Sustainable web design: how to reduce your website’s carbon footprint

Sustainable web design: how to reduce your website’s carbon footprint

By Substrakt


Creating, storing and consuming digital content is hugely resource intensive and consequently highly polluting. Caspian Turner, Head of Strategy, Substrakt talks us through how to reduce our website's carbon footprint.

Digital has often been cited as a means for going green, cutting down on paper, and reducing the carbon footprint of an organisation.

We all know the negative impact of single use plastics, but the carbon footprint of the internet is something that is not well known and often overlooked.

In recent years, studies from the likes of Boston Consulting Group, The Guardian, and University of Bristol have shown that creating, storing and consuming digital content is hugely resource intensive and consequently highly polluting.

In 2018, Netflix usage accounted for 300m tonnes of carbon dioxide globally, which is as much as Spain emits in a year.

Had the world not been hit by the global pandemic in 2020, I’m sure that reducing environmental impact would have been high on the list of priorities for every organisation.

Proactively reducing carbon footprint should be something that all organisations are thinking and caring about.

So, what is sustainable web design?

Given that we are all living and working during a global pandemic, computer and internet usage has risen quite dramatically for many people. From Zoom quizzes to singing classes, workshops and family chats, everyone is using the internet more.

What many people don’t realise is that each of these activities has an environmental cost associated with it – a few grams of carbon dioxide are emitted due to the energy needed to run the devices being used.

Significant amounts of energy are required to store digital content, to transfer that content from a data warehouse, to use the broadband and wifi in your homes, and the computer and screen you’re using to access digital tools and products. These have all become an integral and critical element of our everyday lives, and they all have a carbon footprint.

And, you might think – what’s a few grams of carbon dioxide between friends?

But if you think about the number of people using your website every day, every week, every year – the number of page views, documents downloaded and videos watched – then you realise that it all adds up.

Although the energy needed for a single page view is small, approximately 4.1 billion people (or 54% of the global population) now use the internet. So those few grams of carbon, when combined with the greenhouse gases emitted with each activity, are therefore far more significant.

It’s estimated that the carbon footprint of our devices, the internet and the infrastructure supporting them, account for between 2 and 4% of global greenhouse emissions.

It is similar to the amount produced by the airline industry globally. And these emissions are predicted to double in the next four years.

It’s worth noting that some of these stats are about a year old now and so don’t account for the surge in internet usage during the pandemic – however, these are only expected to grow.

“If the internet were a country, it would be the sixth most polluting country in the world. Similar to the entire carbon dioxide emissions of Germany.” – Tom Greenwood, Sustainable Web Design

Historically, replacing offline paper-based services with digital alternatives has been seen as a means of ‘going green’. In fact, the benefits of digital products and services are more about ease, accessibility and lower operating costs. While it’s good to save paper, and prevent further deforestation, there are carbon-costs associated with websites too.

By no means am I suggesting that we all return to paper-based systems, but there are ways we can be conscious of how we design, build and maintain websites in a more sustainable way.

Calculating your website’s carbon footprint

It’s incredibly difficult to establish the full energy chain of internet usage because everyone has different devices, are operating in different temperatures and are all in different locations. Each website has multiple assets which may be hosted on a variety of different platforms. Each of these impact the energy consumption of your website.

To complicate matters further, efficiencies are gained on a regular basis. According to Koomey’s Law energy efficiency of computing has doubled roughly every 2.7 years since 2000.

Your website hosting is one of the primary considerations when it comes to your overall digital carbon footprint. This includes where the data centre is located in relation to the majority of your users, and the type of energy used by that data centre.

Amazon is known for its retail operation, but what you might not know is that they are also responsible for powering an estimated 40% of all websites around the world through Amazon Web Services.

Along with Google and some of the other technology giants, these companies have huge data centres all around the world. Google has been carbon neutral since 2007, and aims to become carbon free by 2030.

In using the internet, regardless of who you choose to host your own website with, we are at the mercy of these organisations and their environmental policies.

Amazon has co-founded The Climate Pledge, a commitment to becoming carbon neutral, yet there are still a number of years before they will become net carbon zero. This means parts of their operations are powered by renewable energy already, and other parts are not.

The Green Web Foundation keeps a directory of website hosting services running on renewable energy.

The energy requirements from websites can, broadly speaking, be broken down into three types of activity:

  1. Data storage: the servers on which your website is saved available to be served up by anyone visiting your website
  2. Data transfer: the retrieval or sending of data – a visitor loading your website on their computer
  3. Processing power: the energy used by your computer to generate dynamic page elements

There are other considerations such as the website design, the colours used and the subsequent energy usage of each screen, but if we’ve learned anything over the past year of lockdowns it is that we make the most impact by prioritising the things that we have direct control over.

So how do we measure this?

Tools such as the Website Carbon Calculator, Google’s Lighthouse tools and Google Analytics can all provide measurements of the inefficiencies on your website, from large images, outdated file formats and slow page load speeds.

Through using these tools and analytics you can focus on the areas of your website that have the slowest page load speeds and then start to assess why. Are there hundreds of images, are those images serving a purpose, have they been formatted correctly, have they been resized appropriately?

What can we do about it?

I hope that this article has demonstrated the significant global impact digital has in terms of carbon dioxide emissions. So then the question becomes, what can we do about it?

In the same way that we have been wasteful with physical products and services, we have also been wasteful online.

It is so easy to create web pages, add videos and images, and include dozens of paragraphs of text, that we don’t always stop to consider the impact that it has, the purpose it serves, or whether what we’ve created even meets the user’s needs.

Steps to reducing carbon footprint

If your website has been around for a few years, it’s likely that you’ll have published hundreds or thousands of pages.

You might have a content strategy in place but the rules might have been flexed to meet outlier requirements and one-off events.

You may have uploaded several different images while working out which one worked best.

It may be that you have content that is so old it’s no longer relevant.

You can change this. And in doing so, reduce your website’s carbon footprint. There are numerous small changes that you can make to significantly reduce your website’s carbon footprint.

Assess the situation: Audit your content

Part of maintaining your website will involve periodically auditing the content. Systematically analysing the state of your content, using analytics to assess the effectiveness, and make changes accordingly.

Auditing your website content ensures that you know whether your content is delivering on your strategy. And if it’s not, you know it’s not and you can make changes as needed.

If a page no longer serves a purpose, is out of date or ineffective, you can decide whether to improve, amalgamate with another page or delete any pages that are underperforming.

Do the images used on your site really serve a purpose? Have the images been optimised or saved in the relevant file format? If the answer to either of these questions is no, you can change that. Use tools such as ImageOptim to compress images and reduce the file sizes and in turn data transfer.

Review your content strategy

Your content strategy should define how content is planned, created and maintained throughout your organisation, in addition to articulating who you are trying to reach and why. This should cover content in all its forms, whether that be written content, imagery or video.

Does your website content contribute to achieving your organisation’s mission? Is content delivered in the way that your audiences want to consume it?

If your content does not serve a purpose it is wasting energy and frustrating your users.

By having a considered and coherent content strategy, you can ensure that the content on your site is both current and meets your audience’s needs, while doing so with ease and efficiency.

Search Engine Optimisation

It’s highly common that people using your website have a goal in mind. A task that they are looking to complete.

On average 68% of users start their journey through search.

Through search engine optimisation you can enable your website users to find the pages they’re looking for, removing the need to navigate through multiple pages unnecessarily, and therefore emit carbon unnecessarily.

Making your website more efficient will benefit everyone

If the climate crisis wasn’t enough of an incentive to encourage you to do everything you can to reduce carbon emissions, you might be interested to know that each of these activities may also result in improvements in usability, accessibility and conversion rate.

Speed, usability and conversion 

Studies from Google, BBC and Nielsen Norman Group all show that page speed directly impacts user experience and conversion rate. By reducing the file size of your web pages through compressing images and using the appropriate file formats, your website will load faster and in turn improve user experience.

Accessibility and SEO

There are a number of crossover benefits when it comes to accessible content and search engine optimisation. Structuring content using the correct HTML markup, with meaningful title tags, headings and lists will ensure both that your website is navigable when using a screen reader, and also more easily indexed by search engines.

Ensuring your website is optimised for search will help direct users straight to the content they are looking for without needlessly browsing other pages (or simply giving up).

Final thoughts

There are a number of other considerations for reducing the carbon footprint of your website including caching, font files and minifying code to reduce file sizes by removing any unused code or formatting.

If you make any of these changes to your website, you will not only be reducing your carbon footprint, but also improving the experience for your users. This should in turn improve the effectiveness of your content.

Caspian Turner, Head of Strategy, Substrakt

If you want to talk through your efforts to reduce the carbon footprint of your website, audit its performance, discuss search engine optimisation or content, then please do get in touch by emailing team@substrakt.com

This article is sponsored by Substrakt as part of their sponsorship of Inclusivity and Audiences Day 2021.

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Resource type: Guide/tools | Published: 2021