Every day, people watch more than a billion hours of video on YouTube. According to a new study by researchers at the University of Bristol, all those hours add up to a large carbon footprint over the course of a year. They calculated that in 2016, people watching videos on YouTube resulted in approximately 11.13 million tons of carbon dioxide equivalent, a standard unit of measure that indicates carbon footprint. That’s similar to the amount of greenhouse gases emitted by a city the size of Frankfurt or Glasgow, Scotland, over a year.
We don’t usually think about the environmental impact of our internet use, but the researchers point out that today’s websites are designed in a way that’s inherently wasteful, using more electricity than is necessary to maintain the same user experience. That’s certainly the case with YouTube, and there are a few easy ways that YouTube could update its interface to make its entire service greener.
One common practice for users is to play a YouTube video just to access its audio. In their paper, which was presented at the annual ACM Computer-Human Interaction conference this week, the researchers show that YouTube’s carbon footprint could be meaningfully reduced if the company were to design a feature that would stop playing videos if they’re running in a browser tab that a user isn’t actively watching. If 25% of music videos are played in the background of a user’s browser, then YouTube could save 323,000 tons of carbon dioxide equivalent. This conservative estimate saves about 3% of the total annual greenhouse gas emissions associated with watching videos, and is about the same as the carbon footprint of 50,000 cars over the course of a year.
YouTube isn’t the only internet platform that has wasteful design that could be avoided. According to Chris Preist, a professor of sustainability and computer systems at the University of Bristol and one of the paper’s co-authors, other examples of digital waste include downloading documents to the same device multiple times, storing almost identical photos in the cloud, and video autoplay.
“The environmental impact of each of these for one individual will be small–so it isn’t something worth feeling eco-guilt about–but when totaled over global services, they could have a noticeable impact,” Preist tells Fast Company via email. “So spotting them, and designing to avoid them where possible, is worth doing.”
In the paper, Preist and his co-authors suggest a methodology for calculating the carbon footprint for digital waste that includes a host of estimations because they aren’t privy to company data. But their work shows that it’s possible for companies to invest in understanding more about the way their designers are unintentionally causing extra emissions. Ultimately, their model only works for very basic design decisions (like playing a video or not), but Priest indicates that the goal is for tech companies to have an algorithm that quickly assesses any interface design as well as the code underlying it and determines its carbon footprint. That way designers could take this metric into account as they’re developing an interface, as well as other more traditional measurements like engagement.
Currently, many companies already report carbon emissions through the CDP (formerly known as the Carbon Disclosure Project), a nonprofit that’s backed by investors who manage trillions in assets. Tech companies, including Google and Apple, participate in the initiative, but mostly focus on the manufacturing of hardware, instead claiming that people’s use of their digital products is negligible. But by putting numbers to YouTube, the researchers point out that the emissions that come from the use of digital services should be part of companies’ accounting for their impact on global emissions.
But this isn’t just about holding tech companies accountable for their carbon footprint. The researchers believe that reducing wasteful design will also improve user experience. Take autoplaying videos: They’re a deliberate way to ensnare users into watching more than they otherwise would have. While that might be good for YouTube’s business model, it’s bad for someone who is trying to curb their internet use and enjoy the service in a healthy way–something YouTube professes to care about.
For Daniel Shien, a lecturer in computer science at the University of Bristol and a co-author on the paper, digital waste includes elements of a service that people are not enjoying or not using–so if you eliminate it, that means you are “removing something that wasn’t worthwhile for the user,” he says. “In this sense [I] would expect that the effect would not be a less visual internet but one of a higher quality.”
Since the study was published, the BBC has expressed interest in working with the researchers to understand its energy impact. YouTube did not respond to a request for comment by press time.