One last time then Im done with the crazy. There is no solid evidence linking CO2 as the driving force for temperature. In fact you will read that the experts are divided on the issue of man-made global warming. So comparing different cars CO2 output to see which one is green friendly is premature.

The science is not far enough along to make decisions about what humans should and should not be doing.

you're incorrect. there is massive consensus among the thousands of climatologists at hundreds of quality universities (pretty much every single one except lindzen) that global warming is happening and caused by human co2 emissions.

At one time there was a world wide consensus that the earth was flat. That one didnt hold up to well. Read the papers on the topic, they are full of words like 'maybe', 'possibility', 'we think', etc. This is not something to hang your hat on. Second, math models for highly isolated problems can predict the future with a fair amount of accuracy. Math models on a global scale are not worth wiping your hiney with. Before you write anything telling me the opposite, Im a math grad and Ive worked directly with math modeling for my grad studies. I know what the predictions are worth.

Global warming frenzy in a nut shell. Government hands out large sums of money to the scientific community with emphasis on an outcome. The scientists publish their results making predictions with the 'possibility' tag attached and these governments run wild with interpretation because of the mass consensus (mass stupid) you mention.

What is the motivation? Money. Its happening right now. The economy is stagnant, so what better way to get money circulating than enforcing tighter emissions rules. Of course, not to tight, because we need some flexibility in the future for more regulation.