Construction is on its way to becoming greener: Scientists have created a new building material using seawater and electricity, according to a study published in the journal Advanced Sustainable Systems. The material is not only carbon-neutral — it doesn't produce any carbon emissions — but also carbon-negative, as it absorbs carbon from the atmosphere. The discovery comes at a time when reducing our carbon footprint is more important than ever.
"Cement, concrete, paint and plasters are customarily composed of or derived from calcium and magnesium-based minerals, which are often sourced from aggregates — what we call sand," said Alessandro Rotta Loria, a professor of civil and environmental engineering at Northwestern University and leader of the study. "Currently, sand is sourced through mining from mountains, riverbeds, coasts and the ocean floor." But this research team found a way to "grow sand-like materials in seawater" instead, taking inspiration from how mollusks create their shells.
"If the cement industry were a country, it would be the world's third- or fourth-largest emitter of carbon dioxide," said the World Economic Forum. In 2022, cement manufacturing accounted for approximately 8% of the world's CO2 emissions, proving to be a significant contributor to climate change.
Now, building materials have the potential to be a part of the solution rather than the problem. "Replacing conventional building materials with CO2-storing alternatives in new infrastructure could store as much as 16.6 ± 2.8 billion tons of CO2 each year," said a January 2025 study published in the journal Science. | 
