Cloud carbon footprint calculation and optimization is a critical part of an organization’s overall sustainability strategy. Forrester’s technology sustainability framework highlights the importance of addressing cloud and technology architecture for reducing the overall scope 1, 2, and 3 emissions in any industry.

I recently talked with the core leadership team at Thoughtworks that led the development of its open source Cloud Carbon Footprint calculation tool (CCF). Lisa McNally, head of cleantech and sustainability at Thoughtworks, and Danielle Erickson, green cloud product and senior consultant developer, share insights on the CCF tool’s capabilities and the elements of cloud sustainability.

Abhijit: How do you help clients in carbon footprint reduction activities, and what key initiatives led to the use of your open source tool, the Cloud Carbon Footprint?

Lisa: Over the last 30 years, Thoughtworks has been working with enterprise clients to help them evolve their digital capabilities. And we believe that sustainability is foundational to becoming a modern digital business. Most of our client engagements are multiyear engagements, and we typically work with clients who are already working with Thoughtworks for their digital transformation or modernization. Then we would offer additional sustainability-related solutions, helping our clients measure and take action on their carbon footprint.

The framework for customers who have already committed to scope 3 reductions — their digital footprint could be a significant focus for strategic action — and this is typically what leads us to using the open source Cloud Carbon Footprint (CCF) tool for our customers.

First, to understand where a client is in their sustainability journey, we start by asking what the key drivers are for their sustainability transformation. Typically, those drivers are categorized as either risk, reputation, or reward. Many of our clients have already publicly announced their decarbonization goals, if they are becoming net zero, or if they have a specific percentage reduction target they want to meet by a set time.

Then we use a methodology that looks at their milestones: 1) first in measuring and baselining their emissions; 2) then, where are they in their planning to reduce those emissions? 3) how are they optimizing? and 4) what do they need to report?

We think of this as a circular step-by-step process.

As a technology company, we can offer a few solutions that help a client with all of these steps, but we’re really focused on integrating sustainability into tech itself. In other words, we can leverage technology to help clients reduce the carbon footprint of their IT operations (greening “of” IT), including software, or we can use technology, such as scenario modeling, to reduce the carbon footprint across a client’s value chain (greening “by” IT).

Specifically, through the CCF tool, we’re bringing transparency to clients’ scope 3 emissions, generated by using cloud computing services. Cloud computing generates a lot of emissions, and there’s a lot of opportunity for companies to reduce scope 3 emissions. CCF helps our clients visualize, assess, and act on their carbon footprint. The CCF tool is very valuable to clients who are already using multiple cloud vendors or are looking to migrate from on-premises to cloud and want tactical insights all in one platform showing where the emissions benefits could be in addition to cost benefits.

Right off the bat, we are able to help organizations that may be just starting their sustainability journey but that want to have an immediate impact in their digital carbon footprint to show progress, or we can help those clients that may have already done everything they could around scope 1 and 2 and, now, looking deeper at scope 3 emissions and what they can do in the cloud computing area.

Abhijit: Do cloud carbon footprints fall exclusively into scope 3 for all industries?

Lisa: For our clients that are purchasing cloud services, strategically reducing emissions under scope 3 will be where they can see impact. If they are using on-premises infrastructure, their digital carbon footprint will have a different profile, and impact would also need to be considered under their approach to scope 2 mitigation. Considering that many clients may be using both the cloud and on-prem infrastructure, Thoughtworks can also help the client baseline their on-prem emissions and combine those findings with the outputs of the CCF tool to help develop a more comprehensive strategic plan.

Abhijit: Can you elaborate on the CCF tool’s capabilities and how it helps clients?

Danielle: Thoughtworks has a commitment to open source and open knowledge. Two years ago, there was no easy way for companies to understand the carbon emissions coming from their cloud use.

Realizing this gap, we wanted to create a way for any company to get an initial understanding of what their emissions might be, monitor them, and enable their engineering teams to take action toward reducing their cloud carbon impact.

So that was the premise of the tool. We worked on it as a small Thoughtworks team over the course of roughly the past two years and wanted to make it community-driven: leveraging the knowledge and experience of community experts and building features that meet the needs dictated by those who would potentially use it. It was important to us that it was a one-stop shop, a place where clients can see all of their cloud use and emissions.

To accomplish this, we built it as a multicloud tool, with AWS, GCP, and Azure supported out of the box. But again, in the spirit of open source and meeting the needs of anyone who wants to use the tool, we have made it easy to customize setup, specifics of the methodology, and integration into other platforms or applications, and it can be extended to other cloud providers fairly easily. We’ve scoped out a few platforms — for example, Oracle Cloud — that we think we could easily support and that we have heard demand for. This level of customization and flexibility is one of the really beneficial things companies can get from the tool.

With the dashboard itself and with the various ways for data to be accessed, the Cloud Carbon Footprint tool allows companies and engineers to baseline and monitor emissions and cost over time. The tool also has features that allow you to view a timeline of your energy use and emissions for identification and analysis of spikes or trends of particular services or accounts that have increased in emissions in the recent past. It gives clients a way to break down and dig into these finer details of where emissions and energy use might be coming from. CCF also has a recommendations dashboard that gives a forecast of what the potential emissions and energy savings could be. To provide automated recommendations for specific actions that can be taken, it connects to cloud providers’ right-sizing and optimization APIs and shows the carbon and energy savings organizations can achieve, in addition to the cost savings. By combining many of these seemingly smaller actions over time, organizations can begin to see measurable emissions reductions. With these two views in the dashboard, we intended to provide value for a variety of different personas — not only to the developers and practitioners but also for CXOs and sustainability leadership.

We also wanted it to be very configurable so that it can be useful to organizations of varying sizes, maturity levels, and structures. For example, if you do have a strong understanding of your particular setup, you can customize certain variables to improve the accuracy of the estimates, or if you want to bring carbon and energy metrics into your existing applications and workflows, you can access the data via API, CLI, CSV, or use the Lookup Table approach.

Abhijit: We now have tools from public cloud providers, so what is the particular application of the CCF tool? One that you mentioned already is as a comparison of data that public cloud tools provide. What else?

Danielle: One of the main differences is that CCF is cloud-agnostic and the methodology is the same across AWS, Azure, or GCP, which is especially helpful for organizations that are multicloud users. Organizations looking to make comparisons across their cloud providers can do so safely, because the estimates are calculated in the same way.

Further, CCF also includes the calculation of embodied emissions and the application measures using a location-based cloud emissions estimate. We’ve decided to go that route in an attempt to give a fuller picture of carbon being produced in the first place.

Another difference with the Cloud Carbon Footprint tool is that the data you see is updated in real time — as frequently as your billing and usage data is updated, which is typically daily, you can have updated carbon and energy metrics.

This can bring the opportunity for engineers to integrate sustainability in their day-to-day work, which could be used in combination with the cloud provider carbon tools for a deeper understanding. For instance, with the GCP tool, a client may want to use CCF for those day-to-day changes and nuances and then enrich their understanding using the monthly information that comes out of the GCP tool. So in some ways, they’re complimentary to one another.

Abhijit: What are some primary drivers for cloud carbon footprint measurement in the industry? How are you seeing the industry demand and implementations?

Lisa: For clients that have identified cloud optimization as an area of focus, drivers primarily are improving costs, optimization, and platform upgrades. Such organizations are already aware of tools provided by cloud providers, such as the GCP tool, AWS, or Azure tool. They are still interested, however, in having access to an agnostic tool that provides transparency and insight into the methodology, enabling emissions comparisons across cloud services. They know they could just as well use the tool that their vendor provides, but they are often using more than one cloud provider, so they are wanting assurance that the comparative information is something they can “trust” to help drive investment decisions.

Because they have insights into what CCF does from a methodological standpoint, users can feel better about doing comparisons with using the tool and then comparing it to, say, what the GCP tool may provide. Additionally, our tool can allow the user to integrate the outputs from a cloud vendor’s tool into the CCF tool so they can make a side-by-side comparison, as well.

Abhijit: What are the top problems and questions clients are asking about?

Lisa: There’s a high level we often hear: I want to know what my costs are and what I should do to optimize, and I’m not sure I really trust what the information is that I’m getting from my vendor’s tool, and I want to make comparisons across.”

Related to that is the on-prem piece of, “Well, we haven’t even moved to the cloud yet, or we want to make big investments moving to the cloud, and we don’t know where to start and we’re afraid it’s going to impact our emissions, because we have a pretty good handle on our emissions today, and if we make this big investment decision now and we’ve already committed to something, how much is that going to take us off track?”

And then, of course, scope 3 emissions: “We’ve hired a vendor to do scope 1 and 2, we’ve aggregated the data, we don’t know where to start with scope 3 … is there a lot of opportunity there to optimize costs and reduce emissions with how we operate our current IT infrastructure? How do we get insight into that? What changes should we make, if any?”

The last one I want to mention, which I think is very interesting, is focused on incentives and behavior change within the company. We see CIOs who are tasked with achieving certain emissions reductions and may or may not have a budget. There’s the expectation that emissions are going to be reduced and costs are going to be optimized within the IT department. We were just talking with one client who asked “How are we going to incentivize people to make these changes?” Some people might not be incentivized by costs, while executives might be incentivized by it. But how are the developers and those who are in charge of day-to-day management of the systems incentivized, and how do they measure their impact? Through some of our collaboration with some of our innovation partners, cloud carbon footprint measurement has proven to have an impact on the midlevel developer, practitioners making infrastructure changes. Having insights into the emissions impact can actually incentivize and help drive behavior change and shift the mindset around sustainability, thereby not only having a cost impact but also getting people excited about making sustainability-related changes in their day-to-day work.

Danielle: Adding to that, one of the things that we see more digitally mature clients ask in order to empower developers is how they can integrate sustainability metrics in various ways across their existing platforms — so not necessarily just having the CCF as a tool that you look at once a month, or once a week, but something that developers are looking at every single day in real time, allowing them to monitor their sustainability impact in existing platforms or developer tools.

Abhijit: Thank you for an insightful interview on the needs of cloud customers and the capabilities of the Cloud Carbon Footprint tool!

Thoughtworks: Thank you!


Special thanks to Reyne Quackenbush, global head of analyst relations, and Cameron Casher, senior software engineer and cleantech strategist, both of Thoughtworks.

This interview was conducted by Forrester Senior Analyst Abhijit Sunil in association with Researcher Renee Taylor. To learn more about Forrester’s research on technology sustainability, reach out to or