Spamming can also be eco-unfriendly: McAfee

India is among those countries that report higher emissions per e-mail user

The global annual energy used to transmit, process and filter spam e-mail could power 2.4 million homes or 3.1 million passenger cars, according to a study by security technology company McAfee.

The study titled "Carbon Footprint of Spam" noted that the average business email user is responsible for 131 kg of carbon dioxide (CO2) per year in email-related emissions and 22 per cent of that is spam-related. In 2008, a worldwide total of 62 trillion spam emails were sent and the greenhouse gas emission from a single spam message is 0.3 grams of CO2.

“As the world faces the growing problem of climate change, stopping spam at its source, as well as investing in state-of-the-art spam filtering technology, will save time and money and will pay dividends to the planet by reducing carbon emissions as well,” said Jeff Green, senior vice president of product development and McAfee Avert Labs.

The study noted that though spam filtering accounted for just 16 per cent of spam-related energy use, around 80 per cent of the energy consumption associated with spam came from end-users deleting spam and searching for legitimate e-mail (false positives).

Spam filtering, the study revealed, saves 135 terawatt hours (TWh) of electricity per year and that is equivalent to taking 13 million cars off the road. Besides, if every inbox were protected by a state-of-the-art spam filter, organisations and individuals could reduce today’s spam energy by 75 per cent or 25 TWh per year, the equivalent of taking 2.3 million cars off the road.

The study also focussed on countries and revealed that those with greater Internet connectivity and users, such as the United States and India, have proportionately higher emissions per e-mail users.

The US for example, had emissions that were 38 times that of Spain. While Canada, China, Brazil, India, US and the UK had similar energy use for spam by country, Australia, Germany, France, Mexico and Spain tended to come in about 10 per cent lower.

Keying in emissions

Annual energy used to transmit, process and filter spam is 33 bn kilowatt-hours (kWh)

Greenhouse gas emission from a single spam message is 0.3 grams of CO2

80% energy consumption related to spam comes from end-users deleting it

Spam filtering accounts for 16% of spam-related energy use

Spam filtering saves 135 terawatt hours (TWh) of electricity per year