Take, for example, my own carbon footprint. It is notably lower when I'm at home in D.C. and when I am in most places I go in Western Europe, Tokyo, Singapore, Bangkok and NYC, among other places. It goes up considerably when I go, for instance, to Los Angeles, Aspen, Tahoe, Jackson Hole, Jupiter, FL, China, St. Moritz, Barcelona/Ibiza, St. Barts, and the towns in which my kids are/were in school.
What makes for the difference? When I'm in the former locales, I walk or use public transportation almost exclusively, and even when I don't, the trips I find myself taking by private car are very short. In contrast, when I'm in the latter group of places, nothing of the sort is the case.