the second most widely used commodity
globally, with estimated production at over 15 billion tons per year.
It is estimated that 3.6 billion tons of cement was produced in 2012,
accounting for approximately 5% of the global anthropogenic
CO2 emissions. The Cement Sustainability Initiative (CSI), along
with the International Energy Agency (IEA), has developed a road
map for CO2 reductions in the cement industry. The IEA/CSI
“blue map” calls for a reduction of approximately 50% in the
specific CO2 emissions per ton of cement by 2050. The blue map
emphasizes continued progress in the three traditional levers for
CO2 reduction but also indicates that these three levers will only
achieve half of the targeted reduction. Many cement companies
are exploring additional ways to achieve CO2 reductions. This
paper reviews the progress to date and some of the many projects
underway in the cement industry.