Is Air Travel being made a scapegoat?

Yesterday, Gary made the important point about why Air Travel is currently being targeted for carbon reductions.
Make no mistake, mile for mile, air travel is the most polluting way of travelling, and it is predicted to expand in the future. But, this aside, Gary's point was that air travel accounts for such a tiny proportion of everyday travel (~3%) that, if it suddenly becomes twice as expensive, there's not going to be too much of a fuss.
I also think people expect air travel to be expensive - I was surprised that a return flight from Manchester - London was ~£70, which is tempting when an off-peak return by train is ~£60.
We've recently seen the uproar created by suggesting that the road users pay per mile. No politician is going be be popular by suggesting the cost of using your car should reflect it's impact on the environment. British society is too focused around the car for that.