Cement could be paying its way as new research suggests that the building material reabsorbs carbon dioxide, and draws it away from the atmosphere for good.
The University of California Irvine (UCI) said in an online report that a study undertaken by its faculty showed that “cement is a large, overlooked and growing net sink” across the globe, with “sink” meaning a feature such as a forest or ocean that permanently removes carbon dioxide from the atmosphere so it can no longer add to climate change.
“It sounds counterintuitive, but it’s true,” Steven Davis, associate professor of Earth system science at the UCI explained. “The cement poured around the world since 1930 has taken up a substantial portion of the CO2 released when it was initially produced.”
Davis is one of the proponents of a study recently published in Nature Geoscience¸ which computed the amount of emissions from cement manufacturing and compared it with the carbon dioxide reabsorbed by the material in its normal life cycle, according to the report.
Cement manufacturing emits twice as much carbon compared with other processes because one, the limestone, releases carbon when converted to lime, which is a key ingredient in cement. Another source of carbon emissions is the large amounts of coal, natural gas and fossil fuels used to generate the necessary heat to break down limestone.
New data from the study, however, reveals, that cement draws carbon from the atmosphere in a process called carbonation, absorbing it from the surface, and deeper into the structures.
“Cement has gotten a lot of attention for its sizable contribution to global climate change, but this research reinforces that the leading culprit continues to be fossil fuel burning,” Davis concluded.
