Bits o’ carbon: digital downloads are greener than CDs
This is hardly a shocking result, but it’s kind of fun nonetheless: a life cycle analysis reveals that downloading music digitally creates less than one sixth the carbon emissions of buying it from a retail store (pdf).
The study compares six scenarios:
1. Music purchased from a traditional retail store
2. Music purchased from an online retailer and delivered by truck
3. Music purchased from an online retailer and delivered by plane
4. Digital music purchase (e.g., via iTunes or Amazon.com)
5. Digital music purchase burned to CD
6. Digital music purchase burned to CD and then stored in a plastic jewel case
As the graph above shows, the jewel case and the CD do add meaningfully to the carbon impact of the music download, but all three digital versions of the album are environmentally friendlier than the physical versions, despite the electricity consumed by the internet delivery infrastructure and the shopper’s computer.
Note that well over half of the emissions of the album purchased from a physical store come from the car ride to the store. This portion of the footprint will vary dramatically based on the purchaser’s proximity to the store and choice of transportation. In the best case — a trip on foot or by bicycle — buying a CD in a physical store has about the same impact as downloading it, burning it to CD, and storing it in a jewel case.
In semi-related news, several universities are experimenting with using the Amazon Kindle electronic reader to deliver electronic textbooks to students — and they’re claiming sustainability as a primary motivation. This notion rubs some people the wrong way. Books are low-tech, durable, and ostensibly derived from renewable resources. Electronic readers are cheap-looking plastic devices that need to be plugged into an outlet and presumably will end up in a landfill when newer models come out.
It’s not clear to me, though, which way the scales tip. Book are not, of course, completely benign. Energy goes into their manufacture, transport, and disposal. Beyond that — and here I speak as a Kindle owner — electronic readers do result in at least some energy savings by supplanting computer use. I suspect that physical books retain an edge over their digital cousins, possibly a substantial one. But I’d be curious to see some actual numbers.