Researchers are developing a cement production process that replaces limestone with volcanic rock to lower carbon dioxide emissions [1, 2].
This shift is critical because cement production accounts for about eight percent of global CO2 emissions [1]. The industry creates nearly as much CO2 as passenger cars, making it a primary target for climate mitigation efforts [5].
Scientists working in laboratories and pilot plants in the U.S. Pacific Northwest are focusing on the use of basalt, a common volcanic rock [3, 1]. Traditional cement relies on limestone, which releases carbon dioxide during the chemical process of heating. By substituting this with volcanic rock, the chemical profile of the production process changes, reducing the amount of gas released into the atmosphere.
Data on the effectiveness of this substitution varies by study. One report indicates the volcanic-rock formula cuts carbon emissions by 67 percent [2]. Other research suggests that replacing limestone with basalt could cut emissions by as much as 80 percent [3, 4].
These efforts involve international collaboration among research institutions to scale the technology from the lab to industrial use [3, 1]. The goal is to move toward a zero-emission way to make cement by utilizing abundant volcanic materials rather than scarce limestone additives [1, 3].
While the technology has been studied since early 2024, recent findings published this month continue to refine the numbers on energy use and emission reductions [3, 1]. The researchers said the process could slash both energy use and carbon output simultaneously [4].
“Cement production accounts for about 8 percent of global CO2 emissions”
The transition from limestone to basalt addresses a fundamental chemical problem in construction. Because limestone releases CO2 as a byproduct of its decomposition, the only way to truly decarbonize cement is to change the raw material itself. If these volcanic-rock formulas can be scaled to global industrial levels, it would remove one of the most stubborn barriers to achieving net-zero emissions in urban infrastructure.
