Cement’s carbon emissions

Carbon dioxide emissions from cement production are a major contributor to climate change, accounting for some 2.4 gigatonnes*, or around seven percent of global CO2 emissions in 2019


1 tonne 
Each tonne of cement releases 1,000kg of CO2


1. Cement production: Limestone and clay are crushed and mixed with iron ore or ash

2. Pyroprocessing: Raw materials fed into rotating kiln and heated to 1,450 degrees C. High temperature causes chemical reaction which releases huge amounts of CO2

Limestone and clay
Rotating kiln

3. Calcination: Limestone (CaCO3) plus heat produces lime (CaO) and CO2

4. Clinker: Aluminosilicates from clay form minerals with lime – calcium silicates, aluminates, and aluminoferrites – which produce cement clinker


Carbon dioxide emissions from cement production (2019, million tonnes)

826.9 China
143.7 India
41.3 U.S. 
32.2 Vietnam 
30.5 Indonesia
30.4 Turkey 
25.8 Japan 
24.6 Saudi Arabia 
22.6 South Korea 
21.3 Russia

*1 gigatonne = 1,000,000,000 tonnes


Sources: CemNet.com, IEA, Chatham House, Reuters 
Pictures: Wikipedia 
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