Hey Mr. Green,

Could you give your thoughts on the greenness of online shopping and home delivery? I'm sure it varies by product and home location, but what should a person think about in terms of things like transportation usage and added packaging waste.

—Dick, in Philadelphia

It all depends on how far you drive to buy stuff, according to the life-cycle studies that I’ve looked at. If you simply walk or bike to an ordinary, old-fashioned store to make your purchase, you burn through half the energy that it takes for e-commerce, because online delivery requires more packaging, and fuel for its delivery trucks. However, if you drive as far as the average American on the average shopping expedition, online shopping wins. Obviously, a car going to and from a store and hauling a few items is nowhere near as efficient as a UPS truck delivering a load of merchandise to houses only a few blocks apart in a neighborhood. It’s kinda like what I pointed out awhile back regarding the transportation of food: half the fuel used to haul food is burned by cars going to and from the store.

So the moral is the same old one I’ve harped on endlessly: walk, bike, take the bus, or car pool with fellow shoppers instead of driving alone to the store. If this is truly not possible, then go online, with my green blessings, unless you’re a shopaholic, in which case you might be better off deprived of both your car and your internet service.