In a 55-43 vote on October 30, the Senate defeated the radical Global Climate Stewardship Act, whose provisions to cap carbon dioxide emissions stood to have far-reaching, negative impact on domestic portland cement production. Sponsored by Sen. John McCain (R-AZ) and Joe Lieberman (D-CT), the bill (S.139) proposed limits on the amount of CO2 gas that could be emitted in power generating and industrial operations that rely heavily on coal combustion. Portland cement production is a major source of CO2 emissions, with the gas generated in equal quantities by a) coal combustion, serving to effect the pyroprocessing needed to form clinker; and b) calcining, the preheating phase in which carbon content is removed from limestone and other raw kiln feed.

Global Climate envisions a market-based “cap and trade” system, where credits are issued to allow fixed volumes of CO2 emissions. Those credits could be traded among cement companies and other CO2 gas sources as business warrants. Staff from the Portland Cement Association's Washington, D.C., office note that the cement industry opposes any legislation that would effectively cap domestic powder output. As an alternative to the extreme measures spelled out in the McCain-Lieberman plan, cement companies have enlisted in the Bush Administration's Climate Vision program.