Every day, we send and receive dozens and dozens of e-mail. What if we told you that sending and receiving emails has a significant environmental impact? This is what some researchers discovered by analyzing the potential pollution due to the use of emails which, like any digital activity (including artificial intelligence), contribute to global emissions CO2And or CO2 equivalenta unit that measures the overall impact of greenhouse gases equivalent to carbon dioxide (CO2 precisely). Even if individually an email message generates a few grams of CO2Andthe total volume of emails exchanged globally in 2021 reached 306 billion, a figure that is expected to exceed 376 billion by 2025. The global impact? The emails are estimated to have generated approx 150 million tons of CO2and in 2019representing 0.3% of global emissions. The average use of e-mail, in practice, pollutes as much as a person driving a small petrol car for approximately 206 km. Reducing the sending of useless emails or optimizing their management, if done jointly by a considerable number of users, could make a surprising difference for our planet.
Because emails pollute
Every email we receive and send has a complex system behind it made up of devices, data centers and complex network infrastructures. From the computer or smartphone you use to write the message, to the energy needed to send it across global networks, everything consumes resources. The simpler emailslike those of spam filtered by the systems, have a minimal footprint, around 0.03 grams of CO2And. However, attaching large files, images or logos can cause this value to rise up to 50 grams per single message.
The emissions figures may seem small, but accumulated over time and with billions of users, they become significant. In the UK alone, if every adult sent one less courtesy email per day (the classic responses here we reply «Thank you!» to our contacts), 16,433 tons of CO could be saved2and per year. That’s the equivalent of taking the emissions of 3,334 diesel cars off the road.
According to some estimates, the production and management of digital technologies (which concern not only emails) already represent 3.7% of global greenhouse gas emissions, a figure similar to that of the entire airline industry. Most of these emissions come from data centersthe giant “digital warehouses” that store and distribute information on a global scale. Although many are increasingly efficient, thanks in part to the use of renewable energy, a significant portion is still powered by fossil fuels.
How many CO emissions2and produce the emails
But let’s now come to the main question of the article: How much do emails pollute? Making exact calculations is not a simple task, as there are many variables at play. It all depends on the device used to write the email, how long it took the sender to write it and the recipient to read it, the presence or absence of images, emojis, large attachments, signature with company logo, and many others factors again.
In the latest edition of his book, How Bad are Bananas?: The Carbon Footprint of Everything (2020), Mike Berners-Lee (brother of the much more famous Tim Berners-Leeinventor of the World Wide Web), places this range between 0.03 g and 26gdepending on the message examined, as outlined in this table.
| Type of email | CO emissions2and produced |
|---|---|
| Spam email detected by your inbox filters | 0.03g |
| Short email sent and received on a smartphone | 0.2g |
| Short email sent and received on a laptop | 0.3g |
| Long email that takes 10 minutes to write and 3 minutes to read, send and receive on a laptop | 17 g |
| Newsletter message that takes 10 minutes to write and send to 100 people, of which 1 reads it and the other 99 look at it for 3 seconds | 26 g |
How to reduce the environmental impact of emails
Having understood the polluting potential generated by e-mail, we can only close the article with a small handbook on how to reduce the environmental impact of emails.
- Subscribe only to the newsletters that you find interesting, unsubscribing from those that you no longer find useful.
- Use short, simple messages that get straight to the point.
- Rather than attaching large documents, consider inserting links to online storage services that contain them.
- Avoid unnecessary responses, such as “courtesy” responses.
