Hot Mail

In today's Journal, Marisa Taylor revisits the popular internet-as-emissions-monster theme and adds a twist. The emissions generated by a year's worth of spam, she writes, are equivalent to 1.6 million car trips around the earth. That's because some 6.2 trillion spam messages are sent every year. Some details:

Legitimate emails release four grams of CO2 compared with spam's 0.3 grams, but since spam accounts for one-third of all business and personal messages, it adds up, says Dave Marcus, director of security research and communications for McAfee Avert Labs. "At this point in time, everyone has an email address," he says. "I think it should resonate with a lot of people. The more we can keep [spam] away from users, the better the planet ends up."

This is reminiscent of the heat Google took not too long ago after a story was written suggesting that the energy used in a single Google search could boil a half a kettle of water. That, unsurprisingly, isn't true. Google estimates that a typical search uses way less energy than would be necessary to boil water, and adds that each query probably generates about 0.2 grams of CO2. So while the emissions estimate for spam seems reasonable, I have a difficult time understanding why the computing power necessary to handle a legitimate email would be some thirteen times greater than that for a spam email (or a Google search).

In any case, the interesting question, as Google notes, is how the emissions generated by these processes compare to the but-for world in which such technologies weren't available. Without internet search capabilities, individuals would have a lot less information available, and would emit more carbon trying to get it (driving to the library, say). Similarly, email technology allows for quicker, easier communication than dirtier alternatives -- face-to-face meetings, phone calls, or snail mail. Taking that into consideration, the net benefits from email, including spam, are easily positive. To achieve the level of communication it allows by non-internet means would require a much greater quantity of energy than we currently devote to communications.

But that doesn't mean that things wouldn't be even better without the spam (especially since spam eats up bandwidth). As far as that goes, a fraction of a cent tax on email seems like a pretty good way to eliminate the problem. It would hardly register with most email users but destroy spammer business models.