Each internet search, song played, video streamed, message sent, route planned via GPS, cashless payment, and social media scroll contributes to growing energy consumption, global demand for electricity, and rising CO2 emissions. The world’s digital carbon footprint is becoming increasingly difficult to ignore.

We hate to be the ones to break it to you, but pretty much anything we do has an effect on the environment — emails are no different. Most emails, including spam ones, unread ones, and those you simply forgot you never deleted are generally stored on the cloud. Cloud storage requires quite a lot of electricity, which in most parts of the world is still generated by  fossil fuels. This means that while emails no longer contribute to paper pollution, they still contribute to carbon emissions. According to The Good Planet, the average American has around 500 unread, most likely junk, emails. If we assume that each email contributes 0.3 grams of CO2 based on carbon emissions, then we are dealing with 150 grams of extra carbon dioxide per U.S. citizen.

No one is going to stop Google from creating more data but we as individuals can lower our own environmental impact by taking charge of our own junk... well, junk mail, anyway. Deleting emails is the easiest way to reduce your carbon footprint on the computer, but that’s not all you can do. You could also unsubscribe from emails or newsletters you don’t actually intend to read, or delete those emails once you’ve read them.

According to The Good Planet, nearly 107 billion spam emails were sent and received a day in 2019. If every person only deleted 10 of those emails, they could save 1,725,00 gigabytes of storage space and around 55.2 million kilowatts of power.

A one-megabyte email (= 1 MB) during its total life cycle emits 20 g of CO2 , i.e. the equivalent of an old 60 W lamp lit for 25 min. Twenty emails a day per user over one year, create the same CO2 emissions as a car travelling 1000 km.

A single router consumes 10,000 watts (10 kW). A very large data centre comes close to 100 million watts (100 MW), or one-tenth of the output of a thermal power station. In fact, on top of the consumption required to run the servers, the electronic circuits must be cooled using air conditioning.

The search for a web address represents 3.4 Wh (0.8 g CO2 equivalent). But the total rises to 10 g after an internet search producing five results. If a web user makes an average of 2.6 web searches per day, this user can be extrapolated to be emitting 9.9 kg of CO2 equivalent per year.

When browsing the web, an average internet user yearly needs about 365 kWh electricity and 2,900 litres of water, which corresponds to the CO2 that is emitted when you travel a good 1,400 km by car.

Lets assume we get nearly 10 emails per day, that would be 1,400 email a year which emits around 7 kg of CO2 which is a huge amount. You will process around 1,400 emails this year which in turn will create around 7kg of CO2. The impact of your annual email load on the planet is about the same as if:

Measuring our individual impact isn’t easy, but you can take steps to reduce it.

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