Downloading music: The environmental angle

You're not just saving yourself a lot of hassle by downloading songs directly to your computer instead of buying them as CDs and ripping them later. You're doing the environment a favor, too.

That's the conclusion of a study (funded by Microsoft and Intel but performed by researchers at Carnegie-Mellon and Stanford University) which has attempted to accurately measure how much carbon dioxide production is associated with various methods of buying music. (Actual study [PDF format] is here.)

In the study, the researchers looked at six different usage scenarios: A standard drive-to-the-store retail CD purchase, an online retail purchase shipped by road, an online retail purchase shipped by air, a digital download, a digital download burned onto a bare CD, and a digital download burned onto CD and stored in a plastic case.

As you might guess, the digital download was -- by far -- the method of purchase with the smallest CO2 impact. Specifically, less than 500 grams of CO2 on average are generated by downloading an album online. Even adding in a CD burn and case keeps the numbers relatively low: About 1200 grams of CO2 are produced if you back up your music to CD and pop it in a jewel case, with the bulk of that production associated with the production of the case.

The worst way to get music? Driving to your local retailer and taking it home. Due to the general inefficiency of non-commercial vehicles, you're wasting well over half of your 3000-plus grams of CO2 produced just driving to and from the store. By comparison, e-tail delivery generally produces 2000 to 2500 grams of CO2 per album, depending on whether the primary shipment method is via truck or plane, respectively.

Naturally, the numbers are only an average and are subject to substantial debate. If you live next door to the mall and walk there to buy a CD, you're generating far less CO2 than someone who has to drive 10 miles to and from Wal-Mart. There's also the question of whether it is more efficient for a music studio to mass produce thousands of albums than it is for you to burn a CD at home.

Still, it's an interesting study and one that puts a number on something we probably know in our gut but never think about explicitly. Now, knowing that buying a CD at a store produces six times the carbon of downloading the same album online, does that weigh into your decision on how to make the purchase?