And probably no issue is more highly debated at this time of year than what type of tree to put up, a real one or an artificial one? Assuming of course that you aren't going to forgo trees altogether.
The Victoria, Australia, government is pushing trees in pots, particularly the Wollemi Pine, a rare ancient tree. Not only does it keep your carbon emissions down, but it can help recover a disappearing species at the same time! Of course, here in Canada, Wollemi Pines aren't an option, but there are plenty of pine trees in pots that you could bring in and decorate.
But if you want to stick with tradition, which one should it be? Both sides have their proponents, although it turns out there are strong lobby groups for each option, pointing out the benefits and weaknesses of real versus artificial. The strongest argument I've found was in this article, where the carbon emissions of both are compared. The bottom line? You need to keep an artificial tree for 20 years if you want to compare its carbon emissions from construction with cutting down a local grown tree that was grown specifically for harvesting. And if you know that artificial trees begin to break down after about 9 years, and are mostly made in other countries and then shipped here, real seems to be the best option.
Then, once you've decided on the tree, there's the question of travel. Well, according to this BBC article, if you have to travel, and it's a few hours drive away, you might consider flying. Sure, flying uses a lot of fossil fuels, but a plane is actually more efficient in fuel conversion than a car, so if you fill a plane then your damage per person will be less than if each of you drive. Of course, this doesn't count if you're flying across the continent, or somewhere south, but that's a whole different issue.
In the end though, enjoy the holiday season. It's what we do all year round that really counts. A couple of weeks at this time of year is only a fraction of our carbon footprint. Try and be reasonable, maybe a couple fewer strings of lights, or a slightly smaller portion of meat, and less leftovers, but have a good time!