Concrete for a Warming World(black & white version) Over 5% of global CO2 emissions can be attributed to portland cement production. This two part report describes opportunities for climate change mitigation by reducing the consumption of cement. Part one is a summary of experimental research. Cement is replaced in part by three industrial by products: fly ash, rice husk ash and limestone flour. The intent was to find a mix that would outperform blends of cement and fly ash. The