The Cool Climate Concrete (C3) carbon dioxide offset program...

C3 is a monitored and verified CO2 offset program based on the use of blended cement concrete in construction and civil works projects. Program participants create offsets by decreasing the use of Portland cement. By doing so, participants are compensated financially. More about the program.

This strategy for reducing CO2 was developed because the major CO2 burdens of concrete come from Portland cement production. For every metric ton of Portland cement clinker produced, approximately one metric ton of CO2 is produced. With sound technical advice, and based on individual location and projects, supplementary cementitious materials, such as ground granulated blast furnace slag and flyash, can be used to decrease the amount of Portland cement in a concrete mix and its associated environmental burdens. Additional program details and sample calculations.

C3 is funded through the Climate Trust, a non-profit organization in Oregon that implements offsets for CO2 emissions in excess of Oregon’s carbon dioxide standard. Horst, Inc. is a sustainable materials firm that is running the C3 Program. More on program management and background.