The three things that a traveler can do to be environmentally sensitive are:Choose your destination wisely. Some places are more sustainable than others, and some places are better to visit than others during certain times (e.g. Outside of peak summer months). There are other places that are rebuilding after natural disasters that need more volunteers to help with their efforts.Use a site like bookdifferent.com to check out your carbon footprint for your accommodations.Incorporate sustainable habits into your travels, like packing a reusable water bottle that has a built-in filter.Also: 12 gift ideas for travelers this holiday season