I buy a lot of music, both CDs and vinyl from my local record shop and downloaded albums from iTunes. That got me wondering: Is one of those options more environmentally friendly than the other? An album of MP3s doesn't come with excess packaging, but what about the energy cost of all that downloading?
Lucky for you, a few enterprising researchers have looked into this very question—or at least, the CDs-vs.-MP3s aspect of it. Music downloads are better for the environment than compact discs, in just about every category. But that doesn't mean you need to do all your record shopping from your desk—there are a few key things consumers can do to close the gap.
Earlier this summer, researchers from Carnegie Mellon and Lawrence Berkeley National Laboratory prepared a report for Microsoft and Intel that tallied up the greenhouse gas emissions and energy usage (PDF) associated with downloading albums and buying CDs at the store. Back in 2003, a European team working with the record company EMI compared MP3s and CDs from the perspective of "material intensity"—i.e., the amount of materials and resources, like metals and fuel, that go into creating a product.
The impact categories for CDs are pretty obvious: You've got to manufacture those discs, booklets, and jewel cases and then shuttle the finished product along a supply chain until it reaches the final consumer. When it comes to digital files, the environmental costs come from the energy consumed by data centers, those rooms full of servers and network equipment that serve as the backbone of the Internet. Plus, you have to consider the electricity used by your home computer and some (tiny) fraction of the resources associated with manufacturing it.
In both analyses, the downloaded album came out ahead of the store-bought disc: The computer version produced 13 percent as much carbon dioxide and used 13 percent as much energy; it was also 37 percent as materially intensive. In both studies, buying a CD at the store was somewhat worse for the environment than ordering online and having it shipped directly to you. That's because direct mailing eliminates the need for electricity use in the retail store and because it's often more efficient for a product to travel to your doorstep as part of a larger delivery on the back of a mail truck than for you to hop in your car and make a special trip. (As the Lantern has pointed out before, e-commerce isn't always the greener option: Much depends on how efficiently the route is planned and whether the packages travel by air or by road.)
Two other factors are what you do with the albums once you've downloaded them and how you get to your local record store. According to the American study, downloading an album of 60 to 100 megabytes uses an estimated 7 megajoules of energy and produces 400 grams of carbon dioxide. Burn that album onto blank CD, and the figure increases to roughly 12 megajoules and 700 grams; put that CD in a jewel case, and the figures go up even further, to 23 megajoules and 1,100 grams.
Meanwhile, the American researchers found that half the impact of buying a CD from the store comes from driving over to pick it up. If you walk or bike to your local record shop, your purchase will incur, on average, just 1,330 grams of carbon dioxide—about the same as a homemade CD in a jewel case.