Carbon Storing Building Materials Could Be Key to Fighting Climate Change

Carbon storing building materials designed to store CO2 could be the key to meeting global climate targets.

Carbon storing building materials like concrete and bricks might hold the answer to combating climate change, according to a new study. Researchers suggest that widespread use of these materials could help remove billions of tons of carbon dioxide (CO²) from the atmosphere each year. This could be a critical step in meeting global climate targets set by the Paris Agreement.

The Intergovernmental Panel on Climate Change (IPCC) estimates that 2 to 15 billion metric tons of CO² must be removed annually to limit global warming to 1.5°C or 2°C. Traditionally, strategies like injecting CO² underground have been considered, but they can be costly and complicated. Instead, this study focuses on using building materials to store carbon—a more practical solution given the sheer volume of construction materials used globally.

These specialized carbon storing building materials incorporate carbon-capturing technologies into their design. For instance, biochar (produced by heating agricultural waste) can be added to concrete. Biomass fibers can strengthen bricks, while artificially carbon-loaded rocks can serve as aggregates in concrete and asphalt.

If all conventional building materials were replaced with carbon-storing alternatives, the study estimates that up to 16.6 billion metric tons of CO² could be captured each year. This amount is nearly half of all human-caused emissions in 2021.

Concrete, asphalt, and bricks are the top contributors because of their massive production volumes. While they store relatively small amounts of carbon per unit, their global usage means the impact is significant. For example, replacing standard cement and concrete aggregates with carbon storing building material options could remove 13.1 billion metric tons of CO² annually.

Some real-world examples show the potential of these materials. In Norway, a startup called “CarbonCure” has been adding captured CO² to concrete mixes, resulting in a stronger material that permanently locks away CO². Similarly, a housing project in India incorporated biochar-infused bricks, reducing the carbon footprint of construction while maintaining durability. These examples highlight how these innovations can be scaled for broader use.

While the potential is enormous, implementing these technologies on a large scale requires overcoming several hurdles.

1. Resource Availability
   Agricultural waste biomass could meet the demand for bio-based materials, but production of biochar would need to grow from 0.4 million metric tons in 2021 to 600 million metric tons.
2. Supply Chain Adjustments
   Minerals that react with atmospheric CO² to form stable carbonates could face supply challenges. Industrial byproducts like steel slag or coal ash can be used, but these may dwindle as industries adopt greener practices.
3. Industrial Changes
   Transitioning to carbon-storing materials will require adjustments across industries, including construction, agriculture, and manufacturing. However, the researchers believe the benefits outweigh the challenges.

A major concern is ensuring that stored carbon remains secure. According to the study, carbonate-based aggregates, used in materials like concrete, offer highly stable storage. Even after a building’s demolition, these materials could continue to store carbon in landfills or through recycling.

However, stricter regulations will be needed for materials like bio-based plastics and wood to guarantee durable carbon storage. Without proper recycling or disposal protocols, these materials may release their stored carbon back into the atmosphere.

The researchers highlight that even partial adoption of carbon storing building materials by 2045 could significantly impact climate targets. Using currently available resources, the transition could help the world stay within median warming targets of 1.5°C.

This approach not only aligns with global climate goals but also offers a practical and scalable solution. By leveraging existing industries and materials, it minimizes the risks and costs associated with other carbon storage methods, such as deep-sea or underground injection.

Adopting carbon storing building materials could revolutionize construction while combating climate change. For homeowners and builders, this means more sustainable material choices in the future. For policymakers, it highlights the need to support innovation and regulate the construction industry to prioritize low-carbon solutions.

This research shows that everyday materials, like bricks and concrete, can play a pivotal role in reducing global emissions. It’s a reminder that solutions to the climate crisis may lie in the very foundations of our built environment.