The carbon footprint of a single email is negligible, but new research from ICF International  and McAfee  shows that the 62 trillion spam emails sent each year waste 33 billion kilowatt hours of power, or enough to power 2.4 million homes. The majority of energy is wasted at the end user's computer in sifting through messages to find and delete spam.
There's a relatively easy solution to this massive energy suck: install a spam filter or use an email service like Gmail that provides a built-in filter. If everyone took that simple step, it would be the energy equivalent of taking 2.3 million cars off the road. That's unlikely to happen, but there are immediate benefits for companies that take the initiative for spam filtering. According to ICF, a single business user spends 28 kg of CO2 on spam email each year. Removing spam from that person's email equation would be the same as eliminating 93 km of driving. For a 1000-person company, it's the same as taking five cars off the road.
We're far too reliant on email for communications to completely stop using it, and that's a good thing. The carbon footprint of email is nothing compared to the energy required to transport physical mail--not to mention the paper wasted on mailed letters. But if we can significantly cut our carbon footprints by switching to spam-filtering email services or installing free software, why not?
|Emissions for spam (kg CO2-e / yr)|
|Spammers Harvesting addresses||<1%|
|Spammers Creating Spam Campaigns||<1%|
|Zombies/bots sending spam||<1%|
|Non-bots sending spam||<1%|
|Internet (excluding mail servers) transmitting spam||2%|
|Incoming mail servers processing spam||1%|
|Users searching for false positives||27%|
|Users viewing/deleting spam||52%|
Table courtesy of Cody Taylor, ICF International.
[Via eWeek Europe ]