Concrete (specifically, the cement used to produce it) accounts for 5% of global CO2 emissions: http://blogs.ei.columbia.edu/2012/05/09/emissions-from-the-ceme

Concrete (specifically, the cement used to produce it) accounts for 5% of global CO2 emissions: http://blogs.ei.columbia.edu/2012/05/09/emissions-from-the-cement-industry/ http://blogs.ei.columbia.edu/2012/05/09/emissions-from-the-c...