Cement and $\hbox{CO}_{2}$: What is Happening

Concrete is 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 $\hbox{CO}_{2} $ emissions. The Cement Sustainability Initiative (CSI) , along with the International Energy Agency (IEA), has developed a road map for $\hbox{CO}_{2} $ reductions in the cement industry. The IEA/CSI “blue map” calls for a reduction of approximately 50 $\%$ in the specific $\hbox{CO}_{2} $ 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 $\hbox{CO}_{2} $ reductions. This paper reviews the progress to date and some of the many projects underway in the cement industry.