The best way to decarbonise that you’ve never heard of

June 26, 2023

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Nat Darke

If you are someone that likes to impress your friends with a fact or two, tell them that 4-5% of the world’s CO2 emissions are caused by software. That is as much as aviation, shipping, and rail combined. Cue the look of incredulity, some head scratching, and some questions.

In fact, the internet, and data centres, together with our phones, laptops and TVs, use as much energy as the whole of Russia per year. Even more concerning is the ICT sector’s rapid growth in energy use. The Harvard Business Review predicts that it will account for 14% of the global carbon footprint by 2040.

These figures come as a surprise to most people – testament to the lack of exposure this issue has compared to air travel, fashion, home insulation, the oil industry, and many other climate bogeymen.

“It’s not unrealistic to claim that green web apps can be as much as 80% less polluting than traditional web apps”

Every time we send an email, browse the web, or watch a video, data is sent across the internet. Our devices, as well as the computers that transfer and process this data, require power and cooling.

So the more data that is transferred, and the more processing that is needed, the greater the power consumed and CO2 emitted.

In our daily lives, we might consider the amount we recycle, the meat we consume, and the way we get from A to B. But we never think about the device in our pocket, the thousands of miles travelled by each Instagram post and the servers chugging away to process our demands in unknown part of the world.

The growth of this problem is inevitable. More of our personal and business lives are moving online. And the rapidly emerging middle classes in India, China and elsewhere are helping to create four hundred thousand new internet users every day.

The emergence of AI brings new risks, too. Inappropriate use of AI in web applications, for example, could lead to an unprecedented new spike in energy use.

Tech for good

It is not all bad news, though. Software and the internet can have a carbon-reducing effect on other parts of the economy, and not only by allowing us to work from home and reduce our commuting footprint. There are several other ways in which software can help lower CO2 emissions. Supply chain analysis, carbon credit markets and the management of green energy certificates are just a few.

Climate tech start-ups are abundant despite fewer investment opportunities in 2023. And some of them focus solely on using software to provide useful information in the drive to net zero. For example, The Other Way is a South London start-up whose API provides climate data for the lifecycle of every vehicle model.

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Green software

So, all software pollutes, but this can be offset by its green utility. We can also reduce the CO2 emissions of the software itself. This can be achieved by writing better code, having better architecture, and making the right choices for cloud hosting and services. Incredibly, it is possible to make as much as an 80% reduction in the carbon footprint of websites and web apps by simply making the right decisions and writing code in a mindful way. This is true carbon reduction – not offsetting.

As computing and internet speeds have gone up and data costs have come down, the trend has been to regard excessive data transfer and processing as inconsequential. The average webpage has seen a three-fold increase in data use in the last 10 years, with no discernible benefit to the user.

“The internet and data centres, together with our phones, laptops and TVs, use as much energy as the whole of Russia per year”

This shift has been as much cultural as technical. The demand to produce code quicker and more cheaply has been the driving force. But, ironically, the quest for efficiency has caused over-engineering and bloated, inefficient code. We have created the code-equivalent of the Soviet factory – the inefficient, mass production of cheap products that destroy the environment.

But green software needn’t take any longer to make. It is more about making the right decisions and avoiding the most egregious errors. What’s more, its improved efficiency makes it faster, which is better for users – especially when network conditions are not ideal. It can also mean huge savings on the cloud; removing unnecessary processing and gratuitous server configurations is, as it happens, cheaper to run.

It is not unrealistic to claim that green web apps can be as much as 80% less polluting than traditional web apps. They can also run 80% faster and incur 80% fewer costs on the cloud. Green software engineering companies like Figoya are already able to build web apps in this way and it looks like there will be a surge in demand for these types of services in the coming years.

The movement

The green software movement is still young but it has a lot of momentum. The Green Software Foundation is a well-funded, non-profit organisation that has representatives from Microsoft, Intel, Accenture, BCG and UBS on its steering committee. They are “building a trusted ecosystem of people, standards, tooling and best practices,” but also increasing public and corporate awareness.

Public pressure or consumer demand might motivate companies to change, but government action could be the thing that creates the “burning platform” necessary for real change. A wave of new policy and legislation is already on its way: France’s Digital Environmental Footprint Reduction Legislation and the EU’s Corporate Sustainability Reporting Directive are two of the more imminent examples.


Green software is the best way to decarbonise that you have never heard of. The problem is growing but awareness is growing even faster. In just a few years consumers and corporations will be looking for answers in their own lives or in their ESG reports. The biggest challenge might be training software engineers to meet the forthcoming demand.