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The world has enough minerals for low-carbon electricity
Total reserves are not the issue – mine construction and geopolitical risks are likely to be larger barriers to progress.
A low-carbon energy system will need a lot less fossil fuels, but a lot more of other minerals and metals.
One concern is that we’ll run out of these materials. Is that something we should be concerned about?
In a paper earlier this year, Seaver Wang and colleagues published a paper in the journal Joule looking at the demand for materials in low-carbon electricity systems.1 They looked at 75 different pathways to 2050 – using different combinations of technologies – that were compatible with keeping global temperature rise below 1.5°C and 2°C. In other words, scenarios with varying combinations of solar, wind, nuclear, hydropower, biomass etc.
They estimated the demand for 15 critical minerals and bulk materials.
They then compared this demand to global reserves and resources, and current rates of production.
Below, I’ll run through the findings, but here’s the summary:
We have enough of most materials to decarbonise our electricity systems. Demand through 2050 is equal to less than 15% of reserves for most materials.
Tellurium is one exception: cumulative demand was equal to 136% of global reserves, and 88% of resources. That means we’d need to find new deposits, or bring deposits that are currently uneconomic into production.
Maximum annual demand for most materials is in the range of 5% to 15% of current annual production. In other words, global production of these materials would need to increase by a maximum of 15% to build low-carbon electricity technologies.
There were four materials – polysilicon, neodymium, dysprosium, and tellurium – where annual demand would more than double. In some cases, it increases by more than 300%.
The embedded carbon emissions of building this infrastructure would be equal to half a year of current carbon emissions or less. It would take up around 6% of our remaining budget for 1.5°C and 1% for 2°C.
One important point is that this study only looks at materials for low-carbon electricity. It doesn’t include electric vehicles or other industries. I hope to cover this in another post. If you know of any studies that estimate the demand for transport, do let me know. Otherwise, I’ll crunch some numbers on my own.
Do we have enough materials?
Do we have enough minerals and critical materials to build a low-carbon electricity system?
In summary, yes. In the table, I’ve shown the cumulative demand for each material in a 1.5°C compatible pathway as a share of global reserves, and global resources.
Reserves refer to deposits that we know we can extract economically with the technologies we have today. Resources are the total deposits that we know are there – regardless of whether they’re economically viable to extract today. Reserves are therefore a subset of resources. If you’re still confused about this, you might find my short explainer useful.
Estimates for reserves and resources often change over time because we discover new deposits and known ones become viable to extract.
As you can see, demand for most minerals is less than 15% of global reserves and 5% of resources.
The one exception to this is tellurium, where demand is equal to 36% more than reserves. We do, technically, have enough global resources, but some of that would need to become economically viable to extract. I’m somewhat skeptical that we’ve put intense effort into finding as much tellurium as we can, so I would expect that we would find more of it if this mineral was in high demand.
How much would global production have to increase?
It’s not just total cumulative demand over decades that matters, but how much we need to produce every year. Are we capable of extracting enough, quick enough?
Let’s first look at some of the bulk materials – like aluminum, cement, copper, nickel, and steel – that are needed, compared to how much the world produces right now.
In the chart, we see the maximum annual demand for these materials for low-carbon electricity as a share of current annual production.
Annual demand for aluminum, for example, would increase by 11% to 17%. For nickel, 4% to 6%.
What’s clear is that building low-carbon electricity infrastructure will not lead to dramatic increases in production. Typically in the range of 5% to 15%. A challenge, but it seems do-able.
Demand for some minerals would increase a lot though. In the chart below we see the same, but for rarer minerals.
Many – such as silver and cadmium – are in the range of 5% to 15%. But for materials like dysprosium and tellurium, maximum annual production would be at least 300% higher than today. Global production would have to increase a lot.
How much greenhouse gases would we emit to build this?
People are often concerned about the greenhouse gases emitted in the production of these low-carbon technologies. To be clear: emissions from the mining and construction of these sources pales in comparison to fossil fuels, per unit of electricity.
Seaver Wang and his colleagues ran a range of different electricity mix scenarios and found that in nearly all cases, the cumulative emissions for the 1.5°C mitigation scenarios – all the way through to 2050 – were less than 20 billion tonnes of CO2eq. That’s around half of our current annual emissions.2
The median emissions were 12 billion tonnes (and ranged from 4 to 30 billion).
While these emissions are not negligible, they’re very small compared to the amount we’d emit with a fossil fuel system through to 2050.
In the chart, I’ve also shown the estimated remaining carbon budgets to keep the global average temperature rise below 1.5°C and 2°C. These figures are the latest estimates from Piers Foster and colleagues.3 To have a 50% chance of staying below 1.5°C, we can emit just 209 billion tonnes from 2024 onwards.4 Low-carbon infrastructure would eat up around 6% of that budget.
For 2°C, we could emit around 1109 for a 50% chance. Building our low-carbon electricity systems would take up just 1% of the budget.
Of course, the emissions from building low-carbon infrastructure in other areas – transport, industry, and construction – will be higher. But the point is clear: the embedded emissions in building low-carbon electricity is no excuse not to do it. It’s small in comparison to continuing to burn fossil fuels.
Total mineral supplies will not be the constraint – manufacturing and refined supply chains will be more critical
It’s unlikely that we’ll run out of the minerals we need to build low-carbon electricity systems in the coming decades.
A bigger issue is actually developing and opening mines in time, where and how they are produced, and the distribution of supply chains. Geopolitical risks are likely to be much higher than purely physical ones.
We should put less focus on the question of whether we’ll have enough minerals, and more on how secure supply chains are, short-term ramp-ups in production, and how responsibly they’re extracted.
In a future post, I’ll try to take a look at mineral availability for electric vehicles and transport.
Wang, S., Hausfather, Z., Davis, S., Lloyd, J., Olson, E. B., Liebermann, L., ... & McBride, J. (2023). Future demand for electricity generation materials under different climate mitigation scenarios. Joule, 7(2), 309-332.
The Global Carbon Project estimates current annual emissions to be around 41 billion tonnes of CO2.
Forster, P. M., Smith, C. J., Walsh, T., Lamb, W. F., Lamboll, R., Hauser, M., ... & Zhai, P. (2023). Indicators of Global Climate Change 2022: annual update of large-scale indicators of the state of the climate system and human influence. Earth System Science Data, 15(6), 2295-2327.
The estimate by Forster et al. (2023) was 250 billion tonnes. But we'll have used up another 41 billion tonnes this year, so the total from 2024 onwards will be around 209 billion tonnes.