Is online video catalysing climate change?

Scientists debate the carbon cost of binging on a box-set...
29 February 2020


A viewer watches streaming media online


Binge watching online may not be as bad for the climate as we first feared, a new study finds...

Data centres are buildings stacked with computers that serve up the content we download from the web. In the last decade, the Internet traffic through these facilities has surged by over 500%, leading to claims that the energy cost has more than doubled. Others, including Eric Masanet who has penned an article in the journal Science this week, argues that the real number is closer to a 6% increase.

Either way, data centres are certainly energy intensive installations, accounting for a third of Internet energy use. And based on current growth trends, within ten years this could reach 8% of global energy use.

Nevertheless, Masanet is reassured that technology with come to the rescue. “We should not worry just yet. History has shown us that the energy efficiency of technology has outpaced expectations. The decrease in energy use for cooling and powering data centres is enough to offset the increase in power demand from our IT devices.”

According to Masanet, a lack of data has led some studies to exaggerate the current energy footprint of the Internet. “There is a lack of data transparency,” he says, pointing out that the big players in the field ought to share more details about their environmental footprints. 

But claims from some quarters, warning that the carbon footprint of the world's collective "Netflix habit" has the same energy use as the whole of Chile, are probably just hot air. It's certainly true that YouTube, Netflix and pornography websites account for 60% of current web traffic, singling out online video as a major carbon culprit, but a CarbonBrief analysis published on 25th February shows that the data underpinning claims like these could have overestimated the emissions from viewing online video by a factor of 30 to 60.

In fact, according to Masanet, data centres have become 91% more energy efficient over the last 10 years, an achievement made possible by the use of more powerful servers, innovative cooling methods, and the move to hyperscale data centres.

Put simply, the computational efficiency of the servers doing all the work in data centres has doubled every two years, but without any additional energy use.

At the same time, a general transition from numerous smaller data centres, which accounted for 79% of global web traffic in 2010, to a smaller number of “hyperscale” data centres doing 89% of the web's heavy lifting in 2018, has also significantly reduced energy use. Operating at scale like this translates into savings because servers produce a lot of heat. So establishing large data centres in colder climes, or positioning them under the sea, together with the use of more advanced, energy-efficient cooling systems, has led to significant savings.

Another factor is that energy use also does not equate carbon emissions, because data centres may be renewably powered, or involved in offset programmes. Google, for example, aims to offset its emissions by funding renewable energy projects.

Not everyone is quite so sanguine though. According to data centre specialist Ian Bitterlin, “4K streaming is bad for the climate. There is only a finite amount of renewable energy we can produce.”

So what does the future hold? “It is difficult to say what the environmental footprint of data centres will be in 10 years,” Masanet admits. “But looking at the next 3-5 years, increased efficiencies will keep pace with demand, if policies enforce the current efficiency trends.”


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