Climate: emails are for (almost) nothing

Luciano Rodrigues Viana and Jean-François Boucher are doctoral students in environmental sciences and eco-consulting professors at the University of Quebec at Chicoutimi (UQAC), respectively. Mohamed Cheriet is a professor in the Department of Systems Engineering at the École de technologie supérieure (ETS) and the CEO of the Interdisciplinary Research Center for the Operationalization of Sustainable Development (CIRODD – ETS).

The alleged enormous carbon footprint of e-mails is a topic that is often covered in the media, but often exaggerated or even wrongly.

According to them (and even French Minister of Energy Transition), reducing the amount of emails sent and deleting them would be important measures to reduce our carbon footprint.

The impact of digital services (streaming movies and series, listening to music, sending e-mails, meeting people via video conferencing, etc.) has been real for several years and is growing. The information and communication technologies (ICT) sector accounts for 2.1% to 3.9% of annual global anthropogenic greenhouse gas (GHG) emissions. However, the inflated carbon footprint of emails is misleading compared to other levers of action that will significantly reduce the impact of ICT-related users.

As researchers working to quantify anthropogenic GHG emissions, including from ICT use, we believe it is important to debunk this myth that has persisted for several years so that we can focus on reducing the largest sources of GHGs. In the ICT sector.

The origin of the popularity of emails’ carbon footprint

Before getting to the heart of the matter, it is important to understand the origin of the first figures released by the media regarding the impact of emails.

The idea that sending fewer emails will reduce IQ by a significant amount was popularized by Mike Berners-Lee in his book. How bad is a banana? The Carbon Footprint of EverythingIt was published in 2010. It should be noted that the author is the brother of Tim Berners-Lee, the creator of navigation through web addresses (www, URL) and one of the precursors of the Internet.

The figures mentioned in this book have been collected by many media around the world, even in Canada, which has helped to reinforce this idea.

Moreover, in the statement for Financial Times In 2020, Mike Berners-Lee was cautious when commenting on his calculations. He said his estimates are useful for starting broader conversations, but it’s important to focus on the larger issues surrounding ICT.

Sending fewer emails or deleting them is just a gesture

What would happen if we decided to send fewer emails or delete those that are no longer useful? Apart from freeing up some space on the servers that host them, there is nothing to suggest that this can significantly reduce the energy consumption of digital infrastructures. The reason for this:

1. Digital data storage and transmission systems operate 24 hours a day, 7 days a week with more or less constant basic power consumption, even when there is no demand. Indeed, networks are scaled to meet peak demands. Whether emails are sent or not, they will consume roughly the same amount of energy.
2. It’s true that an incredible amount of spam (122 billion in 2022) and genuine email (22 billion) is sent every day. Although these numbers may seem alarming, e-mail exchanges represent only 1% of Internet traffic. In comparison, video services account for about 82% of internet traffic and may grow even more in the coming years.
3. Knowing that 85% of email traffic is actually spam, sending less email on an individual level has a limited effect on reducing the number of emails circulating on the Internet.
4. Whether email is being sent or not, our computers and routers will always be on. The electricity consumption associated with electronic devices will therefore be more or less always the same. Very rarely do we turn on a computer just to send an email.
5. The impact associated with the use of data centers and transmission networks when sending e-mail is extremely low. To get an order of magnitude, driving 1 km in a compact car emits as much greenhouse gas as the electricity used to transmit and store 3,500 5MB emails. Another example: the electricity needed to heat a cup of tea in a kettle. 1500 1MB emails are required to be forwarded and stored.
6. Depending on the time it takes to sort and delete e-mails, the carbon footprint of computer use and the impact attributable to its production may be greater than what can be reduced by deleting messages. For example, deleting 1,000 emails will have a carbon benefit of about 5 g eq. CHO₂. Based on Alberta’s electricity mix (high-carbon electricity), using a laptop for 30 minutes produces 28 g eq. CHO₂ (production + electricity). In the Quebec context (low-carbon electricity), this figure drops to 5 g eq. CHO₂. In summary, manually deleting emails can have a greater impact than keeping them because it represents time spent in front of a computer.

How can we reduce the carbon footprint of our emails?

To measure the carbon footprint of an email, all stages of its life cycle, from writing to receiving and reading, must be considered.

The carbon footprint of e-mails is mainly related to the production of the electronic devices used to write and read them (about 70%-90%). When the electricity consumed to power electronic devices is produced primarily from fossil fuels (as in Alberta), the use phase becomes more important and may even be more important than production.

The best way to reduce the carbon footprint of e-mail is to extend the life of electronic devices and use those that consume less electricity.

Let’s pick our battles

Therefore, it is more appropriate to focus our time and energy on activities that are truly effective in reducing our carbon footprint associated with the use of digital services (buying fewer electronic products and above all extending their service life) and other high-impact daily activities (transportation). , food and heat).

In short, you can delete your emails to save memory or find what you’re looking for faster… but not necessarily to save the planet!