This is how much CO2 is produced creating one tonne of concrete. Whereby the production of burnt lime for concrete is the main source of emissions. The calcium carbonate of the limestone is converted into calcium oxide. The proportion of binder (clinker) in concrete can be reduced, but concrete production will not become “green” this way. The decisive lever is therefore capturing CO2 in order to store it (CCS) or to use it as a raw material across sectors (CCU). Cement production worldwide is over 4 billion tonnes and rising. The Asian region – especially China – dominates with almost 80 per cent.