top of page

What is the carbon footprint of an email and how can it be reduced?

Updated: Apr 11, 2023

Don't throw away your cigarette butt, turn off the light, limit your air travel or your meat consumption... These gestures now seem normal and allow us to participate in our own way to the preservation of the environment. Even if the trend is not yet widespread, more and more people are taking action on a daily basis to reduce their carbon impact. However, there is still a small gesture that we do in a harmless way and that, without us knowing it, pollutes very largely. It is the sending of an email.

You are probably wondering: how can a simple email pollute? It's true, the plastic we can understand. Exhaust gases too. But a digital mail doesn't seem to have an impact? And yet it does. Only, the consequences are not directly visible, it is called the digital pollution.

The carbon footprint of emails in a few figures

Digital technology has changed our lives considerably. Gone are the days when documents sent by mail could take weeks or months to arrive. With dematerialization, sending anything in a few clicks has become easy. No more archive shelves, no more paper and no more deforestation. Digital is the solution to all our problems.

Digital pollution

Unfortunately, it's not all that simple. Even if digital technology has many advantages, it also has disadvantages. One in particular: it pollutes. When we talk about digital pollution, we are talking about the production and recycling of electronic devices, but also their use.

Indeed, all these new technologies consume a lot of energy. On their own, they are responsible for more than 4% of global GHG (greenhouse gas) emissions, which is 1.5 times more than air transport.

Email, a small, banal and polluting gesture

Within this digital pollution, we find email in particular. A simple computer mail generates about 4g of CO2 according to the Carbon Literacy Project. And this can rise to 50g with a large attachment. The ADEME estimates that sending an e-mail with an attachment is equivalent to leaving a light bulb on for 24 hours.

So it's true, taken one by one, emails are not very polluting. But, on a global scale, more than 306 billion emails are sent every day, including 1.4 billion in France alone. All this while 80% are never opened.

How to reduce the carbon footprint of your emails?

As with everything today, if we want to preserve our environment, we need to be careful with our emails. It may sound boring, but it's a simple and easy habit to adopt.

1. Send less

As for plastic, paper or clothes: recycling is good, but the best thing is to be careful with your consumption. So before emptying your mailbox, get into the habit of sending them when it's really useful.

You may not know it, but an email sent to your office colleague right next to you to ask him what he wants for lunch, will travel thousands of kilometers, pass through servers, routers and finally be stored on a datacenter for years. The storage of this email alone generates 10g of CO2 per year.

2. Choose an instant messaging system

The idea is not to prevent you from communicating with your office colleagues. For that, prefer an instant messaging system or a chat like Slack or Hangout for example. Much less polluting and more practical!

3. Control the recipients

It is common to copy an email to your colleagues, your intern and your hierarchy. Everyone can thus follow the file. However, very few of these recipients are concerned and many will not open the email.

The more recipients you put, the more you pollute. So, think carefully about whether or not it is useful to add someone in copy. If necessary, forward the email to them.

4. Limit the volume

Another good habit is to limit the size of your email. The heavier it is, the more it pollutes. Therefore, prefer text format to HTML format, which is on average 12 times lighter.

Also consider reducing the size of your signature. Is it really necessary to put a banner, an image or a logo? Your name, first name, title and the name of your company should be enough. If necessary, add a link to your online business card.

Finally, avoid attachments. As said before, a heavy document sent by email pollutes a lot. If you absolutely must send this file, use a site that allows you to compress it like WeTransfer.

5. Choose Wi-Fi over 4G

This is often a detail that we don't pay attention to, yet connecting your smartphone to Wi-Fi avoids unnecessary pollution. Indeed, when you send an email with 4G you pollute 20 times more than when you use Wi-Fi.

Yes, emails represent a significant part of digital GHG emissions.

The ADEME estimates that in a company with 100 employees, a French employee receives an average of 58 emails per day and sends 33. On a yearly scale, this pollutes as much as 14 round trips between Paris and New York!

So, do you want to start? Start by sorting out your mailbox. Unsubscribe from useless newsletters. Delete your emails that have been stored for years. Do it regularly to avoid it becoming a real chore. Tools such as Cleanfox will help you do this faster.

Preserving the environment is everyone's business. The vast majority of us use the internet on a daily basis. We must therefore limit our digital pollution by adopting the right habits and thus reduce our individual carbon impact.


bottom of page