Climate conferences’ websites intensify carbon emissions tenfold, study warns
Delegates at the ongoing COP30 summit in Belém, Brazil.
What you need to know:
- This year’s summit comes at a critical juncture amid soaring global temperatures that are reaching alarming levels, surpassing the 1.5∘C threshold.
- This has triggered oceans to warm, ice sheets and glaciers to melt, and sea levels to rise with catastrophic outcomes.
All eyes are on the 2025 United Nations Conference on Climate Change (UNFCCC), which has convened global delegates and climate enthusiasts in the heart of Amazon rainforest for this year's COP30 summit in Belém, Brazil.
The ongoing COP30 has drawn key representatives of the COP21 Paris Agreement signatories, engaging in intensive negotiations between November 10, and November 21. The main three themes for COP30 are: climate finance for developing countries, adaptation to climate change, and reducing greenhouse gas emissions.
This year’s summit comes at a critical juncture amid soaring global temperatures that are reaching alarming levels, surpassing the 1.5∘C threshold. This has triggered oceans to warm, ice sheets and glaciers to melt, and sea levels to rise with catastrophic outcomes.
The COP30 is especially symbolic in relation to two turning point global treaties that have seen climate interventions accelerated, marking 10 years since the Paris Agreement was adopted and 20 years since the Kyoto Protocol.
In an ironic twist, however, a new study warns that annual COP climate conferences, including the underway COP30, could be achieving the exact opposite of their intended purpose by magnifying greenhouse gas emissions and consequently exacerbating climate change.
Recent scientific evidence reveals that COP websites have rapidly grown in size, with average carbon emissions spiralling by over 13,000 per cent since the first climate conference was held 30 years ago. Experts note that the amount of carbon emissions from COP conference websites has skyrocketed between 1995 and 2024, and is currently 10 times more than the average websites in the host country.
During this year’s Amazon COP (COP30) in Brazil, a total of 313 kilogrammes of carbon is projected to be emitted by the climate conference websites; equivalent to the amount of carbon that 15 mature trees would take one year to fully absorb.
“Our analysis reveals an exponential increase in website size, with average emissions rising over 13,000 per cent, and many recent COP pages emitting roughly 10 times the global average of approximately 0.36g of CO₂e per pageview,” a new study says.
Researchers based at the University of Edinburgh examined the evolution of host country websites for the UNFCCC (COP), dating back 30 years from the first climate conference, COP1, in 1995, up to the COP30 (2025). They used archival data from the Wayback Machine of the Internet Archive to evaluate the environmental footprint of all available COP host websites.
Madrid COP
According to the findings, the COP25 (2019) climate conference held in Madrid registered the highest carbon emissions on average for every page view.
The experts attribute this to the fact that “the largest website was heavily media-based and structured as a single-page application, with some individual webpage links dynamically updating content on the same webpage without fully reloading.”
The website format required intensive computing power compared to older internet pages that were more basic.
A significant shift began from COP15 (2009) onwards, showing a substantial increase in style sheets, scripts, and multimedia content.
Since COP15, there has been a surge in carbon emissions from host websites, with over 2.4 grammes of carbon on average emitted for every page visit, with some websites registering substantial amounts.
This is a stark contrast to the period until COP14 (2008), when carbon emissions remained relatively low, equivalent to 0.02 grammes per page view. The current website average of 0.36 grammes per page view puts the emissions from recent COP sites in stark relief.
These figures only account for registered in-session participants and do not include additional visitors accessing the site independently, or visits to other pages beyond the homepage, the researchers say.
The researchers say the actual emissions could be significantly higher: “For instance, COP28 (2023) was estimated to have attracted over 400,000 total visitors—a difference of just over 320,000 from those recorded by the UNFCCC, meaning actual emissions could be significantly higher.”
“If the same scaling applied, homepage visits to the COP28 (2023) host website alone could have generated approximately 649.32 kg CO₂e, an amount that would take an estimated 26–65 mature trees a year to absorb.”
The analysis titled ‘The Growing Environmental Impact of COP Websites: An analysis of UNFCCC COP host country websites (1995–2025)’, highlights the contribution of the internet to global warming.
In the study published in the PLOS journal, the experts emphasise the urgency for global effort to limit global warming to 1.5°C in line with the Paris Agreement; with just under five years left to act.
“The internet, and particularly websites, play a critical role in this challenge.”
This evidence comes amid rising popularity of the sustainable web design (SWD), which is often overlooked, even by organisations central to climate action.
While digital systems may reduce some emissions associated with printing and distribution, they introduce their own environmental costs in ways that are often hidden or externalised, the experts say.
“Recognising this entanglement challenges the perception that digitalisation inherently reduces environmental impact and calls for more systemic thinking about both formats’ infrastructural and ecological footprints.”
Without intervention, the study warns that the growing impact of host country websites risks not only exacerbating ‘COP fatigue’, but also increasing individual countries’ environmental footprint.
“It underscores the need to support a range of targeted interventions to mitigate the digital footprint of future COP host country websites.”
For mitigation measures, the team recommends integrating SWD principles into the Host Country Agreement and the ‘How to COP’ handbook, ensuring that digital platforms align with the United Nations’ broader sustainability objectives. These comprise using renewable energy-powered website hosting, optimising layouts to streamline page architecture and setting website size limits.
“COP host country websites are to be hosted using sources with the lowest possible carbon intensity (ideally generated by wind or solar rather than from non-renewable sources). Where feasible, host countries should prioritise domestic hosting providers that meet sustainability standards, reducing data transfer-related emissions. This information should be stated publicly, for example in the website footer or in the colophon.”
