The online world has a real-life environmental impact - here's how to reduce it
Every time we go online to visit a website, stream a TV show, catch up on social media or join a video call, we’re using energy.
Devices such as smartphones, tablets, TVs, laptops and game consoles all use electricity when in use – but this is usually in low amounts compared to other household appliances. However, behind the scenes, a vast amount of energy is being used to keep the internet running 24/7.
Wireless streaming, digital downloads and cloud storage might all sound light as air, but the data centres that underpin online services leave a heavy footprint on the physical environment. The recent boom in artificial intelligence (AI) has increased the energy demand and carbon emissions of computing at an alarming rate.
We are all increasingly reliant on online services, so how can we use them more efficiently? Here's why online activity can be so energy hungry, and where you can make choices that cut down your impact.
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Why does using the internet use energy?
Your digital carbon footprint is made up of the energy your devices use and, more significantly, by the vast data centres and global networks involved in storing, processing and delivering online data as it moves to and from your devices.
A data centre is a physical building, or group of buildings, that houses the IT equipment needed for creating, delivering and maintaining applications and services online, and storing all the data needed to make this possible. They are incredibly energy (and water) hungry, and are powered by electricity grids around the world using varying amounts of polluting fossil fuels – such as coal and gas – to generate energy.
Digital and online services are a crucial part of modern life. As our reliance on technology continues to grow, so too does our need for data centres. In 2024, around 5.35 billion individuals were using the internet, or 66% of the total global population. On average, each internet user spent around 6 hours 40 minutes online every day.
Data Centre & Network News magazine recently reported that data centres are responsible for producing around 3% of worldwide carbon dioxide emissions, which is more than global aviation (around 2.5%). AI tools such as ChatGPT, Microsoft CoPilot and Google Gemini use far more energy than non-AI tools, which has resulted in a recent surge in energy consumption. The International Energy Agency reported that data centres accounted for around 1.5% of the world’s electricity consumption in 2024, or 415 terawatt-hours (TWh). It expects this will more than double to around 945TWh by 2030. That’s around three times the annual electricity consumption of the UK.
When it comes to your home's electricity, your white goods and appliances tend to use the most. We've crunched the numbers so you can see where you can make savings on your energy bills: how much your appliances cost to run
How to be more energy-efficient online
There are several ways to reduce your energy consumption when online or using digital services. While they won't affect your home energy use much, they will cut the amount of energy needed by data centres and reduce carbon emissions.
1. Cut down social media use
If you've been looking for a reason to reduce your social media scrolling, this could help make the case.
According to a study conducted by Channel 4, a single Instagram post from footballer Cristiano Ronaldo to his 240 million followers consumes as much energy as ten UK households use in a year. Fortunately, most of us don’t have that kind of impact, but spending time on social media platforms can quickly add up.
A 2023 study compared the top 10 social networking applications and ranked them according to their environmental footprint. The greenhouse gas (GHG) impact is around twice as great between the most and least impacting platforms.
Applications with a lot of multimedia content – particuarly video-based platforms – consume more energy, as they exchange lots of data over the network to display this content.
TikTok was found to be the most energy-hungry, consuming 22.4 mAh at launch and exchanging a lot of data as it scrolls through the news feed, due to the constantly running video content. Its GHG emissions were 0.96gCO2e/min (grammes of carbon dioxide equivalent per minute).
Text-based content, on the other hand, is much easier to load and consumes much less energy. LinkedIn consumed the lowest amount of energy (13.9 mAh), and its GHG emissions were 0.47gCO2e/min.
Switch off autoplay fucntions on video apps where possible to prevent videos playing automatically in the background or when you’re not watching.
2. Reduce streaming and video calls
According to the International Energy Agency, global internet traffic has grown by more than 40% since early 2020. The start of the Covid-19 pandemic accelerated a shift to increased video conferencing, video streaming, online gaming, and social networking, all of which are firmly here to stay.
The carbon footprint of our video calls increases with the number of participants on the call as well as by having your camera turned on. Unless you’re giving a presentation, or otherwise need to be seen, switching off your camera saves energy.
Streaming video at the highest resolutions available uses more energy. If you don't need the highest quality, choose a lower default setting and adjust up as needed.
Many music streaming apps now default to playing accompanying snippets of video content – switch this off if you're just listening rather than watching.
3. Game efficiently
While most day-to-day online devices don't make much of a dent in your household's energy use, gaming is an exception. If you or someone in your household is a serious gamer, it could add almost £100 a year to your electricity bill to play the most energy-hungry titles.
Research from GameTop, an online gaming platform, found that the game Cyberpunk 2077 played on a PC uses an average 30kWh of power per month.
The popular title Fortnite wasn’t far behind, using an average 24kWh a month.
A high-performance gaming rig can draw as much power as a small fridge, especially if you play for long periods of time running titles with intense graphics or CPU usage.
To reduce energy bills, lower your graphics settings to reduce the strain on your system, which means it uses less power. Consider switching to energy-efficient modes or choosing games that are less demanding on your PC or console.
Get the latest Which? advice for buying gaming equipment, laptops and monitors
4. Manage emails
According to OVO Energy, if everyone in Britain sent one less email a day, we would save 16,433 tonnes of CO2 a year.
If your inbox piles up with marketing emails you don't read, audit the mailing lists you subscribe to, and unsubscribe from companies you're no longer interested in.
Delete old emails when they’re no longer needed. Simply storing them takes energy, so by decluttering your inbox you’ll also reduce your carbon footprint.
Don’t add large attachments like photos or graphics unless you have to. Check the size of your email signature – if you're attaching a large image file to every email you send, removing this will immediately cut your digital carbon footprint.
5. Organise your cloud storage
Cloud storage is a way to store digital files and data on remote servers accessible over the internet. Instead of storing files on your local computer or a physical hard drive, you upload them to a cloud service provider, which allows you to access your files from any device with an internet connection.
If you use services such as Google Drive, Dropbox, Microsoft’s OneDrive, or Apple iCloud, you can declutter your cloud storage and reduce demand for energy hungry data storage by deleting things you no longer need.
Media files such as videos and high-resolution photos take up the most space. As well as using less energy, you’ll free up space that can then be used to store new data, potentially saving you money from having to upgrade to a larger storage option.
Not sure where to start? Here's how to back up your important files on your computer or on your phone or tablet.
Rather use your own hard drive? See our latest best external hard drive test results.
6. Opt out of AI when it's not needed
The introduction of artificial intelligence – specifically generative AI, which creates new text, images or other content based on prompts – has rapidly increased data centres’ energy demand. A ChatGPT query uses around 10 times more energy than a standard search query.
This recent and rapid surge in energy demand casts doubt on the ability of big tech companies to achieve their public climate goals.
Microsoft has previously pledged to become carbon negative, water positive, zero waste, and to protect ecosystems by 2030. However, the company is a major investor in OpenAI, the maker of ChatGPT, and has positioned AI tools at the heart of its product offering. Microsoft’s latest sustainability report, for 2023, revealed a 30% increase in emissions since 2020 due to data centre expansion.
Similarly, Google reported that its 2023 greenhouse gas (GHG) emissions were almost 50% higher than those in 2019, largely due to the extra energy used by data centres. Google also has an ambitious plan to achieve net zero (ie. to release no more greenhouse gases into the air than it removes) by 2030, but its emissions are currently heading in the wrong direction.
There's no doubt that AI can be very useful, completing certain tasks much more efficiently than humans. Andy Davies, of Wholegrain Digital (an agency that specialises in digital sustainability), told us that that while it is ‘almost impossible to benefit from AI without increasing energy use', not all AI has the same impact. 'Task-specific "Narrow AI" – for example, the sort used for medical research – uses a limited dataset, which is very different from generative AI’, he says. When used responsibly and in a targeted way, the associated energy and carbon costs may be justified. But we should use AI software knowingly, where it’s needed, and understand the additional costs.
You'll find AI assistants, tools and search suggestions popping up in more and more places as a default addition. In some cases, you might not even know it's there or particuarly have wanted it in the first place.
Google’s AI Overview is now a permanent feature of its search function; however, adding -ai to your search prevents the AI-generated text from appearing.
You could also switch to a different search engine that doesn't generate AI results, or that at least allows you to switch off the AI function.
Google has around 90% of the UK's online search market, and a recent Which? investigation found that online search is now a messy, inconsistent experience filled with invasive and potentially harmful advertising.
Find out more, and why Which? is urging the Competitions and Markets Authority (CMA) to improve competition in this consumer market, in our guide: 6 tips for better online searches.
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