What's the climate impact of digital technology - and what can you do to reduce it? Here we share some emission-saving tips to consider.

When we think of carbon emitters, 'websites' are not usually the first things that come to mind. However, Information and Communication Technologies (ICTs) contribute 4% to global emissions, and an average website produces 4.6g of CO2 per page view. This means that if one page is viewed 100,000 times per month, it produces a staggering 553kg of carbon every year, which is equivalent to heating a typical UK home with natural gas.

Various global factors, including increased internet usage and the demand for sustainability officers, are driving product specialists to implement best practices that alleviate environmental stress on the planet. If you manage, design, or build websites, here are some techniques to consider when launching your next product.

Sustainable Design Practices

As a general rule, the more complex a website, the more energy it consumes. This means that animations, effects, videos, GIFs, and large images contribute significantly to the carbon footprint. However, this does not imply that you must compromise on aesthetics, but rather be mindful of how you implement them. For example, if you're using images and videos, optimise them for size and save them as SVG files instead of pngs or jpegs files.

Furthermore, designing for dark mode saves electricity by requiring less energy to light up the screen. Although you may not always have a choice in the colours you use for your website, it's worth noting that not every colour uses the same amount of energy, with shades of blue using more energy than greens or reds, for example.

At Tangent, we bundle and minimise frontend assets, optimise images using Next.js/WebP, and cache all assets on a Content Delivery Network (CDN).

Optimise Web Performance

Improving your website's performance can help reduce its carbon footprint. This can be done by optimizing your website's CSS and JavaScript files, reducing the number of HTTP requests, and enabling browser caching. You can reduce HTTP requests by using the JAMstack (Java, API, Markup) architecture, updating legacy dependencies, which typically improves the performance of libraries and ultimately the carbon footprint. You can also consider limiting the number of third-party JavaScript libraries and fonts on the frontend. Tools such as Google PageSpeed Insights or GTmetrix allow you to analyse your website's performance and identify areas that need improvement.

Efficient Code

Writing efficient code can significantly reduce the amount of energy required to load a web page. Using minification tools such as UglifyJS or Grunt can help reduce the size of your code, making it load faster and use less energy. You can also use lazy loading techniques that load content as the user scrolls, reducing the amount of data that needs to be transferred upfront. Similarly, you can load relevant information to specific individuals when working with real-time data. For example, on the UK Power Network’s site we delivered, we redesigned the power cut search experience so that we only returned relevant individual power cut data.

Choosing Green Web Hosting Providers

It's easy to forget that your digital life takes up space, and things in the cloud are actually on the ground or in oceans. They are the homes for our data and, like any home, need energy and plumbing to run. Green web host providers like GreenGeeks and HostGator use renewable energy to power their servers. Other resources to consider are water management and whether the manufacturing of the servers is done within a circular economy system.

Infrastructure considerations

Selecting the right infrastructure for your website can have a significant impact on its carbon footprint. One approach is to migrate from traditional Infrastructure as a Service (IaaS) to a Kubernetes or cloud-native solution with shared infrastructure. Microsoft estimates that this type of migration could reduce carbon emissions by up to 95%. Additionally, load testing and right-sizing the infrastructure can help keep energy consumption at a minimum. By batching data processing during off-peak hours, when electricity usage is naturally lower, you can further reduce the environmental impact of your website.

These are just a few of the techniques you can use to build or improve sustainable websites. The beauty of these techniques is that they not only reduce the carbon footprint of your website, but they can also improve its overall performance and cost-effectiveness.

At Tangent, we recently implemented these changes on an existing website and saw a 40% reduction in emissions. We believe this is just the beginning of what we can achieve by experimenting and learning more about sustainable web development practices. By making environmentally conscious choices when building websites, we can help reduce the impact of ICTs on our planet.