social dimensions. This will extend the LCA methodology and form the basis for the digitalisation road-map (SCEnATi based) that can be used to support supply chain implementation. Manuscripts are in development based on the initial work. Future research will focus on developing a sustainable enhanced supply chain by interacting with researchers from themes 1 and 3 to gather data inputs for the required modelling.

2017-2018 

We have undertaken an extensive literature review of the integration of Life Cycle Assessment and Geographical Information System (GIS) for the environmental and socioeconomic assessment of enhanced rock weathering. Alongside this we have begun developing the research methods, data requirements, and acquiring support databases to provide a framework for global analysis of the enhanced rock weathering supply chain. The next steps in the research work include assessment of sources of silicates for the major crop production regions and transportation logistics and undertaking full life-cycle economic analysis of the cost-benefit of enhanced rock weathering, with and without carbon credits. There is also a need to undertake social LCA and indicators to assess societal impact of climate change mitigation strategies. 

Following our initiation of a global supply chain LCA methodology for ERW, we started discussions with Professor Richard Darton and Dr. Aidong Yang in the Dept. of Engineering Science at the University of Oxford. Prof Darton and Dr Yang were tasked with LCA analyses for the NERC consortium on weathering of mine wastes. It became clear that a standardized LCA approach is needed for the different strategies and that LC3M researchers are at the forefront of this area. In consequence, Prof. Lenny Koh and other LC3M LCA analysts participated in a LCA Methodology Workshop for Greenhouse Gas Removal at Cranfield University to discuss strategies for ways forward. Participants include Cranfield, Oxford, Edinburgh, UCL. 

We have also initiated a further strand of LCA research to understand the environmental sustainability of basalt rock dust as a supplement, or alternative to, synthetic fertilisers. In this work, we compare the environmental impact of basalt rock dust as a fertiliser to that of synthetic conventional NPK fertilisers. The study uses LCA methods to trace and estimate environmental impacts, including greenhouse gases, associated with producing synthetic fertilisers, such as ammonium nitrate phosphate, and compares them to those of basalt rock dust fertiliser. Preliminary results indicate that there are significantly fewer environmental impacts associated with producing basalt rock dust fertiliser than synthetic fertiliser production. This is mainly because production of basalt rock dust fertiliser requires low energy input compared with synthetic fertilisers.

2018-2019 

Over the past year, Post Doctoral Research Associate (PDRA) Dr Rafael Espinosa has been working closely with the modelling team from Theme 1. This has involved assessment of basalt transport from source regions to croplands based on road and rail network GIS analyses to calculate distances, costs, and carbon emissions to feed into the performance modelling. This approach improves on prior analyses, which assumed a fixed radius between rock dust source and site of application. We now go beyond global cost estimates of ERW by using national fuel (diesel) and labour costs to undertake logistical operations, and the price of energy inputs to grind rocks. The results of this GIS analysis feed into the performance modelling activities in Theme 1, and enables us to present the first techno-economic assessment in which detailed ERW carbon and economic costs vary between nations.

In the coming year, we are planning to extend this work using GIS tools developed by Dr Rafael Espinosa and Prof Lenny Koh to undertake geographical mapping of Life Cycle Assessment for Enhanced Rock Weathering supply chain for natural silicates and artificial silicates (cement/concrete waste materials) with potential for ERW application. We are also identifying and establishing modelling topics for research collaboration with Professor Neil Edwards and Dr Negar Vakilifard from the Open University, who also work on Theme 4 projects.

As part of her PhD studies, Eunice Oppon attended COP24 in December 2018, and has been undertaking comparative lifecycle that basalt rock dust fertiliser, a potential source of phosphorus (P) and potassium (K), has minimal embodied environmental impacts during production, compared with five widely used industrial P and K fertilisers. These results suggest transitioning to milled basalt as a natural geo-fertiliser to support food production may help address the UN Sustainable Development Goal of ‘responsible consumption and production’ with implications for changing sustainable crop farming practices and climate change mitigation.

Eunice is now moving on from the environmental pillar of sustainability to assess the social impact potential of enhanced weathering. Specifically we have acquired a database known as the Social Hotspot database (SHDB) and developed a social lifecycle assessment methodology (Social Input-Output method) to use in conjunction with this database. The aim of the social lifecycle assessment of enhanced weathering is to identify the social hotspots within the implementation of EW and estimate the social risk and opportunities at country, regional and global level.

2019-2020 

During the past year, Dr Rafael Espinosa and Prof Lenny Koh completed LCA of the ERW supply chain in twelve countries framed around the CO₂ removal goals of Beerling et al., (2020) and is writing this work up for publication. This work involved methodology extension of the spatial LCA and provides geographical mapping of environmental impact assessments. In collaboration with Prof. Neil Edwards (IAM team on Theme 4) Business-As-Usual vs. 1.5 degree C modelling scenarios for 2050 have been added to advance our understanding of the influence of decarbonised energy on ERW supply chain using spatial LCA. Importantly, transport network and supply chain analyses contributed to the nation-by-nation ERW carbon dioxide drawdown analysis of Beerling et al., (2020).

LC3M graduate student Eunice Oppon completed the development of social input-output methodology, LCA of ERW in developed and developing economies, and comparative LCA of virgin vs. circular feedstock of basalt, and of industrial fertilizers. Eunice plans to submit her PhD thesis in September 2020, which the empirical chapters of the thesis being formatted for journal articles. Progressing forward, we’ll be looking at LCA and Life Cycle Costing (LCC) with primary data for four ERW field sites located in Malaysia, Australia, USA and UK and the hybrid LCA-Input-Output (IO) for ERWUK for 2030-2050; with time series data inputs from Cambridge Econometrics will be converted into publications. We will be completing SCEnAT 4.0 resource efficiency modelling (land use, health and nature resources) in collaboration with Microsoft, and comparative LCA of negative emission technologies. The same will be applied to circular LCA-IO of cement/concrete waste materials for potential ERW application (waste-to-resource).

2020-2021 

Over the past year, Rafael and Lenny have developed a new Spatial Life Cycle Assessment (S-LCA) assessment mapping of environmental impacts associated with CO₂ drawdown goals. S-LCA combines process-based LCA with Geographical Information System (GIS) spatial analysis, allowing us to conduct a life cycle environmental impact assessment by geography, time and supply chain sectoral component activity, identifying impacts and their sources, as well as the effects of a low-carbon energy system on supply-chain impacts. This method delivers results for eighteen impact categories denoted ‘midpoint indicators’ and three ‘end-point indicators’ which are the aggregated impact categories showing effects on human health, ecosystems, and resource scarcity. Both mid-point and end-point impacts calculation are standard procedures aligned with ISO14040 standards. Dr Rafael Espinosa and Prof Lenny Koh considered two future energy scenarios – business as usual and decarbonising energy supplies to assist with limiting warming to 2^oC.

Analysis of end-point indicators, representing aggregation of eighteen environmental impact categories, consistently revealed two groups; countries with relative large (USA, Germany, India, China) and small (France, Brazil, Italy and Canada) ERW LCA impacts . In both groups, environmental impacts are reduced by the transition to decarbonised energy supplies. We can conclude that 

1. the net benefits of ERW as a NET for CDR outweigh the costs;
2. environmental sustainability depends on national and local conditions, in particular energy and transport systems infrastructure;
3. reducing the fossil fuel content in the energy mix under the 2°C policies will reduce the environmental impacts by improving carbon sequestration efficiency and mitigating environmental side-effects in the supply chain. Thus, scaling up ERW as a CDR strategy benefits substantially from future decarbonisation of the energy supply grids.

This work is being written up for submission. Alongside this major contribution, Dr Rafael Espinosa and Prof Lenny Koh have contributed extensive transport analyses for the UK ERW study.

Image: Environmental end-point impacts of the ERW supply chain across 12 countries associated with delivering an annual net 2 billion tonne CO2 drawdown. The position of the countries changes in each impact category. Summary of the LCIA categories with impact on the (a) Resource Depletion, (b) Ecosystems and (c) Human Health. End-point impacts are based on 0-120 weighted units; 120 represents higher impacts per hectare, whilst 0 indicates no impacts. As a rule of thumb, the closer it is to the centre, the lower is the impact; the further from the centre, the higher the impact.

2021-2022 

During this annual period within LC3M, Rafael and Lenny  have continued the research activities focused on the LCA applied to all the processes involved in the ERW supply chain. In early 2022, we published our analyses (Eufrasio et al. 2022) that address the requirement of diverse stakeholders for informative studies quantifying possible environmental and health risks of ERW. Using life-cycle assessment modelling of potential supply chain impacts for twelve nations undertaking ERW deployment to deliver up to net 2 Gt CO₂ yr⁻¹ CDR, we find that rock grinding rather than mining exerts the dominant influence on environmental impacts. 

This finding holds under both a business-as-usual and clean energy mix scenario to 2050, but transitioning to undertaking ERW in the future with low carbon energy systems improves the sustainability of the ERW supply chain. We find that ERW is competitive with other large-scale Carbon Dioxide Removal (CDR) strategies in terms of energy and water demands. 

In addition to our quantitative results that have utility in defining quantitative pathways towards achieving net-zero emissions targets, we highlight the following key policy-related messages from our results, aligned with Intergovernmental Panel on Climate Change recommendations in terms of the supply chain environmental impacts of the largescale CDR strategies considered here. 

1. Our LCA outputs weigh the sustainability of the ERW supply chain against other CDR technologies to assist policymakers in combining CDR solutions to achieve national net-zero targets and aid decision making for investment and adoption of CDR strategies.
2. Our derived national impact indices translate to a nation’s suitability to employ ERW. These results provide an initial basis for nations to consider ERW as a possible CDR strategy, or even remap and distribute national CDR targets from high to low impact countries to balance capture efficiency and sustainability impacts in their supply chains.
3. Obtained national end/mid-points impacts (e.g. resource/ water depletion, natural land transformation) can offer nation-specific CDR solutions by allowing policymakers to forecast and alleviate impacts while at the same time avoiding combining CDR technologies with overlapping demands. Results can play a major role in countries’ prioritisation of sustainable CDR solutions mix to mitigate climate change whilst protecting biodiversity and the planet. 

Image: Sustainability index (SI, per hectare) calculated as the mean of the three end-point Life Cycle Assessment scores for a) China, India and the USA and b) 9 other countries relative to the cropland area of ERW deployment and carbon dioxide removal (CDR) potential. Panels c) and d) show the area-integrated sustainability index for the same nations as in a and b, respectively, (i.e. SI × cropland area used for ERW deployment). For each nation, we highlight results for ERW with under business-as-usual (BAU) (bright flags) and 2 °C energy policy scenarios (shaded flags) (Eufrasio et al. 2022).

2022-2023 

During this period, Rafael and Lenny  made significant contributions to our techno-economic and transport network analyses for the potential implementation of EW in the U.S. In terms of techno-economics, we conducted detailed projections of rock availability and employment at the state level under various application scenarios. For transport analysis, we utilized GIS modelling techniques to calculate transport costs and emissions associated with the implementation of EW. The outcome of this collaborative effort with Prof David Beerling and Dr Euripides Kantzas, among others, is a manuscript that has been submitted to the Science journal.

Additionally, Rafael and Lenny have been actively involved in conducting a comprehensive life cycle analysis for the application of EW in the UK. This study serves as a continuation of a previously published article in the respected journal Nature Geosciences. By considering all the conditions outlined in the previous article, the team has performed calculations across 18 different categories to assess the potential environmental impacts associated with each process in the supply chain. In this effort, Rafael and Lenny have collaborated with Prof Pete Smith and Dr Sylvia Vetter from the University of Aberdeen. Notably, some of the preliminary findings are presented in the graph below , demonstrating that the utilisation of renewable energy sources in the power supply, coupled with low-energy grinding methods, can significantly reduce the impacts on ecosystems, natural resources, and human health resulting from the implementation of this innovative technology. 

The team is also in the initial stages of our case study focusing on Australia. Our primary focus is on gathering existing geographical databases for spatial analysis, specifically relating to country resources such as rocks and crops, as well as conducting comprehensive transport analyses to determine their potential distribution across the country. These initial steps are necessary for setting the basis of the study and will serve as valuable input for further analyses and research. 

Image: UK-ERW-LCA: Plot A) shows time series change in end-points resources (RE), ecosystems (EC), and human health (HH) per ton of processed rock , Plot B) shows time series change in end-points per hectare, Plot C) shows time series change in end- points per ton of CO2 removed, Plot D) shows time series change in percentage (%) for the three end-point impact categories. 

2023-2024

Rafael and Lenny have performed the GIS-based transport network analysis for USA-EW case study. We contributed to the techno-economic and transport network analysis for the Australia case study, utilising GIS modelling techniques to calculate transport costs and emissions associated with the implementation of ERW. We have also recently completed the LCA of the UK case study with 18th mid-point and 3 endpoint indicators . This case study is being undertaken in collaboration with Prof Pete Smith and Dr Sylvia H. Vetter from the Institute of Biological and Environmental Sciences, University of Aberdeen, linking across from LC3M to Prof David Beerling’s UKRI funded project, the UK ERW GGR Demonstrator. These links have been strengthened by developing collaborations with Prof Phil Renforth and Dr Mohammad Madankan from Heriot-Watt University, who are working on ecosystem services assessment and mining optimisation. A paper is under review with Energy Economics, based on the research from LC3M’s first successful graduate Dr Eunice Oppon’s PhD work on triple bottom line sustainability of negative emissions technologies (NETs) between developing and developed countries.

Image: Example of EW LCA Supply Chain Environmental Impacts for UK deployment.

2024-2025

Rafael and Lenny conducted a comprehensive prospective life cycle assessment of ERW implementation in the UK across three deployment scenarios (low, medium, and high) from 2020 to 2070. Following on from the previous years’ work on this point, our analysis included tracking eighteen LCA mid-point indicators and three end-point indicators of environmental and human health impacts over decades (see image below). Prospective LCA allows assessment of the environmental impacts of each stage of the technology's supply chain, including raw material extraction, mineral processing, transportation, application, and end-of-life scenarios in the future. 

Image: Prospective life cycle mid-points environmental impact of ERW attribution to the three end-points.

Our findings indicate a potential decrease in impacts on ecosystems, human health, and resources over time, primarily due to the projected decarbonisation of the energy used throughout the ERW supply chain life cycle. The UK’s robust supply chain, comparatively close proximity of quarries to croplands, and focus on a 1.5°C energy policy scenario, position it favourably compared to other national ERW supply chains. Additionally, in comparison to other CDR strategies, ERW has relatively low impacts on environmental and human health indicators. These insights underscore ERW’s role as a sustainable pathway to help the UK achieve its net zero emissions commitment by 2050 and offer insights for policymakers, researchers, and stakeholders involved in implementation of climate change mitigation strategies.

Rafael and Lenny conducted transport network analysis and contributed to the USA ERW paper which has been published in Nature (Beerling et al. 2025 ). Additionally, we conducted transport network analysis and contributed to the Australia ERW paper being finalised by Euripides Kantzas and David Beerling. We have also conducted LCA for the Australia ERW.

Rafael and Lenny also contributed to the three ERW CDR removal projects (UK, China and India) joining David’s modelling team to understand the supply chain system and policy impacts. Papers will be developed from these projects and a podcast will be produced in collaboration with Euripides Kantzas, Mark Lomas, Lyla Taylor and David Beerling.

Finally, Rafael and Lenny are collaborating with the UKRI GHG removal with UK agriculture via ERW team on supply chain and LCA, especially with Pete Smith, Sylvia Vetter, Phil Renforth and Mohammad Madankan. A supply chain framework paper (focussing on UK mining as part of the ERW supply chain) has been revised and resubmitted to Nature Communications Earth and Environment.

Papers featuring our LCA work

Eufrasio-Espinosa, R.M. & Koh, S.C.L. (2019) The UK Path and the Role of NETs to Achieve Decarbonisation. In: Shurpali N., Agarwal A., Srivastava V. (eds) Greenhouse Gas Emissions. Energy, Environment, and Sustainability. Springer, Singapore. Pages 87-109. https://doi.org/10.1007/978-981-13-3272-2_7. Published 1 November 2018.

Smith, P., Adams, J., Beerling, D. J., Beringer, T., Calvin, K.V., Fuss, S., Griscom, B., Hagemann, N., Kammann, C., Kraxner, F., Minx, J.C., Popp, A., Renforth, P., Vicente-Vicente, J.L. & Keesstra, S. (2019) Land-Management Options for Greenhouse Gas Removal and Their Impacts on Ecosystem Services and the Sustainable Development Goals. Annual Review of Environment and Resources, 44:1, 255-286. https://doi.org/10.1146/annurev-environ-101718-033129. Published 11 June 2019.

Beerling, D. J., Kantzas, E., Lomas, M. R., Wade, P., Eufrasio, R. M., Renforth, P., Quirk, J., Sarkar, B., Andrews, G., James, R. H., Pearce, C. R., Khanna, M., Koh, L., Quegan, S., Pidgeon, N. F., Janssens, I., Hansen, J. & Banwart, S. A. (2020) Potential for large-scale CO₂ removal via enhanced rock weathering with croplands. Nature, 583, 242-248. https://doi.org/10.1038/s41586-020-2448-9. Published 8 July 2020.

Eufrasio, R. M., Kantzas, E. P., Edwards, N. R. et al. (2022) Environmental and health impacts of atmospheric CO₂ removal by enhanced rock weathering depend on nations’ energy mix. Nature Commun Earth Environ 3, 106. https://doi.org/10.1038/s43247-022-00436-3. Published 5 May 2022.

Oppon, E., Richter, J. S., Koh, S. C.L., and Nabayiga, H. (2022) Macro-level economic and environmental sustainability of negative emission technologies; Case study of crushed silicate production for enhanced weathering. Ecological Economics, Volume 204. https://doi.org/10.1016/j.ecolecon.2022.107636. Published 27 October 2022.

Beerling, D., Kantzas, E., Val Martin, M., Espinosa, R., Pidgeon, N. & Banwart, S. (2023):  UK Government Policy Brief: Potential of enhanced rock weathering deployed with UK agriculture to sequester atmospheric carbon dioxide. Available at figshare. Online resource. https://doi.org/10.6084/m9.figshare.22888646.v3. Published 17 May 2023.

Oppon, E., Koh, S.C.L., Eufrasio, R. et al. (2023): Towards sustainable food production and climate change mitigation: an attributional life cycle assessment comparing industrial and basalt rock dust fertilisers. Int J Life Cycle Assess (2023). https://doi.org/10.1007/s11367-023-02196-4. Published 18 July 2023.

Eufrasio Espinosa, R.M. & Koh, S.C.L. (2024) Forecasting the ecological footprint of G20 countries in the next 30 years. Nature Sci Rep 14, 8298. https://doi.org/10.1038/s41598-024-57994-z Published 9 April 2024.

Oppon, E., Koh, S.C.L. & Eufrasio, R. (2024) Sustainability performance of enhanced weathering across countries: A triple bottom line approach. Energy Economics 136, 2024, 107722. https://doi.org/10.1016/j.eneco.2024.107722 Published 20 June 2024.

Beerling, D.J., Kantzas, E.P., Lomas, M.R., Taylor, L.L., Zhang, S., Kanzaki, Y., Eufrasio, R.M., Renforth, P., Mecure, J-F., Pollitt, H., Holden, P.B., Edwards, N.R., Koh, L., Epihov, D.Z., Wolf, A., Hansen, J.E., Banwart, S.A., Pidgeon, N.F., Reinhard, C.T., Planavsky, N.J. & Val Martin, M. (2025) Transforming US agriculture for carbon removal with enhanced weathering. Nature. https://doi.org/10.1038/s41586-024-08429-2 Published 5 February 2025.

Eufrasio, R.M., Kantzas, E.P., Vetter, S.H., Smith, P., Koh, S.C & Beerling, D.J. (2025) Life cycle assessment analysis identifies enhanced weathering as a possible sustainable pathway to assist with UK decarbonization goals, Nature Communications Earth and Environment. (submitted) 

Madankan, M., Kantzas, E.P., Espinosa, R.M.E., Vetter, S. H., Koh, L., Smith, P., Beerling, D. & Renforth, P. (2025) A spatio-temporal supply-chain framework for Enhanced Rock Weathering deployment at scale: a UK case study, Nature Communications Earth and Environment., in press

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See all of our publications here.