Dr Stephen Northey is a Chancellor's Postdoctoral Research Fellow (CPDRF) at the Insitute for Sustainable Futures, UTS. Stephen's research seeks to understand the interaction between material supply and sustainable development outcomes as we transition towards a decarbonised economy.
Stephen is currently focused on developing long-term supply scenarios for the specialty mineral and metal commodities of relevance for the global battery sector (e.g. lithium, cobalt, etc.). This will help us to understand the required investment in battery material supply capacity required to decarbonise the global economy, as well as understand the natural resource requirements (e.g. energy, water and land use) and environmental impacts of battery material supply overtime (e.g. greenhouse gas emissions).
Prior to this, Stephen worked in a range of roles with Monash University and CSIRO, where he assessed the global supply and demand of mineral products, evaluated water and energy consumption throughout the mining industry, and conducted techno-economic and life cycle assessment studies of technologies being developed for mining, mineral processing and metal production.
Can supervise: YES
Current research interests:
- Long-term scenarios for battery related mineral and metal supply chains
- Development of large-scale datasets for benchmarking industry environmental performance (e.g. greenhouse gas emissions, water use intensity, etc.)
Broader Areas of Expertise:
- Sustainable development
- Life cycle assessment (LCA), especially water and mineral resource use impact assessment methods
- Industrial ecology, material flow analysis (MFA)
- Carbon footprint
- Water footprint, water accounting, regional water stress
- Scenario modelling
- Mining, mineral processing and metallurgy
- Mineral and metal supply chains (particularly copper, steel, gold, nickel, lithium, cobalt, rare earths, platinum group elements and zinc)
- Mineral resource availability and depletion
- Environmental performance indicators, benchmarking and communication
- Corporate sustainability reporting
Teaching areas and interests:
- Environmental engineering and management
- Sustainable development
- Mineral resource governance
Specialty short-courses available on request:
- Life cycle assessment
- Water footprint assessment (both ISO14046 and WFN methodologies)
- Environmental performance monitoring and communication
Azadi, M, Northey, SA, Ali, SH & Edraki, M 2020, 'Transparency on greenhouse gas emissions from mining to enable climate change mitigation', Nature Geoscience, vol. 13, no. 2, pp. 100-104.View/Download from: Publisher's site
Sonderegger, T, Berger, M, Alvarenga, R, Bach, V, Cimprich, A, Dewulf, J, Frischknecht, R, Guinee, J, Helbig, C, Huppertz, T, Jolliet, O, Motoshita, M, Northey, S, Rugani, B, Schrijvers, D, Schulze, R, Sonnemann, G, Valero, A, Weidema, BP & Young, SB 2020, 'Mineral resources in life cycle impact assessment-part I: a critical review of existing methods', INTERNATIONAL JOURNAL OF LIFE CYCLE ASSESSMENT.View/Download from: Publisher's site
Werner, TT, Mudd, GM, Schipper, AM, Huijbregts, MAJ, Taneja, L & Northey, SA 2020, 'Global-scale remote sensing of mine areas and analysis of factors explaining their extent', Global Environmental Change, vol. 60.View/Download from: Publisher's site
© 2019 Elsevier Ltd Mines are composed of features like open cut pits, water storage ponds, milling infrastructure, waste rock dumps, and tailings storage facilities that are often associated with impacts to surrounding areas. The size and location of mine features can be determined from satellite imagery, but to date a systematic analysis of these features across commodities and countries has not been conducted. We created detailed maps of 295 mines producing copper, gold, silver, platinum group elements, molybdenum, lead-zinc, nickel, uranium or diamonds, representing the dominant share of global production of these commodities. The mapping entailed the delineation and classification of 3,736 open pits, waste rock dumps, water ponds, tailings storage facilities, heap leach pads, milling infrastructure and other features, totalling ~3,633 km2. Collectively, our maps highlight that mine areas can be highly heterogeneous in composition and diverse in form, reflecting variations in underlying geology, commodities produced, topography and mining methods. Our study therefore emphasises that distinguishing between specific mine features in satellite imagery may foster more refined assessments of mine-related impacts. We also compiled detailed annual data on the operational characteristics of 129 mines to show via regression analysis that the sum area of a mine's features is mainly explained by its cumulative production volume (cross-validated R2 of 0.73). This suggests that the extent of future mine areas can be estimated with reasonable certainty based on expected total production volume. Our research may inform environmental impact assessments of new mining proposals, or provide land use data for life cycle analyses of mined products.
Yuan, Y, Yellishetty, M, Mudd, GM, Munoz, MA, Northey, SA & Werner, TT 2020, 'Toward dynamic evaluations of materials criticality: A systems framework applied to platinum', RESOURCES CONSERVATION AND RECYCLING, vol. 152.View/Download from: Publisher's site
Northey, S, Mohr, S, Mudd, GM, Weng, Z & Giurco, D 2020, 'Corrigendum to “Modelling future copper ore grade decline based on a detailed assessment of copper resources and mining” (Resources, Conservation & Recycling (2014) 83 (190–201), (S0921344913002127), (10.1016/j.resconrec.2013.10.005))', Resources, Conservation and Recycling, vol. 154.View/Download from: Publisher's site
© 2019 The authors regret that equation 1 is incorrect. The correct equation is: [Formula presented] The authors would like to apologise for any inconvenience caused.
Northey, SA, Madrid López, C, Haque, N, Mudd, GM & Yellishetty, M 2019, 'Corrigendum to “Production weighted water use impact characterisation factors for the global mining industry” [J. Clean. Prod. 184 (2018) 788–797] (Journal of Cleaner Production (2018) 184 (788–797), (S0959652618306450), (10.1016/j.jclepro.2018.02.307))', Journal of Cleaner Production, vol. 224.View/Download from: UTS OPUS or Publisher's site
© 2019 Elsevier Ltd Cristina Madrid-Lopez has received funding from the Marie Curie International Outgoing Fellowship within the 7th European Community Framework Program under grant agreement No 623593-IANEX. This information was not included in the acknowledgements. The authors would like to apologise for any inconvenience caused.
Northey, SA, Mudd, GM, Werner, TT, Haque, N & Yellishetty, M 2019, 'Sustainable water management and improved corporate reporting in mining', Water Resources and Industry, vol. 21.View/Download from: UTS OPUS or Publisher's site
© 2018 The Authors. The advent of corporate sustainability reporting and water accounting standards has resulted in increased disclosure of water use by mining companies. However, there has been limited compilation and analysis of these disclosures. To address this, we compiled a database of 8314 data points from 359 mining company reports, classified according to mining industry water accounting guidelines. The quality of disclosures is shown to have improved considerably over time. Although, opportunities still exist to improve reporting practices, such as by ensuring that all relevant water flows are reported and to explicitly state non-existent flows (e.g. discharges). Initial data analysis reveals considerable variability in water withdrawals, use efficiency and discharges between mining operations. Further work to improve industry coverage and to analyse the influence of mine specific factors such as ore processing methods and local climate will provide insights into the interactions of mining and water resources at a global scale.
Pradinaud, C, Northey, S, Amor, B, Bare, J, Benini, L, Berger, M, Boulay, A-M, Junqua, G, Lathuillière, MJ, Margni, M, Motoshita, M, Niblick, B, Payen, S, Pfister, S, Quinteiro, P, Sonderegger, T & Rosenbaum, RK 2019, 'Defining freshwater as a natural resource: A framework linking water use to the area of protection natural resources.', The international journal of life cycle assessment, vol. 24, no. 5, pp. 960-974.View/Download from: UTS OPUS or Publisher's site
Purpose:While many examples have shown unsustainable use of freshwater resources, existing LCIA methods for water use do not comprehensively address impacts to natural resources for future generations. This framework aims to (1) define freshwater resource as an item to protect within the Area of Protection (AoP) natural resources, (2) identify relevant impact pathways affecting freshwater resources, and (3) outline methodological choices for impact characterization model development. Method:Considering the current scope of the AoP natural resources, the complex nature of freshwater resources and its important dimensions to safeguard safe future supply, a definition of freshwater resource is proposed, including water quality aspects. In order to clearly define what is to be protected, the freshwater resource is put in perspective through the lens of the three main safeguard subjects defined by Dewulf et al. (2015). In addition, an extensive literature review identifies a wide range of possible impact pathways to freshwater resources, establishing the link between different inventory elementary flows (water consumption, emissions and land use) and their potential to cause long-term freshwater depletion or degradation. Results and discussion:Freshwater as a resource has a particular status in LCA resource assessment. First, it exists in the form of three types of resources: flow, fund, or stock. Then, in addition to being a resource for human economic activities (e.g. hydropower), it is above all a non-substitutable support for life that can be affected by both consumption (source function) and pollution (sink function). Therefore, both types of elementary flows (water consumption and emissions) should be linked to a damage indicator for freshwater as a resource. Land use is also identified as a potential stressor to freshwater resources by altering runoff, infiltration and erosion processes as well as evapotranspiration. It is suggested to use the concept of recove...
Yuan, Y, Yellishetty, M, Muñoz, MA & Northey, SA 2019, 'Toward a dynamic evaluation of mineral criticality: Introducing the framework of criticality systems', Journal of Industrial Ecology, vol. 23, no. 5, pp. 1264-1277.View/Download from: UTS OPUS or Publisher's site
© 2019 by Yale University A new methodology to quantify minerals’ criticalities is proposed—the criticality systems of minerals. In this methodology, four types of agents—mineral suppliers, consumers, regulators of the market, and others, such as the communities near mining operations—interact with each other through three types of indicators: constraints, such as the political stability in the mining regions, the mineral's substitutability and economic importance; agents’ interactions, such as buyer–seller bargaining; and interactive variables, such as the demand, supply, and price. When the criticality systems of two mineral groups are constructed, analyses that compare the indicators of these criticality systems can determine which group is more critical than the other. This methodology allows evaluation of criticality in a dynamic and systemic manner.
Ilankoon, IMSK, Tang, Y, Ghorbani, Y, Northey, S, Yellishetty, M, Deng, X & McBride, D 2018, 'The current state and future directions of percolation leaching in the Chinese mining industry: Challenges and opportunities', MINERALS ENGINEERING, vol. 125, pp. 206-222.View/Download from: Publisher's site
Northey, SA, Madrid Lopez, C, Haque, N, Mudd, GM & Yellishetty, M 2018, 'Production weighted water use impact characterisation factors for the global mining industry', JOURNAL OF CLEANER PRODUCTION, vol. 184, pp. 788-797.View/Download from: Publisher's site
Northey, SA, Mudd, GM & Werner, TT 2018, 'Unresolved Complexity in Assessments of Mineral Resource Depletion and Availability', NATURAL RESOURCES RESEARCH, vol. 27, no. 2, pp. 241-255.View/Download from: Publisher's site
Werner, TT, Ciacci, L, Mudd, GM, Reck, BK & Northey, SA 2018, 'Looking Down Under for a Circular Economy of Indium', ENVIRONMENTAL SCIENCE & TECHNOLOGY, vol. 52, no. 4, pp. 2055-2062.View/Download from: Publisher's site
Northey, SA, Mudd, GM, Werner, TT, Jowitt, SM, Haque, N, Yellishetty, M & Weng, Z 2017, 'The exposure of global base metal resources to water criticality, scarcity and climate change', GLOBAL ENVIRONMENTAL CHANGE-HUMAN AND POLICY DIMENSIONS, vol. 44, pp. 109-124.View/Download from: Publisher's site
Northey, SA, Mudd, GM, Saarivuori, E, Wessman-Jaaskelainen, H & Haque, N 2016, 'Water footprinting and mining: Where are the limitations and opportunities?', JOURNAL OF CLEANER PRODUCTION, vol. 135, pp. 1098-1116.View/Download from: Publisher's site
Northey, SA, Hague, N, Lovel, R & Cooksey, MA 2014, 'Evaluating the application of water footprint methods to primary metal production systems', MINERALS ENGINEERING, vol. 69, pp. 65-80.View/Download from: Publisher's site
Northey, S, Mohr, SH, Mudd, GM, Weng, Z & Giurco, D 2014, 'Modelling future copper ore grade decline based on a detailed assessment of copper resources and mining', Resources, Conservation and Recycling, vol. 83, pp. 190-201.View/Download from: Publisher's site
The concept of 'peak oil' has been explored and debated extensively within the literature. However there has been comparatively little research examining the concept of 'peak minerals', particularly in-depth analyses for individual metals. This paper presents scenarios for mined copper production based upon a detailed assessment of global copper resources and historic mine production. Scenarios for production from major copper deposit types and from individual countries or regions were developed using the Geologic Resources Supply-Demand Model (GeRS-DeMo). These scenarios were extended using cumulative grade-tonnage data, derived from our resource database, to produce estimates of potential rates of copper ore grade decline. The scenarios indicate that there are sufficient identified copper resources to grow mined copper production for at least the next twenty years. The future rate of ore grade decline may be less than has historically been the case, as mined grades are approaching the average resource grade and there is still significant copper endowment in high grade ore bodies. Despite increasing demand for copper as the developing world experiences economic growth, the economic and environmental impacts associated with increased production rates and declining ore grades (particularly those relating to energy consumption, water consumption and greenhouse gas emissions) will present barriers to the continued expansion of the industry. For these reasons peak mined copper production may well be realised during this century.
Northey, S, Haque, N & Mudd, G 2013, 'Using sustainability reporting to assess the environmental footprint of copper mining', JOURNAL OF CLEANER PRODUCTION, vol. 40, pp. 118-128.View/Download from: Publisher's site
Berger, M, Sonderegger, T, Alvarenga, R, Bach, V, Cimprich, A, Dewulf, J, Frischknecht, R, Guinée, J, Helbig, C, Huppertz, T, Jolliet, O, Motoshita, M, Northey, S, Peña, CA, Rugani, B, Sahnoune, A, Schrijvers, D, Schulze, R, Sonnemann, G, Valero, A, Weidema, BP & Young, SB, 'Mineral resources in life cycle impact assessment: part II – recommendations on application-dependent use of existing methods and on future method development needs', The International Journal of Life Cycle Assessment.View/Download from: Publisher's site
Browning, C, Northey, S, Haque, N, Bruckard, W & Cooksey, M 2016, 'Life cycle assessment of rare earth production from monazite' in REWAS 2016: Towards Materials Resource Sustainability, pp. 83-88.View/Download from: Publisher's site
© 2016 by The Minerals, Metals & Materials Society. The environmental life cycle impacts of conceptual rare earth production processes were assessed. An average greenhouse gas emission of 65.4 kg CO2e/kg was estimated for the 15 rare earths produced from monazite, ranging from 21.3 kg CO2e/kg for europium to 197.9 kg CO2e/kg for yttrium. The average water consumption of rare earth production was 11,170 kg/kg ranging from 3,803 kg/kg for samarium and gadolinium to 29,902 kg/kg for yttrium. The average gross energy requirement for production was 917 MJ/kg, ranging from 311 MJ/kg for samarium and gadolinium to 3,401 MJ/kg for yttrium. Given the low concentration of HREE in monazite, the high impacts across all categories for yttrium and other HREE are not necessarily representative of HREE sourced from all rare earth resources. Further studies into other rare earth mineral resources (e.g. bastnasite and xenotime) are recommended to improve the overall understanding of environmental impacts from rare earth production.
Browning, G, Northey, S, Haque, N, Bruckard, W & Cooksey, M 2016, 'Life cycle assessment of rare earth production from monazite', TMS Annual Meeting, pp. 83-88.
The environmental life cycle impacts of conceptual rare earth production processes were assessed. An average greenhouse gas emission of 65.4 kg CO2e/kg was estimated for the 15 rare earths produced from monazite, ranging from 21.3 kg CO2e/kg for europium to 197.9 kg CO2e/kg for yttrium. The average water consumption of rare earth production was 11,170 kg/kg ranging from 3,803 kg/kg for samarium and gadolinium to 29,902 kg/kg for yttrium. The average gross energy requirement for production was 917 MJ/kg, ranging from 311 MJ/kg for samarium and gadolinium to 3,401 MJ/kg for yttrium. Given the low concentration of HREE in monazite, the high impacts across all categories for yttrium and other HREE are not necessarily representative of HREE sourced from all rare earth resources. Further studies into other rare earth mineral resources (e.g. bastnasite and xenotime) are recommended to improve the overall understanding of environmental impacts from rare earth production.
Haque, N, Norgate, T & Northey, S 2014, 'Life cycle based greenhouse gas footprints of metal production with recycling scenarios', TMS Annual Meeting, pp. 113-120.
Life cycle assessment (LCA) is a recognized tool to evaluate various processing routes for metal production. Declining ore grades and higher specific energy requirements for primary metal production put greater emphasis on recycling. Greenhouse gas (GHG) emissions of steel and aluminium metal production were quantified with recycling scenarios using material recovery facility (MRF) data from the database of SimaPro LCA software. The GHG footprint of the MRF is relatively minor compared with that of associated transport during collection (i.e. 10 times more than MRF) of curbside recyclable material. Additionally, if the bulk recyclable material is sent overseas (i.e. Australia to China) from the MRF for further processing, the GHG footprint of shipping can significantly be larger compared with the sum of the collection and MRF (assuming electricity is from same source). Thus opportunities exist for reducing GHG emissions from secondary metal production if it is processed close to the MRF.
Bao, C, Mortazavi-Naeini, M, Northey, S, Tarnopolskaya, T, Monch, A & Zhu, Z 2013, 'Valuing flexible operating strategies in nickel production under uncertainty', 20TH INTERNATIONAL CONGRESS ON MODELLING AND SIMULATION (MODSIM2013), 20th International Congress on Modelling and Simulation (MODSIM), MODELLING & SIMULATION SOC AUSTRALIA & NEW ZEALAND INC, Adelaide, AUSTRALIA, pp. 1426-1432.