Stephen Morse

Professor Stephen Morse

Chair in Systems Analysis for Sustainability
+44 (0)1483 686079
04B AA 02
Personal tutees: Wednesdays from 12.00-13.00

Academic and research departments

Centre for Environment and Sustainability.


Affiliations and memberships

Higher Education Academy
Royal Society of Biology


Research interests

Research collaborations




Morse, A, Andries A and Murphy RM (2022) (editors). Space for Sustainability: Using Data from Earth Observation to Support Sustainable Development Indicators. MDPI, Basel, Switzerland. ISBN 978-3-0365-4265-2 (Hbk); ISBN 978-3-0365-4266-9

Global progress toward living sustainably is now urgently needed. Actions for sustainability are typically informed through the use of indicator-based frameworks that encompass diverse attributes of the environmental, social and economic dimensions of ‘sustainability’. Reporting on such indicators is embedded in frameworks such as the United Nations Sustainable Development Goals (SDGs), with the primary responsibilities for reporting borne by national and local governments. Additionally, many businesses and public bodies (e.g., universities, health services) are increasingly under internal and external pressure to similarly report via these sustainability indicators, especially as part of the SDGs, and such reporting is of increasing interest to investors and the financial services sectors from a risk and assurance perspective. However, the use of these indicator-based frameworks involves many challenges, and one of the most significant of these is the challenge of acquiring sufficient, timely and good-quality data to populate these indicators via ‘conventional’ methods (e.g., surveys at the local, national or corporate level) as this is often expensive and time consuming. Many developing regions, in particular, suffer from a lack of resources or established systems for such data collection and, indeed, this is also proving to be challenging for more developed economies. One approach to address this issue of data provision for indicators of sustainable development (SD) is the use of Earth Observation (EO). EO-based data, geospatial information and ‘big data’ can support the population of sustainability indicators at all scales, and the integration of these sources is a step forward in advancing the well-being of our societies. While EO-derived data have been used for many years to assess important issues such as deforestation and changes in land use, their use to address more socioeconomic issues (e.g., inequality, poverty, corruption, health care) within SD remains limited. Nonetheless, EO tools and technologies are developing rapidly with an expanding range of capabilities, resolutions, frequency, data power, accuracy, etc., and this is anticipated to continue into the foreseeable future. The papers in this book set out some of the frontiers regarding the use of EO data for SD indicators, and given the rapid progress in the field, it provides a timely and welcome milestone in the journey.

Morse S., McNamara, N., Adamu S., Nathan N, Adedipe Y, Kabir M, Onwuaroh A and Otene N. (2020). Social Networks and Food Security in the Urban Fringe. Part of the ‘Urban Perspectives from the Global South’ series. Springer Nature, Cham, Switzerland.

The book explores how social groups in the urban fringe of Abuja, Nigeria, engaged with a series of development projects spanning 15 years (2003 to 2018) which focused on the enhancement of food security for farming households. The groups were at the heart of these development projects and the book presents the many insights that were gained by farmers and project agents working within these partnerships and provides advice for those seeking to do the same. The book also explores how the social groups attempted to lever benefits from being near to the fastest growing city in Africa and a centre of economic and political power. While much has been written about social groups and their embeddedness within wider social networks in Africa and in other parts of the world, the exploration of the role of social groups within development projects is an area that remains relatively unchartered and this book seeks to fill that important gap in knowledge. It provides an important contribution for all those researching and working with social groups in the developing world

Morse S. (2019). The Rise and Rise of Indicators: Their History and Geography. Routledge, London. ISBN 9780415786812

This book makes indicators more accessible, in terms of what they are, who created them and how they are used. It examines the subjectivity and human frailty behind these quintessentially ‘hard’ and technical measures of the world. To achieve this goal, The Rise and Rise of Indicators presents the world in terms of a selected set of indicators. The emphasis is upon the origins of the indicators and the motivation behind their creation and evolution. The ideas and assumptions behind the indicators are made transparent to demonstrate how changes to them can dramatically alter the ranking of countries that emerge. They are, after all, human constructs and thus embody human biases. The book concludes by examining the future of indicators and the author sets out some possible trajectories, including the growing emphasis on indicators as important tools in the Sustainable Development Goals that have been set for the world up until 2030. This is a valuable resource for undergraduate and postgraduate students in the areas of economics, sociology, geography, environmental studies, development studies, area studies, business studies, politics and international relations.

McNamara N and Morse S. (2018). Food Most Royal - Nurture for Posterity. On-Stream Publications, Cork, Ireland. ISBN: 9781897685518

Food security is a term that is hardly on the tips of most people’s tongues, especially those living in the Northern Hemisphere. But while the term may be unfamiliar, we can all recognise the outcomes of its opposite – food insecurity – namely, hunger, food banks and crop contamination. This book is about how we can work towards growing enough for everyone, available at the right quality and an affordable price. While food’s cultural significance is not always fully appreciated, most eating habits are strongly cultural, with indigenous foods prepared and presented in many ways. Can you imagine Ireland without the potato, or China without rice? The authors explore many aspects of food security within the context of a single African crop of major cultural significance — the white yam. Food Most Royal is a tribute to those who have worked for over four decades with a crop they cherish. It aims to encourage others to value food resources as a key element in preserving our environment.

Morse S (2022) The role of plant health in the sustainable production of seed yams in Nigeria: A challenging nexus between plant health, human food security and culture. Plant Pathology 71(1), 43–54
Yam () is a root and tuber crop throughout West Africa and has significant nutritional, economic, and cultural value, which underpins its importance for the food security of many people who live there. The crop is propagated vegetatively, primarily via the planting of small whole tubers (seed yams) and pieces (setts) cut from larger tubers. However, the use of such vegetative material means that a variety of pests (primarily insects and nematodes) and diseases (primarily fungal and viral) can carry over and multiply from season to season. This paper sets out the plant health issues associated with yam, and how these have been addressed by improving the availability of good quality planting material, especially via the Yam Minisett Technique (YMT) and the more recently developed Adapted Yam Minisett Technique (AYMT). Both approaches are based on the planting of “minisetts” treated with pesticide to produce seed yam free of pests and fungal pathogens, but there have been challenges regarding their adoption by farmers. The paper explores these challenges and how these attempts to improve plant health fit into a wider discussion of the sustainability of yam production in West Africa given that there are other driving forces of climate change, globalization, and urbanization at play in the region.
Dioscorea rotundata
Andries A., Morse S., Murphy R.J., Lynch J. and Woolliams E.T. (2022) Using Data from Earth Observation to Support Sustainable Development Indicators: An Analysis of the Literature and Challenges for the Future. Sustainability 14(3), 1191
The Sustainable Development Goals (SDG) framework aims to end poverty, improve health and education, reduce inequality, design sustainable cities, support economic growth, tackle climate change and leave no one behind. To monitor and report the progress on the 231 unique SDGs indicators in all signatory countries, data play a key role. Here, we reviewed the data challenges and costs associated with obtaining traditional data and satellite data (particularly for developing countries), emphasizing the benefits of using satellite data, alongside their portal and platforms in data access. We then assessed, under the maturity matrix framework (MMF 2.0), the current potential of satellite data applications on the SDG indicators that were classified into the sustainability pillars. Despite the SDG framework having more focus on socio-economic aspects of sustainability, there has been a rapidly growing literature in the last few years giving practical examples in using earth observation (EO) to monitor both environmental and socio-economic SDG indicators; there is a potential to populate 108 indicators by using EO data. EO also has a wider potential to support the SDGs beyond the existing indicators. 
Chukwu T.M., Morse S. and Murphy R.J. (2022) Poor Air Quality in Urban Settings: A Comparison of Perceptual Indicators, Causes and Management in two Cities. Sustainability 14(3), 1438
Poor air quality (PAQ) is a global concern, especially in urban areas, and is often seen as an important element of social sustainability given its negative impact on health and quality of life. However, little research has been undertaken in cities of the developing world to explore how residents perceive poor air quality, its main causes, what control measures should be used to address PAQ and where the main responsibility rests for implementing control measures. The research described in this paper sought to address these points, using a questionnaire-based survey (n = 262) in Nigeria’s federal capital city of Abuja (n = 137) and the state-capital city of Enugu (n = 125). The survey took place during the Covid-19 pandemic (October 2020 to March 2021), and was stratified to ensure representation across a number of demographic groups such as gender, age, education and income. The results were analysed using the Kruskal-Wallis non-parametric test and Hochberg’s posthoc test available in SPSS version 28. The study found that the ranking of perceptual indicators and the main causes of PAQ had much agreement between respondents from both cities and between demographic groups. Smoke, odour and dust particles were perceived to be the most important indicators of PAQ, while the main sources of PAQ were waste and bush burning, vehicle use and power generators. The two most preferred control measures were proper waste management and the avoidance of bush burning. However, there was a significant difference between the two cities in terms of the main organisations responsible for addressing PAQ, with respondents from Abuja citing the federal government while those from Enugu cited the state government. Interestingly, younger people in Enugu noted that the government should take more responsibility in controlling PAQ than did the older demographic in that city, but this difference was not seen in Abuja. Overall, this study reveals that residents in these two Nigerian cities clearly recognise their exposure to PAQ and it suggests that these perceptual indicators, and views on sources and interventions should be central to designing policies to control this important issue.
Andries A., Morse S., Murphy R.J., Lynch J. and Woolliams E.R. (2022) Assessing education from space: Using satellite Earth Observation to quantify overcrowding in primary schools in rural areas of Nigeria. Sustainability 14(3), 1408.
Nigeria is a country with a rapidly growing youthful population and the availability of good quality education for all is a key priority in the sustainable development of the country. An important element of this is the need to improve access to high-quality primary education in rural areas. A key indicator for progress on this is the provision of adequate classroom space for the more than 20 million learners in Nigerian public schools because overpopulated classrooms are known to have a strong negative impact on the performance of both pupils and their teachers. However, it can be challenging to rapidly monitor this indicator for the over 60 thousand primary schools, especially in rural areas. In this research, we used satellite Earth Observation (EO) and Nigerian government data to determine the size of available teaching spaces and evaluate the degree of overcrowding in a sample of 1900 randomly selected rural primary schools across 19 Nigerian states spanning all regions of the country. Our analysis shows that 81.4 % of the schools examined were overcrowded according to the minimum standard threshold for school size of at least 1.2 m2 of classroom space per pupil defined by the Federal Government of Nigeria. Such overcrowding can be expected to have a negative impact on educational performance, on achieving universal basic education and UN Sustainable Development Goal (SDG) 4 (Quality Education), and it can lead to poverty. While measuring floor area can be performed manually on site, collecting, and reporting such data for the number of rural primary schools in a large and populous country such as Nigeria is a serious, time-consuming administrative task with considerable potential for errors and data gaps. Satellite EO data are readily available including for remote areas, are reproducible and are easy to update over time. This paper provides a proof-of-concept example of how such EO data can contribute to addressing this socio-economic dimension of the SDGs framework.
Cerbaro M., Morse S., Murphy R. Middlemiss S. and Michelakis D. (2022) Assessing urban vulnerability to flooding: A Framework to measure resilience using remote sensing approaches. Sustainability 14(4), 2276
Assessing and measuring urban vulnerability resilience is a challenging task if the right type of information is not readily available. In this context, remote sensing and Earth Observation (EO) approaches can help to monitor damages and local conditions before and after extreme weather events, such as flooding. Recently, the increasing availability of Google Street View (GSV) coverage offers additional potential ways to assess the vulnerability and resilience to such events. GSV is available at no cost, is easy to use, and is available for an increasing number of locations. This exploratory research focuses on the use of GSV and EO data to assess exposure, sensitivity, and adaptation to flooding in urban areas in the cities of Belem and Rio Branco in the Amazon region of Brazil. We present a Visual Indicator Framework for Resilience (VIFOR) to measure 45 indicators for these characteristics in 1 km2 sample areas in poor and richer districts in the two cities. The aim was to assess critically the extent to which GSV-derived information could be reliable in measuring the proposed indicators and how this new methodology could be used to measure vulnerability and resilience where official census data and statistics are not readily available. Our results show that variation in vulnerability and resilience between the rich and poor areas in both cities could be demonstrated through calibration of the chosen indicators using GSV-derived data, suggesting that this is a useful, complementary and cost-effective addition to census data and/or recent high resolution EO data. Furthermore, the GSV-linked approach used here may assist users who lack the technical skills to process raw EO data into usable information. The ready availability of insights on the vulnerability and resilience of diverse urban areas by straightforward remote sensing methods such as those developed here with GSV can provide valuable evidence for decisions on critical infrastructure investments in areas with low capacity to cope with flooding.
Martinez-Hernandez E., Sadhukhan J., Aburto J., Amezcua-Allieri M.A., Morse S. and Murphy R. (2022) Modelling to analyse the process and sustainability performance of forestry-based bioenergy systems. Clean Technologies and Environmental Policy 24, 1709–1725
This study develops a novel mathematical modelling framework for biomass combined heat and power systems (CHP) that links biomass and process characteristics to sustainability assessment of the life cycle. A total of twenty-nine indicators for the process (four-indicators), economic (five-indicators), environmental (eight-indicators) and social global (five-indicators) and local (seven-indicators) aspects have been analysed for sustainability. These are technological: biomass throughput, electricity and steam generations and CHP efficiency; economic: internal rate of return, capital, operating and feedstock costs and cost of production; environmental: global warming, fossil, land and water use, acidification, urban smog, eutrophication and ecotoxicity potentials; social (global): labour rights and decent work, health & safety, human rights, governance and community infrastructure; social (local): total forest land, direct/indirect jobs, gender equality and energy-water-sanitation access for communities, from biomass characteristics (carbon and hydrogen contents), energy demands and economic parameters. This paper applies the developed methodology to a case study in Mexico. From 12.47 kt/year forestry residue, 1 MWe is generated with an associated low-pressure steam generation of 50 kt/year, at the cost of production of $0.023/kWh. This makes the energy provision “affordable and clean” for marginalised/poor communities (the UN Sustainable Development Goals, SDG7). Bioenergy can curb > 90% of the greenhouse gas emissions and primary energy use, 6 kt CO2 eq and 74 TJ annually. Bioenergy reduces other environmental impacts considerably, water consumption, acidification and eutrophication by 87–53%, and urban smog and ecotoxicity by 29–18%. Bioenergy can improve all five social themes in the Central American cluster countries. In addition to the SDG7, the forestry-based bioenergy system can also achieve the SDG6: "clean water and sanitation for all".
Talubo J.P., Malena R.A., Morse S. and Saroj D. (2022) Practitioners’ Participatory Development of Indicators for Island Community Resilience to Disasters. Sustainability 14(7), 4102
Despite the existence of a wide range of literature on indicators of disaster resilience in various geographical contexts that have been developed by different agencies and academia, not much has been done to include the insights of practitioners at the local level. This paper seeks to address the lack of practitioner insight and perspective by proposing a mixed methodology in developing composite indicators for the resilience of an island community to disasters. We used a combination of participatory approaches, such as semi-structured interviews with key informants, the web-based Delphi method, and expert interviews through a case study site in the Philippines—the Batanes island province. Principal Component Analysis (PCA) was utilized to analyse the data from web-Delphi, and the results from the content analysis of the interviews were used to support these findings. From a broad list of 144 indicators, the process identified 22 composite indicators for assessing the disaster resilience of an island community. We conclude that the development of new approaches for assessing disaster resilience of island communities is a positive step towards a better understanding and operationalization of the concept of resilience. The process followed in this paper is a significant milestone in developing new approaches to answer the question of what makes an island community resilient to disasters.
Talubo J.P., Morse S. and Saroj D. (2022) Whose resilience matters? A socio-ecological systems approach to defining and assessing disaster resilience for small islands. Environmental Challenges 7, 100511
Resilience is a multi-faceted concept that traces its evolution based on the field of discipline wherein it was used. Various researchers have defined the term throughout the years according to their own expertise. This has impacted the development and evolution of the concept and how it was used in each specific discipline. One of the most recent and important use of the term is in the disaster paradigm. This paper traces the evolution of the definition of resilience and narrows it down to the disaster realm, eventually focusing on small islands as a socio-ecological system. It also discusses the relationship of resilience with vulnerability and enumerates the various tools and methods that have been used to measure both concepts. This review also presents an integration which identifies social, economic and ecological resilience as the different facets of disaster resilience of small islands. This paper reveals that there are gaps in defining disaster resilience of small islands through a socio-ecological systems approach. Moreover, there are few studies on using the participatory approach for determining indicators of disaster resilience which contributes to a research-policy gap in resilience studies. The paper recommends a strong future research direction on how to translate research findings into a tool that could help communities at the local level, especially those living in small islands.
Zhang D., Lu S., Morse S. and Liu L. (2022) The impact of COVID‑19 on business perspectives of sustainable development and corporate social responsibility in China. Environment, Development and Sustainability 24, 8521–8544
The new coronavirus (COVID-19) has generated an unprecedented degree of social and economic impact on the planet, but few researchers have explored the repercussion of COVID-19 for sustainable development (SD) and corporate social responsibility (CSR), especially from the perspective of Chinese businesses. This paper is the first to outline the priority changes of both SD and CSR over the period of COVID-19 incidence in China. An online questionnaire survey of 1161 owners and managers of Chinese companies was conducted, and respondents were asked to score the priorities of their company over the pre, during and post COVID-19 periods. The research was carried out at the end of the first COVID-19 wave in China but during the period of lockdown in some parts of the country. It was found that there was a priority change regarding three dimensions of sustainable development and 13 aspects of CSR. While the social dimension of SD was prioritized during and post COVID-19, the environmental dimension was the only one deemed to be less important and less prioritized over the longer term after the pandemic. The top three short-term CSR priorities were having in place a workplace health and safety plan, engaging in philanthropic activities and protecting biodiversity, and the top three longer-term CSR priorities were job creation, protecting biodiversity and having in place a workplace health and safety plan. Environmental protection and using clean energy were not reported as a CSR priority. The paper concludes that China’s recovery mode cannot be called ‘green’ and suggests ways this could be changed.
Nubi O. O., Morse S. and Murphy R. J. (2022) Prospective Life Cycle Costing of Electricity Generation from Municipal Solid Waste in Nigeria. Sustainability 14(20), 13293
Waste management and electricity supply have always been among the main challenges faced by developing countries. So far, the use of waste to energy (WtE) is one strategy that could simultaneously address these two challenges. However, the use of such technologies requires detailed studies to ensure their sustainability. In this paper, the potential of WtE in two cities in Nigeria (Abuja and Lagos) using anaerobic digestion (AD), incineration, gasification and landfill gas to energy (LFGTE), is presented with the aim of evaluating their economic viability using life cycle costing (LCC) as an analytical tool. This economic feasibility analysis includes LCC, levelised cost of electricity (LCOE), net present value (NPV), internal rate of return (IRR) and payback period. A sensitivity analysis was conducted to investigate the influence of several parameters on the economic viability of the selected technologies for the two cities. The economic assessment revealed that all the WtE systems were feasible and viable in both cities except for LFGTE in Abuja where the NPV was negative (−USD 105.42/t), and the IRR was 4.17%. Overall, incineration for both cities proved to be the most favourable economic option based on its positive LCC (Lagos USD 214.1/t Abuja USD 232.76/t), lowest LCOE (Lagos USD 0.046/t Abuja USD 0.062/t), lowest payback period (Lagos 1.6 years Abuja 2.2 years) and the highest IRR (Lagos 62.8% Abuja 45.3%). The results of the sensitivity analysis also indicated that variation in parameters such as the capital cost and discount rate have significant effects on the LCC. This paper provides information for potential investors and policy makers to enhance optimal investment in WtE technologies in Nigeria.
Nubi O. O., Morse S. and Murphy R. J. (2022) Electricity Generation from Municipal Solid Waste in Nigeria: A Prospective LCA Study. Sustainability 14(15), 9252
Diverse opportunities and environmental impacts could occur from a potential move towards waste-to-energy (WtE) systems for electricity generation from municipal solid waste (MSW) in Lagos and Abuja, Nigeria. Given this, the purpose of this study is to use life cycle assessment (LCA) as a primary analytical approach in order to undertake a comparative analysis from an environmental impact perspective of different WtE scenarios, along with diesel backup generators (DBGs) and grid electricity. A functional unit of 1 kilowatt-hour of electricity produced was used in assessing the following environmental impact categories: abiotic depletion (fossil fuels) potential (ADP), global warming potential (GWP 100a), human toxicity potential (HTP), photochemical oxidation potential (POCP), acidification potential (AP), and eutrophication potential (EP). The overall result indicated that anaerobic digestion (AD) had the highest energy generated per one tonne of MSW processed for both Lagos (683 kWh/t) and Abuja (667 kWh/t), while landfill gas to energy (LFGTE) had the lowest for both (Lagos 171 kWh/t, Abuja 135 kWh/t). AD also had the lowest environmental impacts amongst the four WtE systems for both cities based on all the impact categories except for POCP. In contrast, LFGTE had the highest impact in all the categories except ADP and HTP. Extending the analysis to include diesel-based generators (DBG) and grid electricity saw the DBGs having the highest impact overall in ADP (14.1 MJ), HTP (0.0732 Kg, 1.4 DB eq), AP (0.0129 Kg SO2 eq), and EP (0.00313 Kg PO4 eq) and grid electricity having the lowest impact in GWP (0.497 Kg CO2 eq), AP (0.000296 Kg SO2 eq), and EP (0.000061 Kg PO4 eq). It was concluded that additional electricity supply from AD to the grid, with its potential to reduce the reliance on DBGs (worst scenario overall), would be a positive action in environmental impact terms.
Nubi O. O., Morse S. and Murphy R. J. (2022) Life Cycle Sustainability Assessment of Electricity Generation from Municipal Solid Waste in Nigeria: A Prospective Study. Energies 15(23), 9173
Globally, rising population and rapid urbanisation have resulted in the dual issues of increased electricity demand and waste generation. These exacerbate diverse global problems, ranging from irregular electricity supply and inadequate waste management systems to water/air/soil pollution, climate change, etc. Waste-to-Energy (WtE) approaches have been proposed and developed to address simultaneously these two issues through energy recovery from waste. However, the variety of available waste materials and different WtE technologies make the choice of an appropriate technology challenging for decision-makers. The evaluation of the different WtE technologies in terms of their sustainability could provide a solid comparative base for strategic decision making in the power and waste management domains. This paper presents research conducted using a multidimensional Life Cycle Sustainability Assessment (LCSA) approach to estimate and compare the environmental, economic, and social impacts associated with the generation of electricity from Municipal Solid Waste (MSW) in two major cities, Lagos and Abuja, in Nigeria. These cities provide case studies in a developing world context to explore how their similarities and differences may influence the LCSA impacts for four WtE systems (Anaerobic Digestion, Incineration, Gasification, and Landfill Gas to Energy), and this is the first research of its kind. An LCSA ranking and scoring system and a muti-attribute value theory (MAVT) multi-criteria decision analysis (MCDA) were employed to evaluate the overall sustainability of the prospective use of WtE over a 20-year timeframe. The results from both approaches indicated that the adoption of WtE offered sustainability benefits for both cities, marginally more so for Lagos than Abuja. It was concluded that, for optimal benefits to be achieved, it is vital for decision-makers to think about the various trade-offs revealed by this type of analysis and the varying priorities of relevant stakeholders.
Chukwu T.M., Morse S. and Murphy R.J. (2022) Spatial Analysis of Air Quality Assessment in Two Cities in Nigeria: A Comparison of Perceptions with Instrument-Based Methods. Sustainability 14(9), 5403
The air quality (AQ) in urban contexts is a major concern, especially in the developing world. The environmental and social challenges created by poor AQ have continued to increase despite improvements in monitoring AQ using earth observation (EO) satellites, static and mobile ground-based sensors and models. However, these types of equipment can be expensive to purchase, operate, and maintain, especially for cities of the developing world, and, as a result, there is growing interest in the elicitation of residents’ perceptions of AQ. However, there is a need to analyse how the results obtained from sensor measurements and models match the AQ as perceived by residents. This study explored AQ in multiple locations in two developing world cities (Abuja and Enugu) in Nigeria by analysing the perceptions of 262 residents and how these compared with findings obtained from ground-based instruments. The results suggest that the perceived AQ of the locations broadly matches those obtained using instruments, although there were statistically significant differences between respondent groups based on the demographic factors of income-education (Abuja) and age (Enugu). This research supports the contention that perceptual AQ assessment provides a valuable source of data for policy and decision-makers when addressing poor AQ and can support action in the absence of instrument-based measurements.
Suckling J., Morse S., Murphy R., Astley S., Halford J.C.G., Harrold J. A., Le-Bail A., Koukouna E., Musinovic H., Perret J., Raben A., Roe M., Scholten J., Scott C., Stamatis C. and Westbroek C. (2023) Environmental life cycle assessment of production of the high intensity sweetener steviol glycosides from Stevia rebaudiana leaf grown in Europe: The SWEET project. The International Journal of Life Cycle Assessment (available online)
There is an increasing interest in the use of non-nutritive sweeteners to replace added sugar in food and beverage products for reasons of improving consumer health. Much work has been done to understand safety of sweeteners, but very little on sustainability. To address that gap, this study presents the results of a life cycle assessment (LCA) of production of rebaudioside A 60%, 95% pure (RA60) steviol glycoside mix from  leaf grown in Europe. An attributional cradle-to-factory-gate life cycle assessment was conducted on growing of stevia leaves and extraction of steviol glycosides in Europe. Primary data were used from a case study supply chain. Results are reported in impact categories from the ReCiPe 2016 (H) method, with focus given to global warming potential, freshwater eutrophication, water consumption, and land use. Impacts are expressed both in terms of production mass and sweetness equivalence, a common metric for understanding high intensity sweetener potency. Sweetness equivalence of RA60 is typically 200 to 300 times that of sugar. Comparison of environmental impact is made to sugar (sucrose) produced from both cane and beets. The research is part of the EU project SWEET (sweeteners and sweetness enhancers: impact on health, obesity, safety, and sustainability). Global warming potential for production of RA60 was found to be 20.25 kgCO2-eq/kgRA60 on a mass basis and 0.081 kgCO2-eq/kgSE on a sweetness equivalence basis. Field production of stevia leaves was found to be the main source of impact for most impact categories, and for all four focus categories. Extraction of the RA60 was the main source of impact for the others. Leaf processing and seedling propagation were minor contributors to life cycle impact. Removal of international transport from the supply chain reduced global warming potential by 18.8%. Compared with sugar on a sweetness equivalence basis, RA60 has approximately 5.7% to 10.2% the impact for global warming potential, 5.6% to 7.2% the impact for land use, and is lower across most other impact categories. This is the first LCA of steviol glycoside mix RA60 produced from leaf in Europe. The results indicate that RA60 can be used to reduce environmental impact of providing a sweet taste by replacing sugar across all impact categories. However, it is important to note that specific formulations in which RA60 is used will have a bearing on the final environmental impact of any food or beverage products. For solid foods, this requires further research.


Stevia rebaudiana


Results and discussion