(AP) -- There are plenty of reasons to hate spammers. Add this to the list: They're environmentally unfriendly.
A report being released Wednesday by security company McAfee Inc. finds that spammers are a scourge to your inbox and the environment, generating an astounding 62 trillion junk e-mails in 2008 that wasted enough electricity to power 2.4 million U.S. homes for a year.
The "Carbon Footprint of E-mail Spam Report" estimated the computational power needed to process spam - from criminals tapping their armies of infected PCs to send it, Internet providers transmitting it, and end users viewing and deleting it.
The report concluded that the electricity needed to process a single spam message results in 0.3 grams of carbon dioxide being released into the atmosphere - the equivalent of driving 3 feet in a car.
"While the spam that arrives in any individual's inbox may create just a small puff of (carbon dioxide), the puff multiplied by millions of users worldwide adds up," McAfee wrote. McAfee relied on data generated by energy and environmental consultancy ICF International Inc. to reach its greenhouse gas estimates.
The report found that almost 80 percent of spam's greenhouse emissions come from the energy that PCs consume while users are viewing, deleting, or sifting through spam looking for legitimate messages.
McAfee says it takes users about three seconds to view and delete a spam message. Although most spam doesn't get through because of sophisticated spam filters, people spend a lot of time - 100 billion user-hours per year - dealing with the messages that do land in inboxes, McAfee estimates.
The findings are significant because most e-mail is spam. The latest figures from Microsoft Corp. show that unwanted messages account for 97 percent of all e-mail.
There is one area, however, where spammers might claim the environmental high ground.
Spammers need to limit the size of their attachments to evade detection, so their messages wind up consuming much less energy than legitimate e-mail. McAfee's report estimates that the emissions from processing a single piece of legitimate e-mail are around 4 grams of carbon dioxide - 13 times spam's emissions - because users linger on them longer and attach bigger files.
©2009 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
Explore further: Internet in 'coma' as Iran election looms