Trains - This is the best way to go on a holiday (aside from bicycles or on foot of course). The carbon footprint is less than a third of driving. Some places though (like Canada for me) trains are uncommon and difficult to coordinate.
Automobiles - Driving alone is never a good option, but if you're ridesharing, carpooling, or driving with family, it helps. I have previously written about getting the best gas mileage you can out of your car in the Green Wheels post which you can check out for some great tips not only for the holidays but all year around. Better fuel efficiency will improve the eco-friendliness of the trip.
Planes - The emissions from airplanes are up to 90% greater than those of trains for the same distance traveled. Yikes. Another interesting fact about air travel is that because the emissions are released so high in the atmosphere, they actually do twice the damage. This is not the ideal way to travel green.
Cruises - Though this is not something individuals usually participate in frequently, there are millions all together who do each and every year. I have no doubt that a cruise would be a beautiful, relaxing experience, but for myself, the consequences are not worth it. Where do you think the food waste, grey water (from laundry, dishwashing, bathwater), sewage (passengers going to the bathroom), and fuel end up? In the sea. I don't think this needs much more explanation.
Lodgings - Once you've arrived to your destination, you'll need somewhere to stay. Check into different hotels' green rankings. Websites like Expedia are beginning to rate hotels based on a general criteria for environmental friendliness with regard to energy use, water consumption, cleaning products, etc. If there are options to use the same towels or not change the sheets each day, take advantage of those.
What method of transportation do you use?
