The carbon footprint of the internet: what’s the environmental impact of being online?

20 January 2021 | Aimee Tweedale

When we talk about our carbon footprint, what’s the first thing that comes to mind? It’s easy to see how carbon emissions come from transport, home heating, water use, and even fast fashion. But you might be surprised to learn that there’s also a carbon footprint to the internet – and even this web page.

The carbon footprint of the internet

How does scrolling through social media relate to climate change? It might seem abstract, but the internet actually accounts for 10% of global electricity demand. And, as more and more people around the world gain access, that percentage is set to rise to as much as 20% by 20301.

Here’s the lowdown on the carbon footprint of being online, where it comes from, and how to build good digital habits. Plus, find out how we’ve started to decarbonise our online presence here at OVO.

What’s the environmental impact of the internet?

A study by the Boston Consulting Group found that the internet is responsible for around 1 billion tonnes of greenhouse gas emissions per year. That’s about 2% of total emissions. 

In other words, the internet has an impact on the climate that’s roughly comparable to the aviation industry, which is responsible for 2% of CO2 emissions worldwide.

We talk a lot about giving up flying for climate change. So, is it time we started talking about spending less time online, too?

How does the internet create carbon emissions?

It might feel hard to wrap your head around how something like a Google search could emit carbon. After all, we tend to think of the internet as existing in a “cloud”, not part of the physical world. Of course, the truth is a bit more complicated. The carbon footprint of the internet comes from a few different sources.

First of all, there’s the devices you use to actually access the internet. Your laptop, smartphone, TV, and any other connected device has a carbon footprint. That comes both from the manufacturing of your device, and the electricity you use to power it. 

Then there’s the question of all the infrastructure around the world that stores our information and keeps us connected. The many satellites, cables, and data centres that make up the internet (and the electricity used to power them) have a CO2 footprint of their own.

The carbon footprint of each individual action we take online is small. But with approximately half the world’s population (4.1 billion people) being internet users2, the overall effect can be pretty huge. The exact amount of carbon emitted for each click of your mouse will depend on a few different factors, such as the size of the device you’re using, the data centre you’re accessing, and most importantly, where the electricity to power both of them is coming from

Want to learn about some other ways you can fight climate change from home? Here are a few easy ways to reduce your carbon footprint. And it's not only humans who have a carbon footprint, find out how you can reduce the carbon pawprints of your pets too! 

What’s the environmental impact of an email?

Each email you send racks up an average of 1g of carbon emissions3. That’s about the same weight as a teaspoon of sugar, or a paperclip.

It doesn’t sound like much – until you think about how many emails you actually send and receive. According to our research, Brits send an average of 64 unnecessary emails per day. How many times have you fired off a message just to tell someone “Okay”, or “Thanks!”? 

That’s why we launched our Think Before You Thank campaign, featuring a browser extension and email signature that help you send fewer one-word emails (and explain to people that you’re not doing it to be rude!). Remember, while the carbon footprint of an email is fairly tiny on its own, making daily habit changes like this can be good for our wellbeing, and help us to decarbonise our lives.

What’s the environmental impact of streaming?

Streaming is one of the biggest energy consumers online. In the US, Netflix and YouTube alone represent more than 50% of peak internet traffic4.

One study by the University of Bristol in 2016 estimated that the amount of YouTube videos watched that year amounted to over a billion hours, and resulted in in 11.13 million tonnes of carbon dioxide being released into the atmosphere5. This was roughly the same amount of carbon emitted by a city the size of Frankfurt or Glasgow in the same year6.

When it comes to music, the carbon footprint of streaming a song once is very small. But it’s been shown that if you want to listen to a song more than 27 times, it’s actually greener to buy a physical copy of it rather than streaming.

How about Netflix? Analysis from the International Energy Agency (IEA) suggests that the carbon footprint of streaming is a bit smaller than alarmist media stories have reported in the past. The IEA estimates that an hour of watching something streamed online, such as Netflix, generates about 36g of CO2. That’s relatively little, compared to travelling by bus for an hour (150g of carbon emissions), or driving a car for a mile (710g)7.

So when it comes to the impact we have as individuals, streaming a song or video isn’t the worst thing we can do for the planet. After all, we all need a little light entertainment in our lives sometimes! But when all that streaming is combined, our individual behaviours eventually add up to some pretty big emissions, so it’s important to be aware of the overall impact – even if it’s small. 

How to decarbonise your digital life

What has the biggest carbon footprint: online or high-street shopping? 

In the age of convenience and next-day shipping, many of us have been guilty of having items speedily delivered to our door. But what’s the carbon footprint of online shopping? Just like anything else, it depends how often you do it, how much you buy, and what your alternatives would be. 

In general, shopping online is seen as better for the environment than shopping in person. But this is only the case if you’d otherwise be driving to the shops. Importantly, the carbon footprint of your online basket will be bigger if you choose the next-day delivery option – and even more so if you return your items, as 1 in 3 shoppers do8.

To learn more about sustainable shopping, read our guide to fast fashion and how it impacts the environment.

How to measure your carbon footprint online

The average person’s carbon footprint works out at around 5.8 tonnes of CO2 per year. While your online habits are part of the picture, remember that how you power and heat your home, and the transport you use are the biggest pieces of the pie9.

OVO members can also calculate the carbon footprint of their home energy and transport using our handy Carbon Tracker.

Interested in switching to a greener energy supplier? At OVO, we supply 100% renewable electricity as standard10, and plant a tree for every member, every year11. Find out more about how to switch energy supplier and get a quote today.

How the internet can help us fight the climate crisis

It’s not all doom and gloom. While we should of course be concerned with how much electricity the internet’s eating up, there are also reasons to be optimistic about the digital revolution.

There have been huge improvements in energy-efficiency in recent years. This means that even though we’ve become greedier for data, the electricity use of data centres has not rocketed upwards as you might expect. That’s because the data centres are using electricity more efficiently. Lots of tech giants also invest in renewable energy, including Google – which is the largest corporate purchaser of renewables in the world. 

The internet can also help us to make greener choices in our everyday life. For example, while the carbon footprint of an email can be up to 4g, the footprint of sending a letter can go up to 29g12. Plus, connected devices like smart meters and other smart home technology will help us to decarbonise home heating, and make our homes more energy-efficient – which will be a huge step forward in our fight against the climate crisis.

8 ways to reduce your digital carbon footprint

  • Shut down your computer when you’re done: we may not be able to control how data centres are powered, but we can make sure that we use electricity efficiently in our homes. It’s always best to make sure devices are switched off when they’re not needed. Make sure you unplug your chargers, too – devices that are plugged in but switched off still use up a small amount of electricity. This is what’s known as “vampire power”13!
  • Downsize your gadgets: smaller devices use less power. So try doing things on your phone rather than on a computer as much as possible – and if you can, invest in smaller, more efficient gadgets.
  • Choose a “conscious” cloud: if you back up your data in a cloud, check whether your provider is using renewable electricity to power their data centres. All of the Big Three providers (Google, Amazon, and Microsoft) have pledged to decarbonise their clouds. Find out how they’re doing here.
  • Make your searches green: your the search engine Ecosia is a green alternative to major search engines – and they use the profits generated from your searches to plant trees around the world!
  • Think before you thank: every time you send an email, ask yourself: does this need to be an email? One message might not make much difference, but if we all get used to saying less online, we could make an impact on our collective carbon footprint.
  • Change your autoplay settings: one study by Lancaster University found that many people use YouTube or other streaming services as “background noise”, or even fall asleep to them. So help clean up your online habits by avoiding doing this. In most streaming apps, you can adjust your settings so that they won’t keep automatically playing new content once you’ve fallen asleep, or stopped paying attention. 
  • Spend more time offline: this one sounds simple, but it’s the biggest step of all. The internet is a necessary part of our lives for many of us – but to combat the impact on our climate, we need to collectively rethink how much time we spend online. Even the smallest changes – like limiting your social media use, or buying something locally rather than online – could make a real difference if we all work together.
  • Switch to green energy: of course, the best way to make sure you’re powering your gadgets in an eco-friendly way is to use 100% renewable electricity. Get a quote from OVO today and join us on the journey to net zero carbon.

How we’re lowering our own digital carbon footprint

As part of our wider mission to become a net zero business, we’ve started taking steps to decarbonise our website. 

The biggest change so far is to migrate away from our legacy CMS, which was pretty inefficient. Now, we’re using a more modern system, and we’re also making sure we use images that are easier to load on your phone or computer (which not only improves your experience, but also uses less data!). 

The impact of these changes has so far been pretty promising. Our homepage used to generate 1.49g of carbon per visit – but now, it’s 0.59g. This website carbon calculator currently estimates that is cleaner than 65% of other web pages. Not a bad start!

We also considered sustainability and renewable energy use when choosing which cloud providers to use to back up our data.

These actions are a good beginning to help minimise the impact of our internet use. But we know there’s always more to do. So we’ll keep working on it – because getting to zero carbon is a journey we’re all on together.

Go green with OVO Beyond

Taking these types of small actions is a good place to start, when it comes to climate action. But don’t forget that a much bigger part of our carbon footprint comes from the energy we use at home. 

Read more about how to make your home more energy-efficient, and other steps you can take to fight climate change at home

Ready to make the switch to 100% renewable electricity14, and have 5 trees planted every year as a bonus15? Read up on OVO’s commitment to renewables, and then get a quote for switching to our greenest tariff, OVO Beyond

Sources and references

3  Mike Berners-Lee, How Bad are Bananas?: The carbon footprint of everything, Profile Books, 2020

7  Mike Berners-Lee, How Bad are Bananas?: The carbon footprint of everything, Profile Books, 2020


9  How we worked out what makes up an average person’s carbon footprint: we commissioned analysis to be carried out by the Carbon Trust for OVO Group (2020) to look at the GHG emissions of the average UK person. In this analysis, the carbon footprint includes the following lifestyle categories: energy, transport, shopping, food and drink and holidays. This excludes emissions from things that the average person cannot directly control, such as supporting the NHS, defence and government bodies etc.

10 The renewable electricity we sell is backed by renewable certificates (Renewable Energy Guarantee of Origin certificates (REGOs)). See here for details on REGO certificates and how these work.  

11 Each year, OVO plants 1 tree for every member in partnership with the Woodland Trust. Trees absorb carbon dioxide from the atmosphere, so tree-planting helps to slow down climate change. And we plant an extra 5 trees with The Conservation Volunteers through our I Dig Trees programme for every member that joins our OVO Beyond upgrade. Since 2015, we have planted over 1 million trees through our I Dig Trees programme.



14 The renewable electricity we sell is backed by renewable certificates (Renewable Energy Guarantee of Origin certificates (REGOs)). See here for details on REGO certificates and how these work.  

15 OVO plants 5 trees for every OVO Beyond member through our award-winning I Dig Trees programme with The Conservation Volunteers. Trees absorb carbon dioxide from the atmosphere, so tree-planting helps to slow down climate change. Since 2015 we have planted over 1 million trees.

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