McAfee charges environmental costs for spam

The worldwide flood of spam would consume an amount of energy equivalent to the consumption of two and a half million American households. Not so much sending, but especially viewing spam takes a lot of energy.

Software security company McAfee commissioned the American research agency ICF International to investigate the environmental consequences of unwanted e-mail messages. The research report, which can be downloaded as a PDF after registration to download, states that the 62 trillion messages that could be classified as spam in 2008 were responsible for consuming 33 billion kilowatt-hours of electricity. That amount would be equivalent to the annual consumption of 2.4 million American households or the burning of approximately 7.5 billion gallons of gasoline. When the environmental impact of the spam messages is expressed in terms of greenhouse gas emissions, spam is responsible for the emission of 17 million tons of carbon dioxide, about two per thousand of the total global CO2 emissions.

ICF assumes in its calculations that a single spam message is responsible for a CO2 emission of 0.3 grams. For comparison: a legitimate e-mail would be good for four grams of CO2. The emission costs were broken down by ICF into various spam-related activities, with the actual sending and storage of the unwanted messages being the least burden on the environment. It is precisely the viewing of spam by the recipient and the search for so-called false positives in spam folders that account for the lion’s share of the energy demand, almost eighty percent. Spam filtering accounts for about 16 percent of waste.

An American business user would generate 131 kilos of CO2 from email-related activities, and 22 percent of those emissions would be caused by spam. Of the eleven countries surveyed, America is responsible for the largest share of spam-related CO2 emissions, followed by China. The spam-related energy consumption of residents of the other countries is proportional to the number of e-mail users. McAfee concludes that since most of the energy consumption is caused by viewing and deleting spam, using good spam filters would result in significant energy savings.