The carbon intensity of cement measures the average amount of carbon dioxide (CO2) emitted for each tonne of cement produced. That includes direct emissions from fuel combustion, process emissions and indirect emissions from electricity consumption.
The carbon intensity of global cement production has declined in the last couple of decades. This largely stemmed from the use of alternative fuels, substitution of clinker with other materials, and increased energy and process efficiency. However, the rate of change has leveled off in recent years as the energy efficiency of the equipment used for cement production nears optimum levels.
Even if the decline in carbon intensity continues at the pace set between 2019 and 2023, it would still decrease only marginally and fall far short of the 2030 and 2050 climate targets. Targets compatible with the Paris Agreement's long-term temperature goal require the carbon intensity of cement to reach 360–370 kilograms (kg) CO2/tonne in 2030 and 55–90 kg CO2/tonne in 2050, with an aspirational target of net-zero emissions in 2050.
Achieving these targets will require using less cement in construction through more efficient designs, as well as developing and scaling technological solutions for decarbonization such as substituting clinker, the main binder used in cement, with other less emissions-intensive materials (e.g., calcined clay, fly ash) to produce blended cement.
Given these targets, this indicator is well off track. For industry to follow a 1.5 degrees C-compatible pathway, improvements in the carbon intensity of cement need to accelerate by a factor of four.