Study Finds COP Climate Websites Are Major Polluters, Emitting 10x More Carbon

A new study reveals that COP climate conference websites emit up to ten times more carbon than typical sites. Researchers found their digital emissions have surged 13,000% since 1995, highlighting a major sustainability gap. 

Most people think of pollution as smoke from factories or exhaust from cars, but few realize that our online activities also leave a carbon footprint. Every email we send, video we stream, or website we load uses electricity, much of which still comes from fossil fuels. In fact, if the internet were a country, it would rank among the world’s top carbon emitters. Now, a new study has found that even climate conference websites, designed to promote environmental awareness, are not as green as they seem.

The annual United Nations climate summits are meant to combat global warming, yet the websites built for these events are surprisingly heavy polluters. Researchers have discovered that official COP (Conference of the Parties) websites emit up to ten times more carbon than the average webpage.

As this year’s summit opens in Brazil, scientists have highlighted a dramatic increase in the digital emissions of COP websites over the past three decades. Their analysis shows that between 1995, when the first COP was held, and 2024, the average emissions from these official sites have increased by an astonishing 13,000 per cent.

The study estimates that the website for this year’s conference alone could generate the equivalent of 313 kilograms of carbon dioxide, about as much carbon as 15 mature trees absorb in a year.

The Hidden Cost of Digital Growth

Part of this rise is due to the huge expansion of internet use and computing power, but researchers say the carbon output of COP websites remains much higher than that of most modern webpages.

The reason? These sites increasingly rely on high-resolution images, animations, and videos, all of which require more energy to load and display.

Professor Melissa Terras from the University of Edinburgh, who led the research, said the findings reveal a major blind spot in how we think about sustainability.

“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.”

Tracking 30 Years of Online Emissions

Using archived web data, the team measured changes in carbon output from official COP websites. The findings, published in PLOS Climate, show that emissions stayed low until around COP14 in 2008, when an average page produced only 0.02 grams of carbon per view.

Since COP15, emissions have risen steeply. Modern sites now release around 2.4 grams of carbon per visit on average, with some much higher. In comparison, a typical webpage emits roughly 0.36 grams per view.

PhD researcher David Mahoney, a co-author of the study, noted that websites still make up a major share of the internet’s overall environmental impact.

He says, “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.”

Making the Web More Sustainable

The study points out that some of the most polluting COP websites, such as COP25 in Madrid, were filled with constantly updating multimedia features. To make future sites greener, the team suggests limiting page size, reducing unnecessary graphics, optimising layouts, and using servers powered by renewable energy.

The findings serve as a reminder that sustainability must extend beyond what we see in the physical world. Tackling the climate crisis means cleaning up not just our industries and cities, but our digital spaces too.