A new study has found that the digital face of the world’s most influential climate talks – their websites – has quietly been adding to the very problem they aim to solve.
Researchers from the University of Edinburgh have revealed that official websites for the annual United Nations climate summits now emit up to seven times more carbon than an average webpage. Their analysis, which examined archived versions of every COP website since 1995, shows that digital emissions have ballooned by more than 13,000% over that time.
Back in the early years of the internet, COP websites were simple, text-heavy pages that used little energy. By COP14 in 2008, a typical page generated just 0.02 grams of carbon per view. Today, the average COP page emits more than 2.4 grams per visit – while a standard webpage produces around 0.36 grams. The shift reflects a wider trend in web design: pages have become richer, flashier, and far more energy-intensive.
Videos, high-resolution images and dynamic design elements now dominate modern COP sites. While they help showcase the scale of the summits, they also demand more computing power, both from servers and from the millions of devices accessing them. As a result, the environmental impact of web traffic to these sites has risen sharply.
When researchers crunched the numbers, they found that the 1997 COP3 website generated the equivalent of just 0.14 kilograms of carbon dioxide – an amount a single tree could absorb in two days. By COP29, that figure had soared to nearly 117 kilograms, which would take up to ten trees a full year to offset.
It’s too early to know the footprint of the upcoming COP30 site, but the researchers note that it isn’t hosted on renewable-powered infrastructure. They warn that without conscious design choices, even digital platforms built for climate advocacy risk undermining their own messages.
The team recommends that future conference sites keep things light: limit page size, optimize media content and run on servers powered by verified renewable energy.
Their research is the first to use web archives to trace a website’s environmental impact over time.
Professor Melissa Terras, of the Institute for Design Informatics at Edinburgh College of Art, said: ‘The digital footprint of websites, and how they have grown over time, deserves further scrutiny. In this innovative use of web archives as a data source to measure how websites have expanded, we chose first to look at the COP conferences themselves, given they are the focus of so much discussion on climate change.
‘Our research shows that the carbon cost of digital presence is often overlooked by even those who care about, and are meant to protect, the environment. We hope that our recommendations, and our tool, can help institutions identify and tackle this issue.’
PhD student David Mahoney, of the Institute for Design Informatics at Edinburgh College of Art, said: ‘While AI rightly captures much of today’s attention, websites remain the longest-standing and most widespread form of human–computer interaction, and one of the largest contributors to the internet’s environmental impact.
‘Our work shows how reusing web archives can expose this growing blind spot, even among organisations at the heart of climate discussions, and help identify practical ways to cut digital emissions.’