Okay, Chemists. How are CO2 Emmisions Reduced?

If you burn carbon isn’t CO[sub]2[/sub] a natural byproduct? So how how does the new California law force a reduction in such emissions from automobiles and power plants as reported on KNBC news tonight?

Never mind. A follow up story says that they are putting a limit on CO[sub]2[/sub] and that is possible by increasing efficiency.