62 Trillion Spam E-mails = ? Energy spent on spam could have powered 2.4M homes, 3.1M cars and more.

April 16, 2009 -- All of those junk e-mails that clutter up your inbox aren't just a massive annoyance but a colossal waste of energy.

According to a report released this week by computer security company McAfee, spammers last year generated a whopping 62 trillion junk e-mails.

What does that mean in terms of energy?

Instead of sending messages asking for money or marketing Viagra, the electricity used sending the e-mails could have powered 2.4 million homes for a year or driven a car around the planet 1.6 times, according to the report.

That waste of energy is also polluting the environment.

Anything powered by electricity also emits greenhouse gases. McAfee researchers say each junk e-mail emits 0.3 grams of the greenhouse gas carbon dioxide (CO2). That may not sound like much, but when you consider the volume of global annual spam, it all adds up.

Spam Has a Big Carbon Footprint

Spam-related emissions for all e-mail users around the world in 2008 totaled 17 million metric tons of CO2, according to ICF International, the consulting firm that partnered with McAfee on the study. That's .2 percent of the total global emissions.

"The amount released into the atmosphere is significant," said Dave Marcus, director of security research for McAfee. "Spam has a big carbon footprint. It's something people should be aware of."

The report said that nearly 80 percent of the spam-related greenhouse gas emissions came from the energy burned by PC users viewing, deleting and searching for legitimate e-mail under mounds of junk. To view and trash a piece of spam takes about 3 seconds, McAfee said.

Marcus said about 85 to 91 percent of all e-mail is spam, but consumers can decrease their spam load by surfing the Net with a bit more care.

For example, anytime you use a Web site to participate in online discussions or post comments, make sure your name is nothing like your e-mail address. And think twice before using the auto-complete feature on your browser because it may allow spammers to harvest personal information. Some experts also advise changing your e-mail address yearly.

But, what else could all that wasted spam-related energy do? Click on to the next page to find out these estimates based on McAfee's report and Carbonfund.org.

Spam-Related Energy: What Else Could it Have Powered?

-- All the cars that traverse San Francisco's Golden Gate Bridge in one month.

According to McAfee's report, annual spam energy emits the same greenhouse gas emissions as 3.1 million passenger cars. To put it in perspective, that's the number of cars that cross the Golden Gate Bridge in one month.

-- All of the homes that were foreclosed in 2008.

In 2008, foreclosure filings were submitted for more than 2.3 million homes in the United States, according to the real estate Web site, RealtyTrac. Spam-related energy could have powered these homes for one year, with some left to spare.

-- The energy use of Vermont, Alaska, North Dakota, Wyoming or Washington, D.C.

McAfee's report said spam is responsible for 17 million metric tons of CO2. According to Carbonfund.org, that's greater than the annual carbon footprints of the people living in those areas.

-- The homes of everyone who flew on an airplane on one day in 2008 (if they were all American).

According to the Department of Transportation's Bureau of Statistics, there were 804 million worldwide passengers in 2008 or 2.2 million a day.

-- The country of Jordan. According to the United Nations, the Middle Eastern country emitted about 15.5 million tons of CO2 in 2000. (The numbers are dated but the most recent available.)