Researchers at the University of East London (UEL) have found an extraordinary new purpose for discarded seashells. Once processed into a fine powder, shells can replace up to a third of the cement in concrete, offering a highly scalable method to reduce carbon output.

Cement, the binding agent in concrete, accounts for roughly 7 per cent of global carbon emissions. It is everywhere, its carbon footprint enormous. UEL’s study found that ground scallop shells — which typically end up in landfills or waste streams — can be substituted for cement, delivering a 36 per cent reduction in carbon emissions for the material.