The Carbon Footprint of 'Thank you' Emails

The sending of one email is estimated to produce 0.000001 tonnes of CO2 equivalent. That doesn't seem like much, but if you consider that the average person sends ten unactionable, 'unnecessary' emails per week, you very quickly have a far larger carbon footprint when looked at on a national scale.

The calculations by OVO Energy featured here have been done for the UK, but the assumptions could reasonably be adapted for most industrialised countries. If every email user in the country were to send one less unnecessary email per day, that would reduce carbon emissions by 16,433 tonnes - equivalent to a staggering 81,152 flights from London Heathrow to Madrid.

Now, one criticism of the methodology could be that yes, while 87 percent of adults 'use email', most written personal communication is conducted via social media or messaging apps nowadays. It is people who use email in their professional lives that are regularly sending emails, and therefore the ones most likely to be sending 10 unactionable mails per week. Adjusting the calculation to people who are employed, you have a pool of 33 million people in the UK. Being even stricter, removing jobs from sectors which largely don't involve the regular sending of emails leaves you with 19 million people. Let's add half of the country's 5 million self-employed to give us a total of 24 million regular emailers. Under this set of 'lower estimate' assumptions, the figure still comes to 8,760 tonnes of carbon - equivalent to 43,260 flights to Madrid.

But how does something as seemingly insignificant as a short email create a carbon footprint? Speaking to the Guardian, Mike Berners-Lee, a professor at the Environment Centre in Lancaster University, explained: "When you are typing, your computer is using electricity, when you press send it goes through the network, and it takes electricity to run the network. And it’s going to end up being stored on the cloud somewhere, and those data centres use a lot of electricity. We don’t think about it because we can’t see the smoke coming out of our computers, but the carbon footprint of IT is huge and growing.”