How Much It Emits — And Where Emissions Happen
Understanding the emissions profile of cement and concrete is essential to evaluating which solutions can actually move the needle — and which cannot.
Executive Summary
Concrete's footprint is mostly a cement story, and cement's footprint is mostly a clinker story.
Process emissions from converting limestone to clinker are inherent to the chemistry — not an efficiency problem.
Energy emissions from extreme heat and power matter especially for electrification pathways.
Most emissions concentrate at the kiln — this is the center of gravity for abatement.
If you don't know where the emissions live, you'll fund the wrong things — or demand the impossible from the right things.
How Much Does Concrete Emit?
Not a rounding error — a top-tier climate sector
Concrete is everywhere. And the emissions are not subtle. Cement manufacturing is responsible for ~7–8% of global CO₂ emissions. That's not "a material problem." That's a top-tier climate sector.
A useful mental model: if the cement industry were a country, it would rank among the world's largest emitters. This is why concrete belongs in the same category as power, oil & gas, and steel — whether we treat it that way or not.
If Cement Were a Country
Relative CO₂ emissions (illustrative scale)
So "7–8%" isn't trivia. It means cement is not a rounding error, you don't hit net zero without it, and if you do solve it, you've solved something country-scale.
Concrete vs. Aviation
And what SAF tells us about how markets get built
Here's the gut-check comparison: aviation is ~2.5% of global CO₂ emissions. Cement is ~7–8%. So cement is roughly 3× aviation's CO₂ footprint on a share-of-global basis.
~2.5%
Aviation's share of global CO₂
~7–8%
Cement's share of global CO₂
3× aviation
Where the Emissions Actually Come From
Most of the footprint comes from one chemical reaction
Cement emissions come from two buckets. Most of the emissions sit at the kiln/clinker step. That's the bullseye.
Process Emissions (~60%)
When limestone (CaCO₃) is heated to form clinker, it undergoes calcination — a chemical reaction that releases CO₂ as a byproduct. These process emissions are inherent to the chemistry. No amount of energy efficiency or fuel switching can eliminate them. They are not a problem of how we burn — they are a problem of what we burn.
Energy Emissions (~40%)
Kilns require temperatures above 1400°C, typically fueled by coal, petcoke, or natural gas. Additional electricity is consumed for grinding and other plant operations. These energy emissions can theoretically be addressed through fuel switching, electrification, or renewable power — but each pathway faces significant technical and economic barriers at kiln scale.
Where Emissions Show Up in the Value Chain
Emissions are not evenly distributed across concrete production. They concentrate heavily at one stage — the kiln. Understanding this concentration is essential for prioritizing abatement strategies and allocating capital effectively.
Why This Matters for Solutions
Because emissions concentrate at the kiln and stem from both chemistry and energy, the solution space is constrained but well-defined. Every viable decarbonization lever must address either the calcination reaction, the thermal energy demand, or both. Here are the five primary levers:
Clinker substitution — replacing a portion of clinker with SCMs like fly ash, slag, or calcined clay to reduce the most carbon-intensive ingredient.
Carbon capture and storage (CCS) — capturing CO₂ at the kiln before it reaches the atmosphere, then transporting and permanently storing it.
Alternative chemistries — replacing Portland cement with novel binders that avoid the calcination reaction entirely.
Electrification of heat — replacing fossil fuel combustion in kilns with electric or plasma heating powered by renewables.
Process optimization — improving energy efficiency, fuel switching, and waste heat recovery across the production chain.
Now that you understand where emissions come from, explore the technology pathways being developed to address them — or browse the full research library.