Storing carbon in construction materials could address climate challenges

Los Angeles CA (SPX) Jan 10, 2025
Materials like concrete and plastic used in construction could sequester billions of tons of carbon dioxide, according to a study conducted by researchers from the University of California, Davis, and Stanford University. Published in the journal Science on Jan. 10, the research suggests that incorporating carbon storage into building materials could play a significant role in reducing global greenhouse gas emissions, particularly when paired with efforts to decarbonize the economy.

"The potential is pretty large," said Elisabeth Van Roijen, the study's lead author and a graduate student at UC Davis.

Carbon sequestration involves capturing CO2 from emission sources or the atmosphere, transforming it into a stable form, and storing it permanently. While traditional approaches like injecting CO2 underground or depositing it in oceans have been explored, they face practical and environmental hurdles.

"What if, instead, we can leverage materials that we already produce in large quantities to store carbon?" Van Roijen proposed.

Van Roijen, alongside Sabbie Miller, an associate professor of civil and environmental engineering at UC Davis, and Steve Davis of Stanford University, assessed the carbon storage potential of widely used materials such as concrete, asphalt, plastics, wood, and brick. Their findings indicate that these materials, manufactured at a global scale of over 30 billion tons annually, hold substantial potential for carbon sequestration.

Concrete's remarkable potential

The researchers evaluated various carbon-storing methods, including integrating biochar (a product derived from heating waste biomass) into concrete, using artificial carbonated rocks as aggregates for concrete and asphalt, and employing bio-based plastics and asphalt binders. Additionally, bricks reinforced with biomass fibers were studied. These technologies range from experimental lab stages to market-ready applications.

The study found that bio-based plastics have the highest carbon uptake per weight. However, concrete's dominance as the most widely used building material-with over 20 billion tons produced annually-makes it the most promising candidate for large-scale carbon storage.

"If feasible, a little bit of storage in concrete could go a long way," Miller explained. By substituting 10% of the world's concrete aggregate production with carbonateable materials, the potential exists to store one gigaton of CO2 annually.

The new methods primarily utilize low-value waste materials like biomass as feedstocks. Van Roijen noted that adopting these processes would not only enhance the value of these materials but also promote economic development and a circular economy.

While further development is required to validate material performance and carbon storage potential in some cases, many of these technologies are ready for broader adoption, Miller added.

A vast potential for carbon storage

The study estimated that building materials could potentially store over 15 billion tons of CO2 annually, underscoring their critical role in addressing climate change.

Research Report:Building materials could store more than 16 billion tonnes of CO2 annually