Energy for the Next Century: Why We Need to Be Honest About Carbon and Materials

When people talk about clean energy, we often hear neat labels: “zero-carbon”, “renewable”, “green”, “sustainable”. But if we are planning our energy system for the next 60 to 100 years, the lifespan of the infrastructure we build today we need to talk about the entire emissions and materials journey.

That means facing two realities at once:

1. all energy systems use materials and produce some emissions, and

2. some uses of materials and emissions are strategically worth it, and some simply are not.

In a recent podcast, Rory Stewart raised nuclear energy:

“It's a really, really interesting report because nuclear is going to be absolutely at the centre of the government's strategy.

Needs to be because it's not emitting carbon, but it's generating energy which acts as backup for wind and solar.”

Rory Stewart -  from The Rest Is Politics: Does Reeves' Budget Really Change Anything? What It Means For You, 26 Nov 2025

And it struck me for sounding so simple, and missing the underlying issue. If we want reliable, low carbon energy far into the future, we must learn to prioritise our use of materials and plan for our carbon emissions.

Nuclear is not zero carbon but it is genuinely low carbon

A common claim in energy debates is that nuclear power is “zero-carbon.” It isn’t. But that doesn’t make it high-carbon either.

To compare energy sources fairly, we use life-cycle assessments (LCA) a measure of all emissions associated with building, fuelling, operating, and eventually decommissioning a power source. That includes concrete, steel, mining, fuel processing, transport, and long-term waste storage.

What the reputable data shows

• The IPCC reports a median life-cycle emission for nuclear of about 12 gCO₂e per kWh — the same as onshore wind.

• The UN Economic Commission for Europe’s more recent analysis puts modern nuclear even lower, around 5–6 gCO₂e per kWh.

• Coal is around 820 gCO₂e/kWh, and gas around 490 gCO₂e/kWh.

Nuclear is therefore not zero-carbon, but it sits firmly in the lowest-carbon category of energy technologies humanity has ever deployed.

This is because the emissions of nuclear power come almost entirely from up-front construction and the fuel cycle. Once a reactor is running, its operational emissions are essentially negligible.

In other words:

Nuclear doesn’t give us “zero-carbon electricity,” but it does give us “very-low-carbon electricity for 60 years or more.”

And that matters a reactor built today will still be generating power in the 2080s.

All energy sources rely on finite materials including nuclear and wind

Another uncomfortable truth is that no energy technology is free of material constraints. There is no escape from mining, refining, manufacturing, or the environmental footprint that comes with them.

Nuclear’s material footprint

A nuclear station is overwhelmingly made of concrete and steel, which require large quantities of limestone, aggregate, iron ore and energy. On top of that, the fuel cycle requires uranium, a finite mined resource, and the reactor core uses specialised metals like zirconium alloys.

These materials are not rare, and nuclear energy has a lower material requirement per unit of electricity than most alternatives. But they are still finite, and a large global nuclear build-out would increase demand for them.

Wind’s material footprint

Wind power also depends on heavy, mined materials:

• Steel, copper, and aluminium for towers, generators, and cables

• Concrete for foundations

• Composite materials for blades

• And in many turbines, rare-earth elements such as neodymium and dysprosium
  minerals with genuinely constrained global supply chains

So wind energy, like nuclear, has a material footprint that must be managed responsibly.

No energy source is infinite, but not all uses of materials are equal

The key point is not that nuclear or wind are “bad” because they use finite resources.

The real point is:

If we are going to use finite materials and release unavoidable carbon in their production, we must use them for the highest value longterm purpose: low carbon energy.

And conversely, we should urgently deprioritise the wasteful uses of those same materials and emissions, notably:

• burning oil and gas for electricity

• flaring fossil fuels

• producing single-use plastics

• feeding high-carbon industries that have low public benefit

If producing a nuclear plant or a wind turbine emits some CO₂ and uses finite materials, that is a strategic carbon use, because it creates decades of low-carbon electricity.

Burning those same materials and releasing far more carbon for short-term energy?

That is a strategic error.

A century-scale investment needs century-scale thinking

Nuclear reactors can last 60 to 80 years. Offshore wind farms can last 30 to 35 years before major renovations. The infrastructure we choose today will define our energy landscape for generations.

This means we must be honest about what matters most:

• Carbon cost: low-carbon is good; zero-carbon is ideal but not required

• Material cost: finite materials should be used efficiently

• Longevity: infrastructure that provides clean power for decades is a good investment

• Opportunity cost: every tonne of CO₂ spent, and every tonne of material mined, should go toward long-term energy, not short-term combustion

We don’t live in a world of infinite copper, steel, uranium or rare earths.

And we no longer have a carbon budget that lets us burn oil and gas freely.

But we can build a long-term, low-carbon, resilient energy system if we prioritise:

• materials for clean energy, not disposable consumption

• carbon for infrastructure, not fossil fuel combustion

• strategic investment, not short-term fixes

The honest conclusion

• Nuclear isn’t zero-carbon.

• Wind isn’t material-free.

• Solar isn’t impact-free.

But all of them are vastly better uses of our remaining carbon and materials than continuing to burn fossil fuels.

If we want a stable, low-carbon energy system for the next century, the question isn’t:

“Which technology is perfectly green?”

None are.

The real question is:

“How do we use our finite materials and limited carbon budget to build the most reliable, lowest-carbon energy system that will last for generations?”