Circular Cement Decarbonisation: Towards a Net-Zero Built Environment

With the 2015 Paris Agreement aiming to limit climate change to below 1.5 °C, SBTi’s Net Zero Standard presents companies with the following challenges. In the short term, they will need to act quickly and deeply to halve their greenhouse gas (GHG) emissions by around 2030. In the longer term, they will need to reduce these emissions to a residual level (<10%) by 2050 at the latest. Even if all companies reduce their emissions by at least 90%, there will still be residual emissions (10%) that need to be neutralised (removed and stored) to achieve net zero emissions. In addition, companies can accelerate the transition to global net zero by investing in mitigation activities, but this option is not a substitute for reducing their own GHG emissions. Circularity must be applied to all products whose life cycle generates large amounts of GHG (in mobility, food systems and the built environment). This is the case for cement, which accounts for 90% of CO2 emissions from global industrial processes. Today, it accounts for about 8% of the planet’s total CO2 emissions, which is three times more than the emissions from aviation. This chapter discusses the actions, trends, and prospects for the cement industry to respond to the net zero challenge. In conclusion, the cement industry will not reduce the production of clinker in the coming decades but will seek to store the CO2 it emits through calcination in the form of carbonates (mineralisation), so that cement in the form of concrete will reach a point where, through constant use and over-recycling, it will absorb (store) all the CO2 it has emitted in this way, thus closing the emissions cycle. It will also make extensive use of renewable fuels to replace the fossil fuels that will have been depleted by then. However, for the sake of the survival of the entire planet, it would be a priority to eliminate the calcination of limestone without delay.