Could sustainable websites increase energy consumption?

Written by Tom Greenwood - July 15, 2022

I recently wrote an article in Oxymoron, my sustainable business newsletter, about the Jevons paradox. If you’re not familiar with it, the Jevons paradox says that contrary to conventional wisdom, making technology more energy efficient can actually lead to increased energy consumption when viewed across society as a whole. This is because more efficient technology leads to people using the technology even more. More efficient technology can also support new uses of technology that fuel economic growth and stimulate more energy consumption in other parts of society. The Jevons paradox is named after the economist William Jevons who presented this idea in the 1800’s having noticed that more efficient steam engines were actually increasing Britain’s consumption of coal.

Most environmentalists and technologists don’t like to talk about the Jevons paradox. It undermines energy efficiency efforts and offers no clear solutions or alternatives. The result is that there is a cognitive bias to simply ignore it.

William Jevons has been haunting me

The Jevons paradox has been on my mind for some time. The work that we do at Wholegrain Digital has a big focus on making the web more energy efficient and less harmful to the environment but the Jevons paradox implies that doing this might actually increase energy consumption and make the web even more polluting! This is something that I have literally lost sleep over in the past few months.

I’m now working on a theory of change for Wholegrain and I can’t complete it without knowing whether the Jevons paradox applies to our work. If it does, then it would undermine everything that we are trying to achieve. So I’ve given this a lot of thought and finally reached a conclusion. Although there is no definitive answer to the question of whether the Jevons paradox applies to Sustainable Web Design, my assessment is that it only applies in some circumstances. Let’s take a look at what those circumstances are.

The direct rebound effect

Energy efficiency and performance gains in digital technology are driven first by hardware, rather than software. Data centers, telecoms networks and end user devices continue to advance, meaning that more computational work can be done and more data can be consumed with the same amount of energy. This is a good thing.

The problem is that a rebound effect then kicks in. Advances in hardware efficiency make data cheaper and faster. This leads to people consuming more data and for tech companies to invent more complex products and services that were not previously possible. Jevons paradox is alive and well!

But there is good news. Sustainable web design, as an approach that to eliminate waste and make web software more efficient, is actually a proactive intervention to stop this rebound effect. Those of us designing and developing web services have a choice as to how we use the ever increasing hardware efficiency. Do we make our code and designs more bloated now that computers and networks are more efficient? Do we invent new gimmicks to consume the new computing power available to us? Or do we maintain a frugal mindset to deliver real value to users in the most efficient way.

We have evidence that as a community, web designers and developers have been causing the rebound effect rather than preventing it. Just look at these charts from HTTP Archive as one small glimpse of what we have been doing.

HTTP Archive line chart showing web page sizes increasing over time

The first chart shows that the average web page size has increased enormously over the past ten years, more than doubling on desktop and increasing six fold on mobile. We have been making web pages bigger and more complex. 

The second chart shows one of the consequences of this growing page weight. Average page load times have not improved to any significant degree in many years. The HTTP Archive data for load times only seems to go back 6 years, but we can see that load times have remained mostly static despite computers and networks becoming significantly faster. While performance and energy consumption are not the same metric, load speeds can give us a useful glimpse into the overall efficiency of the web.

This is not a hardware issue. The hardware has become faster, more powerful and more energy efficient. This is a software issue. Those of us who commission and create the software that runs on the web that are responsible for the primary rebound effect by adding more bloat whenever the hardware allows us to. However, it is also those of us on the software side who can make a conscious decision not to erode the improvements in efficiency, and instead create a super efficient, low energy, modern web. 

The secondary rebound

So far so good, but doesn’t end there. We also need to consider secondary rebound effects. Do sustainable web design practices have any impact on the end users behaviour? 

When we make web products more efficient, we also make them faster. It’s a well-known principle that conversion rates improve when websites get faster. Fast online experiences are easier and more enjoyable, meaning that people are more likely to engage with them positively. If more sustainable websites potentially have better conversion rates, then the secondary rebound effect would be the increased impact of the behaviours that the website drives.

Whether this is good or bad depends on what the website or service is intended for. If the website’s purpose is to encourage behaviour or share information that is good for the world, then improving the user experience will increase the positive impact. On the other hand, if the website is designed to encourage behaviours that could be environmentally destructive, then improved user experience could amplify these negative impacts.

This should be a particular consideration for web services that are specifically intended to impact offline behaviours, such as e-commerce websites where improved conversion rates inherently increase consumption of physical goods.

Now, the elephant in the room here is that no organisation would want to deliver a poor user experience. A company that cares about its environmental impact would never ask for its website to be made slower in order that people buy fewer products from them. When it comes to some behvaiours, our consumption based economy is inherently at odds with environmental protection and that isn’t something that some simple UX changes can solve. However, those of us working in digital agencies or as freelancers may sometimes be able to consider the broader impact of web projects before we agree to take them on. If the most talented designers, developers and marketers opt to use their skills for projects that positively impact society, we can hopefully play a part in shifting these secondary rebound effects in the right direction. That might mean turning down some work, and not everyone is in a position of privilege to be able to do that, but perhaps those of us who can, should. If that’s something that makes you curious, check out my earlier article on Having the guts to say no to bad money.

Solving the Jevons paradox on the web

Having lost some sleep over this, I am relieved to find that when it comes to the web, Sustainable Web Design is the solution to the Jevons paradox. By maximising efficiency in web design, development and content creation, we can ensure that we preserve the benefits of more efficient hardware. Then by trying to ensure that the web projects we work on are actually good for the world, we can harness the secondary rebound effect to create positive rather than negative environmental impact. 

Here at Wholegrain Digital, we’re obsessed with optimising efficiency to create super fast, low energy online experiences for a better world. We also screen every project that we work on to ensure that it aligns with our values.

If you share our passion for using design and technology to create a positive impact, check out our current vacancies for the opportunity to join our unique team of people who truly care.