By Chris Amico 
California's cement industry is in the crosshairs of the state's efforts to combat global warming. Can cement kilns in northern California resolve this or will they be shut down and moved to other states? How is the state walking the fine line of regulation and innovation to keep this industry going?
California has committed to reducing greenhouse emissions to 1990 levels by 2020 (AB32). The cement industry is at the center of this effort. Making cement is one of the dirtiest industries in the state, and California's 11 kilns produce about 10 percent of the total US cement output each year.
Making cement naturally releases CO2. It's part of the chemical process. On top of that, most kilns burn coal or petroleum coke, which adds to the pollution. Other fuels are possible--natural gas, saw dust, biosolids--but those come with added costs and other issues.
If plants leave or shut down, they'll likely be replaced by kilns in other states with less stringent environmental laws, or by international competitors like China, which already produces half the world's cement and more carbon dioxide than the US.
