Ellen Phiddian
Cosmos science journalist
A recent study suggests that new buildings and infrastructure could become huge sinks for carbon dioxide if they switched out their construction materials.
Building materials that store carbon, like biomass-derived plastics and CO2 mixed into concrete, are at varying levels of technological readiness.
The study, published in Science, suggests that if all building materials were CO2-sequestering, the construction industry could store roughly 16.6 billion tonnes of CO2 per year.
“The potential is pretty large,” says Dr Elisabeth Van Roijen, who led the study at the University of California, Davis, USA.
Humans worldwide are currently emitting roughly 40 billion tonnes of CO2 into the atmosphere each year.
The researchers examined the potential for storing carbon in concrete, bricks, asphalt, plastic, and wood, then calculated how much carbon might be stored if each of these materials was adopted on the global scale.
They found that the amount of material used was far more important than the storage potential of each material.
For instance, bio-based plastics can take up the most amount of carbon by weight, but plastic is used much less in construction than concrete.
Concrete’s weight-related carbon storage is relatively low, but because it’s so widely used, it had the most potential as a carbon sink.
“If feasible, a little bit of storage in concrete could go a long way,” says co-author Associate Professor Sabbie Miller, a civil and environmental engineer at US Davis.
“This paper is critically important for the next stages in the construction industry being able to play their part in the net zero economy,” says Professor Peter Newman, a researcher at Curtin University in Australia, who was not involved in the study.
“We have solved the solar, batteries and EVs in urban development and we just need simple ways to add decarbonised materials into the buildings, roads, pathways of our cities, to begin truly having a full net zero approach.”
The researchers point out that the building industry is generally risk-averse, avoiding new materials because of the potential for liability if they fail.
“Before confidence in using these materials builds, the application of such building materials may be initially more suitable for non- or low-load-bearing applications (such as insulation, flooring, and pavements),” they write in their paper.
Newman terms this a “common sense approach”, adding that “clearly there are significant steps that need to be taken with certification and safety issues needing to be resolved”.
“I think the opportunity for Australian builders and construction material providers to start down the net zero journey using these new materials, is one that should not be missed,” says Newman,
“It has all the character of a major breakthrough in delivering net zero cities.”
