Reduce CO2 emissions from your website

We had the great opportunity to speak with Torsten Beyer, author and expert on "Sustainable Websites".

Torsten has been active on the topic for several years and has attracted attention with specialist publications in renowned trade journals and, most recently, with the publication of his book, "Sustainable Websites". We are therefore particularly pleased to have secured him for an interview.

Hello Torsten, could you briefly introduce yourself?
My name is Torsten Beyer and I am a chemist with a doctorate. In 1998 I founded Dr. Beyer Internet-Beratung to combine my passion for the internet with chemistry. The design and optimisation of websites with regard to loading speed and search engine rankings has been a central part of our offering from the start. Without this specialised knowledge, the founding and establishment of our advertising-funded online lab magazine Analytik NEWS in competition with well-funded publishers would have been impossible. I have therefore remained true to chemistry to this day and use the site to test sustainable optimisations and their effectiveness. This year we have expanded our portfolio to include sustainability audits for websites. We support companies in optimising existing sites and in the strategic planning of new, more sustainable sites. We also produce CO₂ balances of websites, including metrics to document the status quo and to assess optimisation measures.

In your opinion, is hosting in Germany sensible or rather problematic because of climate change, and should we be looking for long-term alternatives in Northern Europe?
You can't make a blanket statement. Currently hosting is concentrated in the Rhine-Main area because of the internet hub in Frankfurt, which is problematic due to water scarcity, a warmer climate and the limited availability of renewable electricity on site.
In the north and south some hosts produce renewable energy themselves or buy it locally. In general we need stronger environmental requirements for new builds and transparency when using the label "Green Hosted". Purchasing climate certificates (guarantees of origin), for example bought in Scandinavia, is qualitatively different from using renewable energy on site.

Electricity is consumed in four places that produce CO₂ emissions when loading websites. Can you briefly introduce these and which is the most relevant?
In addition to data centres, the entire network infrastructure, all internet-enabled end devices and the whole hardware sector including recycling must be considered. Common tools calculate the CO₂ emissions based on the so-called "Sustainable Web Design Model". They rely on the volume of data transferred for the homepage and simplified assumptions about the energy mix. However, the accuracy of these figures is limited, since a precise determination of the amount of data transferred and a correct accounting are only possible by analysing server log files.

Dr Torsten Beyer in an interview

Photo: Torsten Beyer

Do you have an approximate figure — compared with road or air traffic — for what percentage of global CO₂ emissions browsing the web is responsible for?
For years the figure 3.7 per cent has been circulating, which would correspond to global aviation. Other studies already put us in the 6-7 per cent range. I would treat such figures with caution, as it is unclear what is being included (e.g. cryptocurrencies, the dark web, IP television, autonomous driving, AI applications) and how reliable data from Russia, China or Africa are. I would rather argue that we should focus on specific areas and identify optimisation potential.

Could you show our readers how they can, with little effort, save CO₂ e on their website?
The greatest potential lies in the area of video content. Are videos really necessary and how are they embedded in web pages? For example, they should not autoplay. Next comes the optimisation of images. This includes using modern formats (e.g. webp), lazy loading and correct scaling. Custom fonts and PDF files should also be reviewed. Avoiding unnecessary JavaScript and CSS frameworks, as well as responsive design, is more of a topic for the next site relaunch, since changes to existing pages can be very time-consuming or even impossible.

Which testing tools can you recommend to see how much saving potential still exists on your own website?
A helpful tool for an initial rough estimate is the Website Carbon Calculator. It lets you assess the data volume of the homepage compared with other sites and check whether an environmentally friendly hosting provider is being used. For a more detailed analysis of other subpages based on the data formats used, the tool Beacon is suitable. Technically proficient users can also read the transferred data volume directly in the browser console. The professional tool Ecograder uses, among others, all checks from Google Lighthouse and lists concrete optimisation suggestions.

If someone wants to dive deeper into the topic, can you tell us how that is possible?
A good introduction to the topic is my freely available lead article in the magazine WebSite Boosting from August 2022. For a deeper insight with background information and numerous practical tips, my book "Nachhaltige Websites" (Springer Gabler Verlag) was published at the end of May 2023. In addition, I have been a guest on several podcasts on the subject and regularly share interesting news and practical tips on LinkedIn.

Thank you for your time!

The interview was conducted by Marco Keul, founder and operator of hosttest.

Profile of Dr Torsten Beyer

Company: Dr Beyer Internet Consultancy
Name: Dr Torsten Beyer
Position: Founder and Owner
Company established since: April 1998
Offered services:

• Sustainable website optimisation
• CO₂ accounting for websites
• Online magazine Analytik NEWS