Previous discussion on cement and CO2 emissions: https://news.ycombinator.com/item?id=24604335 tl;dr cement releases lots of CO2 when manufactured (you are basically running CaCO3 → CaO + CO2), but the reaction runs partially in reverse when the cement cures. There was no clean conclusion on what is the overall result.
A more serious essay: https://slatestarcodex.com/2015/01/04/ethics-offsets/
Previous discussion on cement and CO2 emissions: https://news.ycombinator.com/item?id=24604335 tl;dr cement releases lots of CO2 when manufactured (you are basically running CaCO3 → CaO + CO2), but the reaction runs partially in reverse when the cement cures. There was no clean conclusion on what is the overall result.