Concrete is everywhere. From homes and offices to bridges and motorways, it is the backbone of modern society. Concrete is also the most widely used material on Earth after water. Yet the convenience of concrete comes with a cost. Cement, the key ingredient, is the single largest industrial emitter of carbon dioxide, responsible for 2.8 gigatons of CO₂ per year.
Why Cement Production Creates Higher Emissions
Cement is produced by heating limestone to around 1,600°C, a process that requires huge amounts of fossil fuel. For every kilogram of concrete made, nearly an equal amount of CO₂ is released into the atmosphere. With global construction expected to double by 2060—equivalent to building another New York City every 30 days—the scale of emissions is staggering.
Decarbonising Concrete: Global Approaches
Researchers across the world are racing to make greener cement and concrete. Current innovations include:
- Carbon capture and storage, locking emissions underground or under the seabed
- Injecting CO₂ directly into concrete to trap carbon while increasing strength
- Recycling cement from demolished buildings to reduce emissions at the source
Among these options, cement recycling is emerging as one of the most promising breakthroughs.
A Breakthrough: Electric Cement from Recycled Materials
A team at Cambridge University has developed a method to recycle used cement in steel furnaces without releasing new CO₂. The process works by using slag, a by-product of steel recycling that has a similar chemical structure to cement. By feeding old cement into these furnaces, and powering them with renewable energy such as wind, solar or green hydrogen, the process can create what is being called “electric cement”.
Scaling Up with Cesla
Cardiff-based startup Cesla is working to scale this method with electric furnaces. Early results show potential for lower costs than traditional cement, reduced environmental impact and the ability to supply up to a quarter of the UK’s future cement demand. If rolled out globally, electric cement could transform one of the world’s most polluting industries into a driver of sustainable development.
Sublime Systems and Industry Partnerships
Another innovation comes from Sublime Systems in the United States. Their process uses an electrolyser to produce cement at room temperature, making it easier to capture CO₂ released during production. Microsoft has committed to purchase over 600,000 tons of Sublime’s low-carbon cement, supporting the company’s first full-scale factory.
According to Dr Leah Ellis, Sublime’s CEO and co-founder, this deal helps secure long-term customers and investment, enabling faster scale-up and proving that clean cement can move from the lab to mainstream construction.
Why Green Cement Matters
The challenge of decarbonising concrete is not optional. Urbanisation is accelerating, infrastructure demand is rising, and climate targets are tightening. Innovations like electric cement, cement recycling and low-energy production systems are critical to building a future where construction materials reduce emissions rather than drive them.
The hope is that the buildings of tomorrow will not only provide shelter and the bridges of tomorrow will not only connect communities, but they will also protect the planet itself.