Flying, driving a car, and eating meat and dairy are not exactly climate-friendly activities, as everyone knows by now. But what people are usually much less aware of is that our digital lifestyle also leads to high CO2 emissions. When was the last time you heard someone say that they decided to watch less Netflix because of sustainability considerations?
Online behaviour is not as ‘tangible’ as offline activities like buying things, travelling, and eating, so its effects are often invisible. But emailing, video streaming, social media and gaming all consume electricity and are therefore a source of CO2 emissions. The impact of surfing the internet at home is not as dramatic on our carbon footprint as boarding a plane, but it is most definitely not negligible, says Bernard van Gastel, Assistant Professor of Sustainable Digitalization at Radboud University in Nijmegen. “We underestimate our digital energy consumption precisely because many electronical devices are always ‘on’.”
Is our digital behaviour really that polluting?
In terms of energy use: yes. The internet is a huge energy guzzler. “Playing video games online easily consumes as much energy as turning on a radiant heater with a 1000-watt power supply,” says Van Gastel. “I decided to measure where the energy guzzlers were in my own household. Much to my surprise, I discovered that the WiFi and internet router accounted for approximately 9% of my electricity bill. Simply because the router is always ‘on’, regardless of how much I use it. The reason that Wifi and internet browsing are polluting is simply that they use up a lot of electricity, which is still largely generated with coal and gas.”
Which internet activities consume most energy?
There are huge differences in the computing power, and hence the energy consumption, of different online activities. Video streaming and online gaming, for example, consume more energy than sending emails, not only at home but also in
data centres. If you send 20 emails a day, a quarter of which contain an attachment, the CO2 emissions per year amount to approximately 21.5 kilograms, the equivalent of a 144 km drive in a petrol-powered car. Playing video games online for two hours a day emits 50 kilos of CO2, equivalent to a 337 km car journey. “Just like with your own router at home, having internet services available at all times costs energy. Computers are on all day long to cater to visitors, even when those visitors are not there.”
Will the CO2 emissions from our daily internet use rise in the coming years?
It looks like our digital lifestyle is costing increasingly more energy. Van Gastel believes that Artificial Intelligence (AI) is partly to blame for this. “AI is getting more and more applications and it is a real energy guzzler.” He calculated how much energy it took to train ChatGPT: 190.000 kWh, the equivalent of what 76 Dutch households consume in electricity in one year. “These are huge figures, in my opinion. It will take a very long time, decades probably, before we can source all our electricity from green sources like sun and wind, and even then our energy production will remain limited. Until then, we have a serious problem, because we still have to rely on fossil fuels to provide all the energy for IT if there's no sun or wind. As far as I'm concerned, finding ways to reduce our digital energy consumption will remain an important priority for a long time.”
How does more sustainable online behaviour affect your overall carbon footprint?
If you want to drastically reduce your own carbon footprint, then flying less has by far the most impact, followed by driving less and eating less meat. According to MilieuCentraal, an average Dutch household of 2.2 people emits 19,000 kilos of CO2. A return flight to Istanbul for two, for example, already leads to emissions of approximately 2,000 kilos of CO2 per person. For that amount of pollution, two people can send 20 emails a day for 47 years. Sending fewer emails may not make much difference, but reducing streaming can go a long way towards saving energy. “You can try to be as green as possible online and avoid activities like video conferencing. But the fact that people can meet online means that they need to travel less by car, or even by plane, to all kinds of meetings. You have to see every choice as a factor in the bigger picture. What does have an immediate effect is turning off your WIFI and internet router when you’re not at home.”
How can you make your online behaviour more sustainable?
You don't have to stop playing video games online or watching Netflix to reduce CO2 emissions from your online behaviour. When you stream a film, for example, you can adjust the streaming quality to ‘medium’, which will reduce data usage by 40%. Van Gastel: “If you have young children who are constantly watching the same videos on YouTube, you can simply download those videos. It's better to store them locally than to stream them over and over again.” You can also reduce your screen resolution and brightness while gaming; you won't really notice the difference. If you want to get fewer emails, unsubscribe from any newsletters you don't read. And during a video conference, turn off your camera, which requires by far the most data traffic, when someone else is presenting. When it comes to holiday photos, it is best to store them on an external or local hard drive, rather than on Facebook or Google Photos. “And clean up old unused accounts from file-sharing services.
Figures on carbon emissions from internet activities come from the website E-missions. Want to know more about the impact of your digital lifestyle? On E-missions there is a calculator you can use to calculate your digital carbon footprint. Here you can also find more tips on how to be greener online.
This article is a translation of a piece written by Mariska van Sprundel, previously published on the website of Kennislink. Photo: Canva Studio via Pexels.
See also: More attention for sustainable IT - on the development of more environmental friendly IT