I recently did some calculations on car vs plane travel. For commuter flights, it surprised me to find out that for gasoline cars, car travel isn't better than a flight until you get to a carpool of four passengers. For electric cars, a solo driver is about the same as air travel (in an average airport flight) - a second passenger makes it better than air travel. (This was for a flight halfway across the country.)

So yeah, limiting long distance travel is the way to go. I just found it surprising because I think a lot of people might choose to drive instead of fly, thinking it's better for the environment - usually not unless you're carpooling.