A new study from the University of East London suggests that crop leftovers usually burned or left to rot could instead be turned into building materials that store carbon for decades. The work highlights a largely untapped climate solution hiding in plain sight on farms around the world.
Agricultural leftovers that are usually burned in fields or left to rot could become a powerful tool for fighting climate change, according to new research from the University of East London.
The study, published in the journal Cleaner Environmental Systems, finds that fibrous residues from crops such as wheat, rice and maize, produced in billions of tons every year, could lock away carbon for decades if they are turned into long-lasting building materials instead of being treated as waste.
Today, much of this material is burned, used as animal feed or allowed to decompose, sending carbon back into the atmosphere within months. In many regions, open burning of crop residues also worsens air pollution and public health.
Led by Bamdad Ayati, a senior research fellow at UEL’s Sustainability Research Institute, the team set out to quantify what would happen if that pattern changed.
They focused on using agricultural fibers in construction products such as insulation, boards and panels. These materials can last for decades in buildings, effectively turning structures into temporary carbon stores.
As Ayati explained, the problem starts with what happens to most residues now.
“Each year, large volumes of agricultural residues are burned or left to decompose, returning carbon to the atmosphere within a short time,” he said in a news release.
The team used a “dynamic” life-cycle approach to assess the climate impact of different uses of crop residues on a global scale. Instead of just counting total emissions, this method tracks when carbon is released or stored over time, which can significantly change how a material’s climate impact is understood.
By looking at timing, the researchers showed that diverting residues from burning or rapid decay into long-lived building products could create a sustained cooling effect over the next century. The longer the material stays in a building, the longer the carbon remains out of the atmosphere.
The study also examined what happens when this strategy is combined with clean energy. In some regions, crop residues are burned as a low-cost fuel. The researchers found that if renewable energy replaces that biomass energy, the climate benefits of using residues in buildings become even stronger.
The scale of the opportunity is large. The study notes that around 4.4 billion metric tons of agricultural residues are generated each year worldwide. Yet only a small share currently ends up in durable products. Most is still burned, fed to animals or left to decay in fields.
Even if the market for bio-based insulation grows rapidly, the researchers conclude that it would absorb only a small portion of the available material. To make full use of this resource, they argue, the construction sector will need to expand bio-based materials beyond niche or specialty uses.
That could mean incorporating crop fibers into a wider range of products, from wall panels and composite boards to other structural or semi-structural components, where appropriate standards and safety requirements can be met.
The findings change how we should think about farm waste.
“Our research shows that if these fibres are redirected into long-lived building materials, they can store carbon for decades and produce a measurable cooling effect. This reframes residues from a disposal issue to a potential climate resource,” Ayati added.
The work underscores a broader shift in climate strategy: looking not only at how to cut fossil fuel use, but also at how to manage carbon already cycling through plants and soils. Turning agricultural byproducts into building materials is one way to slow that carbon’s return to the atmosphere.
It also aligns with growing interest in “nature-based” and bio-based solutions in the construction industry. Buildings made with more plant-based materials can reduce reliance on emissions-heavy products such as conventional concrete and steel, while also storing carbon in the fabric of the structure.
Additional co-authors include researchers from UEL’s School of Architecture, Computing and Engineering.
While the research focuses on global potential, putting these ideas into practice will require changes on the ground: new supply chains to collect and process residues, updated building codes and standards, and investment in manufacturing capacity for bio-based products.
Still, the message from the UEL team is that a major climate opportunity is already available, scattered across fields after every harvest. With the right policies and industry innovation, the straw, husks and stalks that farmers now struggle to dispose of could help build the next generation of low-carbon buildings.
Source: University of East London