Streaming’s carbon footprint was a hot topic a few years ago. Then came AI and, in particular, generative AI. The new, immensely energy-and water-intensive technology has blown streaming out of the water (or, lack thereof) as the major climate polluter.
But even though the environmental impact of streaming has become quieter, its impact hasn’t disappeared. On the contrary, more and more video and music is being streamed. Video streaming already accounts for the largest share of global internet data traffic at 60-70 percent. So, with the growing carbon footprint of digitalisation, it’s time to put the topic of “sustainable streaming” back on the agenda.
A lot has actually happened in this area in recent years. We still don’t understand exactly how high the CO2 emissions of streaming are in detail. But we do know enough to be able to suggest areas where significant reductions are possible.
We are in the middle of a constantly swelling stream of data
Video platforms such as YouTube, as well as social media, flood us with millions of videos every day. Media libraries of public broadcasters provide us with a permanently available range of entertainment on our screens at home. Hours of binge-watching on streaming platforms is now part of everyday life for many. Spotify and other music streaming platforms provide the music to everything we do. And if the Metaverse and video streaming glasses really do catch on, we will be streaming with practically every blink.
When we click on ‘play’ online, it’s not just about pure entertainment, of course. We take part in online training courses, learn with video tutorials and our meetings take place in video conferences. The streaming of images and sounds permeates all areas of life.
There are hardly any limits to data transmission. Until a few years ago, the data economy was still important to ensure that content flitted smoothly across our screens. But with ever more powerful devices, almost unlimited phone and internet flat rates and subscriptions to streaming services, it doesn’t matter to us or the providers how much video content we play every month.
All of this adds up to a large, unchecked data stream that is constantly growing.
Total emissions from streaming: many rivulets become a raging river
The world’s largest on-demand streaming platform, Netflix, reported 301.63 million memberships worldwide at the end of 2024, some with multiple viewers. According to the company, these users streamed an incredible 94 billion hours of content over the course of the year. In the ranking of the largest platforms, this is followed by Amazon Prime with an estimated 200 million paying core subscribers and Disney+ with 122.7 million. At the same time, new platforms are also growing in popularity. India’s largest streaming platform, JioHotstar, reported around 280 million subscribers in 2025 thanks to its cricket league broadcasts.
We are dealing with a massive volume of data that is sent from servers to our screens. But how high are the CO2 emissions of streaming? A large number of research projects and studies have already looked into this question.
“However, the studies show a wide spread, from 36 to 440 grams of CO2 equivalents per hour,” says Maria Zeitz, who heads the “Green Streaming” project at KlimAktiv, funded by the German Federal Ministry for Economic Affairs and Climate Protection (BMWK), in an interview with RESET. 100 to 175 grams of CO2 per hour of streaming were estimated in 2020, for example, in a study by the Hamburg-based Borderstep Institute. This is roughly equivalent to the emissions of a small car driving one kilometre. A study by the UK organisation Carbon Trust came to a less alarming conclusion in 2021. This study suggests that one hour of streaming in Europe only causes around 55 grams of CO2.
This figure seems low at first. However, due to the enormous global streaming consumption, the CO2 footprint is also considerable. Based on 55 grams of CO2 per hour, a recent article estimates the streaming emissions of Netflix, Amazon Prime Video and Disney+ at around 11 million tonnes.
However, the three most popular on-demand platforms only account for 36.3 percent of global streaming activity. If you take all of the estimated 1.8 billion streaming subscriptions together, the total emissions of all streaming services could amount to around 30 million tonnes of CO2 per year. This corresponds to 13.7 percent of Spain’s annual emissions in 2022 or 48.1 million one-way flights from Paris to New York.
What about the streaming volume of YouTube and Pornhub?
There is one video streaming platform that surpasses all on-demand platforms: YouTube. With over one billion hours of content streamed every day, it is the world’s most used platform.
As the majority of YouTube usage takes place on smaller devices such as smartphones and laptops with a lower resolution, the CO2 emissions per hour of streaming should also be lower. Nevertheless, the sheer number of users alone adds up to a considerable overall footprint. If you multiply the estimated value of 55 grams of CO2 per hour by YouTube’s global streaming volume, the platform’s annual streaming emissions amount to around 20.08 million tonnes of CO2.
While YouTube is the world’s most used video streaming platform, Pornhub is the second largest streaming website by traffic. Pornhub receives an estimated 66 billion visits per year. With an average session duration of 9 minutes and 40 seconds, this equates to around 10.63 billion hours of streamed videos per year. With an estimated value of 55 grams of CO2 per hour, the platform’s annual streaming emissions amount to around 585,000 tonnes of CO2.
With the underlying 55 grams of CO2 equivalents per hour of video streaming, all major platforms together are estimated to produce around 50 million tonnes of CO2 per year. Incidentally, this does not include the TV channels’ streaming services. If other figures are used as a basis, the emissions could also be significantly higher, as many other studies assume.
The very different results in the various studies are because they are based on different methods, assumptions and data sets. This makes it difficult to make a comparison. The Carbon Trust study, which was funded by Netflix among others, is now considered a kind of standard. It includes the power consumption of the end devices, but not their production and the film shoot.
Why music streaming has a lower carbon footprint than video streaming
Music streaming is less CO2-intensive than video streaming for several reasons:
Less data traffic per hour: music files require significantly less bandwidth than high-definition videos.
More efficient playback devices: Music is often streamed on smartphones and laptops, which consume less energy than TVs.
No video processing: Streaming platforms such as Netflix require additional computing power for video encoding and playback, which increases energy requirements.
Despite these advantages, music streaming also has significant environmental costs. On Spotify alone, 640 million users caused an estimated 176.55 million kilos of CO2 equivalent in 2024. However, paid music streaming only accounts for 23 percent of all music streaming. This means that free offerings and other listening methods continue to increase overall emissions – along with new trends. Spotify now plays videos for many songs and the Swedish company has indicated that it wants to develop even more in the direction of YouTube in the future.
This makes streaming’s cost for the environment and climate pretty clear. Streaming must move towards a more economical model if average global temperatures are not to climb even higher. What is particularly challenging is that the current trend is towards higher CO2 emissions, as energy consumption is rising due to the global increase in video-on-demand consumption, autoplay functions, live streaming and high-resolution content (4K, 8K).
But there are ways to at least limit the ecological footprint. In order to understand where these are, we should first look at where the emissions are actually generated during streaming.
When do CO2 emissions occur during streaming?
Probably very few users think about how much CO2 is being blown into the atmosphere while their favourite series or film is flickering across the screen. For most of us, this process is as immaterial as it is magical. However, behind every video is a very physical infrastructure. Data centres store the content, content delivery networks (CDNs) transmit it around the globe and end devices receive and play it back. Each of these steps consumes energy, which contributes to global CO2 emissions.
The guidelines of the “Green Streaming” project, which Fraunhofer FOKUS created together with authors from LOGIC, Deutsche Telekom and KlimAktiv, describe the transmission of video content from the source to the end consumer as a “complex digital and physical system with numerous dependencies and a large number of market participants”. And this is precisely the crux of why it is so difficult to determine the exact CO2 emissions of streaming. This is because the amount varies depending on the device, network and data centre. And many of the market participants do not share their figures.
The “Green Streaming” project, therefore, aims to supplement the estimates used in many studies to evaluate streaming with measured values. “Only when we know exactly how much energy an hour of streaming consumes and how many greenhouse gas emissions are generated can we derive measures for more climate-friendly streaming,” says Maria Zeitz, who is leading the project.
Fortunately, we are no longer at the very beginning. Even if the level of emissions varies depending on the calculation method, many correlations have now been proven. The guide cites the following key findings:
- The majority of the energy in the streaming supply chain, around 70 to 80 percent, is consumed by the user’s end devices. The energy consumption of different device types varies. For example, a smart TV generally consumes more energy during playback than a smartphone.
- Distribution networks also have a high energy requirement when no data is being transmitted. This is referred to as the “idle load”. According to estimates, this accounts for 50 to 70 percent of the total energy requirement of the networks.
- In terms of power consumption, fibre optics is the most efficient technology for distributing streaming content.
Specific recommendations for users can be derived from these findings.
How does green streaming work?
- End devices are the starting point for savings
Use the smallest and most energy-efficient device possible. According to the Green Streaming study, a smart TV with HDR requires 20 times more energy than a smartphone. The recommendation is therefore to stream on the smallest and most energy-efficient device possible.
Many devices also have an energy-saving mode that is worth using.
Use for a long time, repair, buy second-hand: This is also linked to using devices for as long as possible, as this means that fewer need to be manufactured.
- Solution: Good things come in small packages
The resolution of the video has an influence on the energy requirement and the CO2 footprint. According to a study by Bitkom (in German), streaming with SD resolution on a smartphone, tablet or notebook, for example, requires significantly less energy than traditional television or playing a DVD on a larger flat-screen TV.
As a general rule, the lower the resolution of the video, the less energy is required for streaming. Especially on a smartphone or laptop with a small screen, a low resolution makes no recognisable difference. The brightness can also be reduced.
- Wifi before mobile data
A study commissioned by the German Federal Environment Agency has shown that greenhouse gas emissions vary depending on the transmission technology. The lowest CO2 emissions are produced when the video is streamed via a fibre optic connection. Transmission via a copper cable is also more economical than via mobile radio.
There are equally large differences in mobile phone networks. For example, data transmission with 5G technology consumes significantly less than with UMTS (3G).
- Deactivate autoplay
Websites such as Instagram and YouTube, as well as many media libraries, often play clips and videos automatically to keep us glued to the screen. This “unintentional” streaming also drives up data traffic. Therefore, switch off autoplay if possible.
- Use ad blockers
Adverts in the form of short videos make up a not insignificant proportion of streaming content. This means that online marketing could be even more important than the streaming behaviour of individuals. Effective apps such as the free open-source ad blocker uBlocks Origin prevent adverts from being played.
- Less binge, more appreciation
Sustainable streaming is also about changing our relationship with digital content. Instead of immersing ourselves in a frenzy of images, we can slow down our own media consumption and limit our use in terms of time and space. Less binge, more appreciation!
Listen to music properly
Even though music streaming requires less energy, there are a few things that can be tweaked with little effort.
– Download songs: Download the songs and albums you listen to often to your library. This is more economical than streaming them every time.
– No YouTube music: When you listen to music via the streaming service, a video is usually also played. This unnecessarily increases data transfer. The same applies to Spotify: you should also deactivate the video function here.
– Use plugins: If a song or lecture is only available on YouTube or another video platform, you can use plugins such as YouTube Audio. This will only stream the sound of the video.
Beyond that, everyone can still do “the usual”, as Maria Zeitz calls it. “Drive forward the energy transition and vote in favour of a sensible climate policy by purchasing genuine green electricity.”
However, there are also significant levers that companies can use to reduce CO2 emissions during the transmission of sound and images.
What influence do streaming providers have on CO2 emissions?
To understand where companies can start, let’s take a more detailed look at what is happening on the supplier side.
In order for videos to be played on our screens, they must first be made available on the servers of the streaming services. During this ingest and encoding process, the content is made available in various formats and resolutions for the respective end devices and bandwidths.
Content is distributed to end users via specialised networks, the content delivery networks (CDNs). They reduce latency and improve loading speed. They can also reduce data traffic by storing content on servers that are geographically closer to the user.
The content is processed and stored on servers in data centres. The CO2 emissions here vary depending on the type of electricity used to operate the data centre. The greener the electricity, the lower the CO2 emissions.
The streaming supply chain at a glance. In order to save energy when providing video content, data volumes can be reduced with the help of compression processes, also known as video codecs. “The right choice of encoding method can make a relevant contribution to saving energy,” say the authors of the Green Streaming study. However, there is no “one-size-fits-all” solution. The optimal solution depends on the streaming workflow, the end device to be addressed and the usage scenario, i.e. whether it is a live event, an on-demand video or social media.
The problem with the CDN network is that the servers have a high basic power consumption. They are operated 24/7, regardless of how much data is being transported. According to the network equipment supplier Nokia, the networks require around 70 percent of their energy when idle and during periods of low utilisation. A more dynamic design of the distribution networks could therefore save energy.
The same applies to the rest of the “Internet” or the core network, i.e. the infrastructure consisting of data centres, switches and antennas for the mobile network. “In the mobile network in particular, the antennas account for a large proportion of the total power consumption of the infrastructure,” reports Maria Zeitz.
“In future, telecoms providers are planning to switch off parts of the antenna arrays in individual mobile network cells as long as there is no demand. According to initial estimates, this dynamic design could save 15 to 20 percent of the energy required in the mobile network.”
The data centres, on the other hand, which have the highest energy requirements in the fixed network, cannot yet be switched off dynamically. Nevertheless, CO2 emissions are significantly reduced when companies rely on green data centres.
Reducing streaming emissions is therefore not only in the hands of users, but also of network and data centre operators, telecommunications providers and streaming services. But what is really happening in this area?
What are companies and public broadcasters doing?
The big players in on-demand streaming have presented more or less ambitious sustainability strategies in recent years. Netflix, for example, has set itself the goal of reducing its emissions by 50 percent by 2030 compared to 2019 levels. The company also claims to have covered 100 percent of its global electricity consumption with renewable energy certificates since 2022. Amazon Prime, on the other hand, has set itself the goal of becoming climate-neutral by 2040 and Disney+ is aiming to reduce its direct emissions by 46.2 percent by 2030 compared to 2019.
That sounds promising at first. However, these plans should be treated with caution as long as they are voluntary. Furthermore, the more we stream, the more successful the platforms’ business models are.
How Netflix is changing the film industry
What this article is not about is the “Netflixisation” of the film industry and society. If you want to find out more about how the on-demand streaming company has taken films out of cinemas and turned them into a quickly consumable product with the same look every time, we recommend this podcast by Paris Marx in conversation with New York journalist Will Tavlin.
What is very interesting, however, is what happens in public service broadcasting when it comes to sustainability. On the one hand, broadcasters have a special social responsibility due to their financial contribution. On the other hand, streaming accounts for a large proportion of the broadcasters’ CO2 emissions. This was also confirmed to us by Birgit Gabriel, Sustainability Officer at French and German broadcaster ARTE: “In the area of distribution of the ARTE offering, 97 percent of CO2 emissions are attributable to non-linear distribution, i.e. streaming. Only three percent is attributable to the ‘classic’ linear distribution of our signals via satellite and cable.” The situation is likely to be similar for other television channels.
ARTE also offers its users various options in the settings to stream in a more climate-friendly way. As with other streaming providers, the quality can be reduced and the automatic playback of videos can be restricted. ARTE also relies on the downward compatibility of its online offering. This means that older operating systems are also supported for as long as possible. This allows users to use their devices for longer.
The energy-saving options for users are easy to find in the footer of the ARTE website. To ensure that they are used more often, these options could also be placed more prominently on the ZDF website. After all, informing viewers about the CO2 emissions of their streaming behaviour and the options for reducing them can be effective. For example, a study has shown that providing information after just one week led to a reduction in CO2 emissions of up to 30 percent. Of course, it would be even better if all videos were played with maximum energy saving as the default setting.
ARTE has developed an optimised process for video encoding in collaboration with the Fraunhofer Institute and trained it specifically for the ARTE content catalogue. “Video data is additionally compressed with the help of an ARTE-specific AI model in order to save storage space and enable efficient transmission,” reports Kemal Görgülü, CTO of ARTE. “As a rule of thumb, the savings potential with optimised video encoding is around 10 to 25 percent.” However, this depends on the age of the users’ devices and the type of content that is transmitted to the screens. The newer the users’ devices are, the higher the CO2 savings usually are.
“The electricity for our infrastructure is 100 percent green,” Kemal Görgülü confirmed to us. This also includes the data centres. ZDF’s building and studio infrastructure and its own servers are also powered 100 percent by green electricity, says Amelie Jakob.
We also asked the broadcasters how many CO2 savings would be achieved with the various measures. According to Birgit Gabriel from ARTE, this is difficult to quantify. This is mainly due to the fact that several parameters often change at the same time. “For example, the technical scope of the file formats provided has also changed during the period of the introduction of per-title encoding. At the same time, the infrastructure of the distribution networks used by ARTE has continuously improved, while the carbon footprint of these networks has been reduced.” However, ARTE plans to carry out more accurate measurements in the future, which will, among other things, map usage behaviour with greater precision.
ARTE and ZDF are also trying to influence production. ARTE is a member of the French Association Ecoprod and trains its teams in climate-friendly production. The broadcaster’s co-production and acquisition contracts also contain a clause that obliges the contractual partners to submit a carbon footprint for the production. As a founding member of “Green Shooting”, ZDF has helped to develop minimum ecological standards for programme production. According to Jakob, more than half of the broadcaster’s fictional productions are now produced in a climate- and resource-friendly way.
In the UK, the public broadcasting service, the BBC, published a study in collaboration with the Carbon Trust that examined its carbon emissions from streaming. However, the 2021 report doesn’t appear to have been repeated in future years. The BBC’s current webpage on environmental sustainability emphasises its reduction of the climate impact of making programmes, as well as the environmental themes it covers. They don’t mention the carbon emissions of streaming.
Green Streaming develops a CO2 calculator for video streaming
In the “Green Streaming” project, KlimAktiv is developing a calculator aimed at streaming providers and broadcasters to determine the CO2 emissions of streaming services. A tool for viewers is currently being tested for acceptance together with the consortium partner RBB. The main aim is to influence energy consumption on the end device.
Fortunately, none of this happens in a silo. Kemal reports that there is a regular exchange of best practices within the industry, both at EU level and between the German public broadcasters. We were also able to find other initiatives that set out to reduce the environmental impact of streaming. The membership-based global organisation Greening of Streaming, for example, aims to bring the streaming industry together to work on joint measures.
Public service broadcasting is therefore taking the first important steps towards reducing streaming emissions. However, as we have shown, not all sources of emissions are yet known in detail. And many of the measures are currently still in the trial phase. So there is still a lot to do, especially for the major on-demand platforms. What is urgently needed here is a similarly comprehensive approach as in public service broadcasting. However, it is more than questionable whether they will seriously assume social responsibility.
Conclusion: To stream or not to stream – is that the question?
The Öko-Institut has estimated global greenhouse gas emissions from data centres at around 230 million tonnes of CO2 equivalents in 2024. AI is expected to account for 38 million tonnes. This does not include emissions from the use of PCs, laptops and smartphones. If all on-demand streaming providers and YouTube are included, streaming is estimated to cause at least 50 million tonnes of CO2 equivalents. As a reminder, this calculation is based on the “optimistic” figure of 55 grams of CO2 equivalents per hour of video streaming.
As the CO2 emissions from the power consumption of the devices are also included here, the comparison between AI and streaming is somewhat flawed. And anyone who has read this article up to this point now also knows why all these figures should be treated with caution anyway. However, despite all of the uncertainties, it is clear that we are dealing with enormous CO2 emissions with both AI – and GenAI in particular – and streaming. This is reflected not least in the rapidly increasing power requirements of data centres.
So what remains is a clear message: All hands on deck! And: less (streaming) is more (climate protection)! As we have shown, we as consumers have an important role to play, as our usage behaviour is responsible for the majority of streaming emissions. A little reminder: less binge, more appreciation – and be sure to check your settings!
How can we ensure a green digital future?
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At the same time, those who deliver moving images and music to our screens have a special responsibility. We have shown that there are various levers that can be pulled, particularly with regard to formats, delivery networks and data centres. It would also be very effective if low-carbon streaming became the default setting on the provider side.
We have only touched on the major topic of production. Even before a film is on sale, massive CO2 emissions are generated, and both their determination and targeted measures are complex! The guidelines of the “Green Streaming” project contain some exciting calculations.
We have only hinted at another major adjustment screw – or should we say an elephant in the room? We are talking about online marketing. If we recall the countless advertising videos that constantly interrupt what we actually want to see on social media and streaming platforms, their CO2 emissions must be high. We have named a first aid measure for users: Ad blockers. At the same time, however, companies and broadcasters also need to be regulated. And this is not just about restricting advertising content. Rather, it is about obliging companies to do everything possible to make streaming more climate-friendly by default.
