Carbon Footprint of Portland Cement Shrinks

The overall energy efficiency of domestic portland cement manufacture has increased 13% over a ten-year period, according to a report prepared for the U.S. Environmental Protection Agency (EPA) by economists at Duke University.

The decrease in total source energy, researchers wrote, is “equivalent to an annual reduction of 5.4 billion kg [5.9 million tons] of energy-related carbon dioxide emissions”—the equivalent of emissions from more than a million cars. Decreasing the energy used to make portland cement is a high priority, since the material’s manufacture has historically accounted for a full 2% of greenhouse gas emissions in the U.S.

It is an essential ingredient in concrete even when fly ash or other substitutes are used.