Although cement production by companies participating in a 16-year study increased 53 percent from 1990 to 2006, net carbon dioxide emissions increased only 35 percent, proving a decoupling of production and related emissions. These results were part of the recently released WBCSD’s Cement Sustainability Initiative (CSI) report, “Cement Industry Energy and CO2 Performance: Getting the Numbers Right (GNR),” representing the collective effort of 18 leading cement companies from around the world. Perhaps even more encouraging, the study also found that the net CO2/metric ton of clinker had dropped nearly 7.0 percent from 1990 to 2006.

To date, the GNR is the system with the widest data coverage in the cement industry, providing aggregated data on more than 800 individual mills in 100-plus countries. The database includes emissions levels for the years 1990, 2000, 2005 and 2006. CSI participants began independent, third-party assurance of their CO2 emissions with 2006 data reporting. Companies with U.S. operations included in the study were Ash Grove Cement, Buzzi Unicem, Cemex, HeidelbergCement, Holcim, Italcementi, Lafarge, Titan, and Votorantim. In addition to CSI members, Cembureau--the European Cement Association--collects information from non-CSI cement plants in Europe, ensuring nearly complete coverage of all cement installations there.

Despite improved emissions efficiency overall, report authors contend, wherever concrete and cement market demand outpaces the technical potential to reduce CO2 emissions/metric ton of product, absolute CO2 emissions continue to increase.