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26 November 2020updated 02 Dec 2020 2:10pm

Big Tech’s carbon problem

Energy-guzzling data centres and supply chains mean our online lives leave a heavy environmental footprint.

By Laurie Clarke

Every year, 155,000 tonnes of electronic waste is thrown away in the UK – the second highest level in the world, according to a report from the Environmental Audit Committee. MPs are now calling on technology makers including Apple and Amazon to help build a circular economy where products are collected, recycled, or repaired, instead of being tossed into landfill, contributing to a global waste with a potential value of up to $62.5bn each year.

And this is just one of the facets of how the rapacious tech sector contributes to worldwide pollution levels.

One individual browsing the internet uses minimal energy resources. For example, in 2015, Facebook estimated its average user’s annual impact at 269g of CO2, roughly the carbon footprint of a cup of coffee. But cumulatively, the world’s internet consumption adds up. Internet companies’ main source of pollution is data centres – vast warehouses harbouring energy intensive computing systems.

Data centres account for 2 per cent of all electricity usage in the US, but this is projected to rise to 8 per cent of the global total by 2030. At present, this contributes to 0.3 per cent of all global carbon emissions.

This might sound insignificant, but the largest internet companies are substantial polluters. Google released 4.9 million tons of greenhouse gases in 2018 alone, roughly the equivalent of that emitted by more than one million passenger vehicles in a year.

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Greening internet companies is really about greening data centres. “On the supply side, looking at renewable energy purchases, or renewable energy development, and then on the demand side, reducing the energy use and increasing the efficiency,” says Dale Sartor, an engineer at the Lawrence Berkeley National Laboratory, where he specialises in the energy efficiency of data centres.

“The first place you start is with the IT equipment itself,” says Sartor. “The energy efficiency of that equipment doubles about every couple of years.” He believes this is one of the reasons the tech sector has managed to avert catastrophic predictions that at one point suggested data centres would use as much as three quarters of the world’s energy within the next 20 years.

The big players – the Amazons, Googles and Facebooks of the world –  lead the pack in terms of minimising data centre energy usage, according to Sartor. They are maximising the use  of their equipment and moving their energy needs around not just within the data centre itself, but between different geographic locations, too.

Most important for calculating the energy efficiency of the data centre is a measure called Power Usage Effectiveness (PUE). A typical small enterprise data centre, as opposed to a cloud or hyperscale data centre, might have a PUE of 2.0. “That means for every kilowatt going to a piece of IT equipment, there’ll be another kilowatt [used by] the infrastructure, i.e. overhead,” says Sartor, whose group focuses on how to reduce this overhead energy.

Read more: Covid-19 has underscored the urgency of the climate crisis

The ideal data centre would have a PUE of 1.0, because the centre’s overall energy use would be the same as that used to power the IT equipment. The best data centres in the world now have a PUE of under 1.1, but it is difficult to get as close as that – one of the reasons being  the small matter of cooling.  With their energy intensive equipment, data centres get fiendishly hot. Generally speaking, almost 20 per cent of energy used by a data centre is to cool it through air conditioning units or other means.

Typically, servers in the data centre are air cooled. As air is not a very efficient heat transfer mechanism, there are “a lot of fans”, says Sartor. At a site with poor air cooling methods, the thermostat will be very low. “If you go into a cold data centre, you know they’re not doing a good job with their air management,” says Sartor, who adds that liquid cooling techniques keep temperatures down much more effectively.

Even more out-of-the-box approaches have been trialled. Data centres have been sealed in containers and dropped onto the ocean floor, partly to address the cooling issue. In 2015 Microsoft experimented by dropping a data centre (containing 864 servers and 27.6 petabytes of disk) in a steel cylinder and filled with dry nitrogen, into the North Sea. The data centre was  retrieved after two years, and the experiment tentatively announced a success. The cold watery depths kept the unit cool, and it had only an eighth of the failure rate typical of data centres on dry land.

The desire for clean data centres has stoked demand for locations with plentiful renewable energy and low temperatures. As a result, Nordic locales including Iceland, Sweden and Denmark have become popular spots.

In Iceland, renewable energy provides almost 100 per cent of electricity production – about 73 per cent from hydropower and 27 per cent from geothermal power. So many blockchain and Bitcoin data centre companies (which are particularly energy intensive) have set up there that conservationists and some members of the government have begun to complain about the phenomenon.

Outside Scandinavia, explains Sator,  “the percentage of data centers that run on on-site renewable is prety low.” Because data centres are so energy intensive, he says that the ability to build renewable energy power sources big enough to keep them going on site can be tricky. “Data centre operators are really forced to go off site for renewable power.”

Big tech companies mostly use power purchase agreements (PPAs) to offset their carbon usage. Google claims that it has purchased enough carbon offsets to cancel out all the carbon dioxide emissions the company has released since it was founded in 1998. Because of this practice, tech companies are big investors in renewable energy. The amount of clean energy from renewable energy developers bought by companies has tripled in the past two years, led by tech giants including Facebook, Amazon, Google and Microsoft.

Read more: What Joe Biden’s win means for net zero

Whether carbon offsets are enough to qualify an industry as environmentally friendly remains a topic of debate. If Google is buying the renewable energy from an off-site producer, does that qualify its data centres as green? “A lot of people are pretty doubtful of that,” suggests Sartor.

Alongisde the problem of electronic waste, the production process of our devices also contributes to tech sector emissions. According to Greenpeace, more than 70-80 per cent of a personal computing device’s carbon footprint occurs during manufacturing, thanks to supply chains that are heavily reliant on dirty energy. This problem is currently receiving less attention than the issue of dirty data centres. Apple is the only large tech company thus far that has committed to using 100 per cent renewable power in its supply chain and products by 2030.

Planned obsolescence and the upcycling of electronic devices has a heavy carbon price tag, too. Extending the lifespan of smartphones and other electronics by just one year would save the equivalent amount of EU carbon emissions as taking two million cars off the roads every year, according to the European Environmental Bureau.

Mining the materials needed to create electronic devices is also environmentally costly. An estimated 320 tons of gold are used in the production of digital electronics every year, along with other rare earth materials. In addition to being associated with human rights abuses, mining these resources creates a huge amount of waste material that can be poisonous to ecosystems, including releasing toxins that can pollute water sources.

But momentum from employees and the climate movement might push the sector to be more ambitious. Workers from Amazon, Microsoft and Google have joined climate strikes,upping the pressure. In September, Google announced it intends to run operations solely on carbon-free energy by 2030. This is likely in part due to its employees – 2,000 of whom called on the company to make such a commitment.

This article originally appeared in supplement on energy and climate change. Download the full edition here