The popular framing of streaming’s environmental cost has, for much of the past five years, treated digital entertainment as a quiet ecological catastrophe. Articles in the New York Post, the CBC, Yahoo, Deutsche Welle, Gizmodo, the BBC, and dozens of other outlets have repeated a version of the same claim, that watching 30 minutes of Netflix is the carbon equivalent of driving four miles, or that the global streaming industry produces emissions comparable to the entire country of France. The framing is intuitive. It maps onto a wider cultural sense that all internet activity has some hidden but enormous environmental cost, and that the cloud is, in fact, a coal-fired power station with a friendlier name.
The framing is also, on the strongest current reading of the peer-reviewed evidence, wrong by approximately a factor of 90.
The actual peer-reviewed figure for the carbon footprint of one hour of streaming video, in 2019 conditions on the global average electricity mix, is approximately 36 grams of carbon dioxide equivalent. The figure is approximately the same as the emissions from boiling a kettle for six minutes, or driving an average passenger car for approximately 150 metres, or running an older incandescent light bulb for approximately two hours. The cumulative impact of streaming at global scale is genuinely significant, but the per-hour impact is modest, and the actual environmental cost falls in a very different place from where the popular framing has located it.
How the popular framing got so wrong
The widely repeated claim that streaming half an hour of Netflix produces 1.6 kilograms of carbon dioxide originated in a July 2019 report by the Shift Project, a French climate think tank. The report estimated that streaming video produced approximately 300 million tonnes of CO2 in 2018, equivalent to the annual emissions of France, and that streaming one hour produced approximately 3.2 kilograms of carbon dioxide. The figure was picked up across global media and became the foundation of the popular framing.
The figure was also based on a bit-to-byte conversion error. In June 2020, the Shift Project published a follow-up article acknowledging that the original 2019 estimate had overstated streaming’s bandwidth requirements by a factor of eight, and revised the 3.2 kg per hour figure downward to approximately 0.4 kg per hour. The correction received substantially less media coverage than the original error, and the 3.2 kg figure has continued to circulate in popular reporting on streaming’s environmental impact for years after its retraction.
The Shift Project’s corrected 0.4 kg per hour estimate is itself approximately ten times higher than the central peer-reviewed estimate from independent researchers. George Kamiya, a digital energy analyst at the International Energy Agency, published a detailed methodological analysis in December 2020 that identified the remaining assumptions in the Shift Project estimate that produced the residual overestimate. The Shift Project had assumed substantially higher data transmission energy intensity than the available evidence supported, had double-counted certain infrastructure costs, and had used outdated electricity grid carbon intensity figures that did not reflect the rapid decarbonisation of major streaming markets since 2015.
The IEA central estimate, drawing on the peer-reviewed literature and updated infrastructure efficiency data, places the actual figure at approximately 36 grams of carbon dioxide per hour of streaming.
The Shehabi peer-reviewed analysis
The foundational peer-reviewed study of streaming’s environmental cost was published in 2014 by Arman Shehabi of Lawrence Berkeley National Laboratory, with Ben Walker and Eric Masanet of Northwestern University, in Environmental Research Letters. The team applied a full life-cycle assessment methodology to streaming video viewing in the United States in 2011, accounting for energy use and greenhouse gas emissions across data centres, network infrastructure, end-user devices, and the embodied emissions of manufacturing and disposing of all of the above.
The Shehabi team’s central estimate was that one hour of US streaming in 2011 produced approximately 420 grams of carbon dioxide equivalent on a full lifecycle basis, and approximately 360 grams when only operational emissions were counted. The figure was substantially higher than the more recent IEA estimate of 36 grams, but the difference reflects both the dramatic improvement in data centre and network efficiency over the past decade and the substantially different electricity grid mix in 2011 compared with 2019.
The Shehabi team’s most important finding, on the peer-reviewed evidence, was not the headline carbon figure but the breakdown of where the emissions actually came from. Their analysis showed that more than half of streaming’s energy use, in 2011 US conditions, came from network data transmission rather than from data centres, and that end-user device energy was the second-largest contributor. The data centres that store and transmit the content, which the popular framing has consistently treated as the central environmental cost of streaming, were actually a relatively modest contributor to the total footprint.
The Shehabi team also noted that streaming video was already more energy-efficient than the alternative the popular framing was implicitly comparing it against, which was the manufacture, transportation, and physical viewing of DVDs. Streaming used less primary energy than DVD viewing in nearly every realistic comparison. The exception was the case in which the consumer walked or biked to a video rental store, which the team acknowledged was the most environmentally favourable form of DVD viewing but also the rarest in practice.
Where the emissions actually come from
The most striking finding in the recent peer-reviewed evidence on streaming’s environmental cost concerns the distribution of the footprint across the system. Netflix’s own ESG reporting, drawing on detailed lifecycle analyses commissioned from the Carbon Trust and independent auditors, has consistently found that approximately 89 per cent of the carbon footprint of watching Netflix comes from end-user devices, not from data centres or network infrastructure.
The breakdown is substantial. Television screens and other viewing devices account for approximately 46 per cent of total streaming emissions. Home networking equipment, including modems, routers, and Wi-Fi devices, accounts for approximately 38 per cent. Data centres, the part of the system that the popular framing has treated as the central environmental cost of streaming, account for approximately 4 per cent. Network infrastructure between the data centre and the viewer accounts for approximately 7 per cent.
The implication is that the environmental cost of streaming is concentrated in objects the viewer already owns, that the viewer would own and operate regardless of whether they streamed video or not, and that the marginal environmental cost of an additional hour of streaming, given that the screen and the router are already on, is genuinely small. The viewer who replaces a 65-inch plasma television with a modern LED screen of the same size reduces the per-hour environmental cost of their streaming by more than the data centres at Netflix could reduce it through any infrastructure upgrade.
The popular framing has been arguing about the wrong part of the system.
The cumulative scale
The per-hour figures, while modest, accumulate at global scale into something substantial. Streaming video now accounts for approximately 80 per cent of all internet traffic. Netflix’s total annual emissions reached approximately 5.17 million tonnes of carbon dioxide equivalent in 2024, according to the company’s published ESG reporting. The global streaming industry, including YouTube, Amazon Prime Video, Disney Plus, and Spotify, produces emissions comparable to the annual output of a mid-sized industrialised country.
The information and communication technology sector as a whole, including streaming, social media, cloud computing, cryptocurrency, and the energy used by devices to access all of the above, now accounts for approximately 1.9 per cent of global greenhouse gas emissions. The IEA projects that global data centre electricity consumption will reach approximately 945 terawatt-hours by 2030, which would be approximately 3 per cent of global electricity consumption.
The 1.9 per cent figure is substantial but is also, on the available comparison data, smaller than several other categories of activity that the popular framing has generally treated as more virtuous. Aviation accounts for approximately 2.5 per cent of global emissions. The fashion industry accounts for approximately 4 to 8 per cent depending on the methodology. Food waste accounts for approximately 8 per cent. The streaming industry’s environmental cost is real but is not, on any defensible reading of the peer-reviewed evidence, larger than the environmental cost of many activities that produce considerably less public concern.
The honest limitations
Several methodological caveats apply to the literature described above.
The first is that the 36 grams per hour figure is a central estimate based on global average electricity mix in 2019. The actual figure for any specific viewer depends substantially on where they live, how their electricity is generated, what device they use to watch, and what video resolution they choose. A viewer in Iceland streaming standard-definition video on a modern laptop produces approximately one tenth the per-hour emissions of a viewer in West Virginia streaming 4K video on an old plasma television. The popular framing’s tendency to quote a single number obscures genuine variation that depends on choices the viewer can actually influence.
The second is that the 89 per cent figure for end-user device contribution reflects current grid mixes and device efficiencies. As data centres expand to meet rapidly growing artificial intelligence workloads, the balance is shifting. Recent IEA projections suggest that data centre electricity demand may rise faster than the corresponding efficiency gains, and the share of streaming’s footprint attributable to data centres may grow over the next decade even as the absolute per-hour figure continues to fall.
The third is that the lifecycle assessment methodology used by the Shehabi team and others depends on assumptions about device lifetimes, replacement rates, and recycling patterns that are difficult to verify and that vary substantially across populations. The peer-reviewed figures are best treated as informed estimates with substantial uncertainty rather than as precise measurements.
The fourth is that several of the most widely cited sources for streaming’s environmental cost, including the Carbon Trust 2021 analysis that produced the 55 grams per hour Europe figure, were commissioned or co-funded by streaming companies themselves. The findings have been broadly consistent with independent peer-reviewed estimates, but the funding source is worth noting.
What it means
Several things follow from the differentiated picture of streaming’s environmental cost that are worth saying clearly.
The first is that the popular framing of streaming as an environmental catastrophe is, on the strongest peer-reviewed evidence, substantially overstated. The 3.2 kilograms per hour figure that has circulated in major media outlets for years is approximately 90 times higher than the actual peer-reviewed estimate. The framing has produced years of guilt-laden coverage of digital entertainment that the underlying science does not support.
The second is that the actual environmental burden of streaming falls on a different part of the system than the popular framing has located it. Data centres, despite their size, dramatic energy consumption, and visible cooling infrastructure, contribute approximately 4 per cent of streaming’s carbon footprint. The screens that viewers watch on contribute approximately 46 per cent. The home networking equipment that connects those screens to the internet contributes approximately 38 per cent. The popular conversation about how to reduce streaming’s environmental impact has consistently focused on the wrong part of the system.
The third is that the cumulative scale of streaming remains substantial. The 1.9 per cent of global emissions from the broader ICT sector is comparable to the airline industry. The 945 terawatt-hour projected data centre electricity consumption by 2030 is approximately 3 per cent of global electricity. Streaming is not an environmental free pass at scale, even though the per-hour cost is modest.
The fourth, on the strongest current reading of approximately ten years of peer-reviewed evidence and several methodological corrections to the popular framing, is that the most effective way for an individual viewer to reduce the environmental cost of their streaming is not to stream less, but to watch on a smaller and more efficient screen.
The popular framing has been telling people to stop watching Netflix.
The peer-reviewed evidence suggests they should instead buy a smaller television.
The post The environmental impact of watching one hour of video on Netflix is approximately 36 grams of carbon dioxide, roughly equivalent to driving a car for 150 metres, in a figure substantially smaller than the popular framing has claimed and one that demonstrates that the actual environmental burden of streaming comes not from the data centres people imagine but from the screens they watch on appeared first on Space Daily.
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