My name is Fershad Irani, and I’m here to share about the often-overlooked but incredibly important topic of quantifying digital carbon emissions. I’m based in Taiwan, where I’ve been living for the past 11 years, and I work with the Green Web Foundation, a Dutch non-profit organization striving for a fossil-free internet by 2030. My journey in the digital sustainability space involves maintaining a JavaScript library called CO2 JS, which allows developers to easily estimate the carbon emissions of their applications. I also developed “Are my third parties green?”, a tool that helps developers understand whether third-party scripts on their websites are served by green or non-green hosting providers.
I’ll discuss the emerging reporting requirements for carbon emissions, the crucial distinction between estimating and measuring emissions, and the tools available for both tasks.
Laws and Regulations Around Carbon Emissions Reporting
The regulatory landscape around carbon emissions is changing fast, with new legislation emerging that mandates businesses to report on their emissions. For example, Europe’s Corporate Sustainability Reporting Directive (CSRD) and California’s Climate Corporate Data Accountability Act (CCDAA) are coming into effect next year. These regulations are just the beginning of what will likely be a worldwide shift toward mandatory reporting for businesses.
We’re also seeing guidance from regulators in places like China and the United States requiring publicly listed companies to report their emissions. China’s Securities Regulatory Commission, for example, will require businesses to report on Scope 1, 2, and 3 emissions. Scope 1 and 2 emissions are those a company can directly control, such as emissions from its facilities and energy consumption. Scope 3 emissions, on the other hand, encompass emissions from the entire supply chain and product usage, making them harder to control but incredibly significant in the overall carbon footprint.
In contrast, the United States will require Scope 1 and 2 emissions reporting but only require Scope 3 emissions if they are deemed “material” or if the company has made net-zero or emissions reduction commitments that depend on them. This difference will be critical, as Scope 3 emissions often account for the majority of a company’s total emissions. To put that into perspective, Google’s 2022 environmental report shows that 75% of their emissions were Scope 3, while for Mozilla, that figure was 93% in 2019.
Estimating vs. Measuring Emissions
One of the key points I want to make today is the difference between estimating and measuring emissions and when each is appropriate. Estimation models use assumptions and averages, making them quicker and easier to apply but less accurate. They are, however, a great entry point for organizations looking to get a ballpark idea of their carbon footprint.
In contrast, measuring emissions is a more exact process but comes with its own challenges. Accurate measurements require specialized tools and expertise, which can make them harder to implement. Measuring might involve directly tracking energy consumption using devices like smart plugs, then converting that data into carbon emissions figures, which adds complexity.
Both methods have their place in carbon accounting, but understanding their strengths and limitations is crucial. As the statistician George Box once said, “All models are wrong, but some are useful.” It’s important to remember that even an imperfect model can be a powerful tool for understanding and improving carbon efficiency.
Tools for Estimation and Measurement
Now, let’s examine the available tools for estimating and measuring digital carbon emissions. I’ll break these down by the different components of the digital system: front-end, network, and data centers.
- Frontend Estimation
One of the most well-known tools for estimating frontend emissions is the Sustainable Web Design model, which powers popular calculators like WebsiteCarbon.com. This model uses data transfer as a proxy for carbon emissions across data centers, networks, and user devices. While this model has been instrumental in raising awareness about digital emissions, it does come with some assumptions that users should be aware of. For instance, it assumes global average grid intensity, which may not reflect the actual energy mix where a website is hosted.Other methodologies, such as DIMPACT, cater to more specific industries like digital media and entertainment, and can even estimate the emissions of online events. GreenFrame offers the unique ability to simulate user behavior to measure the impact of specific features on emissions. These tools allow developers to estimate emissions not just on a macro scale but also at a more granular level, focusing on individual components or features of a system.
- Frontend Measurement
Measuring frontend emissions is more challenging, but tools like the Firefox Profiler can help. This tool, developed by Mozilla, captures power and energy consumption during web page use and provides carbon emissions estimates. While it’s still a manual process, it’s one of the few tools available for detailed frontend energy analysis. Mozilla’s commitment to sustainable design is evident, and it’s great to see this tool helping to bring more precise carbon accounting to the frontend of web development. - Network Estimation
Estimating network emissions is one of the more complex aspects of carbon accounting. Traditional models rely on data transfer as a proxy for emissions, but this approach is controversial. Network energy consumption is highly variable, and data transfer alone may not provide a complete picture. A more promising approach involves combining data transfer with estimates of bandwidth and duration of usage, creating a more bottom-up model that attributes power consumption to individual components of the network. - Data Center Emissions
Finally, we come to data centers where accurate emissions data can be hard to obtain. Many cloud providers like AWS, Google, and Microsoft offer carbon emissions dashboards, but these often lack granular detail. A tool like Cloud Carbon Footprint can help by offering more detailed insights into data center emissions. This open-source tool connects to cloud provider APIs and even supports regional providers like AliCloud.For those who want to go a step further, tools like Scaphandre offer detailed power consumption reports for bare-metal hosts and Kubernetes environments. While these tools require more technical expertise, they provide some of the most accurate emissions data available today.
Quantifying digital carbon emissions is a complex task, but it’s essential to building a sustainable digital future. Whether through estimation or measurement, the tools we have today can help developers and organizations understand the carbon impact of their digital services. As regulatory pressures mount and Scope 3 emissions become a critical area of focus, we’ll need to embrace both estimation and measurement to get a complete picture of our digital emissions.
If you’re interested in learning more or need help navigating these challenges, please reach out to us at the Green Web Foundation. We offer consulting, workshops, and open-source tools to help organizations take meaningful steps toward a sustainable, fossil-free internet.
