Digital carbon – why your online footprint matters

Tessa Holmes

5 min read

When you think of harmful emissions, you probably picture car exhausts, power stations, factories and so on, but online activity is a stealthy producer of enormous amounts of environmental damage, accounting for 3.7% of global emissions. With over 4 billion people considered active internet users and our lives moving online more and more, that figure is set to double by 2025. In this article we take a look at where our online carbon footprint comes from and a few easy ways of reducing it.     


Your website can be responsible for a lot of energy consumption, from the data centre that hosts it, the transmission network that serves it to users and the power of the devices that people are accessing it on. The Website Carbon Calculator can help you understand the emissions of your website and give you tips on how they could be reduced, including everything from image size reduction to SEO and copywriting designed to reduce the time people spend online.


Every single email sent contributes to carbon footprint, with a typical year of email for a small business generating around 135kg of carbon emissions. Email size matters, as does the use of images and attachments. A small, text-only email produces about 4g of CO2, while an image can bump this instantly to 50g. Some research suggests that if every individual in Britain sent one fewer email a day, it would save over 16,000 tonnes of carbon in a year. You can also cut down the amount you receive, by blocking spam, unsubscribing from newsletters (but not ours, of course) and turning off email notifications for apps and social media.  


According to ethical.net, every web page loaded, including a page of search results, uses about the same amount of energy as it takes to boil a kettle, so cutting down on searches can have a big impact. If you can go directly to a site, you should do so, but there are also things you can do as a site host. Make sure that your site is properly labelled and has its “metadata” in order. This will help people avoid visiting more sites than necessary and making lots of online searches.


It seems obvious, but reducing the brightness of your screens and devices can save energy. A reduction from full brightness to 70% can save up to 20% of energy usage and it’s also much kinder to your eyes. There are also (very) minimal energy savings gained by using dark mode on apps and browsers.  


Good search engines

When you do search, consider doing it through Ecosia, who plant a tree for every 45th search made through their site. It’s powered by Bing, so you lose nothing in terms of search accuracy, but the company donates an astounding 80% of its profits into planting more trees, keeping back 20% for any unforeseen circumstances but, if none arise, ploughing that into trees as well.


Streaming video is one of the worst environmental offenders online, accounting for 60% of global internet traffic and generating 300m tonnes of CO2 annually, according to the BBC. You can help this as a user by lowering the video resolution when you watch, closing unused background tabs that might be running video ads, or opting for audio alternatives and even good old fashioned reading. On your own site, consider reducing the amount of video used, perhaps limiting yourself to one quick walkthrough of a place rather than room-by-room video tours. 

Shutting down

It turns out the planet needs screen breaks as much as we do. The average laptop uses 15-60 watts of energy when active and while this does drop when the machine goes into sleep mode, it only goes down to 2 watts, meaning you’ll still burn through 16 watts or so overnight. Completely powering down the machine is the only way to get that usage down to zero, so make sure that your computer shuts down whenever you do. 

Repair and reuse

As the saying goes, “buy cheap, buy twice”. If you can afford the initial outlay, investment in decent tech can work out cheaper in the long run and usually means not having to replace a device for longer, saving an entire product’s worth of energy usage in everything from manufacture to shipping and the sourcing of materials. Now and then of course, tech will simply give up the ghost. At the moment it does, you may well feel the urge to recycle it into small pieces, but consider repairing the device before replacing it. If replacement is the only option, sites like Backmarket offer a decent range of refurbished tech.

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