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Leiden University

A Circular Economy of Metals: Towards a Sustainable Societal Metabolism

Leiden University via Coursera


Metals are present everywhere around us and are one of the major materials upon which our economies are built. Economic development is deeply coupled with the use of metals. During the 20th century, the variety of metal applications in society grew rapidly. In addition to mass applications such as steel in buildings and aluminium in planes, more and more different metals are in use for innovative technologies such as the use of the speciality metal indium in LCD screens. A lot of metals will be needed in the future. It will not be easy to provide them. In particular in emerging economies, but also in industrialised countries, the demand for metals is increasing rapidly. Mining and production activities expand, and with that also the environmental consequences of metal production. In this course, we will explore those consequences and we will also explore options to move towards a more sustainable system of metals production and use. We will focus especially on the options to reach a circular economy for metals: keeping metals in use for a very long time, to avoid having to mine new ones. This course is based on the reports of the Global Metals Flows Group of the International Resource Panel that is part of UN Environment. An important aspect that will come back each week, are the UN Sustainable Development Goals, the SDGs. Those are ambitious goals to measure our progress towards a more sustainable world. We will use the SDGs as a touching stone for the assessment of the metals challenge, as well as the solutions we present in this course to solve that challenge.


  • Introduction
    • Welcome to the course! This first module aims at introducing you to the main topic of the MOOC and to the teaching staff that you will be seeing throughout the whole course. Before you start with the first lessons we encourage you to have a look at our introductory materials and to introduce yourself in the forum in order to meet your classmates.
  • Metals in Society
    • In Week 1, you will be introduced to the world of metals. What are they, what are their properties, what are they used for and how essential are they? We will address the difference between major and minor metals. Major metals are used in large basic applications such as buildings, cars, pipes, cables, bridges, trains and airplanes. Minor metals that are used mostly in all kinds of electronics and in new technologies, for example for wind and solar energy. The amounts used are much smaller. The minor metals have more attention in the news, because of problems with the supply from international trade, and are subject to criticality assessments. The major metals, on the other hand, are even more important, although less in the centre of attention. Without them, society would fall apart. In this course, we will focus mostly on those major metals. We also introduce the Sustainable Development Goals of the United Nations. These SDGs are agreed on by all nations that are part of the UN, and outline goals for the future of the global society. They include goals on economic development, social development, health and the environment and form a powerful framework to judge developments in resource use, including metal use.
  • Metals Challenge
    • In week 2, the metals challenge is outlined. Metals are indispensable for society, but they are also associated with environmental impacts, especially related to climate change. The challenge is defined as how can we provide society with sufficient metals, now and in the future, without compromising environmental quality? An important part of the challenge is caused by the rapidly rising demand for metals. Over the 20th century demand has risen steeply, and this is expected to continue over the next decades. In this week, we will teach the issues around metal supply, scarcity and criticality, and environmental impacts to sketch the magnitude of the metals challenge. We also will meet the apparent contradiction between some of the SDGs: we need metals to develop societies and build up the infrastructure, on the other hand, we also need to reduce environmental impacts that will only increase if we don’t do anything about it.
  • Dynamics of Metal Systems
    • Week 3 and all subsequent weeks focus on solving the metals challenge. Obviously, we need to make changes in the metals system to reach a more sustainable situation and reconcile the different Sustainable Development Goals. When considering changes, it is important first to understand the system. We will be discussing stocks and flows of metals in society and see how they interact. In society, we do not just obey the laws of justice and economics, but also the laws of nature. It is important to realise that when contemplating solutions for the metals challenge. This week will be rather theoretical but will provide important information for the coming weeks.
  • Solutions to the Metals Challenge
    • Week 4 is rather packed with lectures on the different options to solve the metals challenge. You will meet experts from all over the world, who will lecture on materials and product design-for-environment and design-for-recycling, on the possibilities and also the barriers for remanufacturing, and on recycling as the last, but maybe most important resort to keep the metals in use. All these options aim at keeping up the stock-in-use of metals in society, while at the same time reducing the need to mine new metals. They all have their own strengths and limitations and can be regarded as pieces of the large puzzle aiming at solving the metals challenge, or in other words, reconciling the different SDGs.
  • Circular Economy as an Overarching Solution
    • In week 5, we try to get some idea of what the effectiveness could be of going for a circular economy. We do not consider all changes in society that have to be made to reach that, but simply have a look at whether or not, if we would reach a circular economy, we would indeed solve the metals challenge. Can we, theoretically, maintain supply and at the same time avoid supply problems and environmental issues in that way? And therefore, is it worthwhile pursuing a circular economy to reconcile the different SDGs? We use the case of aluminium to illustrate this.
  • Look into the Future
    • In this final week of the course, we will look briefly into the future. What can we expect for the next decades or even the next century? We’ll introduce the concept of scenarios, storylines about the future that have no predictive value but have their value as imagination of what could happen, and what the consequences would be if it did. And we will apply that to our major metals. Will demand go on rising? What will happen with the environmental impacts? Does it help, from the point of view of metal production, to have a renewable energy system in the background? Will more circularity in our economy make a difference? In short, is it possible to reconcile the SDG development goals with the environmental ones?

Taught by

Ester van der Voet


4.8 rating, based on 5 Class Central reviews

4.7 rating at Coursera based on 92 ratings

Start your review of A Circular Economy of Metals: Towards a Sustainable Societal Metabolism

  • Anonymous
    Particpating in this course was a wonderful experience. The lectures were lucid and the lecturers did well to convey the ideas and help me understand to a good extent, how effects of the global demand for metals can be solved by the circular economy principles.

    I got a lot of ideas and the course modules were helpful and easy to navigate.

    The assignments and peer review tasks also helped me think deeply about what I learned and also get fresh perspectives from my peers.

    I high recommend this course to anyone who has interest in learning about Circular Economy as it relates with metals, mining and Development.
  • Anonymous
    Hard class (at least for me...) but soooo interesting.
    Insights and lectures from top specialists give you an expert point of view, state of the art information, future trends with different scenarios,...
    I had completed "Circular Economy: an introduction" and "Sustainable packaging for a Circular Economy' from Delft University (on Great classes too and great introduction to these topics (which I didn't know much about). But this one on Metal was really in-depth learning for me.

    Keep up the great work and thank you for giving us the opportunity to keep training on these new subjects or issues.

    Bernard Bensoussan.
  • Anonymous
    Several weeks ago, I did not know much about metal life cycle and its challenges. This course helped me get familiar with all aspects of this wide topic. I feel I have a solid background now and that I would know where to look for more in-depth information. The course is about metals from their extraction to their recycling. For each step in the cycle, greener and substainable solutions are proposed and discussed. All the course is based on a solid background, mostly from UNEP. I highly recommend this course that will widen your understanding of the circular enconomy, applied in this case to metals.
  • Madona O. Yagyagen
    Before anything else, I thank all of the instructors online most especially to Ma'am Ester van der Voet. I have learned a lot from this course regarding metals. Even how it is related to SDGs. I found it interesting. It is a bit tough but I made it. I really wanted to have the certificate, so may I ask if there are other terms of payment through accredited banks to pay for it? Thank you for responding.
  • Anonymous
    First I would like to thank Professor Ester van der Voet for the video great lectures and also to the course managers to put together a very precious collections of suggested papers and books related to this subject. The course offers an excellent content and opportunity to initiate the learning on Circular Economy of Metals and how CE can support the UN to succeed on the SDG's goals and targets.

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