In the age of web based email and effective spam filters, it's easy to forget the sheer volume of unsolicited emails hawking larger penises, cialis pills, penny stocks, and millions in unclaimed Nigerian gold bullion. There's literally hundreds of billions of spam messages sent out across the web EVERY DAY, representing more than 97% of all email sent.
Worldwide, spam uses about 33 billion kilowatt hours of energy per year, enough to power 2.4 milllion homes and producing the same amount of greenhouse gas emissions as 3.1 million passenger cars. The report breaks down it down in an interesting way- one spam email produces the same amount of emissions as driving a car three feet.
It's interesting to note that nearly 80% of the energy consumed by spam is used by people deleting it from their inbox and searching spam boxes for legit email. The world would also be a cleaner place if every email user was protected by spam filters, cutting the total amount of spam related emissions by 75%.