The annual energy used to transmit, process and filter
spam totals 33 billion kilowatt-hours (kWh), according to security
software company McAfee.
This is equivalent to the electricity used in 2.4 million homes,
and represents the same amount of greenhouse gas emissions as 3.1
million cars using two billion gallons of petrol.
Jeff Green, senior vice-president of product development and
McAfee Avert Labs, said, "Spam has an immense financial, personal
and environmental impact on businesses and individuals. Stopping
spam at its source, as well investing in filtering technology, will
save time and money, and will pay dividends to the planet by
reducing carbon emissions as well."
The
Carbon Footprint of Spam study from McAfee looked at global
energy expended to create, store, view and filter spam across 11
countries, including Australia, Brazil, Canada, China, France,
Germany, Japan, India, Mexico, Spain, the United States and the
United Kingdom. The study calculated the average greenhousee gas
emission associated with a single spam message at 0.3 grams of CO2.
McAfee said this was equivalent to driving three feet; but when
multiplied by the yearly volume of spam, it is equivalent to
driving around the earth 1.6 million times.
The study also found that nearly 80% of the energy used by spam
comes from end-users deleting spam and searching for legitimate
e-mail (false positives). McAfee, which produces its own spam
filtering technology said that spam filtering would save 135TWh of
electricity per year, which is equivalent to taking 13 million cars
off the road.