Undeleted Emails Might Be Increasing Your Carbon Footprint

“Think before you print” is an admonishment often included in the email signatures of the environmentally conscious, because we all know paper consumption hurts the environment.

But is there any environmental consequence to email?

With humorous intentions, a colleague of mine recently posted a picture of his email notifications on social media, indicating 99,000+ unread and undeleted emails (to the bane of every one of us who relentlessly clicks to clear those notifications!). There was discussion over the madness of having so many notifications, but leaving them undeleted was still considered relatively innocuous.

I have an email account that is nearly 20 years old, and I am certain that in that account there are some emails that have been there since the beginning. After all, I only focus on the new emails, and I do not perform regular declutters.

Then a fellow minimalist mentioned to me that she was deleting old emails in an effort to reduce her carbon footprint, a concept I had not considered. So I began to look into the environmental impact of my undeleted emails.

With email, we do not see the physical impact it may have because it is weightless and seemingly inconsequential. But according to carbon footprint expert Mike Berners-Lee’s 2010 book, “How Bad Are Bananas?: The carbon footprint of everything,” an average email has a footprint equivalent of four grams of carbon dioxide emissions [CO2e]. This figure accounts for the electricity data centers and computers need to send, filter and read messages.

An email with a “long and tiresome attachment” can have a footprint of 50 grams of CO2e. A typical year of incoming email, according to Berners-Lee’s estimations, adds 300 pounds of emissions to a person’s carbon footprint, or the equivalent of “driving 200 miles in an average car.”

The number of emails sent per day in 2015 was estimated to be around 205 billion. This statistic means almost 2.4 million emails are sent every second and some 74 trillion emails are sent per year, which would be the equivalent of driving around the earth 1.6 million times.

What is their cost?

However, that data just relates to the sending of emails. What about undeleted emails that stay in our inboxes or folders for years or even decades? What is their cost?

Anything, including archived emails, that is not stored on your hard drive at home is stored in the cloud.

“The cloud” is quite the deceptive name for internet data centers around the world. While “cloud” denotes a light, fluffy, natural place, in reality these data centers are the dirty factories of the digital age.

There are three million data centers in the U.S. alone. These buildings, the largest of which are 200 acres, consist of rows upon rows of huge stacks of hard drives noisily whirring and buzzing as they store and deliver our messages, photos and videos. These machines can consume as much power as a medium-size city.

In 2012 a Greenpeace analysis placed data centers at just under 300 terawatt-hours per year, roughly 2% of global electricity demand. The report estimated that by 2030 there could be an increase of three to 10 times the current levels.

According to a 2016 Greenpeace report:

“The transition to the cloud could in fact increase the demand for coal and other fossil fuels despite significant gains in energy efficiency and adoption of a commitment to 100% renewable energy because of the dramatic growth in new data center construction by the cloud and colocation companies such as AWS and Digital Realty in Virginia and other hot spots that have some of the lowest percentages of renewable electricity in the U.S.”

That statement means — despite the good faith efforts of some of the larger digital companies such as Apple, Google and Netflix to use clean sources of energy for their data centers — there are some companies that are opting for locations that will provide the cheaper (and dirtier) electricity. If you are concerned about the carbon footprint of these data centers, it’s a good idea to research how the companies you patronize source their energy.

While clearing out your email inbox will not single-handedly save the planet, it’s important to remember that any step made toward a sustainable future is a step in the right direction. If enough people are intentional in what, when and where we save to the cloud, we may begin to see a difference.

Now, I need to go delete some emails I still have from 2001.

To begin your own digital declutter, here are some suggested steps to follow:

1. Clear out unneeded emails from your Inbox and other folders.
2. Delete emails with large attachments that are no longer needed or save the attachments to an external hard drive (rather than the cloud) if you may still need them.
3. Empty your spam folder and trash regularly.
4. If you receive social media notifications in your email that already arrive in other ways, through a phone app for instance, unsubscribe to these notifications.
5. Avoid sending unnecessary emails to someone across the hall when face-to-face contact is possible.
6. Delete archived emails. For instance, in Gmail, you can delete old, archived emails by typing older_than:1y. Everything older than one year will be displayed. Select and delete.
7. Review what you have saved to the cloud. Which documents can be deleted? It may be more than you realize.