First off, commercial aviation has made great strides in terms of efficiency and the carbon footprint. Jet engines are getting more efficient all the time. All airlines around the world also seem to be in the process of up gauging most of their equipment. 50 seat jets are becoming rarer. In the US, we are seeing main line jets supplant regional jets to small and medium-sized cities. I don't understand why these people are vilifying commercial aviation, it would appear to me that two people flying around in a corporate jet are the problem. You won't see this problem attacked though, because it will hit the politicians and their fat cat donors too hard.
Aviation pollutes far, far more than any other method of transport. Relatively speaking, very few people travel by air, but it still makes up a much greater percentage of total transport.
They are only rough numbers, but CO2 emissions per km per passenger are:
Plane: 223 grams
Ferry: 170 grams
Diesel car: 160 grams
Train: 37 grams
Bus: 27 grams
The numbers are rough, and based on Denmark where most trains are from the 1980s and still run on diesel. But even a 50% reduction in emissions by aircraft don't bring them close to trains.
Second, I don't believe trains are the panacea that the greens would have us believe. First off, they require very inflexible infrastructure. The beauty of aviation is demand can be moved around from city to city fairly easily when demand changes.
HSR is built between major population centers where demand doesn't fluctuate.
You can also increase and decrease service by changing the rolling stock composition. Need more? Just put 4 multiple unit sets together. Less? Just run a single set.
Finally, Europe may find that it becomes uncompetitive. If it becomes more expensive to do business in Europe due to draconian environmental regulations. Folks may also elect to spend their tourism dollars elsewhere. Europe is also much more vulnerable to TK and the ME3 than the US 3 are. If it becomes too expensive for the US 3 to transport passengers on their European joint venture partners, they may re-examine the agreements. UA may cozy up to TK and shift some of their onward connection traffic there vs LH. Turkey, the UAE and Qatar a very pro aviation policies. China and India aren't going to slow things down just because Europe wants to. Europe will be cutting off its nose to spite its face.
So what you are saying is that UA will not put passengers on a flight connecting onto an ICE from Frankfurt because it is costly and takes more time, but will happily send passengers via Istanbul to the same destination instead?
1. Car is personal freedom. Public transport does not fit everyone s life style or choices.
A myth if there ever was one. You are limited by traffic and speed limits. You can't do anything while driving, not even speak on the phone. Parking is always limited. If flying from somewhere, you must return to the same airport where your car is parked. Can't drink. Expensive. I could go on and on. The car might make sense for many, but it is no better at providing personal freedom than a good public transport network.