We have to drastically reduce air travel to cope with global warming and excess CO2. It's pretty unethical to fly more than a few times a year. CO2 injected into the upper atmosphere causes 2-3x warming vs ground level CO2 emissions.
End result is the same however - the same fossil fuel is much worse when used in air travel than on the ground.
Air travel is growing exponentially, trend needs to be reversed: http://reports.weforum.org/travel-and-tourism-competitivenes...