By Richard Sadler

The Internet is fast becoming a major source of global carbon emissions—and the main cause is video demand, the increasing popularity of "real time" streamed video content.

Video streaming to Internet-enabled TVs, game consoles and mobile devices already accounts for more than 60 percent of all data traffic—and the latest forecasts suggest this will rise to more than 80 percent by 2020.

Facebook's Prineville data center in Oregon: Demand just keeps on growing.Tom Raftery / Flickr

Increasingly, viewers across the world are watching films and TV series in real time through subscriptions to Netflix or Amazon, while social media platforms such as Facebook and Twitter are offering more and more streamed video content for free.

This is driving a dizzying increase in the amount of information that needs to be stored and transmitted by power-hungry data centers. Up until 2003 the world had accumulated a total of five exabytes—five billion gigabytes—of stored digital content. By 2015 that amount was being consumed every two days, as annual consumption reached 870 exabytes.

As more video is streamed and more of the world's population goes online, annual data traffic is forecast to reach 2,300 exabytes by 2019.

Pressure for Renewables

The IT sector already consumes around 7 percent of electricity worldwide and as data traffic rises, demand from data centers alone could reach 13 percent of global electricity consumption by 2030.

Now leading video content providers are coming under increasing pressure to show what proportion of their power derives from fossil fuels.

A recent report by Greenpeace USA acknowledges that social media platform Facebook has made significant progress towards its target for 100 percent of its electricity to come from renewables, following support from millions of its users for Greenpeace's 2011 "Unfriend coal" campaign. Google and Apple receive praise for progress towards similar commitments made in 2012.

However, major providers of video streaming content including Netflix, Amazon Prime and Hulu are criticized for sourcing more than half of their energy from coal or natural gas.

Cloud computing market leader Amazon Web Services is credited for taking important steps towards renewables but censured for lack of transparency and heavy reliance on new data centers in the state of Virginia powered mainly by fossil fuels.

Elsewhere the lack of access to renewable energy from monopoly utilities in East Asia is seen as a major obstacle towards creating a renewably-powered Internet in the region.

The report concludes: "The dramatic increase in the number of data centers … dominated by utilities that have little to no renewable energy is driving a similarly dramatic increase in the consumption of coal and natural gas."

Attempting to express the effect of increasing Internet traffic in terms of emissions is fraught with difficulty, but one study, published in the journal Environmental Research Letters, has calculated that in 2011 Americans streamed 3.2 billion hours of video.

This would have consumed 25 petajoules of energy (estimated at about the annual consumption of 175,000 U.S. households), resulting in 1.3 billion kilograms of CO2 emissions.

Efficiency Limits

The lead author, Arman Shehabi, a research scientist at Lawrence Berkeley National Laboratory in California, said the IT sector had so far managed to offset its soaring electricity needs by designing more energy-efficient data centers. But there was a limit to how far energy efficiency could go.

"The growth in video streaming is enormous just based on the size of the companies that are providing these services—but they are still reaching only a small part of the global population and we can imagine that's going to just keep increasing," he said.

"You're still going to have this growth of more and more servers needed. We've seen some good efficiency measures but we're getting close to the end of that—we can't go out much further—and with video streaming there's no end in sight."

He added that another major driver of future growth in data traffic would be the Internet of Things—remote digital sensors, devices and driverless cars connected to the Internet.

Richard Sadler, a former BBC environment correspondent, is a freelance environment and science journalist. Reposted with permission from our media associate Climate News Network.