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The internet: the largest coal-fired machine in the known universe

July 23, 2024

By Philip Thornton

The internet is many things: an almost endless repository of information on everything from aardvarks to zygosis, a way to receive news and entertainment, shop, bank, date, keep in touch with friends and family, and much else besides.

But who’d have thought this essential medium of modern life was shaping up to be a climate disaster.

The numbers are staggering. Internet use accounts for nearly 4% of global GHG emissions: this is a larger proportion than the aviation sector. This figure is expected to double by 2025. Forget about not flying, it’s not Googling you should be thinking about.

How did we get here?

The internet dates from the early 1960s, when scientists started developing some of the elements needed, such as packet switching (sending small pieces of data across networks). By 1983, a comms protocol was established that allowed disparate computer networks to be linked together. In the early 1990s, Tim Berners-Lee wrote and publicised the code for the WorldWideWeb, the first web browser and web page editor. The growth of the internet was initially quite slow: by 2002, annual global Internet usage was just 156 GB. In 2022, traffic had increased to approximately 150,000 GB per second.

There are now about 5.4 billion internet users on the planet. This is expected to increase to 7.9 billion by 2029, or 93% of the projected human population. On average, internet users spend six and a half hours online every day. And each day sees 7.5 million blog posts published (like this one).

Just about all of our internet-related actions have a carbon cost. It’s tricky to quantify, but a middle-of-the-road estimate is that storing 1GB of data consumes around 1 kWh of electricity and produces roughly 0.3 kg CO₂ emissions. The average carbon footprint of an email is around 0.3g CO2e. The footprint of a longer email that takes ten minutes to write, three seconds to read, and no time at all to delete, is more: 17g CO2e. And one that has an image or attachment more still: 50g CO2e. I’d love to know the carbon cost of the millions of unread emails sent daily, often with a horde of people in CC. Actually, I wouldn’t; it’s probably terrifying.

It’s not just emails, of course. As I write this, I’m listening to AC/DC’s “Back in Black” on YouTube (you may very well ask why). This too has a carbon cost; it’s been estimated that if you listen to a song 27 times or more during your lifetime on a streaming platform, then energy- and carbon-wise it’s better to buy a hardcopy on CD or LP. Another way to look at it is that “Blinding Lights” by The Weeknd – currently the most streamed song on Spotify with over 4.3 billion listens – has caused the equivalent of more than 13 million kilos of carbon emissions. According to CO2everything, that’s the equivalent of over 800,000 servings of beef. Maybe you should keep that in mind, if you’re Abel.

It’s even worse for movies. Streaming a two-hour show in 4K resolution involves about 7 GB or approximately 7 kWh of energy, comparable to a 45-minute car drive. Binge-watch the latest TV series and you might as well have flown to the premiere. Okay, not quite, but you take the point.

If you carry out 300 Google searches, that’s about 0.1 kWh, the same energy required to boil a litre of water starting from 20 °C. A video call on Zoom can emit up to 1 kg carbon per hour, though switching to audio-only can reduce this by 96%. There’s never been a better reason to turn off your video, or consider whether that monthly team meeting is actually necessary.

The average website produces 1.76 g CO2 for every page view, so a site with 100,000 page views per month emits more than 2t CO2 every year – the equivalent of around 260 servings of beef, or eight hours of flying. Understandably, this can cause cognitive dissonance in those working on sustainability who use internet traffic as a measure of success. Meanwhile, a simple, stripped-back website produces just 0.24 g CO2 per page view. Perhaps minimal will become the new sustainable.

But it’s AI where these numbers skyrocket. Training an AI like ChatGPT uses an estimated 1.3 GWh: this is the amount of energy 120 homes in the US use in a year. ChatGPT already uses more than 0.5 MWh of electricity daily. The energy needed to run AI tasks is accelerating with an annual growth rate of 26-36%. Where will this end up? It’s difficult to say, but one estimate is that by 2027 the AI sector will consume between 85 to 134 terawatt-hours annually: that’s half a percent of global electricity consumption. In terms of energy demand, it’s as if, in the middle of a climate crisis, we just decided to create a whole new Finland, Belgium or Bangladesh.

So what can we do as individuals or small organisations? As usual, it’s the little things that can help:

• Reduce your email use: do you really need to send that email and that attachment? And while you’re at it, do you really need to CC the world and its dog?

• Clean up your email storage: archive it on a flash drive and take it off the cloud. Or consider dragging and dropping most of it to the trash can. After a while, you’ll probably never need it.

• Don’t put up with spam emails: click UNSUBSCRIBE whenever you can.

• Limit your internet searching to only what’s really necessary.

• Reduce your website’s carbon footprint: switch to a green web host (such as those that run on solar power), simplify your web pages, severely limit the flashy graphics and the number of images you show on each page. If you do use images, opt for highly compressed file formats.

• If you don’t need to use the video, do audio-only team calls on Teams, Skype, Zoom etc. Half the time we’re only looking at ourselves or pretending to pay attention.

• If you want to be a “zero hero”, add the internet-related carbon emissions from yourself or your organisation to your annual total and offset it using a reputable scheme, if you can find one.

And you can always read a book instead of streaming yet another terrible Netflix movie.