What Is the Carbon Footprint of Your Netflix Habit? New Study Sheds Insight

There were winners and losers during 2020's pandemic. Among the losers, for example, were movie theaters, which were forced to go dark for more than a year. One of the biggest winners, meanwhile, were streaming services like Hulu and Netflix, which saw a massive influx of business as people everywhere sheltered in place with little to do but binge their favorite TV shows. In fact, subscriptions to streaming services reached the billions for the first time ever during the pandemic, according to the Motion Picture Association, which reported in March 2021 that there were 1.1 billion streaming subscriptions globally, up 26% from March 2020.

Because streaming media relies on the internet, however—and the internet relies on massive data centers with huge environmental footprints—one can’t help but wonder: Is humanity’s appetite for online video harmful to the Earth?

A new study suggests that it isn’t.

At least, not significantly. Published this month by climate group the Carbon Trust, with backing from DIMPACT—a collaboration between researchers from the United Kingdom’s University of Bristol and 13 major entertainment and media companies, including Netflix—the study examines the carbon impact of video-on-demand services with the goal of helping streaming companies become more sustainable. Streaming’s environmental impact is “very small,” conclude researchers, who say watching one hour of video-on-demand streaming generates the equivalent of 55 grams of carbon dioxide emissions.

That means the carbon footprint of streaming is equivalent to that of boiling an average electric kettle three times, or to that of popping four bags of popcorn in the microwave.

The Carbon Trust found most of streaming’s environmental impact comes not from back-end data centers, but rather from front-end viewing devices, which are responsible for over 50% of streaming’s carbon footprint. The larger the device, the greater the impact. For example, the carbon footprint of watching one hour of streaming video on a 50-inch television is roughly 4.5 times that of watching on a laptop, and approximately 90 times that of watching on a smartphone. Consumers who want to view responsibly can therefore do so by streaming on a smaller screen.

But even big-screen viewing is becoming planet-friendlier, noted The Carbon Trust, which said devices of all sizes are becoming more energy-efficient thanks to advances in technology, new industry standards, and increased regulation.

“The carbon footprint of watching an hour of streamed video content is minor compared with other daily activities,” said Andie Stephens, associate director at the Carbon Trust and lead author of the study. “As the electricity grids continue to decarbonize, and telecoms network operators increasingly power their networks with renewable electricity, this impact is set to reduce even further.”

Surprisingly, one thing that doesn’t influence streaming’s environmental impact is video quality, researchers observed. Compared to standard definition, they said, high-definition video produces only a “very small change” in streaming’s carbon footprint. For example, changing from standard definition to 4K resolution increases emissions from just under 1 gram of carbon dioxide equivalents (CO2e) per hour to just over 1 gram of CO2e per hour. Because the internet is “always on,” researchers explained, the extra energy it takes to transmit high-quality video is marginal compared to the energy it takes to continuously power the internet.

Industry welcomed the study’s results. Netflix, for instance, pointed to previous studies of streaming video that showed a much higher carbon footprint—as high as 3,200 grams of CO2e, which amounts to microwaving approximately 200 bags of popcorn instead of four.

In a joint statement, Netflix Sustainability Officer Emma Stewart and University of Bristol Senior Lecturer in Computer Science Daniel Schien say the research brings industry “one step closer to accurately and consistently assessing the climate impact of streaming.” They further added: “Better understanding this footprint means we can better focus on reducing those emissions across industries, countries and the world."

Although the study was based on European consumption, Netflix said it applied the same methodology to its own data and found similar results irrespective of location. Emissions from an hour of streaming are well below 100 grams of CO2e per hour around the world, it said—including in the U.S., Canada, Latin America, and Asia-Pacific, whose power grids are more carbon-intensive than those in Europe. That’s a smaller carbon footprint than driving a gas-powered vehicle for just a quarter mile.

Stephens concluded: “By undertaking this research with the support of the industry and academic experts, we hope to help inform discussions about the carbon impact of video streaming … and address some misunderstandings and outdated estimates that have been previously reported.”