When people talk about sustainability, almost no one thinks of an interface. We think of plastics, airplanes, or heavy industries. But every time we open an app, load a website, or ask an AI a question, energy is moving across physical servers that are water-cooled and largely powered by fossil fuels.
The digital sector is no longer invisible. And as designers, we can no longer act as if it were.
How Much Digital Actually Consumes
The numbers are uncomfortable. According to the OECD, information and communication technologies accounted for between 1.5% and 4% of global greenhouse gas emissions in 2020. Some estimates compare it to the carbon footprint of the entire aviation industry, forecasting it could hit 14% by 2040.
Then there is the fastest-growing segment: data centers. The International Energy Agency (IEA) published very clear data: data center electricity consumption is projected to jump from 485 TWh in 2025 to 950 TWh in 2030, roughly 3% of global electricity demand. To put that into perspective, by 2030, data centers will consume as much electricity as the entire country of Japan does today.
And what about AI? The electricity consumption of AI-focused data centers grew by 50% in 2025 alone. This isn't a future trend—it is already happening.
The Weight of What We Design
This is where something hits close to home for us in UX/UI. Over a 10-year span, the median weight of a web page increased by 210% on desktop and 570% on mobile. In 1995, a page weighed about 14 KB; in 2024, it hovered around 2,200 KB.
Why? Heavier images. Autoplay videos. Decorative animations. JavaScript libraries duplicating features the browser already handles natively. Custom fonts loaded when a system font would work just fine.
Every single one of these is a design decision. And every single one carries a real energy cost.
The French Example: The RGESN
This is my favorite example because it proves this is no longer just theory. Since 2022 (and updated in 2024), France has implemented the Référentiel Général d’Écoconception de Services Numériques (RGESN)—an official framework for digital ecodesign.
The RGESN outlines ecodesign practices applicable within the French state, following the footsteps of other public standards like those for accessibility. The first version was released in late 2022, and the second in May 2024. Developed by Arcep and Arcom in collaboration with Ademe, Dinum, CNIL, and Inria, it brings together 78 practical guidelines on how to ecodesign a digital service.
What does it actually evaluate? The goals are to reduce the consumption of computing and energy resources, and to curb device obsolescence—both for user devices and for servers and networks. In other words, it’s not just about emitting less $CO_2$ today; it’s about not forcing people to buy a new phone just because your app no longer runs on theirs.
And here is a detail I find brilliant as a designer: the 2021 REEN law that sparked the RGESN explicitly mentions criteria aimed at limiting "strategies designed to capture user attention." Meaning: infinite scroll, abusive push notifications, and dark patterns that keep you glued to the screen are on the regulatory radar—not just for ethics, but for their energy impact.
Two Real-World Cases
MEK Studio: A 67% Emissions Drop via Redesign
MEK is a design studio based in Melbourne that decided to practice what it preached. They audited their existing website, measured its carbon emissions, and focused on the most energy-intensive elements: code, typography, color, images, content, and layout.
The result? The site's emissions dropped from 1.21g of $CO_2$ to 0.42g of $CO_2$ per visit—a 67% reduction. All of this was achieved without sacrificing functionality or accessibility. If anything, the site became faster, more readable, and more inclusive for users browsing with slow connections or older devices.
One thing that struck me about their process was how they started with something seemingly mundane: they went through all their email folders and deleted every single message that was no longer useful or that they weren't actively involved in. A simple "data hygiene" strategy—purging accumulated data that sits on servers consuming energy 24/7 for no reason. It sounds like nothing, but multiplied by millions of people, it’s massive.
Low-Tech Magazine: The Website That Goes Offline When It Rains
This is the most radical and fascinating case I’ve come across. Low-Tech Magazine, an online publication about sustainability, decided to walk the talk and rebuilt its website to run entirely on solar power.
The server is a mini-computer powered by a solar panel located in Barcelona. To emphasize its reliance on natural resources, it is designed to go offline during extended periods of bad weather. The site features a permanently visible battery indicator showing how much energy is left.
Their design choices? Every single one aligns with their energy constraints:
