Conservationists have long been uncomfortable with the environmental impact of the mountains of catalogs, credit card offers, coupons, and other direct mailings that accumulate daily in their mailbox, or on the floor near the front door.
Sure, we can recycle all that junk mail, but that process creates an additional layer of energy inputs from collection, sorting, processing and repurposing, to say nothing of the energy and resources needed to make the mail in the first place. Fortunately—in the United States at least—there are several new services that allow people to take back their mailboxes by blocking catalogs and other junk mail from being delivered.
But when it comes to junk mail in your email inbox, even the best “spam” filters will let a few slip by on occasion. But not everyone uses a spam filter and the environmental impact of all that virtual junk mail is now rivaling that of its papery cousin, according to a new study by McAfee (pdf).
The study, commissioned by anti-virus software maker, McAfee, and produced by the consulting firm ICF International, found that spam emails worldwide wasted 33 billion kilowatt-hours of electricity in 2008, an amount equivalent to the electricity used in 2.4 million American homes.
At the individual level, a single spam email emits only 0.3 grams of carbon dioxide into the atmosphere, but with an estimated 62 trillion spam emails sent worldwide in 2008, the cumulative emissions of spam are approximately 17 million metric tons of CO2 — a number equivalent to the emissions from approximately 1.5 million American homes.
The report attributes the vast majority of spam’s greenhouse gas emissions to energy used in the process of viewing and deleting spam or searching for legitimate email erroneously trapped in spam filters.
Obviously McAfee has a horse in this race and it would behoove them to emphasize the energy wasted by spam emails; the company’s SpamKiller software has long been a core part of their suite of security software. As such, the McAfee report finds that effective spam filtering saves 135 terawatt-hours of electricity per year.
While the McAfee report concedes that spam filters themselves account for about 16 percent of the total energy required by PCs to deal with spam, it concludes that, “compared to the energy users consume searching for false positives and viewing and deleting spam messages, the energy expenditure of spam filtering seems like a small price to pay.”