Rare Earth Elements Pose Environmental, Economic Risks for Clean Energy

In 2010 China withheld shipment of rare earth elements to Japan during a territorial dispute between the two countries. Rare earths, a grouping of 17 difficult to mine elements, are essential in the manufacture of goods such as cell phones and computer hard drives. They’re also a critical element in wind turbines and electric vehicle motors.

Today, China is the source of 85% of the world’s supply of refined rare earths, a fact that has raised concern in the United States given the growth of Chinese-American diplomatic tensions and rising demand for clean energy technologies. Any future disruption in the supply of the metals, similar to that experienced by Japan a decade ago, could have a crippling effect on clean energy development in the U.S. and elsewhere.

In the podcast, authors of the recent Kleinman Center report, Rare Earth Elements: A Resource Constraint of the Energy Transition, discuss the market for rare earths, explain why they are so important to clean energy, and examine growing calls to diversify global supply.  The authors, Amy Chu of Mills College, and Oscar Serpell of the Kleinman Center, also talk about the high environmental impact of rare earths production, a reality that is at odds with the environmental promise of clean energy.

Full Transcript

Andy Stone: Welcome to the Energy Policy Now podcast from the Kleinman Center for Energy Policy at the University of Pennsylvania. I’m Andy Stone. In 2010 China withheld shipment of rare earth elements to Japan during the territorial dispute between the two countries. Rare earths are a group of metals that are essential in the manufacture of goods such as cell phones and computer hard drives. They are also a critical element in wind turbines and electric vehicle motors. Today China is the source of 85% of the world’s supply of refined rare earths, a fact that has raised concern in the United States, given diplomatic tensions with China and as demand for clean energy technologies has increased. Any future disruption in the supply of rare earths similar to that experienced by Japan a decade ago could have a crippling effect on clean energy development in the US and elsewhere.

On today’s podcast we’ll look at the market for rare earths, explain why they’re so important to clean energy, and discuss the growing calls to diversify the world’s rare earth supply. We’ll also talk about the dirty underside of rare earths, the mining and processing of which can be environmentally destructive in the extreme. This is a reality that puts the production of the metals at odds with the environmental promise of clean energy. Here to discuss rare earths are two guests. Amy Chu is an Assistant Professor of Chemistry at Mills College, and Oscar Serpell is Associate Director of Academic Programming here at the Kleinman Center. Their recent report “Rare Earth Elements: A Resource Constraint of the Energy Transition” was funded by the Kleinman Center. Amy and Oscar, welcome to the podcast.

Amy Chu: Thank you, Andy. It’s good to be here.

Oscar Serpell: Thanks for having us, Andy.

Stone: Amy, the new report looks at the global trade in rare earths and at the economic and environmental challenges that are linked to their production. To get a start, what are the rare earth elements?

Chu: Rare earth elements are 17 chemical elements in a very specific location on the periodic table of elements. You can search for one of these periodic tables online, which is a really convenient source, and count from the left side of the table to the third column. In this column, the elements in the fourth, the fifth, and the sixth row together — collectively these 17 elements in total — they are called “rare earth elements.” These elements are very interesting because while they all have very similar chemical reactivity, which is what you would expect for elements within the same column of the periodic table, they each have distinct magnetic properties. For example, the element neodymium can be very easily purchased because it’s often made into novelty toys because of neodymium’s strong magneticity.

Before we go any further, I just want to make a very clear distinction here between these 17 specific rare earth elements and the elements lithium and cobalt. So these two elements, lithium and cobalt, are absolutely critical resources to today’s technologies, and they are often called “rare earth metals,” which can be very confusing due to the name being very similar to “rare earth elements,” which are the 17 elements that do not include lithium or cobalt. But lithium and cobalt have very different functions, and they present challenges that are distinct from rare earth elements because of the differences in the ways that they are mined, their geological distribution, and a host of other reasons. I just wanted to be clear that our discussions here today, when we refer to “rare earths,” they do not include lithium or cobalt but just the 17 specific rare earth elements.

Stone: Amy, I understand there are also two particular rare earths that are really relevant to clean energy, and those are neodymium — if I’m pronouncing that correctly — and dysprosium. Is that right?

Chu: Yes, we just talked about neodymium as a strong magnet, and it’s often made into novelty toys. In fact, they can be made into one of the strongest permanent magnets known to us. Permanent magnets mean that they can generate their own magnetic field, and it’s actually one of the more common magnets that we encounter in everyday life. So those magnets that are sitting on your refrigerator right now, those are permanent magnets. Because of this unique physical property of neodymium, it is used in various technologies that require magnets. In addition to neodymium, as you have mentioned, the element dysprosium and also an additional element, praseodymium — these are also really important rare earths that can be added into the strong neodymium magnets to modify their physical properties based on the application that you desire to implement them in.

Stone: Why are rare earths so important to the clean energy industry?

Chu: The intense interests that rare earth elements are receiving today are largely driven by their magnetic properties, which we have just been discussing. In fact, the dominant use of rare earth elements right now is for magnet production. Close to 40% of all rare earths mined are used in making magnets, and this brings us to why they are so important in the clean energy industry. It’s because magnets are absolutely essential to the way that we generate and use electricity.

Two examples that I want to bring up today are related to our discussion. The first one is electric vehicles. The electricity that is released from the vehicle battery first interacts with a strong magnet, and then that magnet turns the electrical motor — which is what drives your vehicle’s wheels forward. This is an example of how electricity can be transformed into the energy of motion through the use of magnets. This process can also be conducted in reverse in the second example that I want to mention, where a force generated by motion can be transformed into electricity through the interaction, again, between a magnet and the force. And this is the case for wind turbines.

Stone: Oscar, my understanding is that rare earths aren’t, in fact, that rare.

Serpell: Yes, Andy, that’s right. I think it’s a name that really emerged because these elements are found in very low concentrations. But actually, when you look at their distribution globally, they’re very dispersed. They can be found in a lot of places, unlike cobalt or lithium or some materials like that, which are very concentrated. In terms of production, they’re really not that rare, either. For example, global annual production of rare earth elements is about 250,000 tons. If you compare that to truly rare metal — something like gold — we produce about a thousand times more rare earths than we do gold every year.

So the name is maybe a little bit misleading, and this is actually a very good thing because the projected demand for rare earths is going to increase rapidly over the coming decades, for nearly all of these 17 elements that Amy mentioned. This is because technologies are going to continue developing to leverage their unique magnetic and also luminosity properties. But the most striking increase in demand is going to be for these three elements that Amy mentioned because of their use in some clean tech. So neodymium, praseodymium, and dysprosium — all three of which are going to see very extreme increases in demand — at least according to the most rigorous estimates that we were able to find.

So neodymium is going to increase 700% by 2035 over 2010 production levels. Dysprosium is set to increase 2,600%, and praseodymium is set to increase by at least 650%. These estimates, frankly, are probably low. These projections have not been updated in the most recent years, since new, very ambitious decarbonization targets have been set around the world. Today it’s looking as though production could be increasing by as much as 10 to 15% per year for the next decade or so.

One of the economic challenges with rare earths is that they are typically co-located with each other, so you don’t find neodymium on its own. You don’t find dysprosium on its own. You find them in combination with many of the 17 rare earth elements. What this means is that if you have increased demand for dysprosium, you’re going to get increased mining and production of these other 17 elements, just as a by-product, essentially. What this means is that for those elements production could increase faster than demand, which could lead to an over-supply of some of these lesser-used rare earth elements, driving costs down for those materials and effectively transferring that cost to the cost of neodymium, praseodymium, and dysprosium, the three elements that are really necessary in the clean energy transition.

As Amy said, fortunately many of these rare earths have similar properties, and so there will be opportunities to substitute for elements with lesser demand. However, balancing production during a period of rapid growth like this and figuring out new uses is going to demand vigilance and innovation on the part of manufacturers.

Stone: The growing demand for rare earths raises a question of vulnerability, and that’s related to China’s dominance in the production of rare earths. Tell us about some of the political and economic concerns that are raised by China’s near monopoly in certain aspects of the rare earth industry.

Serpell: Historically, China’s monopoly over rare earth element production and refining capacity has been of greatest concern to national security and defense agencies, really. It has been seen, and is really still seen, as a national security risk. This is because rare earth elements are required in many military applications. For example, they play a critical role in missile defense systems and nuclear warheads. Fighter jets have rare earths incorporated, and that’s just to name a few examples. So the disruption in supply from China of these refined products — the fear is that it could significantly hobble defense operations. However, when it comes to the actual quantity of rare earth elements used, the energy transition, specifically EVs and wind turbines, represent a much larger source of demand for rare earth elements than the military does. Just as a disruption in supply from China would impact defense preparations, it could also impact domestic clean energy industries. This would be especially troubling if limited supply forced domestic competition between, for example, US defense and domestic energy investments.

So currently, Mountain Pass Mine in Nevada contributes about 15% of global supply of unrefined rare earth elements, and this is really the only sizeable US mine. It is becoming an increasingly large player in mining capacity, but China still dominates production of the refined products. Today China controls upwards of 80% of that processed material.

Stone: Oscar, following up on that, how did China become the dominant supplier?

Serpell: It wasn’t always the case that China controlled supply. Up until the early 1980s, China really had no rare earth production or refining capacity to speak of. Up to that point, Mountain Pass Mine, that I mentioned in Nevada, produced most of the world’s rare earth elements. The trouble was that because rare earth elements are geographically dispersed, as I mentioned, there is no real necessity geologically speaking to mine these materials in the US. And comparing Chinese and US environmental protections, essentially strict environmental laws in the US and relatively lax protections in China gave mining in China just a strong competitive advantage in terms of cost. And it soon became apparent to rare earth producers that it was not worth continuing to produce this material in the US.

Over the following twenty years, there was this massive global pivot in production. By around 2010, China controlled upwards of 95% of rare earth element production. As I said, Mountain Pass has started to increase production again, as are countries like Australia and Brazil. But China still controls the lion’s share. There’s also the added complication that nearly all refining capacity is still in China. So mining in the US doesn’t solve the whole issue. It will add cost, actually, to the production if it has to then be sent to China for refining, and it doesn’t really address the US’s concerns about reliability of supply.

A company called Magnequench was one of the last magnet manufacturers in the US, and this was back in the 1990s. But that was actually sold to a Chinese consortium in 1995. When you look at the last several decades, it just frankly becomes clear that China made rare earth element production a priority, and the US simply did not. We’re now faced with those consequences moving forward.

Stone: I think it’s interesting as well that the market for rare earths isn’t that big. I saw a figure, just over one billion dollars for rare earth exports. But the industries that are dependent on rare earths are many, many, many multibillion-dollar industries. So there is a lot tied, obviously, into this one.

Amy, I wanted to point out — it’s probably pretty obvious by now, but what looks to be a great irony — rare earths are essential to the growth of clean energy and related technologies such as electric vehicles, yet rare earths themselves are environmentally hazardous.

Chu: Yes, you make a really good point, Andy. The environmental hazards that using rare earth elements pose was a major area of focus for our team, specifically our team member, Dr. Benjamin Paren at MIT right now, who couldn’t be here with us today. He wrote a really great piece about this in our digest. The hazards attributed to rare earth elements are largely related to the extraction process which can be roughly separated into the two stages that Oscar mentioned — the mining and refining. So mining of any natural resources always poses environmental consequences on the area where the resources are mined, but what is really challenging for rare earth elements is the refining process, because of what Oscar also mentioned, the low concentrations of rare earths. This means that the mined rock only has a small amount of rare earth elements present and a whole lot of other stuff.

Once the rare earth elements are extracted, we would have to either find other uses for that other stuff or discard it as waste. So I like to think of this challenge in the sense of Skittles. I am particularly fond of green Skittles, and we’re going to use green Skittles as the rare earth element in our analogy. But when you get a bag of Skittles, they come in a variety of colors, and only a small portion of them are green, which are the ones that I want. I either need to find someone else to take all of my non-green Skittles, or throw them away. Unfortunately, a lot of the waste that I need to throw away during the refining process of rare earths — they are radioactive and pose significant health and environmental concerns when they are not stored properly.

Stone: So it’s kind of like the problem with the blue M&Ms, right? You don’t want to throw away the rest of the bag, but you’ve got to do something with it.

Serpell: I love that analogy, Amy. I guess maybe to just assign some numbers to the Skittles — when we’re looking at rare earth elements, it has approximately what we call a “waste-to-yield ratio” of about 2,000:1. So if you think about that as for every 2,000 Skittles you had, there would only be one green Skittle. If you compare this to something like copper mining, which is still not great for the environment, certainly, but only has a waste-to-yield ratio of about 150:1. So 150 Skittles to one green Skittle. It’s about 13 times less than rare earth elements. And this just emphasizes the incredibly low concentrations of rare earth elements in these deposits, and that is definitely a major contributing factor to their environmental impact.

Stone: Oscar, how concerned is industry, the industries that rely on rare earths about the security of rare earth supply?

Serpell: We’re in a position where the US, Australia, Brazil, and others have kind of woken up to the importance of having a reliable supply of these crucial elements. These concerns were further solidified recently when China briefly threatened to restrict rare earth elements as part of the trade war between the US and China. Again, primarily the concern continues to be defense and national security, which I think is somewhat misguided. As I said, in terms of gross volume, turbines and EVs are going to represent a much more significant source of demand in the coming decades, and these two essential technologies are a key part of the energy transition. If the US or really any other country is unable to secure the necessary rare earth elements for manufacturing of those products, that country is going to be frankly left behind in what is really the industrial revolution of our lifetimes.

At the same time, the concern is the increased domestic production of rare earth elements means accepting these very significant environmental risks. In a country like the US that has relatively strict environmental protections, my concern is that we’re heading towards an inevitable conflict between scaling up production quickly enough to support emerging industries versus sufficiently vetting new mining and refining operations to ensure that they’re not having significant detrimental effects on nearby ecosystems and communities.

If we cut through this regulatory red tape too quickly, we risk creating a new environmental catastrophe in the form of rare earth element pollution. On the other hand, if we proceed too cautiously in increasing production, then we risk delaying domestic growth of EV and turbine production. So it is a real Catch-22.

Stone: Oscar, are there any options being considered possibly to bypass or reduce the importance of China as a rare earth supplier?

Serpell: Yes, there certainly are. The Biden administration and Department of Energy are really looking into a number of possible solutions there. Really the first and foremost response has been to try and secure resources from elsewhere or increasing domestic production outside of China. And this means not only opening new mines and expanding existing mines like Mountain Pass, but it also means increasing domestic and allied refining capacity. Again, if mining increases but refining is still all in China, that really doesn’t solve the US or any other country’s concerns about a reliable supply, and it really just adds to cost. So we really need to increase both mining and refining outside of China. I think countries outside of China are exploring a number of options.

There is the possibility, for example, of trying to mine rich sea bed deposits. I’m definitely not an expert on the specifics of this process, but from what I’ve read on it, I am pretty skeptical that that is the right path forward. Currently mining of rare earth elements happens in relatively unpopulated, fairly arid regions like Nevada, like Western China where containment of waste is relatively simple. Sea bed mining strikes me as kind of a proposal borne somewhat out of desperation. I really can’t see how this method would ensure the same level of containment of radioactive waste, for example, as mining on land.

Stone: One of the other issues here, it seems, whenever any country that would seek to expand its production and refining of rare earths could bring some of the environmental problems that are now pretty much concentrated in China, which is the dominant supplier, home. How much is this going to be a realistic barrier to the expansion of significant rare earth production outside of China, Oscar?

Serpell: Yes, I think there are several traits of rare earth element mining and refining that are problematic. As we’ve already mentioned, the high waste-to-yield ratio is a big one. The co-location with radioactive elements like uranium and thorium is obviously a huge concern. Also, as is the case with a lot of mining and refining, it’s just the use of acids and solvent liquids that make production a significant environmental threat, really no matter where it’s performed. So these are not concerns specific to China.

I guess my concern is that if the US or Australia or others feel the need to rapidly increase production in response to either reduced Chinese exports or even just the threat of reduced Chinese exports in the future, that that production may increase perhaps too rapidly and without the environmental due diligence that a process like this really requires.

Stone: Amy, this brings up a related question. If rare earth’s production is to increase in the United States, Australia, and elsewhere, and it’s done in an environmentally responsible way, this, I would assume, implies that the costs of the products are going to go up as well, right? So is the market in all these other countries such as the US willing to foot these costs? And with industry — what would the response of industry be to this, to get maybe clean, yet very expensive rare earths?

Chu: Yes, Andy, I agree with that viewpoint because one of the most common ways that we manage environmental impacts of the extraction of any natural resources is through imposing a pollution pricing scheme. So we can think about doing that for rare earth elements, to impose a pollution tax. As you’ve mentioned, this will inevitably increase the cost of rare earth elements that not a lot of developed countries will be willing to accommodate.

There’s another factor that may further contribute to increased costs of the valuable neodymium and dysprosium that may disincentivize countries other than China to engage in rare earth element extraction and further complicates this picture. This is actually something that Oscar has already briefly mentioned, the cost of the other rare earth elements that are co-extracted. Because these 17 different elements, even though they are not all particularly desirable for technological applications, they are often naturally present together in the same mined rocks. I’d like to go back to the Skittles analogy. If you think about my high desire for green Skittles, and I buy bags and bags of Skittles just to get the green ones out, I inevitably have to bear the full cost of all the different colors of Skittles. If I cannot find someone else to take the non-green Skittles off my hands, that would essentially increase the cost of the green Skittles altogether for me.

So if you think about us not being able to find other applications for the non-neodymium, dysprosium, and praseodymium — which are the highly desirable magnetic elements — if we cannot find other buyers or applications for these non-neodymium, praseodymium, and dysprosium elements, that inevitably increases the costs of the more valuable magnetic elements that we want. So overall these possible scenarios will lead to the price increase and could perhaps pose a risk to the rapid deployment of clean energy technologies on a large scale because not a lot of developed countries like the US are willing to bear the cost of these more expensive materials.

Stone: You also just brought up the issue of time to market, right? Even if we were to aggressively move forward in this country to expand the mining and refining in magnet production based upon rare earths, that’s going to take a decade once you look at all the permits and the physical construction of facilities. But we’ve got a pretty aggressive renewable energy portfolio future right here. The Biden administration is looking for a hundred percent clean energy by the year 2035. Simply put, are we going to have domestic production any time soon that would meet that demand?

Chu: That’s a really good point, and I think Oscar already brought up some really good points about this, as well. I just want to echo some of that. A few things we want to consider: The first one is that if we want to start extraction here in the US, it really takes time to conduct the environmental studies, get the right permits, and then it takes quite some time to ramp up the capacity. So these things are all really important because we want to extract rare earth elements in an environmentally responsible way, but that inevitably will take up more time, which is at odds with what is needed for the rapid deployment of these elements in renewable energy.

Another way that has often been discussed to be a possible way to overcome the price increase challenge is to recycle rare earth elements to decrease the need of the harmful practice of mining. So retired wind turbines and electric vehicle motors are particularly suitable for recycling. However, if you think about the long lifetime of these products, say eight to ten years for an electric vehicle motor and perhaps up to twenty years for wind turbines, it will take a very long time for all of this retired equipment to be able to meet the demand of the expanding capacity of wind energy and electrical vehicle deployment.

So at least in the near future, recycling and also starting up new extraction operations in the US will not be able to meet our near-future goals of rapid deployment. There is really not a very clear best path forward to drastically decrease dependence on foreign producers right now.

Stone: Amy, earlier I asked Oscar a question about what might be done to bypass dependence on China as the primary supplier of rare earths. I want to ask you, and you just started into this a moment ago — Are there ways to bypass the need for rare earths generally? Are there substitutes for rare earths that might be acceptable for industry?

Chu: Yes, there are several possible alternative strategies, and I’m just going to bring up a few here. For example, one alternative strategy is to use magnets that are not made from rare earth elements. We talked about how rare earth elements are permanent magnets, which are like those magnets that you use on your refrigerators. They can also be made from non-rare earth elements. For example, the most common permanent magnets are usually made from metals like iron and nickel, so these are metals that are a lot more abundant and do not have such a large carbon footprint for the extraction. However, the main drawback of that is they have weaker magnetic strength. Right now there’s a lot of research on magnet compositions to reach a desirable compromise in the magneticity versus the amount of rare earth element used, by decreasing the percentage of incorporated rare earth elements, while retaining the magnetic strength, by substituting with other metals that also exhibit permanent magneticity.

And just one more possibility that I want to bring up is to encourage the use of technologies that are based on electromagnetism instead of using permanent magnets. In contrast to permanent magnets, electromagnets generate magnetic fields using an externally applied electrical current, but the magnetic field disappears once the electrical current is cut off.

An important example of how electromagnetism can be used in energy applications is the use of electromagnetic induction designs. These designs have been around for a very long time, and like those that utilize permanent magnets, the induction design uses magnets from electromagnets to generate electricity with that key distinction that they’re not using permanent magnets. These technologies have been around for a while. In fact, the first few Tesla models, like the Model S and the Model X, use induction designs that do not rely on rare earth metals. Most of the wind turbines today also use some sort of induction design. However, induction designs are usually a lot more complicated and require many more components, compared to permanent magnet designs.

So going back to that example of Tesla electric vehicles, they have actually begun using more and more permanent magnets based on rare earth elements in recent years. The newer models are often a combination of induction and permanent magnet designs because of the more simplistic design and lower mass, lower weight of permanent magnets.

In wind turbines, induction designs require gear boxes that need to be maintained on a regular basis, which makes them not very ideal for offshore purposes — offshore wind turbines — because they’re a lot more difficult to get to if you want to maintain these gear boxes. So offshore wind turbines really benefit from having permanent magnet designs that are lighter and do not require as much maintenance.

So here we have discussed at least two alternatives that present significant drawbacks, compared to using rare earth elements. There is really little incentive right now for the industry to move towards these alternatives because of their more complicated designs or larger weights that they will put on the product itself, especially when we can get rare earth elements so cheaply in today’s market.

A pathway to dramatically reduce our dependence using these alternative technologies really remains unclear. But thinking about all the environmental consequences and the geopolitical complications, I think we really need to think about a hybrid approach when adopting these technologies, instead of relying solely on rare earth elements going forward.

Stone: Oscar, I want to jump back for a moment to the question of China’s dominance in supply. We’ve talked a lot about the environmental concerns that any country that again would want to build up its own domestic rare earth supply chain would need to consider. But China is also getting quite serious about the environmental impacts of its own rare earths industry. The question I want to ask is there seems to be a kind of tension here, right? So China is the low-cost leader in rare earths because in the past, my understanding is that it had been quite lax in some of its environmental oversight. It’s now starting to tighten that up. Is China willing to give up its dominance as a supplier of rare earths for environmental considerations and the costs that they would bring?

Serpell: Yes, Andy, I think that’s a very open question. I don’t know that anyone really — well, I’m sure someone knows. I unfortunately don’t know the answer specifically to whether or not China would be willing to do that. I can say that China has generally really been increasingly concerned about their air, water, and soil pollution over the last several years. They’re trying to remedy really decades of environmental disregard that was seen as necessary for building their economy into what it is today. But certainly, yes — for the last several years, the government has been shutting down small-scale and illegal rare earth element mining. President Xi has really stressed the importance of mining rare earths in an environmentally responsible way.

So China is definitely taking steps to address the pollution from rare earth elements. Whether or not that will extend to a willingness to give up dominance in the market, I don’t know. There’s also the clean-up of these legacy sites to consider. This is really a cost that the Chinese government has insisted the industry players share. This alone could lead to increased prices if the rare earth industry is now responsible for cleaning up all of these legacy sites.

The real question is does another country effectively take China’s place supplying these exceedingly cheap and environmentally destructive rare earth materials? Does China or the US, for example, find new ways of mining rare earths cheaply and sustainably? Or do we see really a global increase in rare earth element costs and/or supply shortages?

Stone: Oscar, let me ask you a final question here. In the United States, are there any particular policy or legislative proposals on the table to concretely increase domestic production of rare earths and all the refining that goes along with it?

Serpell: Yes, the Biden administration has initiated a review across federal agencies to address rare earth element supply chain vulnerabilities, and also to look into some ways of incentivizing sustainable domestic production — for example, tax incentives that would encourage domestic production.

There is increased industry activity in the US, I will say, in the last several years. So there is some new refining capacity being built up in Texas and in Utah by various companies. Also Mountain Pass Mine has the goal of reaching the level of capacity that that mine had back in the ’70s.

There has also been, I would say, recent policy progress in international partnerships, particularly between the US and Australia. This has really been in an effort to secure a future supply in case of disruption from the Chinese market, and also to collaborate on new research into sustainable and economical mining and refining methods.

Still the primary motivator behind these policies is national security, the Department of Defense. I think it might be somewhat, as I said, misguided because EVs and wind turbines are going to represent such a major demand in the coming decades. I think any plan, any clean energy plan that seeks to prioritize investments in renewable infrastructure, clean energy infrastructure and manufacturing — it really needs to include proposed solutions for securing a long-term supply of rare earth elements and indeed, other materials like lithium and cobalt, for that matter. These are going to be the essential commodities of the energy transition, and any country that really wants to be an economic leader over the coming decades is going to have to find a way to secure a reliable source and supply of these materials.

Stone: Amy and Oscar, thanks for talking.

Chu: My pleasure. Thank you, Andy.

Serpell: Thank you so much, Andy.

Stone: Today’s guests have been Amy Chu, an Assistant Professor of Chemistry at Mills College, and Oscar Serpell, Associate Director of Academic Programming at the Kleinman Center. Their recent report, “Rare Earth Elements: A Resource Constraint of the Energy Transition” is available on the Kleinman Center website.

This is the last episode of season five of Energy Policy Now.  We’ll be taking a break in the month of August and will return in September with new episodes that make sense of today’s most pressing energy and climate policy topics. In the meantime, visit the Kleinman center’s website where you can find our archive of more than 100 podcast episodes, as well as the latest research and events from the Kleinman center. If you’d like to be notified of the latest from the center, subscribe to our monthly newsletter on our homepage. Thanks for listening to Energy Policy Now, and have a great day.