Reduce the carbon emissions of your website

There’s no direct correlation between a web technology and the sustainability of the websites or web-apps that are built with it. Your carbon emissions estimate will mostly depend on an efficient implementation of the technology, and the correct implementation of web standards, web caching techniques and browser capabilities.

At the end of this page you will find case studies and stories relating to all sorts of web technologies being used to create websites with low carbon emissions.

No, there are lots of ways we can reduce the carbon emissions of a website other than through code. Graphic design, UX, and content choices affect the emissions from a site, so anyone involved in creating a website has a role to play. 

Consumers have an important role to play as well. Raising demand for certain services or changes has a powerful impact on companies, and everyone’s voice matters in helping to catalyze action. Take a look at our Action Guide titled Share the carbon impact of your favorite company’s website for how you can help raise awareness about the carbon emissions that websites create.

Estimating carbon emissions for websites is a really difficult thing to do as there are so many variables to consider.

Things that can vary dramatically for each user include: the distance the user is from the site’s server, what device the site is viewed on (mobile, laptop, TV), whether the data is being received by wifi or a cabled connection, what sort of energy mix is the server running on etc etc. All these things will affect the estimate.

So any tool that offers a calculation has to make some assumptions about these things, and many other varying factors not listed here.

On top of that the numbers that you would use for the calculations, once the assumtions are made, keep changing as well!  For example, the carbon intensity of producing energy in each country changes each year, and the efficiency of transferring data from one place to another also typically rises each year. A calculation using the best data one month will be out of date by the next month, because things shift within the digital world so quickly.

Our advice, is that any tool that offers you a carbon emissions estimate for a website should be taken as an estimate, not as fact. Use these estimates as a guide to let you know roughly how well a site is doing.

Yes! While the big tech giants undoubtedly have a significant responsibility to make their infrastructure sustainable, it’s important to consider two things. 

1. In some ways, having such large operations – and the resources and purchasing power that comes with it – makes it easier to scale more sustainable technologies assuming there is the sheer will to do so. 

2. More importantly, even small websites can have a meaningful carbon output over time. As you can see from this analysis of the USA Today news website by Chris Adams, one of the organisers of ClimateAction.Tech. He calculated that, given the daily traffic their website experienced at the time, it produced just under a quarter of a tonne of CO2 per day, which is “comparable to something like taking a short-haul flight from New York to Chicago”. Even if a website gets far fewer hits per day, it’s important to remember that there are approximately more than 1.5 billion websites on the Internet. This all adds up over time, especially if you also consider things like the energy required to transfer data from a server to your device, often over long distances.

Yes. Although choosing a hosting company that runs on renewable energy may be one of the biggest actions you can take, you also need to optimise your content: both how it is loaded and what it is. Keep in mind that storing and accessing large and inefficient websites takes more resources. Electricity is not the only resource you require either; it is also the server and the hard drive to store your site‘s data. All these physical devices need to be manufactured, maintained, and replaced.

And, unfortunately, fossil fuels are still often required to produce (the equipment that generates) renewable energy.

Caching is a good help, but not the only thing you can do. Caching is what we all should do, for all websites where possible. It is part of the optimisation of the performance of a website at the end of the development process. 

But real optimisation of a web project should start at the beginning with critical assessment of design elements, like images. Do we really need that large (stock) photo, do we really need a bloated framework, etc.

Moreover, browser caching only works on the second and adjacent page loads. The largest impact on the visitor is the first visit: that is where you make the first impression.

The benefits of a carbon-friendly website align with that of a fast, efficient, and user-friendly website, powered by a server on sustainable energy. So help your client understand that they can have a fast, performant website and an eco-friendly one at the same time.

Beyond the immediate performance gains, sustainability is increasingly cited as a priority among both businesses and consumers. After all, going green isn’t just good for the planet; many understand that it also benefits the bottom line.

Why sustainability is the new digital is an interesting read on this topic. It draws parallels between the concept that ‘every business is a digital business‘ which came about in the early 2000s, and a new emerging concept that the business of sustainability has come of age e.g. ‘every business is a sustainable business‘. A review of 100 studies crushes assumptions about conflict between profit and sustainability, published by Anthropocene Magazine, further supports the notion that sustainability is good for business. For a more tech focused read, check out To Green the Internet, We Need RIPE.

Here are a few directories that list people who may be able to help you:

The Sustainable Dev directory
Climate Base People profiles