How deep a footprint do we leave with our digitally dominated lives?

Dig into online activity and data centres and the environmental results may surprise you

Every day, the world’s population generates 500 million tweets, 294 billion emails, four million gigabytes of Facebook data, 65 billion WhatsApp messages and 720,000 hours of YouTube content.

And those figures, collected in May by the Conversation magazine, are already out of date. Nearly everything we do consumes data – the storage of text, video, photos and audio, fuelled by all generations, but especially the young.

Constantly switched on “zoomers”, aka Generation Z (roughly encompassing young people under 25), are the classical manifestation of this species, identified by their extra “limb” – the smartphone.

Given there is an emerging climate crisis, it begs key questions: where are the environmental pressure points arising from this digital lifestyle – and will people change their behaviour?


The evidence on digitally intensive living is often surprising and contrary to public perception. Climate impacts of streaming video, for instance, are relatively modest.

Digital intensity

It also suggests that data centres, the workhorses of big tech, may not be ogres, though Ireland has a particular problem with them at present, given the proportion of the State's energy supply they consume.

So how digitally intensive are our lives? This year’s Behaviour & Attitudes techscape report showed that the use of smart TVs, wearable devices and smart hubs has increased.

Just 7 per cent of people here had personal devices such as Fitbits etc in 2018. Today that number has risen to 32 per cent. Broadband is now a utility not a luxury for all those under 54. Two-thirds of us now buy online.

"The most profound theme emerging over the last two years, however, relates to the extent to which technology has permeated through to all aspects of our everyday lives, says B&A director Anita Mullan.

Covid-19 cemented the dependence on digital. Probably driven by social isolation, almost half of us claim to have increased our social media use since the pandemic. Two in five say they cannot imagine their lives without social media.

DCU climate researcher Sadhbh O’Neill points to contrasting roles of technology in society. It liberated humans from dogged work in the past; today it concentrates incredible power in technology companies. This has digitised social interaction and transformed relationships, including the act of buying and selling something.

“I’m not saying this is morally wrong but it is transforming society in ways not being talked about, which is also a lot more problematic from an environmental point of view,” she adds.

There is a high carbon footprint associated with digitised consumerism, yet technology has huge potential to assist decarbonisation through use of smart devices linked to appliances, O’Neill says.

Pure living

Environmentally pure living is impossible. Human actions more often than not have a carbon footprint; even an email generates 0.3g CO2. Just one email, to be clear.

Sometimes doing what appears environmentally sound may not be – as Prince Charles learned this week about his 50-year-old Aston Martin run on cheese and wine byproducts.

The bioethanol derived from those sources should not be mistaken for a serious solution to decarbonise vehicles, the Transport & Environment NGO declared.

It’s rare that actions are clearly divided between bad and green. Covid prompted many to move from Dublin to rural areas. It spurs remote working and rural communities, but will lead to a greater dependence on cars.

Netflix vs car

Inaccurate studies and misinformation – such as "emissions generated by watching 30 minutes of Netflix is the same as driving a car four miles" – prompted the International Energy Agency to issue a seminal fact-checking paper, including an emissions calculator.

The 2019 research was in response to exponential growth in video streaming. Covid led to people being confined at home and consuming even more. Digital/energy analyst George Kamiya has updated the findings. He showed studies of emissions from watching 30 minutes of Netflix exaggerate the climate impact "up to 90 times".

The low impact is thanks to improvements in the energy efficiency of data centres, networks and devices. “But slowing efficiency gains, rebound effects and new demands from emerging technologies, including artificial intelligence (AI) and blockchain, raise increasing concerns about the overall environmental impacts of the sector over the coming decades.”

In the process of simply existing, cryptocurrencies like Bitcoin use astonishing amounts of electricity, according a New York Times investigation. That usage, 0.5 per cent of global electricity consumed, has increased tenfold in the past five years. Managing a digital currency with no central authority requires a whole lot of computing power – a single bitcoin is worth about $50,000 today.

Flawed assumptions exaggerate the electricity consumption of data centres and transmission networks, Kamiya also concluded.

UCC energy specialist Dr Hannah Daly confirms "in the grand scale of things data and video is very low in terms of carbon footprint" while globally data centres account for just 1 per cent of electricity demand.

Moreover, she says, digitisation can bring carbon benefits as indicated by reading a newspaper online or streaming instead of buying a physical DVD. Such actions are dematerialising the economy. Decarbonisation of electricity is happening very quickly; it will be the first sector to be decarbonised.

Cleaner technology can lead people to consume more – known as the “rebound effect”, she notes, reflected in the way a cordless Dyson vacuum has taken over sweeping floors in her house.

Ireland’s data

The data storage process is becoming more centralised and more efficient “and far less energy-intensive”, Daly notes, especially where data centres are tied into district heating enabling excess heat to warm nearby buildings and homes. Meanwhile, “globally, demand is flatlining”, she confirms.

The picture in Ireland is different because of a mismatch between a huge increase in energy use and a small national grid, she believes. “That threatens Ireland’s climate change targets and energy security. The real focus should be on decarbonising the grid and decarbonising transport and heat – and not on downloading video.”

Digital pollution

Global e-waste for 2021 will total 60 million tonnes and is growing annually by 3 to 4 per cent, due to higher consumption rates of electronics, shorter product lifecycles and limited repair options. In 2019 high-value, recoverable materials conservatively valued at €49 billion were mostly dumped or burned rather than being collected for treatment and reuse. The average home in Europe has one in six electronic items broken or unused.

Change By Degrees director Dr Tara Shine says digital pollution in the form of sheer volume of content is also a growing issue: "Bloated websites with video backgrounds, multi-image carousels, rotating banners and other multimedia formats require large amounts of energy on an ongoing basis. It takes energy to digitally create and launch a website and then more energy again every time it's accessed by someone on their device."

Smaller, more concise newsletters equal smaller, less polluting footprints, she adds.

There is a lack of awareness of the implications, Shine believes, especially on how to store content efficiently as lives become more digital.

Behavioural disconnect

And there is a disconnect between acknowledging the problem yet failing to change behaviour. Covid-19 illustrated how concerted action can reduce carbon pollution; albeit for the wrong reasons. Energy-related carbon emissions dropped by 11.5 per cent last year. The largest fall was in aviation, a 64 per cent reduction – that’s 2.1 million tonnes of CO2e.

Recent figures show air travel is rebounding, indicating people may have unprecedented awareness of the climate crisis yet they favour cheap foreign travel which is not subject to carbon tax.

Young people may not respond, Shine says, because they are “frozen in fear” as indicated by a recent global survey which found 80 per cent of people in the 16-25 age category fear for the future – mainly due to the crisis. It depends a lot on personality. Others are “hyper-concerned” and agitating for action, while with another category, “it’s just not on their radar and they continue to buy fast fashion”.

When lecturing on sustainable energy, Hannah Daly polls students and finds they have huge environmental consciousness combined with being worried and feeling powerless. “They are not to blame for this. Most of them don’t have a car and will be working beyond 2050 trying to decarbonise as quickly as possible . . . and people have handed them an over-heating planet.”

Daly cites changes, as indicated by UK car travel peaking because young people are more inclined to take sustainable options.

The way young people consume media has been transformed so they get their news from technology companies such as SnapChat, Sadhbh O’Neill notes; the same technology companies target them as a product with advertising.

Blocked message

While they have a high degree of environmental awareness, a recent Irish survey found 57 per cent of 15-24 year olds did not know where to get information about climate change. This “extraordinary” finding suggests the message is not getting through. At the same time, they are being influenced by untrustworthy web sources. “I worry about that,” she adds.

Anita Mullan of B&A says consumers gravitate towards those who share their views (confirmation bias), which means those who want to downplay environmental issues or convince themselves it’s all a conspiracy can find plenty of back-up for those views online. “Obviously it works the other way too. This means sensible discussion about the environment is difficult to facilitate online.”

In addition, there is a residual idea among consumers everything that happens online is more environmentally sound than things that happen in the real world. “This is shaped by things like digital is better for the environment than print, online platforms better than travel. People aren’t yet engaging with the idea that the servers needed for our digital requirements are incredibly energy-intensive,” Mullan adds.

All the while, the digital carbon footprint grows and the IEA fears there may be trouble ahead as “it is becoming increasingly likely that efficiency gains from current technologies may be unable to keep pace with this growing data demand” in coming years.