Huge amounts of electricity are consumed by huge data centres powering the internet. They also emit the same amount of CO2 that the airline industry does. To change this, it is essential that data companies drastically improve their energy efficiency by starting to use small server room cooling solutions and cleaner energy sources.

The cloud is returning to Earth, but this time with a bump. The heavenly place where we email the world, stream our movies, and store our data has an actual physical presence. It is housed within the hundreds of gigantic data centres that are taking an increasing toll on the earth.

Data centres are the digital age’s factories. The mainly featureless, windowless boxes are spread across the world – from Bangalore to Los Vegas and Reykjavik to Des Moines. They run the digital services of the planet. Just their construction cost $20 billion worldwide per year.

The largest, which cover one million square feet or even more, consume the same amount of power that a city that has one million residents. Combined, they consume over 2 percent of the world’s total electricity and also emit about the same amount of CO2 that the airline industry does. They are growing very rapidly with global traffic increasing every four years by more than double.

However, even if there is a data centre close to you, there is a good chance you are not aware of it. There is no way to know which centre is delivering your Netflix downloads, or whether it is running on renewable energy that uses processors that are cooled down by Arctic air, or running on coal power while sitting in the heat of the desert, or cooled by highly inefficient refrigerator banks.

We are frequently told that the global economy is dematerialising – with digital data replacing physical analog and that the data’s ecological footprint is minimal. However, that is not entirely true. If the world’s IT industry was a country, only the United States and China would make greater contributions to climate change, according to a report from Greenpeace that was published last year that investigated the race to building a green internet.

Energy is required to analyse, process, move, and store data. A lot of energy. The processors in the largest data centres contain as much energy as a big power station can deliver, 1,000 megawatts or even more. It can also take as much energy as that to prevent the surrounding buildings and servers from overheating.

Practically every keystroke contributes to this. It is estimated by Google that typical searches using the company’s service need the same amount of energy as is required to illuminate one 60-watt light bulb over 17 seconds. It also emits 0.2 grams worth of CO2. This may not sound like much but then think about the number of searches you make in one year.

Google is data-lite these days. What really ramps up the data count is streaming video via the internet. Cisco, an IT company tracks these sorts of things and estimates that by 2021, video will comprise 82 percent of all internet traffic, up from 2016’s 73 percent. About one-third of North America’s traffic is dedicated already to just streaming Netflix services.

An increasing number of IT companies are bragging about their commitment to rely 100 percent on renewable energy. in order to achieve this, some of the largest enterprises are having their very own energy campuses built. In February Switch, one of the cloud giants that runs three of the top 10 data centres in the world, announced plans for a central Nevada solar-powered hub which will be the largest anywhere outside of China.