Sometime in early 2020, I ‘borrowed’ this little statistic from a colleagues e-signature :

I despise pleasantries and adopted this as a suggestion / precaution to those I emailed, lest they mistake me for rude. The signature caused an immediate stir and my boss, Vince, who is a baseball analytics guy and numbers lover, had fun breaking this down, mostly because he didn’t believe it could be true. The study is out of Britain so the flights to Madrid are not so far as we imagine them from here in New York.

This will be my focus for the measurement analysis because it is a puzzle still to be solved. I told Vince that I’m taking this up and I look forward to giving him some answers for once. Here are questions I have:

• what is carbon cost of send button
• cost of viewing it?
• How many times does it prompt a response?
• Personally: how many times has this signature dissuaded me from sending a communication? (MANY times, but what is the energy saved there? This is unknowable)

Original Paper:

Infographic: The Carbon Footprint of 'Thank you' Emails

'Think Before You Thank'

• “In 2013 we sent 182.9b emails, consuming 26 PJ (Peta Joules). It's  yearly electricity consumed in  and 1kg of **matter-energy.” – Gorgias**
• Mike Berners-Lee, a professor at Lancaster University whose research was used to estimate the impact of cutting back on emails, did warn the estimates were based on 'back of the envelope' calculations in work from 2010.

BBC takes incredulous stance:

It claimed that if every British person sent one fewer thank you email a day, it would save 16,433 tonnes of carbon a year, equivalent to tens of thousands of flights to Europe.

The problem, however, is that even if the sums involved roughly worked out, it would still be a splash in the pond.

The UK's annual greenhouse gas emissions were 435.2 million tonnes in 2019 - so the amount in question here is about 0.0037% of the national picture. And that's if every single British person reduced their email output.

How it works

Your wi-fi router sends the signal along wires to the local exchange - the green box on the street corner - and from there to a telecoms company, and from there to huge data centres operated by the tech giants. Each of those runs on electricity, and it all adds up.

"The reality is that a lot of the system will still have impact, whether or not the email is sent. Your laptop will still be on, your wi-fi will still be on, your home internet connection will still be on, the wider network will still use roughly the same amount of energy even with a reduction in volume. There will be a small saving in the data centre hosting the email, particularly if it allows them to use a few less servers. But the carbon saved will be far far less than 1g per email.” – Priest

Climate change: Can sending fewer emails really save the planet?