An often secondary concern when considering how to make the engineering sector more globally responsible, but a significant one nonetheless, with research such as that in Tom Greenwood’s recent book, Sustainable Web Design highlighting; ‘if the internet were a country, it would be the sixth most polluting country in the world’. We asked Tom to explore how a globally responsible mindset goes beyond adjusting engineering practice, to considerations of sustainable web design.

Digital technology has the potential to deliver huge benefits in sustainable development, but we have largely overlooked the fact that it has its own environmental footprint. And while we try to measure and minimise the impact of our materials and energy supplies in so many industries, we overlook that digital technology (and its environmental impact) permeates everything that we do, in every industry. The internet is the largest machine ever created, spanning the entire globe, with data centres, telecoms networks, and billions of connected devices constantly consuming electricity.

Data centres alone use more electricity each year than the United Kingdom, and the internet as a whole is now responsible for emitting more carbon emissions than the global aviation industry.

So, how can we harness the benefits of digital technology to support sustainable development, without creating new environmental problems? 

For digital designers and engineers, there are two big opportunities – renewable energy and energy efficiency.

Powering the web with renewable energy

Unlike many other industries, the digital sector is arguably the easiest to decarbonize because it is already electrified. With a few exceptions, the whole system globally runs on electricity and can be powered by renewables if only there is the supply. We might not have control over our local or global energy grids, but in many digital projects, we can choose to host our digital services in data centres that have made a commitment to powering their servers with renewable energy. The Green Web Foundation provides a free database of these providers, and the more that we make this choice, the more pressure there will be on the data centre industry to use renewable energy sources. While digital technologies’ hunger for electricity is currently hindering our ability to decarbonize global energy grids, the tech industry could be a powerful force for positive change if it demands and invests in new renewable energy capacity.

Pursuing energy efficiency

While choosing a data centre with green energy might be an easy win, perhaps our biggest gains could be made through the pursuit of energy efficiency in design and engineering of digital services. After all, most studies in how to achieve a net zero economy emphasise the need for radical reductions in energy consumption through energy efficiency. So, why should the digital sector be any different?

Our aim with digital services should be to deliver useful services to society while minimising server loads, data transfer, and the amount of computing needed on the end user’s device.

While each individual interaction with a digital service uses a tiny amount of energy, that is in itself insignificant, they add up fast. For example, developer Danny Van Kooten removed 20 kilobytes of JavaScript from the popular MailChimp for WordPress plugin, used by over two million websites, and estimated that when added together it would save 700 tonnes of CO2 emissions per year. It just shows that small efficiency improvements make a big difference when multiplied at scale.

Some common ways to improve energy efficiency of digital services are to minimise file sizes as far as possible. We can do this in development by compressing and optimising all files, but even bigger improvements can be achieved when small file sizes are defined as a required from the outset of the design process. Efficiency can be designed in. Common sources of unnecessary data transfer are images, videos and tracking scripts, making them key area to target when trying to reduce energy consumption. For example, eco-friendly cleaning brand Ecover redesigned their website with efficiency as a criteria and reduced the amount of data transferred for each page by nearly 80%.

Energy efficiency can also be improved through choices of server infrastructure, with efficient caching of files reducing server loads, and the use of content delivery networks to move data closer to the people who are trying to access it.

Even the colour can have an impact, with modern OLED screens using energy roughly proportional to their brightness, making dark designs inherently more energy efficient. Google found that the Google Maps app uses 63% less screen energy in night mode than it does in its standard daytime mode on a mobile phone due to the darker colours.

A sustainable web supports sustainable development

Every step we take to pursue sustainability in digital projects helps to ensure that digital technology is part of the solution and not a part of the problem. Furthermore, when we improve energy efficiency of digital services, it also has a social benefit. Energy-efficient services are generally faster and therefore have better user experience, being easier to access on poor connections, and perhaps most importantly are more affordable to access for the lowest income members of our society.

The actions we must take to pursue digital sustainability can be applied in any project and generally have no downside. A sustainable web is a web that is better for everyone.