Can we turn concrete into a carbon sink by growing sand in seawater?

Art · Published 9 October 2026 Swipe more like this →

In short: Concrete is essential for our roads and bridges, yet the process remains a massive source of carbon emissions. Scientists are now exploring a way to reverse this impact, using electricity and seawater to create a material that actually traps CO2 instead of releasing it.

For roughly 2,000 years, the fundamental method of mixing cement to bind concrete has remained largely unchanged. This consistency comes at a high environmental cost, as concrete production is currently one of the world's largest emitters of carbon. To address this, researchers at Northwestern University are developing a way to transform construction materials into carbon sinks. The long-standing reliance on traditional cement mixing methods poses a significant challenge for modern sustainability goals. This historical continuity makes finding alternatives particularly vital for reducing global emissions.

The innovation involves using seawater, electricity, and carbon dioxide to grow solid, durable materials. These new materials can serve as substitutes for sand or gravel in concrete, or even be used to manufacture cement, plaster, and paint. Remarkably, the resulting material can hold over half its weight in CO2, locking the gas away permanently within the building's structure. By creating these substances, scientists can provide essential finishes for various structures. This method provides a sustainable alternative to mining aggregates from the ocean floor.

This process, led by Alessandro Rotta Loria and Jeffrey Lopez, offers a dual benefit. Beyond capturing carbon, the chemical reaction also releases hydrogen gas, which can be utilized as a clean fuel for transportation. This technique uses CO2 and electricity to produce sand-like substances within seawater, removing the requirement to extract sand from oceans, coasts, riverbeds, or mountains. The production of hydrogen gas provides an additional pathway for decarbonising the transport sector. This chemical byproduct represents a significant opportunity for circular economy applications.

This research is part of a collaboration between Northwestern University and the global building materials company Cemex. While many climate strategies focus on storing CO2 deep underground, this approach seeks to turn that carbon into a valuable, functional asset for the built environment. This partnership aims to move away from traditional mining practices. Instead of digging into the Earth, researchers can harness natural elements to grow necessary components.

General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.

Intellect Plus is a visual educational discovery platform for exploring fascinating facts and ideas. Brain Food, Not Brain Rot. What is Intellect Plus?

Related

• Can we turn concrete into a carbon sink for the planet?
• Can we turn a major pollutant into a building block?
• Could a new type of cement slash global carbon emissions by 40%?
• The second most-used substance on Earth could be a climate solution
• Can we transform one of Earth's greatest climate villains into a hero?
• How a refusal by bankers birthed India's first women-only bank
• Why storytelling is the thread that weaves a cultural legacy together
• Why did work become the defining feature of human existence?
• How to embrace your true self through the power of maximalist costume
• Why data alone is not enough to lead effectively
• The secret to retention is teaching the material to a beginner
• The hidden biography written in your childhood toy box

More in Art · Latest · A–Z · All topics