Energy and emissions for one hour of streamed video, from the data centre to the screen. Each figure counts something different: open its details to see what.
The figures at a glance
Carbon emissions, highest first. On the scale, each line is ten times the one before.
Watching a half-hour show would lead to emissions of 1.6 kilograms of carbon dioxide equivalent, said Maxime Efoui-Hess of French think tank the Shift Project. That's equivalent to driving 3.9 miles (6.28 kilometres).
What one action is
Watching a half-hour show online
Claimed by
Independent: Maxime Efoui-Hess, The Shift Project (in an interview with AFP)
Dispute
George Kamiya (Carbon Brief, February 2020; IEA, December 2020) traced the figure to a bitrate of 3 Mbps converted in error to 3 megabytes per second, and put the 2019 figure at about 18 gCO2e per half hour. The Shift Project accepted the error in June 2020, said the figure came from an unchecked oral interview and is not in its reports, and gave a corrected 0.400 kgCO2e per hour (see shift-project-online-video-hour-2020). https://www.iea.org/commentaries/the-carbon-footprint-of-streaming-video-fact-checking-the-headlines
History
Added.
Streaming Netflix in 2019, Kamiya's original February 2020 estimate
Taken together, my analysis suggests that streaming a Netflix video in 2019 typically consumed 0.12-0.24kWh of electricity per hour ... Powered by the current global average electricity mix, streaming a 30-minute show on Netflix would release 0.028-0.057kgCO2e (28-57 grammes
What one action is
Streaming a Netflix video in 2019 (energy per hour; emissions per 30-minute show)
Scope
end to end
Counts
viewing devices; data transmission networks; data centres
Model or version
Kamiya's bottom-up analysis, original version
Place
global (current global average electricity mix)
Period measured
2019
Method
Bottom-up estimate combining energy intensities of devices, networks and data centres with the global average electricity mix; viewing devices were estimated at 72% of energy use, transmission 23% and data centres 5%.
Claimed by
Independent: George Kamiya, International Energy Agency
Dispute
The Shift Project (June 2020) accepted the bitrate error Kamiya found but disputed his network energy-intensity assumptions. https://theshiftproject.org/app/uploads/2025/04/2020-06_Did-TSP-overestimate-the-carbon-footprint-of-online-video_EN.pdf
History
Added.
One hour of online video, The Shift Project after its bitrate correction
0.4 kg CO2e per hour of video viewed (published as: 0.400 kgCO2e per hour)
3/ After correction of the bitrate, our model yields 0.400 kgCO2e per hour. ... After correction of the bitrate (bit-to-byte conversion error, i.e. a division by 8 of the bitrate), our model indicates 0.77 kWh per hour of video. However, we mention this figure merely on an indicative basis
What one action is
One hour of online video viewed, from The Shift Project's "1byte" model after correcting the bit-to-byte bitrate error
Model or version
The Shift Project "1byte" model
Method
The Shift Project's "1byte" model with the bitrate divided by 8; the Shift Project says the model is not designed to measure the impact of an individual action and gives the energy figure on an indicative basis only.
Claimed by
Independent: The Shift Project (Maxime Efoui-Hess and Jean-Noël Geist)
Dispute
The IEA (George Kamiya, December 2020) puts 2019 streaming at 0.077 kWh per hour, 10 times less than the corrected Shift Project energy estimate (0.78 kWh), and says the Shift Project corrected the bitrate error but did not revise its other assumptions, which overestimate the energy intensity of data centres and networks. https://www.iea.org/commentaries/the-carbon-footprint-of-streaming-video-fact-checking-the-headlines
History
Added.
One hour of streaming video, 2019 global average (IEA revised estimate)
As a result, the central IEA estimate for one hour of streaming video in 2019 is now 36gCO2, down from 82gCO2 in the original analysis published in February 2020. ... my updated analysis suggests that streaming a Netflix video in 2019 typically consumed around 0.077 kWh of electricity per hour
What one action is
One hour of streaming a Netflix video in 2019, based on average viewing habits
Scope
end to end
Counts
viewing devices; data transmission networks; data centres
Model or version
IEA analysis with energy intensity figures for data centres and networks updated in December 2020
Place
global (global average electricity mix)
Period measured
2019
Method
Bottom-up estimate combining energy intensities of devices, networks and data centres with a global average electricity mix; the commentary also gives the same estimate as about 18 gCO2e per 30-minute show.
Claimed by
Independent: George Kamiya, International Energy Agency
Dispute
The Shift Project (June 2020) accepted the bitrate error Kamiya found but disputed his network energy-intensity assumptions, which it says explain most of the remaining gap between the two estimates (this response addressed the February 2020 version of the analysis). https://theshiftproject.org/app/uploads/2025/04/2020-06_Did-TSP-overestimate-the-carbon-footprint-of-online-video_EN.pdf
The calculator uses this figure: Video streaming (IEA, 2019 global average).
History
Added.
One hour of video-on-demand streaming, European average in 2020
The European average footprint estimated in this white paper is approximately 55gCO2e per hour of video streaming for the conventional allocation approach. ... The equivalent energy consumption is a European average of 188Wh per hour of video streaming using the conventional approach
What one action is
One hour of video-on-demand streaming in Europe in 2020, with a representative mix of viewing devices and a modelled average bitrate of 6.40 Mbps
Scope
end to end
Counts
data centres and content delivery networks (encoding and storage); internet network transmission; home routers; end-user viewing devices; TV peripherals such as set-top boxes
Leaves out
content creation; embodied emissions of the equipment; live streaming
Model or version
Conventional allocation approach (average energy per data volume, kWh/GB)
Place
Europe
Period measured
2020
Method
Modelled with the DIMPACT tool from operational electricity use of each component, using a European average grid emission factor of 0.295 gCO2e/Wh (national grid averages, so direct renewable purchases are not recognised); the body of the paper (section 4.1) gives the same estimate as 56 gCO2e per hour.
Claimed by
Industry-funded: The Carbon Trust, in consultation with DIMPACT members
Paid for by
Netflix
History
Added.
One hour of Netflix streaming worldwide, "well below 100 gCO2e"
at most 100 g CO2e per hour of streaming (published as: well below 100gCO2e)
Netflix recently ran its own data through the tool and found that the emissions from an hour of streaming the world over is well below 100gCO2e, or less than driving a gas-powered vehicle a quarter mile or 400 metres.
What one action is
One hour of Netflix streaming worldwide, from Netflix's own data run through the DIMPACT tool
Counts
electricity consumption during use
Leaves out
manufacturing of devices; end-of-life of devices
Model or version
DIMPACT carbon calculator (University of Bristol)
Place
worldwide (includes grids in the U.S. and Canada, Latin America and Asia-Pacific)
Method
Netflix ran its own data through the DIMPACT calculator; it published only an upper bound ("well below 100gCO2e"), recorded as that bound, not as an estimate.
Claimed by
Company: Netflix (Emma Stewart, Netflix Sustainability Officer, with Daniel Schien, University of Bristol)