[DennisR]

Because it is impossible that only four (CO2) out of 10,000 atoms/molecules in the atmosphere could cause climate change to any significant, the Global Warming Cult will have to come up with another scapegoat.

[your local physicist]

Yes, the socialist bureaucrats are determined to find a reason to regulate the driving of motor vehicles by all citizens. If they can't convince the legislators that CO2 is evil then they'll try again with diesel soot, trace amounts of unburned hydrocarbons, or something else. Government regulators in the liberal Northwest are already experimenting with GPS transmitters in cars that transmit the current location and all mileage driven by individual cars. The socialist regulators are grimly determined to make sure "you will be assimilated."

(If they try to put a GPS device in my SUV I will find that device and break it with a spilled beer within 24 hours.)