Several days ago, a friend made a sarcastic comment on Facebook about how much better e-mail is for the environment (in the context of spammers choosing e-mail over paper mail). That made me wonder about the relative impact of paper vs. electronic mail. So, I did what librarians do: I went to Google and started searching. Here’s what I found.
There have been a couple of life cycle studies of paper mail delivery. Pitney-Bowes published a study in 2008 which found that:
…the distribution of letter mail by the Posts generates, on average, about 20 grams of CO2 per letter delivered. In addition, a survey of more than a dozen studies shows that the indicative range of CO2 emissions associated with the upstream mail piece creation process is about 0.9 – 1.3 grams of CO2 per gram of paper. (p. 2).
The U.S. Postal Service commissioned a similar study in 2008, which found:
- Total energy consumed by the four mail products accounts for 0.6% of national energy consumption, a figure that seems reasonable given the quantities of mail in the U.S. economy, and the energy-intensive nature of paper and board production, printing, and motor vehicle transportation.
- At the household level, energy and CO2 emissions associated with the entire mail life cycle are roughly comparable to those from operating any of several common home appliances over the same period of time. (p.ES-2)
Both the Pitney-Bowes and USPS studies also looked at other environmental impacts, including waste generation and recycling rates. The Pitney-Bowes report also did a preliminary investigation of electronic communications compared to mail, which found that energy use of information communication technology is about 2% of total U.S. energy use, which is comparable to that of the paper industry. They were unable to calculate a comparative environmental footprint for the two methods.
In 2009, McAfee commissioned a report on the environmental impact of junk e-mail (spam). The results were eye-opening:
- An estimated worldwide total of 62 trillion spam emails were sent in 2008
- The average spam email causes emissions equivalent to 0.3 grams of carbon dioxide (CO2) per message
- Globally, annual spam energy use totals 33 billion kilowatt-hours (kWh), or 33 terawatt hours (TWh). That’s equivalent to the electricity used in 2.4 million homes, with the same GHG emissions as 3.1 million passenger cars using two billion U.S. gallons of gasoline. (Key Findings)
There are also several research papers which explore the overall environmental impact of electronic communications, including e-mail and e-commerce. These include:
- A review of research on the environmental impact of e-business and ICT, Environment International (2007).
- The global footprint of mobile communications: The ecological and economic perspective, Communications Magazine, IEEE (2011).
- Overall ICT footprint and green communication technologies, Proceedings of the 4th International symposium on Communications, Control and Signal Processing (ISCCSP 2010).
Although on a per message basis, it appears that e-mail has a lower environmental footprint that of paper mail, the comparative ease and perceived low or no cost of e-mail makes it more likely that people will choose it over paper mail, which requires a stamp and a trip to a mailbox or post office. In aggregate, e-mail has a significant environmental footprint, which may be even higher than that of paper mail.
The bottom line: Although e-mail appears to be a better environmental choice than paper mail because there is no obvious up-front waste stream, the research paints a much more nuanced picture, particularly when the including the environmental impact of electronics manufacturing and data center operation.