Scope 3’s Hidden Giant: Confronting Cement’s Massive Carbon Footprint

Concrete is the second most consumed material on Earth after water. Think about that for a second. The world drinks concrete. We build with it, we live on it, and we take it for granted.

The ancient Romans, for instance, pioneered an early form of concrete using volcanic ash, and many of their structures still stand after more than two thousand years, an evidence of concrete’s enduring strength. Yet, while this remarkable material is a pillar of modern infrastructure, its production (specifically cement) is responsible for around 7% of global anthropogenic CO? emissions.

The question, then, is how to keep building without compromising our planet’s climate goals. Enter green cement, a rapidly advancing technology that offers a pathway to dramatically reduce Scope 3 emissions, those indirect emissions stemming from a product’s entire value chain.

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Why Cement’s Carbon Footprint Is So Big

Traditional concrete depends on cement, which is both heat- and carbon-intensive to produce. The problem starts with limestone (calcium carbonate), which must be heated to high temperatures, releasing CO? in the process. With global construction needs on the rise, especially in developing regions, cutting back on building isn’t an option. Instead, the industry is transforming supply chains and production methods to shrink cement’s carbon footprint.

What Are Scope 3 Emissions?

Most companies track Scope 1 (direct emissions from their own activities) and Scope 2 (emissions from purchased energy).

However, Scope 3 emissions occur outside a company’s direct control, making them trickier to manage. For firms reliant on construction, the cement and concrete used in projects typically contribute heavily to Scope 3 emissions.

Reducing these is now a priority for many organizations aiming to meet ambitious climate targets.

Rethinking Raw Materials

Companies are looking to minimize carbon-intensive steps by replacing or supplementing limestone with alternative sources of calcium:

• Basaltic rocks and calcium silicates: Innovators such as Solidia Technologies, Brimstone, Sublime Systems, and C-Crete are exploring new feedstocks that circumvent some of limestone’s CO?-heavy reactions.
• Waste reactivation: Heidelberg Materials is experimenting with recycling the cement paste from old concrete, integrating captured CO? in the process.
• Industrial synergy: Cambridge Electric Cement pairs cement manufacturing with steel production in electric arc furnaces, potentially cutting energy use across industries.

These strategies, which rely on everything from lower-temperature kiln processes to mechanochemical activation, maintain cement’s familiar properties while cutting emissions throughout the value chain.

Industrial By-Products to the Rescue

Substituting part of traditional clinker (the baked limestone product) with Supplementary Cementitious Materials (SCMs), like coal fly ash or granulated blast furnace slag (GBFS), is one of the most established methods to reduce cement’s carbon footprint.

By repurposing these industrial by-products, manufacturers can:

• Lower emissions by reducing the need for fresh clinker.
• Save on raw material costs while giving a second life to what would otherwise be waste.
• Foster cross-industry collaboration, as steel or energy producers find new markets for their waste streams.

According to IDTechEx, increasing the share of SCMs in cement blends will be critical for decarbonization over the next decade, reshaping material sourcing and supply chain logistics worldwide.

Energizing Cement Production with Renewables

Cement kilns demand temperatures up to 1,450°C, traditionally supplied by fossil fuels. Green cement initiatives aim to replace these fuels with renewable energy:

• Electric kilns: Finland-based Coolbrook’s rotodynamic heating can reach 1,700°C using electricity, enabling all-electric cement production.
• Solar power: Synhelion and cement giant CEMEX collaborate to harness concentrated solar energy, storing thermal power to run kilns without reliance on fossil fuels.

In markets like the UK, net-zero ready mixed concrete has already hit the market. CEMEX’s Vertua range aims to offset residual emissions, helping firms comply with climate goals and tightening regulations.

Cutting Scope 3: The Business Case

Even organizations without direct control over cement plants can adopt or support green cement to reduce their Scope 3 emissions.

One emerging model is “book and claim,” where companies fund low-carbon cement production but don’t necessarily receive the physical material. The environmental benefits, however, are credited to the funder’s sustainability targets similar to systems used in sustainable aviation fuel (SAF) markets.

Tech leaders like Microsoft are championing this approach, which broadens access to greener materials and hastens the scale-up of low-carbon cement solutions.

What’s Next for Green Cement?

1. More Innovation: Expect ongoing breakthroughs in alternative chemistries and heat-efficient kiln technologies.
2. Expanded Collaboration: Waste by-products from steel or energy sectors can feed into cement production, creating circular economy models.
3. Regulatory Momentum: As nations impose stricter climate policies, developers and suppliers will face increasing pressure to adopt greener cement options.
4. Evolving Business Models: Carbon offset systems, direct procurement strategies, and new financing approaches will help businesses reduce their indirect carbon footprints.

A Greener Foundation for the Future

Cement may form the literal foundation of human civilization, but it doesn’t have to jeopardize our planet’s future.

Green cement offers a route to maintain the strength, durability, and reliability of concrete while slashing CO? emissions.

For businesses looking to address Scope 3 emissions, embracing these innovations can spell a more resilient, sustainable value chain.

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