What is the Carbon Footprint of Spam?

Posted on 16. Apr, 2009 by Ross in Corporate Policy

According to a new report (PDF) released by internet security firm McAfee, the carbon footprint of global spam emails is larger than anyone would have imagined. Spam was responsible for the use of 33 billion kWh of energy in 2008, resulting in greenhouse gas emissions equivalent to 2.4 million US homes, or driving 1.6 million times around the Earth. Is this revelation meaningful, though, or a shaky piece of greenwashing.

Sounds a little extreme? Well, apparently 62 trillion spam emails were sent in 2008 and McAfee have calculated the total lifecycle carbon cost of each individual spam mail to be 0.3 grams of carbon dioxide. By comparison, they declare that the average carbon footprint of a regular legitimate email to be 4 grams, but since 80% of the world’s emails are spam then spam emails account for a third of all global email-related carbon emissions. The emissions cost of spam are 95% due to the end users’ computer, with spam filtering systems only incurring 16% of the carbon footprint costs.

Spammy Greenwashing

52% of spam’s carbon footprint is then attributed to users viewing and deleting spam (the other 27% is from the retrieval of false positives from the spam filters), based on the average user taking 3 seconds to send the spam to their recycle bins. Herein lies Problem Number 1 with this exercise: who takes 3 seconds to read and delete spam? Most users are now adept at spotting spam in their mail boxes and deleting it without viewing it. By such a massive percentage of spam’s carbon footprint being associated with such a broad approximation, the margin of error on their assessment (not discussed in the document) is huge - and easily exploited. An average of 1.5 seconds per spam email would render the carbon footprint of reading and deleting spam equal to the cost of filtering it and checking for false positives! Conversely, a search in Google for the average time spent on spam emails would appear to make McAfee’s estimate look rather conservative, but the figures floating around the internet on the subject are no less subjective in their intent than McAfee’s report.

Problem Number 2 makes Problem Number 1 totally irrelevant though, and is the source of the main greenwashing accusation levelled at the report. The report states that:

“If every inbox were protected by a state-of-the-art spam filter, organisations and individuals could reduce today’s spam energy by approximately 75% or 25 TWh per year. That’s equivalent to taking 2.3 million cars off the road.”

This gargantuan over-simplification requires the assumption that the time spent with a computer powered on whilst checking spam would be otherwise spent with the computer turned off. This is of course nonsense: if there was no spam to check then the user would simply be using the machine for something else instead. With vast numbers of personal and business computers simply left on 24/7, spam simply becomes an environmental non-issue or at worst retains only 5% of its carbon footprint from the harvesting, crafting, zombies, internet and storage aspects of its energy impact.

This report serves one purpose only: linkbait. By throwing out a large number of blogger-friendly statistics onto the internet, McAfee know that their report will get quoted for years to come, and consequently they will continue to reap the rewards from the exposure in terms of internet traffic and Google Pagerank (NB: the link in this report is nofollowed!) The statistics will be printed in newspaper articles, thrown into debates and relied upon to add emphasis to other agendas, despite the very flawed logic that has led to this greenwash. (Edit: since writing this, the BBC has reported on this too. Genius!)

Not having to deal with spam certainly makes us more productive individuals, but its impact on carbon dioxide emissions is certainly being overstated. More effective email filtering is not the only solution either (plus more stringent controls would increase the already substantial carbon footprint contribution from retrieving false positives). Spam can be cut down by making email addresses on the internet less visible to harvesting software (ask your IT friends/colleagues) about this one and by being selective over which internet sites to submit your details to (or even using a different email account dedicated to this purpose, emails to which can then be safely and totally ignored). Whilst the previously green-as-grass internet industry is starting to come under scrutiny for its energy use and recycling efforts, this sort of unbalanced analysis does nothing but alert the greenwash alarm in all of us.

Picture © threefingeredlord on Flickr