How many times have you opened an email and thought ‘I don’t know why I’m included on this?’, well now you have the perfect justification to remove yourself – saving the environment!
Each activity performed online, including sending and receiving emails, emits carbon dioxide (CO2) into the atmosphere. These CO2 emissions arise as a byproduct of the energy required to run electronic devices and power the wireless networks, data centres and servers needed to support the internet. Unfortunately, CO2 is a greenhouse gas which when emitted goes into the Earth’s atmosphere, absorbing and radiating heat, contributing to climate change.
The carbon footprint of sending an email varies depending on its length and content. According to Mike Berners-Lee, a carbon footprint researcher from Lancaster University, a spam email emits 0.3g of CO2e , a regular email emits 4g (0.14oz) CO2e, and an email that includes a photo or large attachment contributes 50g (1.7oz) CO2e. Berners-Lee also calculated that a typical business user creates 135kg (298lbs) CO2e from sending emails every year, which is the equivalent of driving 200 miles (321.9km) in a family car.
Although the energy needed for a single email equates to only a few grams, approximately 4.1 billion people now use the internet. Therefore, those few grams of greenhouse gases emitted as a result of emails can really start to add up when multiplied by the internet’s billions of users!
Anything we can do to reduce our carbon emissions is important, no matter how small. Here are a few easy steps to reduce your email carbon footprint.
- Unsubscribe from mailing lists that you no longer read. According to estimates by antispam service Cleanfox, the average user receives 2,850 unwanted emails every year from subscriptions, which are responsible for 28.5kg (63lbs) CO2e.
- Get a spam filter. Annually the greenhouse gas emissions from spam emails equate to the emissions of 3.1 million passenger cars. To put this in perspective, that’s the number of cars that cross the Golden Gate Bridge in San Francisco per month.
- Call or text. An SMS text message generates just 0.014g of CO2e. The carbon footprint of making a one-minute mobile phone call is a little higher than sending a text.
- Or talk in person! If you don’t need to use any technology to convey the message this is the most environmentally friendly method. Additionally, gratitude shown in person is much more meaningful.
- Delete emails you no longer need. The more emails saved on the cloud/server requires more energy and therefore more CO2 emissions. If every person deleted 10 emails, we could save 1,725,00 gigabytes of storage space, around 55.2 million kilowatts of power and therefore the associated CO2.
- Swap email attachments for links to the documents.
- Limit the number of people CC’d on an email. Ask yourself, does this person really need to see this?.
- Change your email signature to include a message that lets recipients know you are trying to cut down on unnecessary emails to decrease your carbon footprint. For example:
Please consider this a ‘thanks’ in advance. Every email has a carbon footprint. So if you don’t hear back from me, it’s not because of you, it’s because of the planet. Please feel free to do the same.
If you have any other recommendations please share them in the comments section below!
 Also referred to as the carbon footprint.
 CO2e, or carbon dioxide equivalent, is a standard unit for measuring carbon footprints. The main difference between CO2 and CO2e is that CO2 only accounts for carbon dioxide, while CO2e accounts for carbon dioxide and all the other gases as well: methane, nitrous oxide, and others.
 These figures were crunched a decade ago; Charlotte Freitag, a carbon footprint expert at Small World Consulting, the company founded by Berners-Lee, says the impact of emailing may have gone up due to the devices we use today.
 According to the energy company, OVO.