How building materials emits carbon?

Building materials such as concrete, steel, insulation, and wood all emit carbon dioxide. Concrete releases carbon dioxide when it is produced and during its lifetime, due to the heating of limestone to make cement. Steel releases carbon dioxide during the steelmaking process, while the burning of fuels to power manufacturing plants also contribute to its carbon emissions.

Wood releases carbon dioxide throughout its life cycle, due to the burning of fossil fuels used in harvesting and transportation, as well as in its eventual combustion when used as fuel. Finally, insulation materials contain their own embodied carbon, which is released when they are made and when they eventually decompose.