Oh brother, here we go. Recently, McAfee released a study that measured the carbon footprint of email Spam. Below are the key findings of that study:

• An estimated worldwide total of 62 trillion spam emails were sent in 2008
• Globally, annual spam energy use totals 33 billion kilowatt-hours (KWh), or 33 terawatt hours (TWh). That’s equivalent to the electricity used in 2.4 million homes in the United States, with the same GHG emissions as 3.1 million passenger cars using two billion United States gallons of gasoline
• Spam filtering saves 135 TWh of electricity per year. That’s like taking 13 million cars off the road
• If every inbox were protected by a state-of-the-art spam filter, organizations and individuals could reduce today’s spam energy by approximately 75 percent or 25 TWh per year. That’s equivalent to taking 2.3 million cars off the road
• The average GHG emission associated with a single spam message is 0.3 grams of CO2. That’s like driving three feet (one meter) in equivalent emissions, but
when multiplied by the annual volume of spam, it’s like driving around the Earth 1.6 million times
• A year’s email at a typical medium-size business uses 50,000 KWh; more than one fifth of that annual use can be associated with spam
• Filtering spam is beneficial, but fighting spam at the source is even better. When McColo, a major source of online spam, was taken offline in late 2008, the energy saved in the ensuing lull — before spammers rebuilt their sending capacity — equated to taking 2.2 million cars off the road
• Much of the energy consumption associated with spam (80 percent) comes from end-users deleting spam and searching for legitimate email (false positives). Spam filtering accounts for just 16 percent of spam related energy use

Not only is email spam an annoyance to your email inbox, but it’s also harming the environment? Preposterous or accurate?