Concrete is now the most widely used manufactured material on the planet. It has shaped so much of our built environment, but this comes at a massive environmental cost.

Concrete has a long and rich history, with evidence of its use dating back thousands of years. Ancient Egyptians used mud and straw mixtures to bind bricks. The Romans revolutionized concrete by using a mixture of volcanic ash, lime, and seawater. The Industrial Revolution saw advancements like Portland cement, and modern concrete was further developed with the introduction of steel reinforcement and pre-stressed concrete.

Cement is the key ingredient that makes concrete such a useful building material, and we use over 4 billion tonnes of it globally every year.

Environmental issues with concrete

Cement production alone generates around 2.5 billion tonnes of carbon dioxide (CO2) per year—about 8% of the global total.

Making cement also requires the use of long rotating kilns the length of two football pitches, which are heated to around 1,500°C. The chemical process which turns the raw materials of limestone and clay into cement also releases high levels of CO2.

So what are the alternatives?

On 11 April 2025 the BBC Rare Earth programme published an episode in which Tom Heap and Helen Czerski explore the issues with a panel of experts: Professor Colin Hills from Greenwich University, Smith Mordak Chief Executive of UK Green Building Council, and structural engineer Roma Agrawal, who worked on the construction of London’s tallest building, the Shard.

Listen here.