Member Story
How Accenture, Microsoft, Amadeus, NTT DATA, and partners built the Impact Framework — an open-source tool that democratises software carbon measurement — and validated it through two global hackathons that together drew 900+ participants.
Organisations involved
500+
Participants at Carbon Hack 24
47
Project submissions at Carbon Hack 24
30
New community-built plugins for the Impact Framework
8
Major sponsors investing in the measurement ecosystem
The Problem
By 2023, the SCI specification had given the world a standard way to express software carbon intensity. But having a formula and being able to use it were two different things. Calculating an SCI score required gathering CPU utilisation data, mapping it to energy curves, finding the right carbon intensity factors for the location, estimating embodied emissions from hardware specifications, and choosing an appropriate functional unit. Each step involved specialist knowledge — energy engineering, hardware lifecycle analysis, regional grid data — that most software teams simply didn’t have.
Clients were coming to companies like Accenture, NTT DATA, and BCG X asking for help measuring their software emissions, but even those consulting firms found that the challenges were in “assessing what tools they should use and the methodologies and data used by these tools.” As Eleonore Gueit of Amadeus put it at Carbon Hack 24: “The one question we get all the time is, ‘How do we measure?’ Everyone is craving measurement.”
The result was a growing gap between ambition and execution. Organisations wanted to measure. Regulations like the CSRD and EU AI Act were beginning to require it. But the expertise barrier meant that only a handful of well-resourced companies could actually calculate their software’s carbon footprint. The measurement revolution promised by the SCI standard was stuck behind a wall of complexity.
“While we all know the importance of lowering our carbon footprint, software usually feels cleaner than it is. Furthermore, one cannot improve without measuring.” — Toru Shimogaki, NTT DATA
The Journey
2022
The Foundation's first hackathon ran with 395 participants and 51 project submissions. While focused on the Carbon Aware SDK, it demonstrated a massive appetite in the developer community for practical green software tools — and attracted sponsors including Accenture, Thoughtworks, Goldman Sachs, UBS, and BCG. The message was clear: developers wanted tools to act on sustainability, not just measure it.
Read about CarbonHack22 →2023
Recognising that measurement needed to be democratised, the GSF developed the Impact Framework (IF) — an open-source tool that converts observable data from running systems (CPU utilisation, page views, number of installs) into environmental impacts (carbon, water, energy, air quality) in an auditable, replicable, and transparent manner. Its plugin architecture meant anyone could contribute modules handling specific cloud provider metrics, embodied carbon calculations, or entirely new impact categories.
Explore the Impact Framework →December 2023
The Foundation announced a second hackathon, this time centred squarely on the Impact Framework. The framing was explicit: solving the biggest pain point facing the industry — measuring software for sustainability. Software's ecological impact was approaching 14% of global emissions, and the IF was the tool to make measurement scalable.
Read the Carbon Hack 24 announcement →March–April 2024
Over 500 sustainability software developers and practitioners worldwide participated. Sponsored by Accenture, Amadeus, AVEVA, BCG X, Sentry Software, IMDA, Nedbank South Africa, and NTT DATA, the hackathon produced 47 submissions and 30 new community-built plugins. Winners ranged from LLM carbon footprint evaluation (Thoughtworks) to an Environmental Impact Risk Scorecard covering water, waste, and air quality (Opencast Software Europe) — proving the framework's versatility across domains.
Read the Carbon Hack 24 wrap-up →September 2024
Srinivasan Rakhunathan (Microsoft) and Navveen Balani (Accenture) published a methodology for estimating software emissions during the system design phase using Large Language Models — training AI on architecture blueprints, green design patterns, and emission data to provide guidance before a single line of code is written. This shifted measurement left into the design phase, where architectural decisions that lock in 67–93% of an application's emissions are made.
Read the LLM emissions methodology →2026
Amadeus donated Carmen — their production carbon measurement engine — to the GSF. Carmen was explicitly built on the Impact Framework and delivered transparent, reproducible carbon calculations at scale across hundreds of applications serving 1.9 billion travellers. It was the ultimate validation: a major enterprise had chosen IF as the backbone of their measurement infrastructure.
Read the Carmen announcement →Everyone is craving measurement. The one question we get all the time is, 'How do we measure?'
Eleonore Gueit, Sustainable Engineering Advocate, Amadeus
Who came together
Asim Hussain
Executive Director
Green Software Foundation
Championed the Impact Framework as the tool to "decentralise impact measurement and democratise data" — framing it as open source for the sustainability measurement world.
Navveen Balani
Managing Director and Chief Technologist
Accenture
Co-chair of the Impact Framework project and Carbon Hack 24 sponsor lead. Co-authored the LLM-based emissions estimation approach with Srinivasan Rakhunathan.
Srinivasan Rakhunathan
Technical Product Manager
Microsoft
GSF contributor since 2021. Co-authored the methodology for LLM-powered emissions estimation during the software design phase.
Eleonore Gueit
Sustainable Engineering Advocate
Amadeus
Gave voice to the measurement gap at Carbon Hack 24, articulating the "everyone is craving measurement" reality that drove IF's development. Led Amadeus's eventual contribution of Carmen to the GSF.
Gadhu Sundaram
VP of Application Services
NTT DATA
Advocated making KPI measurement mandatory as part of non-functional requirements, positioning IF as the tool to make that standard achievable.
Bertrand Martin
CEO
Sentry Software
Championed the role of standards in making carbon observable and traceable across software systems.
In their words
"More and more clients want to measure their carbon emissions and reduce them. The challenges come when assessing what tools they should use and the methodologies and data used by these tools. The Impact Framework is one tool that can scale measurement across the software industry. "
Ioannis Kolaxis
Director of Technology Sustainability Innovation, Accenture
"Once you make measurement of KPIs mandatory, as part of your non-functional requirements, and provide an ecosystem of tools and standards, it will lead to greater adoption and improved practice in measuring software for sustainability. "
Gadhu Sundaram
VP of Application Services, NTT DATA
"Two things need to happen for greater adoption of IF. The first is that regulators need to demand that companies report using tools like Impact Framework. The second is to apply AI to the framework so it's baked into the tooling. "
Daniel Lazaro
Senior Technical Program Manager, AVEVA
Amadeus transfers Carmen, an open-source measurement engine, to GSF, enabling organizations to measure emissions across cloud infrastructure and Kubernetes clusters
Carbon Hack 24, the year's largest global green software hackathon, has ended, but its global call to decentralize impact measurement and democratize data has just begun!
Participate in Carbon Hack 24 and redefine how we measure the impact of software.
Five steps can help estimate software emissions during the system design phase using LLMs.
The hackathon engaged the most talented developers from around the globe in building the best carbon aware application using the GSF Carbon Aware SDK.
A contest for developers to build the best carbon aware software application with a total prize pool of USD 80,000
The Impact Framework was built by organisations who came together through the Green Software Foundation. If your teams are struggling to measure software emissions, or you've built something that solves a measurement gap, join us.
Explore the Impact Framework and its plugin ecosystem at if.greensoftware.foundation
