7 January 2026
How to start a capsule wardrobe: a step-by-step guide
- Lifestyle
On 20 September, more than 190 countries take part in World Cleanup Day, the world’s largest bottom-up movement against litter. Imagine millions of people pulling plastic out of rivers, parks and beaches. But another kind of waste is piling up that nobody sees: the one sitting in your inbox, your camera roll, and the cloud right now. We call it digital waste, and invisible or not, it runs on electricity and that electricity has a carbon cost.
Key takeaways:
- The internet and its infrastructure produce roughly 900 million tonnes of CO2 a year, which is more than Germany’s total emissions.
- Everyday actions (a search, an email, a video call) each carry a small, specific, measurable carbon cost.
- A 30 – 60 minute digital cleanup is something anyone can do today, no equipment required.
The mess you can’t see is still a mess.
Every year, the internet and the infrastructure that keeps it running produce roughly 900 million tonnes of CO2. That is more than the annual emissions of a country like Germany, according to World Cleanup Day Germany’s Digital Cleanup Day initiative. And it isn’t slowing down. Data centres alone consumed around 415 terawatt-hours of electricity in 2024, about 1.5% of global electricity use, and the International Energy Agency projects that figure will roughly double to 945 TWh by 2030 as AI and cloud services keep expanding.
Prof. Holger Holland, initiator of Digital Cleanup Day in Germany, puts it simply: “the cloud is not a cloud in the sky.” Behind every stored photo, every streamed episode, and every “just in case” backup sits a data centre running around the clock and drawing power from the grid.
The total impact of our digital activities is enormous – every click, every file and every message contributes to CO₂ emissions. Conscious digital usage can significantly reduce these figures. Prof. Holger Holland, initiator of World and Digital Cleanup Day in Germany
The actual numbers behind your digital footprint
Let’s get concrete and look at the figures published by Digital Cleanup Day:
- A single Google search: around 0.2g CO2
- A ChatGPT prompt: around 4.32g CO2
- An email (depending on attachments): 0.3 – 10g CO2
- A 30-minute video call: 75 – 500g CO2
- A photo stored in the cloud: around 1g CO2, for as long as it stays there
These numbers might not look so dramatic on their own. But multiply the searches, all the unread newsletters, probably thousands of duplicate holiday photos and dozens of apps you downloaded once and never opened, and you get a footprint that’s been quietly growing since the day you got your first smartphone.
The waste adds up fast
Digital waste isn’t only about storage space or unread e‑mails. Remember those old accounts you created years ago, never used and never closed? The apps you downloaded once, used for a day, that still receiving background updates? The backup files you have across multiple devices that keep servers running and consume energy even when you’re not using them? They are basically the digital equivalent of leaving the lights on in a room that nobody is using.
The upside: unlike ocean plastic, this is a mess you can clean up entirely from your sofa, with a coffee in your hand and you don’t even need a bin bag for it.
Your digital cleanup, step by step
If you don’t have time to join a park or river cleanup this World Cleanup Day, why not blocking out 30 – 60 minutes to do a digital one instead:
- Delete unused apps. If you haven’t opened it in six months, you won’t miss it. Delete it.
- Clear out old photos and videos. Duplicates, blurry shots, ten versions of the same sunset > pick your favourite and let the rest go.
- Unsubscribe from newsletters you don’t read. Every unopened email still has to be delivered, stored, and eventually deleted.
- Sort your inbox by size or age, archive what you need, and cut long email threads down to the last relevant message.
- Close old accounts you set up once and never used again > the ones still holding your data on a server somewhere.
- Empty your trash and downloads folder. Deleted isn’t really deleted until you empty it.
None of this requires technical skill. It requires min. ten minutes of honesty about what you actually still need.
What you can do next
Get started! Set yourself a date and a time. Maybe you make it the 20. September, or next weekend, or next holidays. Two habits are already worth changing going forward:
- Camera off! Check whether you really need video on a call. In 2021 researchers at MIT, Purdue University, and Yale University found in a study, that you can lower your carbon footprint by up to 96% if you turn off your camera (MIT Energy Initiative, 2021).
- Lower your streaming quality when you’re not watching on a big screen. The same study found that streaming in standard definition instead of HD can reduce that footprint by up to 86% (MIT Energy Initiative, 2021).
Your digital cleanup may seem like a small action, and, indeed, it won’t undo a data centre’s emissions on its own. It isn’t a substitute for the structural change the tech industry needs in how it sources energy. But it does for sure shrink your own footprint. And it helps making an invisible problem visible. If you’re already checking a brand’s certifications before buying, you’ve got the instinct for this, and it will be easier to change the ithabit. Turn it inward for an hour. And once your phone’s sorted, browse COSH!-verified stores to see where that same scrutiny takes you next.
Frequently Asked Questions
Q: What is digital waste?
A: Digital waste is data that takes up storage and energy without adding value: unused apps, duplicate photos, unread emails, old cloud backups, and inactive accounts. It exists on your devices and on remote servers, and both require electricity to keep running.
Q: How does digital waste cause CO2 emissions?
A: Every file, email or app relies on data centres that run continuously and consume electricity, much of which is still generated from a mix of energy sources that includes fossil fuels. Storing, backing up and transferring data all add to that electricity demand, and more demand generally means more emissions.
Q: Why does this matter if the emissions per action are so small?
A: Individual actions such as one email or one search have a tiny footprint, but billions of people repeat these actions daily, and unused data keeps consuming energy in storage indefinitely. Small numbers multiplied by global scale and years of accumulation become significant.
Q: What can I actually do about digital waste?
A: Start with a digital cleanup: delete unused apps, remove duplicate photos, unsubscribe from newsletters you don’t read, and close accounts you no longer use. It takes less time than you’d expect and immediately reduces the data being stored and processed on your behalf.
Q: Isn’t cloud storage more efficient than keeping files on my own device?
A: Cloud storage can be more energy-efficient per file than many personal devices running in parallel, but it isn’t emission-free; it still relies on data centres running continuously. The most effective step either way is reducing the amount of data you keep in the first place, rather than just moving it somewhere else.
World Cleanup Day Germany – Digital Cleanup Day, IEA – Energy Demand from AI.
