The Climate Change Impact of Spam

Taking off from David Canton’s post on the Economics of Spam, here’s a link to a survey from McAfee published today that has some findings that surprised me – One e-mail is like driving three feet:

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
Spam email takes a toll on the finances and productivity of private and business email users all over the world. It also is a significant drain on the global environment. Because this impact is largely a result of the amount of time end users spend searching for and deleting spam, investments in next generation spam filtering technology can pay big dividends — in economic terms and in a positive impact on the carbon footprint of spam.

We need more than Senator Goldstein’s Bill


  1. Don’t get me wrong – I dislike spam (the electronic kind) as much as anyone. However, I think these figures can be very misleading.

    The relevant amount of energy is not the total amount of energy used by all computers multiplied by the fraction of all computer resources that are used in connection with spam.

    The REAL question is: what is the difference between the amount of energy consumed in connection with all computer use, minus the amount that would be consumed in a world without spam (the electronic kind)? The only important figure is the amount of energy that could be saved potentially.

    In other words – what is the marginal energy consumption cost of spam?

  2. Also, do those figures include the fact that spam is even hitting cell phones now in the form of text messages. AGHAGHA!!! How much more annoying can that be.

  3. This article only addresses the direct increase in CO2 emissions caused by spam. I’d like to know how much of an indirect contribution it makes. For example – I spend several minutes each day picking through the spam that manages to get through the spam filter. That includes the time I spend picking the falsely accused legitimate emails out of my spam folder.

    That is time that I cannot bill for my services as an attorney. I therefore must stay later. When I finally leave the firm, I am more inclined to travel at greater speed. This lowers my fuel efficiency. It also increases the wear and tear on my tires, brakes, etc.

    The true costs of spam could be greater than we ever imagined.