When a hydrocarbon is burned in the presence of oxygen, you get water vapor and carbon dioxide as products. The amount of CO2 depends on the amount of hydrocarbon burnt, and nothing else. The only way to reduce the amount of CO2 is to burn less fuel. Other than increasing fuel economy (a laudable goal, to be sure) I can see no other way of reducing the amount of CO2 in the exhaust. Yes, I am puzzled by this proposed legislation and how they plan to go about it.

Electric cars don't seem to be a solution, since the electricity for the batteries comes out of a wall socket and it is generated...by burning hydrocarbons. Fuel cells, etc have the same drawback, H2 can only be generated by electrolysis of H2O which requires electricity which comes out of a wall socket and which originates with a coal or oil fired plant. Unless nuclear goes on line, all these schemes are robbing Peter to pay Paul. Even ethanol from fermentation involves growing grain, a very fuel-intensive operation. It makes no sense at all unless we use agricultural wastes like the Brazilians do, because they would have to be burned anyway. I have a feeling this is not exactly what the corn lobby has in mind

In my opinion, the only way to reduce the amount of CO2 from vehicle emissions is to make vehicles burn less fuel, either by making them more efficient or by simply making them smaller and lighter. Or both. All these other schemes are simply a way of fooling ourselves so we don't have to do this.

If we determine reducing CO2 is necessary, and if we need to do it right away, there is really only one way. Use the free market to discourage the use of fossil fuels by taxing the hell out of them and force people to adopt smaller, lighter vehicles, and to take other conservation methods or develop new technologies (like nuclear) to make fuel consumption decrease. This will not happen without the financial incentive. And there will be little of that because oil producing states and industries will do whatever is necessary to discourage conservation, including slash prices.

The revenues generated by these taxes can then be used for fuel efficiency research, to mitigate the economic effects of the high cost of fuel and to finance infrastructure needed to support the transition to a low energy economy. It ain't going to be easy, it may not even be possible, and some say it's not even necessary, but the sooner we get started, the easier it will be.

I propose a gradually increasing energy tax, to give the economy time to adjust, and existing low efficiency engines to wear out naturally and be gradually replaced by more economic vehicles. It will also allow for energy exploration to proceed and alternative technologies like nuclear time to come on line, and for economic forces to promote higher density communities, mass transit, energy-efficient buildings, etc. You can't legislate these things into existence, but once people realize its the only way to save big bucks, they will show amazing ingenuity at implementing these measures.

Is all this really necessary? Do we need take such drastic and potentially disruptive measures? I really don't know for certain, I believe the situation is grave but I cannot know for sure, and predicting the future is always risky, even when there isn't the threat of global disaster or economic resource warfare on a vast scale. One thing I do know for certain, the people most qualified to answer these questions are also the ones with the least economic incentive to do anything about the problem. That is a very dangerous situation to find ourselves in.