Before I begin, let me just say that I do not own a big car, I am not a member of Costco or other such bulk store and I generally do not buy in bulk.
But the proto-typical American stereotype of the SUV driving Costco shopping consumer is the subject of much ridicule, especially from enviro-types, and I think unfairly so. Because bulk is efficient. Assuming that overall consumption does not go up (and therefore essentially assuming prices are the same) bulk saves packaging, saves carbon emissions from consumer trips and saves energy from storage.
I bring this up because on the plane ride down to São Paulo, my wife had a very pleasant conversation with a Paulista woman who was very environmentally minded and critical of the US for all the packaging they use. I was very confused, in my mind Brazilians love wrapping things up: here in São Paulo they will bag any purchase in a little plastic single-use bags and if you say you don't need it they look at you cross-eyed. At the grocery store they will practically bag each item individually and plenty of fresh stuff (veggies and such) come pre-wrapped.
But more than that with the small Euro-style packages and refrigerators I go through much more packaging than at home. Little jars of sauce for pasta, small packages of crackers and cereal and so on accumulate rapidly. It may be kind of romantic to stop at the store every day and buy food for one day, but it is terribly inefficient.
Now of course the fact that bulk and low prices lead to increased overall consumption is another matter but as far as saving resources, bigger is often better.
So make fun of big US refrigerators if you like, I prefer to buy my milk by the gallon not the liter and using a quarter of the packaging.